@charset "UTF-8";

:root {
  color-scheme: light;
  --ink: #262c30;
  --muted: #69716a;
  --desk: #b9c8bc;
  --paper: #f6f2e6;
  --paper-deep: #e7dfc8;
  --green: #385d56;
  --red: #a54c38;
  --blue: #356b85;
  --gold: #c4a34c;
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", "SimSun", serif;
  --sans: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; }
html { min-width: 320px; min-height: 100%; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background-color: var(--desk);
  background-image:
    url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.78' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' opacity='.12' filter='url(%23n)'/%3E%3C/svg%3E"),
    radial-gradient(ellipse at 50% 12%, #d0d9c8 0, #bac9bd 52%, #a5b8aa 100%);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}
button, input, select, textarea { font: inherit; }
button, a, input, select, textarea { -webkit-tap-highlight-color: transparent; }
button { color: inherit; cursor: pointer; }
button:disabled { cursor: default; opacity: .38; }
button, a, input, select, textarea { outline-offset: 4px; }
:focus-visible { outline: 3px solid #997524; }
button, select { touch-action: manipulation; }
button { border: 0; }
a { color: var(--green); }
button, .shelf-card { -webkit-user-select: none; user-select: none; }
[hidden] { display: none !important; }
svg { display: block; max-width: 100%; }

#shelf { max-width: 1280px; margin: 0 auto; padding: 65px 40px 48px; }
.shelf-heading { text-align: center; margin-bottom: 54px; }
.shelf-heading h1 { margin: 0 0 16px; font-family: var(--serif); font-size: clamp(30px, 3.7vw, 48px); font-weight: 800; letter-spacing: .16em; }
.shelf-heading .subtitle { color: #515c52; font-size: 15px; line-height: 1.8; letter-spacing: .06em; }
.shelf-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 36px; align-items: start; }
.shelf-card { min-width: 0; }
.shelf-card > button, button.shelf-card { background: transparent; width: 100%; padding: 0; text-align: left; }
.book-cover {
  --cover: #365d68;
  position: relative;
  width: 100%;
  aspect-ratio: .72;
  min-height: 300px;
  padding: 30px 24px 26px 31px;
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--cover);
  background-image: repeating-linear-gradient(90deg, transparent 0 2px, #ffffff04 2px 3px), linear-gradient(90deg, #0002 0 4px, #fff1 7px 9px, transparent 13px);
  border-radius: 3px 9px 6px 3px;
  border-left: 7px solid #0002;
  box-shadow: 1px 2px 0 #ded8c6, 2px 5px 0 #f2ecdc, 2px 8px 0 #cbc4ae, 2px 11px 0 #e9e3cf, 3px 13px 0 #35504a, 8px 21px 28px #293b3440;
  transform: perspective(1000px) rotateY(-6deg) rotateZ(-1deg);
  transform-origin: left center;
  transition: transform .3s, box-shadow .3s;
}
.shelf-card:nth-child(even) .book-cover { transform: perspective(1000px) rotateY(-6deg) rotateZ(1deg); }
.shelf-card button:hover .book-cover, button.shelf-card:hover .book-cover { transform: perspective(1000px) rotateY(-14deg) translateY(-8px); box-shadow: 2px 3px 0 #ded8c6, 3px 6px 0 #f2ecdc, 3px 9px 0 #cbc4ae, 3px 12px 0 #e9e3cf, 4px 14px 0 #35504a, 12px 28px 30px #293b3450; }
.cover-label {
  width: 100%;
  padding: 20px 6px 17px;
  color: #202a2f;
  text-align: center;
  background: #f2efdf;
  border: 3px solid #26363b;
  outline: 7px solid #f2efdf;
  box-shadow: 0 0 0 8px #ebe9da;
  font-family: var(--serif);
}
.cover-label h2 { margin: 0 0 14px; font-weight: 900; font-size: clamp(38px, 4vw, 59px); letter-spacing: .16em; padding-left: .16em; }
.cover-label .edition { font-size: 19px; font-weight: 700; letter-spacing: .08em; white-space: nowrap; }
.cover-label .edition { margin: 0; }
.cover-subtitle { font-size: 12px; letter-spacing: .1em; color: #4d5651; margin: 12px 0 0; }
.cover-subtitle { display: block; }
.cover-art { width: 90%; margin: 27px auto 0; color: #e0cc89; opacity: .85; }
.cover-art svg { width: 100%; height: auto; }
.book-meta { margin-top: auto; padding-top: 18px; color: #f3efdf; font-size: 12px; text-align: center; letter-spacing: .05em; }
.shelf-card > .book-meta { display: flex; justify-content: space-between; gap: 10px; margin: 25px 2px 0; padding-top: 0; color: #4f6051; font-size: 12px; text-align: left; letter-spacing: .02em; }
.cover-footer { margin-top: auto; padding-top: 18px; color: #f3efdf; font-size: 11px; letter-spacing: .1em; }
.shelf-kicker { display: block; margin-bottom: 15px; color: #5a6a57; font-size: 10px; letter-spacing: .22em; }
.chapter-summary { margin: 30px 3px 0; padding: 0; list-style: none; color: #3d4b41; font-family: var(--serif); font-size: 14px; line-height: 1.7; }
.chapter-summary li { display: flex; gap: 10px; margin-bottom: 7px; }
.shelf-card > .chapter-summary { margin-top: 16px; }
.chapter-summary strong, .chapter-summary .chapter-num { color: var(--red); min-width: 18px; }
.shelf-footer { margin-top: 55px; text-align: center; font-family: var(--serif); color: #52604e; font-size: 13px; letter-spacing: .16em; }
.shelf-footer { display: flex; justify-content: center; align-items: center; gap: 22px; }
.shelf-footer button { padding: 3px 0; border-bottom: 1px solid #7d8b7280; background: transparent; color: #52604e; font-size: 12px; letter-spacing: .05em; }
.continue-reading { display: flex; align-items: center; justify-content: center; gap: 12px; max-width: 100%; margin: 42px auto -15px; padding: 12px 21px; border: 1px solid #748d7166; border-radius: 30px; color: #3f5f47; background: #f0f1de80; font-size: 12px; }
.continue-reading:hover { background: #f5f4e4c4; }
.continue-reading b { font-weight: 600; }
.continue-reading > span { margin-left: 7px; font-size: 18px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }

.reader-topbar {
  position: relative;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 66px;
  max-width: 1440px;
  margin: 0 auto;
  padding: 14px 36px 8px;
  color: #3b4e41;
  font-size: 13px;
}
.back-link { display: inline-flex; align-items: center; gap: 8px; background: transparent; padding: 8px 0; text-decoration: none; }
.reader-brand { font-family: var(--serif); letter-spacing: .1em; font-size: 14px; }
.book-switch select { border: 1px solid #546b533b; border-radius: 6px; padding: 7px 27px 7px 10px; background: #f6f3e66e; color: #3d5044; font-size: 12px; }
.desk { max-width: 1480px; margin: 0 auto; padding: 20px 35px 124px; perspective: 2600px; transition: padding-left .35s; }
.book-spread {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  width: 100%;
  max-width: 1320px;
  min-height: 710px;
  margin: 0 auto;
  padding: 0 0 9px;
  background: #ded5bb;
  border-radius: 2px 7px 4px 4px;
  transform: rotateX(2deg);
  transform-style: preserve-3d;
  box-shadow: 0 4px 0 #f8f3e5, 0 7px 0 #c6bfa9, 0 10px 0 #eee8d6, 0 13px 0 #35594f, 0 18px 17px #31493f30, 0 35px 50px #354b3c25;
}
.book-spread::before { content: ""; z-index: 3; pointer-events: none; position: absolute; top: 0; bottom: 9px; left: 50%; width: 35px; transform: translateX(-50%); background: linear-gradient(90deg, transparent 0, #968e7222 35%, #756e563b 49%, #fff5 59%, transparent 100%); }
.paper { position: relative; min-width: 0; min-height: 710px; padding: 29px 34px 45px; background: var(--paper); background-image: radial-gradient(ellipse at 55% 22%, #fff9 0%, #f3eedf00 62%), url("data:image/svg+xml,%3Csvg viewBox='0 0 140 140' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.045'/%3E%3C/svg%3E"); font-family: var(--serif); }
.left-page { border-radius: 3px 1px 0 2px; box-shadow: inset -16px 0 25px -16px #8a816357; }
.right-page { border-radius: 1px 4px 3px 0; box-shadow: inset 18px 0 24px -18px #8a81635c; }
.eyebrow { display: flex; justify-content: space-between; gap: 12px; padding-bottom: 9px; margin-bottom: 19px; color: #6c6c5e; border-bottom: 1px solid #a6a38d5c; font-size: 11px; letter-spacing: .12em; }
.eyebrow span:last-child { color: var(--red); font-weight: 700; }
.left-page h1 { margin: 0 0 14px; font-size: clamp(24px, 2.3vw, 33px); letter-spacing: .03em; line-height: 1.35; font-weight: 800; }
.chapter-no { display: inline-block; min-width: 49px; padding: 2px 10px 3px; margin-right: 12px; color: #fffaf0; background: var(--red); border-radius: 4px 2px 4px 2px; font-family: var(--sans); font-size: .53em; vertical-align: .2em; font-style: italic; letter-spacing: .02em; }
.lead { margin: 0 0 16px; font-size: 16px; line-height: 1.85; text-align: justify; }
.prediction { margin-bottom: 15px; padding: 12px 13px; border: 1px dashed #b6a057; border-radius: 8px 5px 7px 4px; background: #e9da961f; }
.mini-label { display: inline-block; color: #5e512b; background: #e4cb71; border-radius: 3px; padding: 2px 8px; font-size: 11px; font-weight: 700; font-family: var(--sans); letter-spacing: .08em; }
.mini-label > span { padding-left: 8px; font-size: 10px; font-weight: 400; letter-spacing: 0; }
.prediction h3 { margin: 8px 0; font-size: 16px; line-height: 1.6; font-weight: 800; }
.choice-row { display: flex; align-items: stretch; flex-wrap: wrap; gap: 7px; }
.choice-row button { flex: 1 1 95px; display: flex; align-items: center; gap: 6px; min-height: 38px; padding: 6px 9px; border: 1px solid #7d827a; border-radius: 5px; background: #fffdf7b8; font-size: 13px; text-align: left; line-height: 1.45; transition: background .15s, border-color .15s; }
.choice-row button b { flex: 0 0 21px; height: 21px; line-height: 21px; text-align: center; border-radius: 50%; background: #313b3d; color: #fffdf5; font-family: var(--sans); font-size: 12px; }
.choice-row button:hover { background: #e8eddc; border-color: var(--green); }
.choice-row button.selected { border: 2px solid #607866; padding: 5px 8px; background: #dce7d4; }
.choice-row button.correct { border-color: #477b55; background: #deead5; }
.choice-row button.wrong { border-color: #b56851; background: #f2e0cd; }
.answer-sheet { position: relative; display: block; width: 100%; min-height: 57px; margin-top: 9px; padding: 12px; border: 1px solid #c8b67e; border-radius: 3px; background: repeating-linear-gradient(0deg, #e9dfbb 0 7px, #daceaa 8px, #e9dfbb 9px); box-shadow: 0 3px 5px #786a3926; color: #514622; font-family: var(--serif); font-size: 14px; line-height: 1.65; text-align: left; transform-origin: top center; transition: background .25s, min-height .25s; }
button.answer-sheet::after { content: "↗"; position: absolute; top: 50%; right: 15px; transform: translateY(-50%); font-size: 26px; }
.answer-sheet.revealed { background: #fffbee; border-color: #c5ba8f; box-shadow: none; }
.answer-sheet small { display: block; font-size: 11px; opacity: .7; font-family: var(--sans); }
.answer-sheet strong { color: #476744; }
.answer-sheet > span { display: block; margin-top: 5px; font-size: 13px; line-height: 1.7; }
.answer-sheet > strong > span { float: right; font-size: 20px; font-weight: 400; }
button.answer-sheet::after { content: none; }
.activity-card, .key-card { margin: 0 0 14px; padding: 13px 14px 12px; border-radius: 7px 4px 6px 4px; border: 1.5px solid; }
.activity-card { border-color: #497b94; background: #8eabb609; }
.key-card { border-color: #ae624d; background: #d7ae8308; }
.activity-card h3, .key-card h3 { display: inline; margin: 0; font-size: 16px; line-height: 1.7; }
.activity-card h3 { color: #356b85; }
.key-card h3 { color: #a54c38; }
.section-label { display: inline-block; margin-right: 7px; padding: 2px 7px; border-radius: 2px; color: #fffdf0; background: var(--blue); font-family: var(--sans); font-size: 11px; vertical-align: 2px; }
.activity-card ol, .key-card ul { margin: 8px 0 0; padding-left: 22px; line-height: 1.8; font-size: 14px; }
.activity-card li + li, .key-card li + li { margin-top: 4px; }
.activity-card li::marker { color: var(--blue); font-weight: 700; }
.key-card li::marker { color: var(--red); }
.page-number { position: absolute; bottom: 15px; left: 50%; transform: translateX(-50%); font-size: 13px; color: #6b6e62; }
.scene-label { min-height: 25px; padding-bottom: 9px; margin-bottom: 2px; border-bottom: 1px solid #a6a38d5c; color: #6c6c5e; font-size: 11px; letter-spacing: .12em; text-align: right; }
.scene-label { display: flex; align-items: center; gap: 10px; min-height: 32px; padding-bottom: 7px; }
.scene-label > span { margin-right: auto; color: #858675; }
.scene-label > b { font-weight: 400; }
.scene-reset { display: inline-grid; place-items: center; width: 27px; height: 25px; padding: 0; border: 1px solid #b9bca87a; border-radius: 5px; background: transparent; color: #53664e; font: 20px/1 var(--sans); }
.scene-reset:hover { background: #dce3cc; }
.scene-area { position: relative; width: 100%; height: clamp(310px, 29vw, 408px); min-height: 270px; overflow: hidden; border-radius: 4px; cursor: grab; touch-action: none; }
.scene-area:active { cursor: grabbing; }
.scene-area canvas { display: block; width: 100%; height: 100%; outline-offset: -4px; }
.scene-area .scene-fallback { padding: 25px; height: 100%; display: grid; align-content: center; text-align: center; }
.scene-area .scene-fallback svg { max-height: 250px; margin: 0 auto; }
.scene-area .scene-fallback p { font: 12px/1.7 var(--sans); color: var(--muted); }
.scene-controls { padding: 14px; border: 1px solid #c3c1ad; border-radius: 8px; background: #fffdf975; font-family: var(--sans); }
.scene-caption { font-size: 14px; font-weight: 700; line-height: 1.55; }
.scene-caption::before { content: "演示"; display: inline-block; margin-right: 8px; padding: 1px 5px; border-radius: 3px; background: #303b3d; color: #fffdf4; font: 10px/1.8 var(--sans); letter-spacing: .05em; vertical-align: 1px; }
.scene-caption::before { content: none; }
.scene-caption > span { display: inline-block; margin-right: 8px; padding: 1px 5px; border-radius: 3px; background: #303b3d; color: #fffdf4; font: 10px/1.8 var(--sans); letter-spacing: .05em; vertical-align: 1px; }
.scene-error { display: grid; place-items: center; min-height: 260px; padding: 24px; color: #815c48; font: 13px/1.8 var(--sans); text-align: center; }
.coming-lesson { min-height: 320px; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 35px 25px; text-align: center; }
.coming-lesson > span { color: #839d80; font-size: 60px; font-weight: 300; }
.coming-lesson h2 { font-size: 25px; color: #4b614f; margin: 12px 0; }
.coming-lesson p { max-width: 370px; color: #71775f; font: 13px/1.9 var(--sans); }
.coming-lesson button { margin-top: 15px; padding: 9px 17px; border: 1px solid #a5b29a; border-radius: 25px; color: #4b674b; background: #e9eddd; font-size: 12px; }
.scene-hint { margin: 7px 0 11px; color: #626958; font-size: 12px; line-height: 1.65; }
.readouts { display: flex; gap: 8px; margin: 8px 0 12px; flex-wrap: wrap; }
.readout { min-width: 82px; flex: 1; padding: 7px 9px 6px; border: 1px solid #aeb5a7; border-radius: 5px; background: #fffefa; }
.readout small { display: block; margin-bottom: 2px; color: #707267; font-size: 10px; }
.readout strong { display: block; color: var(--red); font-size: 19px; font-weight: 650; font-variant-numeric: tabular-nums; line-height: 1.2; white-space: nowrap; }
.readout:nth-child(even) strong { color: #374d50; }
.parameters { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 16px; row-gap: 8px; margin-top: 5px; }
.parameter label { display: flex; align-items: baseline; justify-content: space-between; gap: 5px; color: #626958; font-size: 11px; line-height: 1.6; }
.parameter output { color: #374f46; font-weight: 600; }
.parameter input[type="range"] { width: 100%; min-height: 26px; margin: 0; accent-color: #547c68; cursor: pointer; }
.scene-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; align-items: center; }
.scene-actions button, .scene-actions label { display: inline-flex; align-items: center; gap: 5px; min-height: 31px; padding: 4px 11px; border: 1px solid #919a8b; border-radius: 18px; background: #fffef9; color: #3d4b3f; font-size: 11px; line-height: 1.4; }
.scene-actions button:hover { background: #e6ebdc; }
.scene-actions input { accent-color: #587768; }

.toolbar { position: fixed; z-index: 20; left: 50%; bottom: 22px; display: flex; align-items: center; gap: 4px; max-width: calc(100vw - 32px); min-height: 65px; padding: 7px 14px; transform: translateX(-50%); border: 1px solid #cbcbb8; border-radius: 19px; background: #faf8efed; box-shadow: 0 9px 20px #344c3d22; backdrop-filter: blur(12px); }
.tool { position: relative; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 3px; min-width: 54px; min-height: 49px; padding: 4px 8px; background: transparent; border-radius: 9px; white-space: nowrap; color: #404a40; font-size: 11px; line-height: 1.2; }
.tool svg { width: 20px; height: 20px; }
.tool .icon { font-size: 23px; font-weight: 400; line-height: 1; font-family: var(--sans); }
.tool > span { min-height: 24px; font: 23px/1 var(--sans); }
.tool > small { font: 10px/1.3 var(--sans); }
.tool[data-action="prev"] > span, .tool[data-action="next"] > span { font-size: 32px; line-height: .7; }
.tool[data-action="more"] > span { font-size: 19px; line-height: 1.15; letter-spacing: -.05em; }
.tool:hover, .tool.active { background: #e5e8d9; color: #375c4b; }
.tool.active { box-shadow: inset 0 0 0 1px #c1cbb1; }
.tool.answer-ready { color: #977625; background: #f6ecc6; box-shadow: inset 0 0 0 1px #cfb661; }
.tool.answer-next { color: #977625; background: #f6ecc6; box-shadow: inset 0 0 0 1px #cfb661; }
.tool.playing { color: var(--red); }
.tool-title { flex: 1 1 auto; min-width: 205px; max-width: 340px; margin: 0 10px; padding: 5px 12px; background: transparent; border-radius: 6px; text-align: center; font-family: var(--serif); line-height: 1.5; }
.tool-title:hover { background: #e9eadb; }
.tool-title small { color: #8b8979; font-family: var(--sans); font-size: 10px; margin: 0 5px; }
.tool-title strong { font-size: 18px; font-weight: 800; }
.tool-title .chapter-no { margin-right: 7px; padding: 0; background: transparent; color: var(--red); min-width: 0; font-size: 17px; font-family: var(--serif); font-style: normal; vertical-align: 0; }
.tool-title em { margin-right: 5px; color: var(--red); font-style: normal; }
.toolbar .tool-divider { height: 34px; width: 1px; margin: 0 4px; background: #c8cbbd; }
.toolbar-divider { flex: 0 0 1px; height: 34px; width: 1px; margin: 0 4px; background: #c8cbbd; }

.toc-heading { margin: 7px 0 25px; color: #303f35; font-size: 37px; font-weight: 700; letter-spacing: .3em; }
.toc-columns { display: grid; gap: 20px; }
.chapter-group h3 { margin: 0 0 9px; color: #a2523f; font-size: 17px; line-height: 1.5; }
.lesson-link { display: flex; align-items: baseline; width: 100%; gap: 12px; padding: 6px 0; border-bottom: 1px dotted #b9b7a866; background: transparent; font-family: var(--serif); text-align: left; line-height: 1.55; font-size: 14px; }
.lesson-link:hover { color: var(--red); background: #c1c6a815; }
.lesson-link span:first-child { min-width: 30px; font-size: 12px; color: #8c5745; }
.lesson-link small { margin-left: auto; color: #849077; font: 10px var(--sans); white-space: nowrap; }
.lesson-link.current { font-weight: 700; color: var(--green); }
.lesson-link:disabled { opacity: .55; }
.toc-view .paper { padding-top: 30px; }
.toc-view .right-page { padding-top: 98px; }
.toc-view.right-page { padding-top: 30px; }
.toc-view .page-number { bottom: 19px; }
.frontis { min-height: 630px; display: flex; flex-direction: column; justify-content: center; align-items: center; padding: 40px 20px; text-align: center; }
.frontis h1 { margin: 25px 0 12px; font-size: 86px; letter-spacing: .18em; padding-left: .18em; }
.frontis h2 { margin: 0 0 32px; font-size: 26px; }
.frontis p { max-width: 360px; margin: 10px auto; font-size: 15px; line-height: 1.9; color: #5d6357; }
.frontis .how-to { max-width: 410px; margin-top: 25px; padding: 18px 22px; border-top: 1px solid #bfc2ac; text-align: left; }
.frontis .how-to h3 { margin: 0 0 10px; font-size: 18px; }
.frontis .how-to h2 { margin: 0 0 10px; font-size: 18px; }
.frontis .how-to ul { padding-left: 20px; margin: 0; color: #626658; font-size: 13px; line-height: 1.9; }
.frontis .how-to ol { padding-left: 20px; margin: 0; color: #626658; font-size: 13px; line-height: 1.9; }
.frontis .how-to li + li { margin-top: 8px; }
.frontis-art { width: 92%; max-width: 450px; margin: auto; color: #58745c; }
.paper.frontis-art { width: auto; max-width: none; margin: 0; padding-top: 60px; padding-bottom: 65px; }
.frontis-drawing { width: 92%; max-width: 420px; margin: auto 0; }
.frontis-art h2 { margin: 12px 0 10px; font-size: 22px; letter-spacing: .02em; }
.frontis-edition { margin: 0 0 5px !important; font-size: 24px !important; font-weight: 600; color: #344a3b !important; }
.closed-cover { width: min(410px, 70vw); margin: 20px auto 30px; }
.closed-cover .book-cover { min-height: 560px; padding: 54px 41px 38px 49px; }
.closed-cover .cover-label { padding-top: 28px; padding-bottom: 24px; }
.closed-cover .cover-label h2 { font-size: 80px; }
.closed-cover .cover-label .edition { font-size: 25px; }
.closed-cover .cover-art { margin-top: 52px; }
.closed-cover > button:first-child { display: block; width: 100%; margin: 0; padding: 0; background: transparent; }
.cover-open-button { display: block; margin: 40px auto 0; padding: 15px 35px; border-radius: 36px; background: #365e62; color: #fffbed; box-shadow: 0 5px 10px #283f3b33; font: 700 23px var(--serif); letter-spacing: .12em; }
.cover-open-button:hover { background: #294e51; }
.open-book-button { display: flex; justify-content: center; align-items: center; gap: 24px; width: max-content; max-width: 100%; margin: 40px auto 0; padding: 15px 31px; border-radius: 36px; background: #365e62; color: #fffbed; box-shadow: 0 5px 10px #283f3b33; font: 700 23px var(--serif); letter-spacing: .12em; }
.open-book-button:hover { background: #294e51; }
.open-book-button > span { font-size: 22px; font-weight: 400; }
.primary-button { display: inline-flex; align-items: center; gap: 26px; margin: 21px auto 5px; padding: 12px 25px; border: 1px solid #54765f; border-radius: 28px; color: #f7f4e5; background: #496d59; font: 15px var(--sans); }
.primary-button:hover { background: #375c48; }

.drawer { position: fixed; z-index: 30; top: 80px; bottom: 110px; left: 20px; width: 282px; padding: 24px 22px; overflow: auto; background: #fbf6d9; border: 1px solid #d2c59c; border-radius: 3px 10px 10px 3px; box-shadow: 7px 10px 25px #3a493c2e; transform: translateX(calc(-100% - 30px)); visibility: hidden; transition: transform .3s, visibility .3s; }
.drawer::before { content: ""; position: absolute; width: 84px; height: 24px; top: 0; left: 50%; transform: translate(-50%, -30%) rotate(-3deg); background: #c5b78566; }
.drawer.open { transform: translateX(0); visibility: visible; }
.drawer h2 { margin: 6px 0 20px; font: 700 23px var(--serif); color: #5a5b3d; }
.drawer h3 { font-size: 14px; margin: 20px 0 8px; color: #747047; }
.drawer p, .drawer li { font-size: 13px; line-height: 1.9; color: #626447; }
.drawer ul, .drawer ol { padding-left: 18px; }
.drawer .close-button { position: absolute; right: 10px; top: 10px; padding: 6px; background: transparent; color: #727255; font-size: 20px; }
.teacher-panel > header { display: flex; align-items: center; justify-content: space-between; padding-bottom: 12px; border-bottom: 1px solid #c9bf9477; color: #7d7751; font: 12px var(--sans); letter-spacing: .1em; }
.teacher-panel > header small { margin-left: 6px; color: #9b946c; font-size: 11px; letter-spacing: 0; }
.teacher-panel > header button { width: 27px; height: 27px; padding: 0; border-radius: 5px; background: transparent; color: #727255; font-size: 22px; line-height: 1; }
.teacher-panel > header button:hover { background: #e2d8ad66; }
.teacher-panel h2 { margin: 20px 0 18px; font-size: 21px; }
.drawer textarea { width: 100%; min-height: 160px; padding: 9px 4px; resize: vertical; border: 0; border-bottom: 1px solid #c8c19d; background: repeating-linear-gradient(transparent 0 27px, #a99f6c33 28px, transparent 29px); color: #54573d; font: 13px/29px var(--sans); }
.drawer .saved-label { display: block; margin-top: 5px; color: #858564; font-size: 10px; }
.note-status { display: block; margin-top: 6px; color: #858564; font-size: 10px; }
.teacher-keys { margin-top: 28px; padding-top: 16px; border-top: 1px solid #c9bf9466; color: #87815c; font-size: 10px; line-height: 2.3; }
.teacher-keys kbd { min-width: 21px; padding: 0 4px; color: #73724e; background: #f2edcf; border-color: #c6c09c; font-size: 10px; }
body.teacher-open .desk { padding-left: 325px; }
body.teacher-open .book-spread { max-width: 1160px; }
body.teacher-open .paper { padding-left: 24px; padding-right: 24px; }
body.teacher-open .lead { font-size: 14px; }
body.teacher-open .activity-card ol, body.teacher-open .key-card ul { font-size: 13px; }
body.teacher-open .left-page h1 { font-size: 26px; }
body.teacher-open .scene-area { height: 320px; }

dialog { max-width: min(560px, calc(100vw - 32px)); max-height: calc(100dvh - 60px); padding: 0; overflow: auto; border: 1px solid #b7bca8; border-radius: 14px; background: #fcf9ed; color: var(--ink); box-shadow: 0 25px 70px #1c342e45; }
dialog::backdrop { background: #253c354d; backdrop-filter: blur(3px); }
.modal { padding: 29px 32px; }
.modal h2 { margin: 0 0 20px; font: 700 25px var(--serif); }
.modal > header { display: flex; justify-content: space-between; align-items: flex-start; gap: 20px; }
.modal > header > button { flex: 0 0 29px; min-height: 29px; margin: -4px -8px 0 0; padding: 0; border: 0; border-radius: 4px; color: #69725a; background: transparent; font-size: 24px; line-height: 1; }
.modal > header > button:hover { background: #e7ebd8; }
.modal p { font-size: 13px; line-height: 1.8; color: #616957; }
.modal button { min-height: 35px; padding: 6px 13px; border: 1px solid #b2bba4; border-radius: 6px; background: #ebefdf; font-size: 13px; }
.modal button:hover { background: #dde5cf; }
.modal .close-button { float: right; margin: -10px -12px 0 15px; border: 0; background: transparent; font-size: 22px; }
.modal label { display: flex; align-items: center; gap: 10px; margin: 15px 0; font-size: 14px; }
.modal input[type="checkbox"] { width: 17px; height: 17px; accent-color: var(--green); }
.modal .modal-actions { margin-top: 24px; display: flex; gap: 10px; justify-content: flex-end; }
.modal .setting-row { display: flex; justify-content: space-between; align-items: center; gap: 25px; width: 100%; min-height: 48px; margin: 0; padding: 13px 0; border: 0; border-bottom: 1px solid #d7dcc5; border-radius: 0; background: transparent; color: #45563d; font-size: 14px; text-align: left; }
.modal button.setting-row:hover { background: #e9eddc99; }
.setting-row > span > kbd { margin-left: 8px; }
.settings-footnote { margin: 24px 0 0; font-size: 11px !important; color: #8a8e78 !important; }
.help-table { width: 100%; border-collapse: collapse; font-size: 13px; line-height: 1.7; }
.help-table th, .help-table td { padding: 10px 7px; text-align: left; border-bottom: 1px solid #d5d8c5; }
.help-table th { font-weight: 500; color: #425c48; white-space: nowrap; }
kbd { display: inline-block; min-width: 24px; padding: 1px 5px; border: 1px solid #bac1ae; border-bottom-width: 2px; border-radius: 4px; background: #f2f4e8; font: 11px/1.6 var(--sans); text-align: center; }
.toast { position: fixed; z-index: 70; left: 50%; bottom: 104px; max-width: calc(100vw - 40px); padding: 9px 17px; border-radius: 20px; color: #fffced; background: #355748ec; font-size: 12px; text-align: center; transform: translateX(-50%); box-shadow: 0 4px 12px #29463a2b; }
#toast { position: fixed; z-index: 70; left: 50%; bottom: 104px; max-width: calc(100vw - 40px); padding: 9px 17px; border-radius: 20px; color: #fffced; background: #355748ec; font-size: 12px; text-align: center; opacity: 0; pointer-events: none; transform: translate(-50%, 7px); box-shadow: 0 4px 12px #29463a2b; transition: opacity .2s, transform .2s; }
#toast.show { opacity: 1; transform: translate(-50%, 0); }

body[data-focus="left"] .right-page, body[data-focus="right"] .left-page { display: none; }
body[data-focus="left"] .book-spread, body[data-focus="right"] .book-spread { grid-template-columns: 1fr; max-width: 670px; transform: none; }
body[data-focus="left"] .book-spread::before, body[data-focus="right"] .book-spread::before { display: none; }
body[data-focus="left"] .paper, body[data-focus="right"] .paper { box-shadow: none; padding-left: 40px; padding-right: 40px; }
body[data-focus="right"] .scene-area { height: 430px; }
body[data-focus="right"] .scene-controls { margin-top: 12px; }

.book-spread.turning-next .right-page { transform-origin: 0 50%; animation: page-turn-next .55s ease-in-out; backface-visibility: hidden; z-index: 6; }
.book-spread.turning-prev .left-page { transform-origin: 100% 50%; animation: page-turn-prev .55s ease-in-out; backface-visibility: hidden; z-index: 6; }
@keyframes page-turn-next { 0% { transform: rotateY(0); filter: brightness(1); } 48% { transform: rotateY(-75deg); filter: brightness(.85); } 49% { opacity: 0; } 51% { transform: rotateY(12deg); opacity: 0; } 65% { opacity: 1; } 100% { transform: rotateY(0); filter: brightness(1); } }
@keyframes page-turn-prev { 0% { transform: rotateY(0); filter: brightness(1); } 48% { transform: rotateY(75deg); filter: brightness(.85); } 49% { opacity: 0; } 51% { transform: rotateY(-12deg); opacity: 0; } 65% { opacity: 1; } 100% { transform: rotateY(0); filter: brightness(1); } }
@keyframes reveal-note { from { transform: rotateX(-20deg); opacity: .3; } to { transform: rotateX(0); opacity: 1; } }
.answer-sheet.revealed { animation: reveal-note .35s ease-out; }

@media (min-width: 1600px) {
  .desk { padding-top: 32px; }
  .book-spread { min-height: 760px; }
  .paper { min-height: 760px; padding-top: 33px; }
  .scene-area { height: 425px; }
  .lead { font-size: 17px; }
  .activity-card ol, .key-card ul { font-size: 15px; }
}
@media (max-width: 1150px) {
  #shelf { padding-left: 35px; padding-right: 35px; }
  .shelf-grid { gap: 27px; }
  .book-cover { padding: 25px 18px 20px 24px; min-height: 280px; }
  .cover-label h2 { font-size: 42px; }
  .cover-label .edition { font-size: 15px; }
  .cover-subtitle { font-size: 10px; }
  .desk { padding-left: 20px; padding-right: 20px; padding-top: 8px; }
  .paper { padding: 25px 25px 43px; }
  .left-page h1 { font-size: 26px; }
  .lead { font-size: 14px; }
  .prediction h3 { font-size: 14px; }
  .activity-card ol, .key-card ul { font-size: 13px; }
  .activity-card h3, .key-card h3 { font-size: 14px; }
  .scene-controls { padding: 11px; }
  .tool-title { min-width: 150px; margin: 0 4px; }
  .tool-title strong { font-size: 16px; }
  .tool { min-width: 48px; }
  .toolbar { padding-left: 10px; padding-right: 10px; }
  body.teacher-open .desk { padding-left: 20px; }
  body.teacher-open .book-spread { transform: none; }
  .drawer { box-shadow: 8px 12px 38px #243a385c; }
}
@media (max-width: 900px) {
  #shelf { max-width: 750px; }
  .shelf-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 48px; }
  .book-cover { min-height: 355px; padding: 34px 25px 24px 32px; }
  .cover-label h2 { font-size: 60px; }
  .cover-label .edition { font-size: 20px; }
  .cover-subtitle { font-size: 12px; }
  .cover-art { margin-top: 35px; }
  .chapter-summary { margin-top: 27px; }
  .paper { padding-left: 21px; padding-right: 21px; }
  .choice-row { gap: 5px; }
  .choice-row button { flex-basis: 100%; min-height: 30px; padding: 3px 7px; }
  .choice-row button.selected { padding: 2px 6px; }
  .toolbar { gap: 0; bottom: 16px; }
  .tool { min-width: 45px; padding-left: 6px; padding-right: 6px; font-size: 10px; }
  .tool-title { min-width: 125px; max-width: 185px; padding: 5px; }
  .tool-title strong { font-size: 14px; }
  .tool-title small { display: block; margin: 0; }
  .parameters { grid-template-columns: 1fr; }
  .scene-area { min-height: 250px; }
  .readout { padding-left: 6px; padding-right: 6px; }
  .readout strong { font-size: 17px; }
}
@media (max-width: 760px) {
  html { scroll-padding-bottom: 95px; }
  .reader-topbar { padding: 10px 18px; min-height: 57px; font-size: 12px; gap: 8px; }
  .reader-brand { display: none; }
  .book-switch select { max-width: 165px; padding: 6px; }
  .desk { padding: 10px 16px 115px; perspective: none; }
  .book-spread { display: flex; flex-direction: column; max-width: 610px; padding-bottom: 7px; min-height: 0; transform: none; box-shadow: 0 4px 0 #f8f3e5, 0 7px 0 #c6bfa9, 0 10px 0 #36594f, 0 18px 28px #31493f36; }
  .book-spread::before { display: none; }
  .paper { min-height: 0; padding: 25px 27px 44px; box-shadow: none; }
  .left-page { border-radius: 3px 3px 0 0; }
  .right-page { border-top: 1px solid #d1ccb7; border-radius: 0 0 3px 3px; }
  .eyebrow { margin-bottom: 17px; }
  .left-page h1 { font-size: 29px; }
  .lead { font-size: 16px; }
  .prediction h3 { font-size: 16px; }
  .choice-row button { flex: 1 1 100px; min-height: 36px; padding: 6px 8px; }
  .choice-row button.selected { padding: 5px 7px; }
  .activity-card ol, .key-card ul { font-size: 14px; }
  .activity-card h3, .key-card h3 { font-size: 16px; }
  .scene-area { height: 360px; min-height: 260px; }
  .scene-controls { padding: 13px; }
  .scene-hint { font-size: 12px; }
  .parameters { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .readout strong { font-size: 20px; }
  .toolbar { width: auto; max-width: calc(100vw - 16px); min-height: 62px; padding: 6px 7px; border-radius: 15px; bottom: 10px; gap: 1px; overflow-x: auto; scrollbar-width: none; }
  .toolbar::-webkit-scrollbar { display: none; }
  .tool { flex: 0 0 auto; min-width: 46px; min-height: 48px; }
  .tool-title { flex: 0 0 120px; min-width: 120px; max-width: 170px; margin: 0 3px; }
  .toolbar .tool-divider { margin: 0 2px; }
  .toolbar-divider { margin: 0 2px; }
  .toc-view .right-page { padding-top: 22px; }
  .toc-heading { font-size: 32px; }
  .toc-columns { gap: 20px; }
  .lesson-link { font-size: 16px; padding: 9px 0; }
  .chapter-group h3 { font-size: 18px; }
  .frontis { min-height: 490px; padding: 25px 0; }
  .frontis h1 { font-size: 75px; }
  .frontis h2 { font-size: 24px; }
  .frontis-art { padding: 20px 0; }
  .paper.frontis-art { padding: 45px 27px; }
  .closed-cover { width: min(370px, 76vw); margin-top: 15px; }
  .closed-cover .book-cover { min-height: 470px; padding: 40px 30px 28px 39px; }
  .closed-cover .cover-label h2 { font-size: 68px; }
  .closed-cover .cover-label .edition { font-size: 22px; }
  .closed-cover .cover-art { margin-top: 36px; }
  .cover-open-button { padding: 13px 30px; font-size: 22px; }
  .open-book-button { padding: 13px 30px; font-size: 22px; }
  .drawer { top: 66px; bottom: 90px; left: 12px; width: min(320px, calc(100vw - 24px)); padding: 26px 23px; }
  body.teacher-open .desk { padding-left: 16px; }
  body.teacher-open .paper { padding-left: 27px; padding-right: 27px; }
  body.teacher-open .left-page h1 { font-size: 29px; }
  body.teacher-open .lead { font-size: 16px; }
  body.teacher-open .activity-card ol, body.teacher-open .key-card ul { font-size: 14px; }
  body.teacher-open .scene-area { height: 360px; }
  body[data-focus="left"] .book-spread, body[data-focus="right"] .book-spread { display: flex; }
  body[data-focus="left"] .paper, body[data-focus="right"] .paper { padding-left: 27px; padding-right: 27px; }
  body[data-focus="right"] .scene-area { height: 360px; }
  .modal { padding: 25px; }
  .modal h2 { font-size: 23px; }
  .toast { bottom: 85px; }
  #toast { bottom: 85px; }
  .book-spread.turning-next .right-page, .book-spread.turning-prev .left-page { transform-origin: 50% 0; animation: mobile-turn .35s ease-out; }
  @keyframes mobile-turn { from { opacity: .35; transform: translateY(9px) rotateX(4deg); } to { opacity: 1; transform: translateY(0) rotateX(0); } }
}
@media (max-width: 460px) {
  #shelf { max-width: 380px; padding: 38px 38px 40px; }
  .shelf-heading { margin-bottom: 38px; }
  .shelf-heading h1 { font-size: 29px; line-height: 1.55; letter-spacing: .08em; }
  .shelf-heading .subtitle { font-size: 13px; }
  .shelf-grid { grid-template-columns: 1fr; gap: 45px; }
  .book-cover { min-height: 365px; padding: 35px 28px 24px 34px; }
  .cover-label h2 { font-size: 61px; }
  .cover-label .edition { font-size: 21px; }
  .book-meta { font-size: 12px; }
  .chapter-summary { margin-top: 28px; font-size: 14px; }
  .desk { padding-left: 10px; padding-right: 10px; }
  .paper, body.teacher-open .paper { padding-left: 20px; padding-right: 20px; }
  .left-page h1, body.teacher-open .left-page h1 { font-size: 25px; }
  .chapter-no { min-width: 42px; margin-right: 9px; padding-left: 7px; padding-right: 7px; }
  .lead { font-size: 15px; }
  .prediction { padding: 11px; }
  .prediction h3 { font-size: 15px; }
  .choice-row { flex-direction: column; }
  .choice-row button { flex: 0 0 auto; width: 100%; }
  .answer-sheet { font-size: 13px; }
  .activity-card, .key-card { padding: 11px; }
  .activity-card h3, .key-card h3 { font-size: 15px; }
  .activity-card ol, .key-card ul { font-size: 13px; }
  .scene-area, body.teacher-open .scene-area, body[data-focus="right"] .scene-area { height: 300px; }
  .parameters { grid-template-columns: 1fr; }
  .readouts { gap: 5px; }
  .readout { min-width: 75px; padding: 6px; }
  .readout strong { font-size: 17px; }
  .scene-caption { font-size: 13px; }
  .scene-controls { padding: 10px; }
  .toolbar { justify-content: flex-start; }
  .tool { min-width: 44px; }
  .tool-title { flex-basis: 104px; min-width: 104px; }
  .tool-title strong { font-size: 13px; }
  body[data-focus="left"] .paper, body[data-focus="right"] .paper { padding-left: 20px; padding-right: 20px; }
  .closed-cover { width: 76vw; }
  .closed-cover .book-cover { min-height: 425px; padding: 34px 25px 24px 32px; }
  .closed-cover .cover-label h2 { font-size: 59px; }
  .closed-cover .cover-label .edition { font-size: 19px; }
  .closed-cover .cover-subtitle { font-size: 10px; }
  .closed-cover .cover-art { margin-top: 34px; }
  .modal { padding: 23px 20px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
  .shelf-card button:hover .book-cover, button.shelf-card:hover .book-cover { transform: none; }
}
@media print {
  body { background: white; }
  .reader-topbar, .toolbar, .drawer, dialog, .scene-actions, .parameters { display: none !important; }
  .desk { padding: 0 !important; max-width: none; }
  .book-spread { transform: none; box-shadow: none; max-width: none; padding: 0; }
  .paper { background: #fff; min-height: 0; box-shadow: none; padding: 20px; }
  .book-spread::before { display: none; }
  .answer-sheet { box-shadow: none; }
}

/* Source-sized pages. The reader projects this 1680 × 1120 plane with the
   same camera geometry as the reference; controls below remain screen-sized. */
@font-face { font-family: "PB Serif"; font-weight: 400; font-display: block; src: url("./vendor/fonts/pb-0-400.woff2") format("woff2"); }
@font-face { font-family: "PB Serif"; font-weight: 700; font-display: block; src: url("./vendor/fonts/pb-1-700.woff2") format("woff2"); }
@font-face { font-family: "PB Sans"; font-weight: 400; font-display: block; src: url("./vendor/fonts/pb-2-400.woff2") format("woff2"); }
@font-face { font-family: "PB Sans"; font-weight: 700; font-display: block; src: url("./vendor/fonts/pb-3-700.woff2") format("woff2"); }
:root {
  --ink: #1f2633;
  --ink2: #3d4556;
  --muted: #555d6b;
  --paper: #f8f4ea;
  --red: #c8432b;
  --blue: #2c6db0;
  --tea: #9a6a2c;
  --green: #2f8a5b;
  --gold: #c99a2e;
  --serif: "PB Serif", "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --sans: "PB Sans", "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", "PingFang SC", sans-serif;
}
body[data-view="reader"] { --fit: 1; height: 100dvh; min-height: 0; overflow: hidden; background-color: #a9b8ae; background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 240 240' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' opacity='.18' filter='url(%23n)'/%3E%3C/svg%3E"); user-select: none; -webkit-user-select: none; }
body[data-view="reader"] #app, #reader { position: fixed; inset: 0; }
body[data-view="reader"] .reader-topbar { display: none; }
body[data-view="reader"] .desk, body[data-view="reader"].teacher-open .desk { position: fixed; inset: 0; width: 100%; max-width: none; height: 100%; padding: 0; margin: 0; perspective: none; }
body[data-view="reader"] .book-spread,
body[data-view="reader"][data-focus="left"] .book-spread,
body[data-view="reader"][data-focus="right"] .book-spread {
  position: absolute; left: 0; top: 0; display: grid; grid-template-columns: 840px 840px;
  width: 1680px; min-width: 1680px; max-width: none; height: 1120px; min-height: 1120px;
  padding: 0; margin: 0; border-radius: 0; background: transparent; box-shadow: none;
  transform: var(--book-transform, matrix3d(.697317866943,0,0,0,-.101555478669,.507455083505,0,-.00014104927593,0,0,1,0,134.2529917683,113.3641029981,0,1));
  transform-origin: 0 0; transform-style: preserve-3d;
}
body[data-view="reader"] .book-spread::before { display: none; }
body[data-view="reader"] .book-spread::after { content: ""; position: absolute; z-index: -1; left: -12px; right: -12px; bottom: -46px; height: 48px; border-bottom: 5px solid #2a5c68; background: linear-gradient(#cfc5a9 0 20px,#e9e1cd 21px 42px,#ded5be 43px); box-shadow: 0 16px 28px #332b2433; }
body[data-view="reader"] .book-base { position: fixed; inset: 0; width: 100%; height: 100%; pointer-events: none; }
body[data-view="reader"]:has(.book-base) .book-spread::after { display: none; }
body[data-view="reader"] .paper,
body[data-view="reader"][data-focus] .paper,
body[data-view="reader"].teacher-open .paper {
  position: relative; display: block; width: 840px; height: 1120px; min-height: 1120px;
  max-width: none; padding: 88px 76px 74px; margin: 0; overflow: hidden; border-radius: 0; box-shadow: none;
  font-family: var(--serif); color: var(--ink); font-size: calc(27px * var(--fit)); line-height: 1.72;
  letter-spacing: .01em; text-align: justify; line-break: strict; word-break: normal; overflow-wrap: anywhere; text-spacing-trim: space-first; font-kerning: normal;
  background-color: var(--paper); background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='p'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.75' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' opacity='.045' filter='url(%23p)'/%3E%3C/svg%3E");
}
body[data-view="reader"] .left-page { background-image: linear-gradient(270deg,#5a462852 0,#5a46281a 30px,transparent 120px),linear-gradient(90deg,#5a462814,transparent 44px),url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='p'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.75' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' opacity='.045' filter='url(%23p)'/%3E%3C/svg%3E"); }
body[data-view="reader"] .right-page { border-top: 0; background-image: linear-gradient(90deg,#5a462852 0,#5a46281a 30px,transparent 120px),linear-gradient(270deg,#5a462814,transparent 44px),url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='p'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.75' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' opacity='.045' filter='url(%23p)'/%3E%3C/svg%3E"); }
body[data-view="reader"] .page-body { position: absolute; inset: 88px 76px 74px; overflow: hidden; display: flex; flex-direction: column; gap: calc(16px * var(--fit)); }
body[data-view="reader"] .page-body > * { margin: 0; flex: none; }
body[data-view="reader"] .left-page:not(:has(.page-body)) { display: flex; flex-direction: column; gap: calc(16px * var(--fit)); }
body[data-view="reader"] .eyebrow { position: absolute; left: 76px; right: 76px; top: 40px; display: flex; align-items: baseline; justify-content: space-between; gap: 0; padding: 0 0 10px; margin: 0; min-height: 0; border-bottom: 1.5px solid #1f26332e; color: var(--muted); font: 400 19px/1 var(--sans); letter-spacing: .08em; }
body[data-view="reader"] .eyebrow > :last-child { color: var(--red); font-weight: 700; letter-spacing: .02em; }
body[data-view="reader"] .right-page .eyebrow { justify-content: flex-end; }
body[data-view="reader"] .right-page .eyebrow > :last-child { color: #555d6b; font-weight: 400; letter-spacing: .08em; }
body[data-view="reader"] .left-page h1,
body[data-view="reader"].teacher-open .left-page h1 { display: flex; align-items: center; gap: 18px; margin: 6px 0 2px; font: 700 calc(56px * var(--fit))/1.15 var(--sans); letter-spacing: .06em; }
body[data-view="reader"] .chapter-no { display: inline-block; min-width: 0; margin: 0; padding: 9px 12px 8px; border-radius: 6px; background: var(--red); color: #fff; font: 700 calc(26px * var(--fit))/1 var(--sans); letter-spacing: .02em; vertical-align: baseline; }
body[data-view="reader"] .lead, body[data-view="reader"].teacher-open .lead { margin: 0; text-indent: 2em; font-size: 1.02em; line-height: inherit; }
body[data-view="reader"] b.em, body[data-view="reader"] .lead b, body[data-view="reader"] li b { font-family: var(--sans); font-weight: 700; }
body[data-view="reader"] .prediction { margin: 0; padding: calc(12px * var(--fit)) 20px calc(14px * var(--fit)); border: 2.5px dashed var(--gold); border-radius: 14px; background: #fff7debf; }
body[data-view="reader"] .prediction-head { display: flex; align-items: center; gap: 14px; }
body[data-view="reader"] .mini-label { padding: 7px 12px 6px; border-radius: 6px; background: #f6c446; color: #5b4206; font: 700 calc(21px * var(--fit))/1 var(--sans); letter-spacing: .1em; }
body[data-view="reader"] .prediction-tip { color: var(--muted); font: 400 calc(18px * var(--fit))/1 var(--sans); }
body[data-view="reader"] .mini-label > span { display: inline; padding-left: 14px; background: transparent; color: var(--muted); font: 400 calc(18px * var(--fit))/1 var(--sans); letter-spacing: normal; }
body[data-view="reader"] .prediction h3 { margin: 8px 0; color: var(--ink); text-align: left; font: 700 calc(29px * var(--fit))/1.5 var(--sans); }
body[data-view="reader"] .choice-row { display: flex; flex-direction: row; flex-wrap: wrap; align-items: stretch; gap: 12px; row-gap: 10px; }
body[data-view="reader"] .choice-row button { display: flex; flex: 1 1 auto; width: auto; gap: 10px; align-items: center; min-height: 58px; padding: 8px 18px 8px 10px; border: 2.5px solid #1f263380; border-radius: 12px; background: #fffdf8; color: var(--ink); font: 400 calc(27px * var(--fit))/1.3 var(--sans); }
body[data-view="reader"] .choice-row button b { display: grid; place-items: center; flex: none; width: 36px; height: 36px; padding: 0; border-radius: 50%; background: var(--ink); color: #fff; font: 700 20px/1 var(--sans); }
body[data-view="reader"] .choice-row button:hover { background: #fffdf8; border-color: var(--ink); }
body[data-view="reader"] .choice-row button.selected { padding: 8px 18px 8px 10px; border-color: var(--ink); background: #fff3c4; font-weight: 700; box-shadow: 0 0 0 3px #f6c44699; }
body[data-view="reader"] .choice-row button.correct { border-color: var(--green); background: #e3f4ea; }
body[data-view="reader"] .choice-row button.correct b { background: var(--green); }
body[data-view="reader"] .choice-row button.wrong { border-color: var(--red); background: #fbe7e2; }
body[data-view="reader"] .choice-row button.wrong b { background: var(--red); }
body[data-view="reader"] .answer-wrap { position: relative; margin-top: 10px; }
body[data-view="reader"] .answer-content { min-height: 96px; padding: 8px 16px; border: 2px solid var(--green); border-radius: 10px; background: #fff; font-size: calc(23px * var(--fit)); line-height: 1.55; }
body[data-view="reader"] .answer-content > strong { display: block; color: var(--green); font: 700 1.05em/1.4 var(--sans); }
body[data-view="reader"] .answer-content p { margin: 2px 0 0; text-indent: 0; }
body[data-view="reader"] .answer-sheet { position: relative; display: flex; flex-direction: column; justify-content: center; gap: 6px; min-height: 152px; width: 100%; margin-top: 10px; padding: 18px 26px; border: 0; border-radius: 10px; background: repeating-linear-gradient(0deg,#785a1e12 0 2px,transparent 2px 34px),linear-gradient(#efe2bf,#e6d6ac); color: #4a3a12; box-shadow: 0 6px 14px #3c280a40,inset 0 0 0 2px #785a1e40; transform-origin: 50% 0; font-family: var(--sans); transition: transform .5s cubic-bezier(.3,.7,.2,1.1),box-shadow .5s; }
body[data-view="reader"] .answer-wrap > .answer-sheet { position: absolute; inset: -4px; width: calc(100% + 8px); min-height: 0; margin: 0; padding: 0 26px; }
body[data-view="reader"] .answer-sheet > strong { display: block; color: #4a3a12; font: 700 calc(30px * var(--fit))/1.2 var(--sans); }
body[data-view="reader"] .answer-sheet > small { display: block; color: inherit; opacity: .8; font: 400 calc(19px * var(--fit))/1.2 var(--sans); }
body[data-view="reader"] .answer-sheet > strong > span { position: absolute; right: 26px; top: 50%; width: 46px; height: 46px; margin-top: -23px; font: 40px/1 var(--sans); }
body[data-view="reader"] .answer-sheet.revealed { background: #fff; border: 2px solid var(--green); padding: 8px 16px; box-shadow: none; animation: none; }
body[data-view="reader"] .answer-sheet.revealed > span { font: 400 calc(23px * var(--fit))/1.55 var(--serif); }
body[data-view="reader"] .answer-wrap:has(.revealed) > .answer-sheet { transform: translateY(-10px) scaleY(.1); box-shadow: 0 2px 4px #3c280a33; border: 0; padding: 0 26px; background: repeating-linear-gradient(0deg,#785a1e12 0 2px,transparent 2px 34px),linear-gradient(#efe2bf,#e6d6ac); }
body[data-view="reader"] .answer-wrap:has(.revealed) > .answer-sheet > * { opacity: 0; }
body[data-view="reader"] .activity-card, body[data-view="reader"] .key-card { --c: var(--blue); margin: 0; padding: calc(12px * var(--fit)) 22px calc(14px * var(--fit)); border: 2.5px solid var(--c); border-radius: 12px; background: color-mix(in srgb,var(--c) 6%,transparent); }
body[data-view="reader"] .key-card { --c: var(--red); }
body[data-view="reader"] .activity-card > header, body[data-view="reader"] .key-card > header { display: flex; align-items: center; gap: 12px; margin-bottom: 4px; }
body[data-view="reader"] .section-label, body[data-view="reader"] .key-card h3 > span { display: inline-block; margin-right: 12px; padding: 6px 10px 5px; border-radius: 5px; background: var(--c,var(--blue)); color: #fff; font: 700 calc(19px * var(--fit))/1 var(--sans); letter-spacing: .1em; vertical-align: 3px; }
body[data-view="reader"] .activity-card h3, body[data-view="reader"] .key-card h3 { display: inline; margin: 0; color: var(--c); font: 700 calc(28px * var(--fit))/1.3 var(--sans); }
body[data-view="reader"] .activity-card ol, body[data-view="reader"] .key-card ul,
body[data-view="reader"].teacher-open .activity-card ol, body[data-view="reader"].teacher-open .key-card ul { margin: 0; padding-left: 1.55em; font: inherit; line-height: inherit; }
body[data-view="reader"] .activity-card li, body[data-view="reader"] .key-card li { margin: 1px 0; padding-left: 2px; }
body[data-view="reader"] .activity-card li::marker, body[data-view="reader"] .key-card li::marker { color: var(--c); font-family: var(--sans); font-weight: 700; }
body[data-view="reader"] .cols2, body[data-view="reader"] .key-card.cols2 ul { display: grid; grid-template-columns: 1fr 1fr; column-gap: 1.6em; }
body[data-view="reader"] .key-foot { margin: 6px 0 0; padding-top: 6px; border-top: 1.5px dashed color-mix(in srgb,var(--c) 45%,transparent); font-family: var(--sans); }
body[data-view="reader"] .en { color: var(--muted); font: 400 .72em/1 var(--sans); letter-spacing: 0; white-space: nowrap; }
body[data-view="reader"] .page-number { left: 0; right: 0; bottom: 34px; transform: none; color: var(--muted); text-align: center; font: 400 19px/1 var(--sans); }
body[data-view="reader"] .scene-label { position: absolute; top: 40px; left: 76px; right: 76px; display: flex; align-items: baseline; justify-content: flex-end; min-height: 0; margin: 0; padding-bottom: 10px; border-bottom: 1.5px solid #1f26332e; color: var(--muted); font: 400 19px/1 var(--sans); letter-spacing: .08em; }
body[data-view="reader"] .scene-label > span, body[data-view="reader"] .scene-reset { display: none; }
body[data-view="reader"] .scene-label > b { font-weight: 400; }
body[data-view="reader"] .scene-area, body[data-view="reader"].teacher-open .scene-area, body[data-view="reader"][data-focus="right"] .scene-area { position: absolute; top: 70px; left: 0; width: 840px; height: 775px; min-height: 0; overflow: visible; border-radius: 0; }
body[data-view="reader"] .scene-controls { position: absolute; left: 60px; right: 60px; bottom: 64px; margin: 0; padding: 14px 18px 16px; border: 0; border-radius: 14px; background: #faf7eff0; box-shadow: 0 0 0 1.5px #1f26332e; font-family: var(--sans); }
body[data-view="reader"] .scene-caption { display: flex; align-items: baseline; gap: 12px; font: 700 26px/1.35 var(--sans); }
body[data-view="reader"] .scene-caption > span { position: relative; top: -3px; flex: none; margin: 0; padding: 6px 9px 5px; border-radius: 5px; background: var(--ink); color: #fff; font: 700 18px/1 var(--sans); letter-spacing: .1em; }
body[data-view="reader"] .scene-hint { margin: 4px 0 0; color: var(--ink2); font: 400 21px/1.5 var(--sans); }
body[data-view="reader"] .readouts { display: flex; flex-wrap: wrap; align-items: stretch; gap: 10px; margin: 10px 0 0; }
body[data-view="reader"] .readout { --c: var(--ink); display: inline-flex; flex: 0 0 auto; flex-direction: column; justify-content: center; min-width: 150px; margin: 0; padding: 4px 16px; border: 0; border-radius: 10px; background: #fff; box-shadow: inset 0 0 0 2px color-mix(in srgb,var(--c) 55%,transparent); }
body[data-view="reader"] .readout:first-child { --c: var(--red); }
body[data-view="reader"] .readout small { margin: 0; color: var(--muted); font: 400 16px/1.2 var(--sans); }
body[data-view="reader"] .readout strong, body[data-view="reader"] .readout:nth-child(even) strong { color: var(--c); font: 700 28px/1.2 var(--sans); font-variant-numeric: tabular-nums; }
body[data-view="reader"] .parameters { display: flex; flex-wrap: wrap; gap: 10px; margin: 10px 0 0; }
body[data-view="reader"] .parameter { display: inline-flex; align-items: center; gap: 10px; padding: 6px 14px; border-radius: 999px; background: #fff; box-shadow: inset 0 0 0 2px #1f263366; }
body[data-view="reader"] .parameter label { display: flex; align-items: center; gap: 10px; color: var(--ink); font: 700 20px/1 var(--sans); }
body[data-view="reader"] .parameter input[type="range"] { width: 180px; min-height: 0; height: 30px; margin: 0; accent-color: var(--ink); }
body[data-view="reader"] .parameter output { color: var(--ink); font-weight: 700; }
body[data-view="reader"] .scene-actions { display: flex; flex-wrap: wrap; align-items: stretch; gap: 10px; margin: 10px 0 0; }
body[data-view="reader"] .scene-actions button, body[data-view="reader"] .scene-actions label { min-height: 48px; padding: 8px 18px; border: 2px solid var(--ink); border-radius: 999px; background: #fffdf8; color: var(--ink); gap: 9px; font: 700 21px/1.2 var(--sans); }
body[data-view="reader"] .scene-actions label:has(input:checked) { background: #fff3c4; }
body[data-view="reader"] .scene-actions input { appearance: none; position: relative; width: 20px; height: 20px; margin: 0; border: 2px solid var(--ink); border-radius: 5px; background: transparent; }
body[data-view="reader"] .scene-actions input:checked { background: var(--ink); }
body[data-view="reader"] .scene-actions input:checked::after { content: ""; position: absolute; left: 4px; top: 0; width: 5px; height: 10px; border: solid #fff; border-width: 0 3px 3px 0; transform: rotate(45deg); }
body[data-view="reader"] .scene-actions button:hover { background: #fff3c4; }
body[data-view="reader"] .toolbar { position: fixed; z-index: 40; bottom: 14px; left: 50%; display: flex; flex-wrap: nowrap; align-items: center; gap: 2px; width: max-content; min-height: 72px; max-width: none; padding: 6px 10px; border: 0; border-radius: 18px; background: #faf8f2f0; box-shadow: 0 6px 24px #281e0f40,0 0 0 1px #1f26331f; transform: translateX(-50%); overflow: visible; backdrop-filter: none; }
body[data-view="reader"] .tool { display: flex; flex: 0 0 66px; flex-direction: column; align-items: center; justify-content: center; gap: 3px; width: 66px; min-width: 66px; height: 60px; min-height: 60px; padding: 0; border: 0; border-radius: 12px; background: transparent; color: var(--ink); }
body[data-view="reader"] .tool svg { width: 26px; height: 26px; }
body[data-view="reader"] .tool > span { min-height: 26px; font: 26px/1 var(--sans); }
body[data-view="reader"] .tool > small { font: 400 14px/1 var(--sans); }
body[data-view="reader"] .tool[data-action="play"] { color: var(--red); }
body[data-view="reader"] .tool:hover:not(:disabled) { background: #1f263314; }
body[data-view="reader"] .tool.active { background: var(--ink); color: #fff; box-shadow: none; }
body[data-view="reader"] .tool.answer-next { color: #7a5a00; background: #fff1c2; box-shadow: inset 0 0 0 2px #e8b931; }
body[data-view="reader"] .tool:disabled { opacity: .35; }
body[data-view="reader"] .tool-title { display: flex; flex: 0 1 auto; align-items: center; justify-content: center; gap: 10px; height: 60px; min-width: 300px; max-width: 460px; margin: 0; padding: 0 14px; border-radius: 12px; background: transparent; overflow: hidden; white-space: nowrap; }
body[data-view="reader"] .tool-title strong { overflow: hidden; text-overflow: ellipsis; font: 700 22px/1 var(--sans); }
body[data-view="reader"] .tool-title em { margin-right: 5px; color: var(--red); font: 700 22px/1 var(--sans); }
body[data-view="reader"] .tool-title small { display: inline; margin: 0; color: var(--muted); font: 400 15px/1 var(--sans); }
body[data-view="reader"] .toolbar-divider { flex: 0 0 1.5px; width: 1.5px; height: 40px; margin: 0 6px; background: #1f26332e; }
body[data-view="reader"] .teacher-panel { position: fixed; z-index: 35; left: 14px; top: 14px; bottom: 100px; width: min(400px,calc(24vw - 20px)); min-width: 300px; margin: 0; padding: 0 18px 14px; overflow: auto; border: 0; border-left: 7px solid #e0b23a; border-radius: 12px; background: #fffbea; color: var(--ink); box-shadow: 0 6px 20px #281e0f40; font: 400 18px/1.6 var(--sans); }
body[data-view="reader"] .teacher-panel::before { display: none; }
body[data-view="reader"] .teacher-panel > header { position: sticky; top: 0; display: flex; justify-content: space-between; align-items: center; gap: 0; padding: 12px 0 6px; border: 0; background: #fffbea; color: var(--ink); font: 700 20px/1.6 var(--sans); letter-spacing: 0; }
body[data-view="reader"] .teacher-panel > header em, body[data-view="reader"] .teacher-panel > header small { margin-left: 6px; color: var(--red); font: inherit; }
body[data-view="reader"] .teacher-panel > header button { width: auto; height: auto; padding: 0; border: 0; background: none; color: var(--ink); font: 28px/1 var(--sans); }
body[data-view="reader"] .teacher-panel h4, body[data-view="reader"] .teacher-panel h3 { margin: 10px 0 4px; color: var(--red); font: 700 18px/1.6 var(--sans); }
body[data-view="reader"] .teacher-panel p, body[data-view="reader"] .teacher-panel li { color: var(--ink); font: inherit; line-height: inherit; }
body[data-view="reader"] .teacher-panel p { margin: 0; }
body[data-view="reader"] .teacher-panel ul { margin: 0; padding-left: 1.2em; }
body[data-view="reader"] .teacher-panel li { margin: 3px 0; }
body[data-view="reader"] .tn-goal b { display: block; color: var(--blue); }
body[data-view="reader"] .teacher-keys { margin-top: 12px; padding-top: 8px; border-top: 1px dashed #0003; color: var(--ink2); font: 400 15px/1.6 var(--sans); }
body[data-view="reader"] #toast { top: 22px; bottom: auto; padding: 12px 22px; max-width: 80vw; border-radius: 999px; background: #1f2633eb; color: #fff; font: 700 21px/1.3 var(--sans); transform: translate(-50%,0); box-shadow: none; }
body[data-view="reader"] .toc-heading { margin: 0 0 4px; color: var(--ink); text-align: center; font: 700 calc(54px * var(--fit))/1.2 var(--sans); letter-spacing: .3em; }
body[data-view="reader"] .toc-columns { display: flex; flex-direction: column; gap: calc(8px * var(--fit)); }
body[data-view="reader"] .toc-view .page-body { gap: calc(8px * var(--fit)); }
body[data-view="reader"] .toc-view.right-page { padding: 88px 76px 74px; }
body[data-view="reader"] .chapter-group h3 { display: flex; gap: 14px; align-items: baseline; margin: calc(6px * var(--fit)) 0 calc(4px * var(--fit)); padding-bottom: 4px; border-bottom: 2px solid var(--ink); color: var(--ink); font: 700 calc(29px * var(--fit))/1.3 var(--sans); }
body[data-view="reader"] .chapter-group h3 > span { color: var(--red); }
body[data-view="reader"] .lesson-link { display: flex; align-items: center; gap: 14px; width: 100%; margin: 0; padding: calc(5px * var(--fit)) 8px; border: 0; border-radius: 8px; background: transparent; text-align: left; font: 400 calc(26px * var(--fit))/1.35 var(--serif); }
body[data-view="reader"] .lesson-link > span:first-child { min-width: 2.6em; color: var(--red); font: 700 .9em/1 var(--sans); }
body[data-view="reader"] .lesson-link small { flex: none; margin-left: auto; padding: 5px 9px; border-radius: 999px; background: var(--blue); color: #fff; font: 700 calc(17px * var(--fit))/1 var(--sans); }
body[data-view="reader"] .lesson-link small.coming { color: #6b6250; background: #78643c1f; }
body[data-view="reader"] .lesson-link:hover { background: #f6c44640; color: var(--ink); }
body[data-view="reader"] .frontis { min-height: 1120px; padding: 108px 76px 74px; text-align: center; }
body[data-view="reader"] .frontis h1 { display: block; margin: 16px 0 0 .3em; padding: 0; text-align: center; font: 700 120px/1.1 var(--serif); letter-spacing: .3em; }
body[data-view="reader"] .frontis .eyebrow { position: static; display: block; border: 0; margin: 6px 0 0; padding: 0; text-align: center; font: 400 22px/1 var(--sans); letter-spacing: .3em; }
body[data-view="reader"] .frontis p { max-width: none; color: var(--ink); font: 400 calc(25px * var(--fit))/1.6 var(--sans); }
body[data-view="reader"] .frontis .how-to { max-width: none; width: 100%; margin-top: 18px; padding: 0; border: 0; text-align: left; }
body[data-view="reader"] .frontis .how-to h2 { margin: 0 0 10px; color: var(--red); font: 700 26px/1 var(--sans); letter-spacing: .2em; }
body[data-view="reader"] .frontis .how-to ol { margin: 0; padding-left: 1.2em; color: var(--ink); font: 400 calc(25px * var(--fit))/1.6 var(--sans); }
body[data-view="reader"] .frontis .how-to li { margin: 6px 0; }
body[data-view="reader"] .frontis-edition { margin: 0 !important; color: var(--ink) !important; font: 700 40px/1 var(--sans) !important; letter-spacing: .4em; }
@media (max-width: 1100px) {
  body[data-view="reader"] .tool { flex-basis: 54px; width: 54px; min-width: 54px; }
  body[data-view="reader"] .tool > small { font-size: 12px; }
  body[data-view="reader"] .tool-title { min-width: 160px; }
  body[data-view="reader"] .tool-title small { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  body[data-view="reader"] .answer-sheet { transition: none; }
}

@font-face { font-family: "PB Shelf"; font-weight: 400; font-display: block; src: url("./vendor/fonts/pb-shelf-400.woff2") format("woff2"); }
@font-face { font-family: "PB Shelf"; font-weight: 700; font-display: block; src: url("./vendor/fonts/pb-shelf-700.woff2") format("woff2"); }
body[data-view="shelf"] { min-height: 100vh; height: auto; overflow: auto; background: #cfc4ae; color: #1f2633; font-family: "PB Shelf", "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif; }
body[data-view="shelf"] #shelf { max-width: none; margin: 0; padding: 0; }
body[data-view="shelf"] .shelf-heading { margin: 0; padding: 48px 20px 8px; text-align: center; }
body[data-view="shelf"] .shelf-heading h1 { margin: 0; padding: 0; color: #1f2633; font: 700 44px/1.2 "PB Shelf", "Songti SC", SimSun, serif; letter-spacing: .2em; }
body[data-view="shelf"] .shelf-heading .subtitle { margin: 10px 0 0; color: #5a5040; font: 400 18px/normal "PB Shelf", "Microsoft YaHei", sans-serif; letter-spacing: 0; }
body[data-view="shelf"] .shelf-kicker, body[data-view="shelf"] .continue-reading { display: none; }
body[data-view="shelf"] .shelf-grid { display: flex; flex-wrap: wrap; align-items: start; justify-content: center; gap: 36px; max-width: 1400px; margin: 0 auto; padding: 36px 24px 20px; }
body[data-view="shelf"] .shelf-card { display: block; flex: 0 0 270px; width: 270px; min-width: 270px; margin: 0; padding: 0; color: inherit; text-decoration: none; transition: transform .15s; }
body[data-view="shelf"] .shelf-card > button { display: block; width: 270px; margin: 0; padding: 0; background: transparent; text-align: left; }
body[data-view="shelf"] .shelf-card:has(> button:hover) { transform: translateY(-6px); }
body[data-view="shelf"] .book-cover,
body[data-view="shelf"] .shelf-card:nth-child(even) .book-cover,
body[data-view="shelf"] .shelf-card button:hover .book-cover { position: relative; display: block; width: 270px; height: 340px; min-height: 340px; aspect-ratio: auto; margin: 0; padding: 34px 22px 0 34px; border: 0; border-radius: 6px 10px 10px 6px; background: linear-gradient(135deg,#2f6672,#234b57); box-shadow: inset 10px 0 0 #21495a,0 14px 26px #281e1459; transform: none; transition: none; }
body[data-view="shelf"] .cover-label { width: auto; margin: 0; padding: 30px 10px 26px; border: 0; outline: 3px solid #1f2633; outline-offset: -12px; background: #f4efe2; color: #1f2633; box-shadow: none; text-align: center; }
body[data-view="shelf"] .cover-label h2 { display: block; margin: 0; padding: 0; color: #1f2633; font: 700 54px/1 "PB Shelf", "Songti SC", SimSun, serif; letter-spacing: 0; }
body[data-view="shelf"] .cover-label .edition { display: block; margin: 16px 0 0; color: #1f2633; font: 700 22px/normal "PB Shelf", "Microsoft YaHei", sans-serif; letter-spacing: 0; }
body[data-view="shelf"] .cover-subtitle { display: block; margin: 10px 0 0; color: #5a6475; font: 400 14px/normal "PB Shelf", "Microsoft YaHei", sans-serif; letter-spacing: 0; }
body[data-view="shelf"] .cover-art, body[data-view="shelf"] .shelf-card > .book-meta { display: none; }
body[data-view="shelf"] .cover-footer { position: absolute; left: 34px; right: 22px; bottom: 24px; margin: 0; padding: 0; color: #f4efe2; text-align: center; font: 700 17px/normal "PB Shelf", "Microsoft YaHei", sans-serif; letter-spacing: 0; }
body[data-view="shelf"] .chapter-summary, body[data-view="shelf"] .shelf-card > .chapter-summary { list-style: none; margin: 16px 4px 0; padding: 0; color: #3a3428; font: 400 15px/1.7 "PB Shelf", "Microsoft YaHei", sans-serif; }
body[data-view="shelf"] .chapter-summary li { display: flex; gap: 0; align-items: baseline; margin: 0; }
body[data-view="shelf"] .chapter-summary b { display: inline-block; flex: 0 0 2.2em; min-width: 2.2em; color: #b5322a; font-weight: 700; }
body[data-view="shelf"] .shelf-footer { display: block; margin: 0; padding: 20px 0 40px; color: #5a5040; text-align: center; font: 400 15px/normal "PB Shelf", "Microsoft YaHei", sans-serif; letter-spacing: 0; }
body[data-view="shelf"] .shelf-footer button { display: none; }
/* Source control flow and the flap's anchored arrow. */
body[data-view="reader"] .box-header > .section-label { margin-right: 0; }
body[data-view="reader"] .answer-sheet .fl-ic { position: absolute; right: 26px; top: 50%; width: 46px; height: 46px; margin-top: -23px; }
body[data-view="reader"] .fig-ctl { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 10px; align-items: stretch; }
body[data-view="reader"] .fig-ctl > .readouts,
body[data-view="reader"] .fig-ctl > .parameters:not([hidden]),
body[data-view="reader"] .fig-ctl > .scene-actions { display: contents; }
body[data-view="reader"] .fig-ctl .readout { flex: none; margin: 0; }
body[data-view="reader"] .control-break { flex-basis: 100%; height: 0; }
body[data-view="reader"] .pb-range { display: inline-flex; align-items: center; gap: 10px; font: 700 20px/1.2 var(--sans); }
body[data-view="reader"] .pb-range input { width: 180px; accent-color: var(--red); }
body[data-view="reader"] .pb-range output { min-width: 50px; font-variant-numeric: tabular-nums; }
body[data-view="reader"] .pb-select,body[data-view="reader"] .pb-tabs { display: inline-flex; align-items: center; gap: 10px; font: 700 20px/1.2 var(--sans); }
body[data-view="reader"] .pb-select select { padding: 7px 10px; border: 2px solid var(--ink); border-radius: 10px; background: #fffdf8; color: var(--ink); }
body[data-view="reader"] .pb-btn,body[data-view="reader"] .pb-toggle { pointer-events: auto; cursor: pointer; border: 2px solid var(--ink); background: #fffdf8; border-radius: 999px; padding: 8px 18px; font: 700 21px/1.2 var(--sans); min-height: 48px; display: inline-flex; align-items: center; gap: 9px; }
body[data-view="reader"] .pb-btn.is-primary { background: var(--ink); color: #fff; }
body[data-view="reader"] .pb-toggle i { width: 20px; height: 20px; border: 2px solid var(--ink); border-radius: 5px; display: inline-block; position: relative; }
body[data-view="reader"] .pb-toggle.is-on { background: #fff3c4; }
body[data-view="reader"] .pb-toggle.is-on i { background: var(--ink); }
body[data-view="reader"] .pb-toggle.is-on i::after { content: ""; position: absolute; left: 5px; top: 1px; width: 5px; height: 10px; border: solid #fff; border-width: 0 3px 3px 0; transform: rotate(45deg); }

/* Native source UI elements. */
.pg-frontis .pg-body{align-items:center;text-align:center;justify-content:flex-start;padding-top:20px}
.fr-top{font:400 22px/1 var(--sans);color:var(--muted);letter-spacing:.3em;margin-top:6px!important}
.fr-title{font:700 120px/1.1 var(--serif);letter-spacing:.3em;margin:16px 0 0 .3em!important}
.fr-sub{font:700 40px/1 var(--sans);letter-spacing:.4em}
.fr-rule{width:70%;height:0;border-top:3px double var(--ink);margin:18px 0!important}
.fr-how{text-align:left;width:100%;font:400 calc(25px * var(--fit))/1.6 var(--sans)}
.fr-how h2{font:700 26px/1 var(--sans);color:var(--red);letter-spacing:.2em;margin:0 0 10px}
.fr-how ul{margin:0;padding-left:1.2em}
.fr-how li{margin:6px 0}
.fr-brand{position:absolute;bottom:18px;left:0;right:0;font:700 30px/1 var(--sans);letter-spacing:.1em;color:#2a5c68}
.pb-menu{position:absolute;bottom:92px;left:50%;transform:translate(calc(-50% + 330px));width:340px;background:#fffdf8;border-radius:16px;padding:8px;box-shadow:0 10px 30px #281e0f47,0 0 0 1px #1f26331f}
.pb-menu hr{border:0;border-top:1px solid rgba(31,38,51,.12);margin:6px 4px}
.mi{display:flex;gap:12px;align-items:center;width:100%;border:0;background:transparent;text-align:left;padding:10px 12px;border-radius:10px;cursor:pointer}
.mi:hover{background:#1f26330f}
.mi b{display:block;font:700 18px/1.3 var(--sans)}
.mi small{display:block;font:400 14px/1.4 var(--sans);color:var(--muted)}
.mi i{flex:none;width:40px;height:24px;border-radius:99px;background:#cfd3da;position:relative;transition:background .15s}
.mi i:after{content:"";position:absolute;left:3px;top:3px;width:18px;height:18px;border-radius:50%;background:#fff;transition:left .15s;box-shadow:0 1px 2px #00000040}
.mi.is-on i{background:var(--green)}
.mi.is-on i:after{left:19px}
.mi-plain{padding-left:64px}
.pb-help{position:absolute;inset:0;background:#1e1a1273;display:grid;place-items:center;z-index:5}
.pb-help[hidden]{display:none}
.hp-card{width:min(1100px,92vw);max-height:86vh;overflow:auto;background:#fffdf8;border-radius:18px;padding:8px 30px 26px;box-shadow:0 20px 50px #0000004d}
.hp-card header{display:flex;justify-content:space-between;align-items:center;font:700 28px/1 var(--sans);padding:18px 0 8px;border-bottom:2px solid var(--ink)}
.hp-card .x{border:0;background:none;font-size:34px;cursor:pointer;line-height:1}
.hp-cols{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.hp-cols h3{font:700 20px/1.3 var(--sans);color:var(--red);margin:18px 0 8px}
.hp-cols ul{margin:0;padding-left:1.1em;font:400 18px/1.7 var(--sans)}
.hp-cols li{margin:6px 0}
.pb-menu{transform:translate(-50%)}
.hp-cols{grid-template-columns:1fr}
dialog.pb-help:not([open]){display:none!important}dialog.pb-help[open]{position:fixed;inset:0;width:100vw;height:100vh;max-width:none;max-height:none;margin:0;padding:0;border:0;background:transparent;display:grid;place-items:center;font-family:var(--sans)}dialog.pb-help::backdrop{background:#1f263366}.pb-menu{position:fixed;z-index:60}.box-header>.section-label{margin-right:0}.frac{display:inline-flex;flex-direction:column;vertical-align:middle;align-items:center;line-height:1.15}.frac>span:first-child{border-bottom:1.5px solid currentColor;padding:0 .12em}.frac>span:last-child{padding:0 .12em}.math-inline{font-family:var(--serif);white-space:nowrap}.formula-main{font:700 1.3em/1.5 var(--serif)}
.pb-control-group { display: flex; gap: 8px; align-items: center; justify-content: center; }
.pb-control-group.vertical { flex-direction: column; }
.c5-tab { border-collapse: collapse; font: 700 17px/1.2 "PB Sans",sans-serif; color: #1f2633; background: #fffdf7f5; font-variant-numeric: tabular-nums; }
.c5-tab th,.c5-tab td { border: 1.3px solid #1f263373; padding: 3px 7px; text-align: center; min-width: 44px; }
.c5-tab th { font-weight: 400; color: #4b5263; background: #f3ecdc; white-space: nowrap; }
.c5-tab td.new { background: #ffe9c9; }
.c5-tab caption { caption-side: top; text-align: left; font: 700 15px/1.4 "PB Sans",sans-serif; color: #7b7466; padding-bottom: 2px; }
.c5-wrap { display: flex; flex-direction: column; gap: 6px; padding: 6px 8px; background: #fffdf7f0; border: 1.5px solid #1f26338c; border-radius: 8px; box-shadow: 0 1px 4px #0003; }
.c5-mag { display: block; border-radius: 50%; border: 3px solid #1f2633; box-shadow: 0 2px 8px #0004; background: #fffdf6; }
.c5-est { color: #d2452c; }
body[data-view="reader"] .motion-records { padding: 4px 6px; }
.motion-records > .t,.motion-records > .control-label { display: none; }

/* Formula typography measured from the source renderer. */
.b-formula{border:2px solid var(--ink);border-radius:10px;padding:12px 20px;display:flex;flex-direction:column;align-items:center;background:#fffdf8}
.fm-title{align-self:flex-start;font:700 calc(20px * var(--fit))/1 var(--sans);color:var(--red);letter-spacing:.1em}
.fm{font:400 calc(48px * var(--fit))/1.3 "Times New Roman",var(--serif)}
.fm i{font-style:italic;padding:0 .02em}
.fm-op{padding:0 .28em}
.fm-frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;margin:0 .1em}
.fm-num{border-bottom:.06em solid currentColor;padding:0 .15em;line-height:1.1}
.fm-den{padding:0 .15em;line-height:1.15}
.fm-txt{font-family:var(--serif);font-style:normal}
.fm-note{font:400 calc(21px * var(--fit))/1.5 var(--sans);color:var(--muted)}
.fm-inline{font-family:"Times New Roman",var(--serif);white-space:nowrap}
.fm-inline .fm-frac{font-size:.85em}
.cover-hit-area { position: fixed; inset: 0; z-index: 20; cursor: pointer; background: transparent; }
.pb-open { position: fixed; z-index: 21; left: 50%; bottom: 100px; transform: translateX(-50%); border: 0; border-radius: 999px; background: #2a5c68; color: #fff; font: 700 26px/1 var(--sans); padding: 18px 40px; box-shadow: 0 6px 20px #0000004d; cursor: pointer; letter-spacing: .15em; }

/* Reader view controls stay outside the projected pages. */
body[data-view="reader"] #app,body[data-view="reader"] #reader { position: static; inset: auto; }
.book-view-panel { position: fixed; z-index: 55; right: 24px; bottom: 102px; width: 288px; max-width: calc(100vw - 24px); padding: 16px; border: 1px solid #1f26332a; border-radius: 16px; background: #fffdf8; color: var(--ink); box-shadow: 0 10px 32px #281e0f38; font: 400 15px/1.4 var(--sans); }
.book-view-panel header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; }
.book-view-panel h2 { margin: 0; font: 700 18px/1.3 var(--sans); }
.book-view-panel button { display: inline-flex; justify-content: center; align-items: center; min-width: 36px; min-height: 36px; padding: 6px 10px; border: 1px solid #1f263332; border-radius: 9px; background: #f7f3e9; color: var(--ink); cursor: pointer; font: 700 16px/1.3 var(--sans); }
.book-view-panel .view-close { padding: 0; background: transparent; border: 0; font: 26px/1 var(--sans); }
.view-adjustment { display: grid; grid-template-columns: 1fr auto; gap: 7px; margin-bottom: 14px; }
.view-adjustment label { font-weight: 700; }
.view-adjustment output { font-variant-numeric: tabular-nums; color: var(--muted); }
.view-slider { display: flex; gap: 10px; align-items: center; grid-column: 1 / -1; }
.view-slider input { flex: 1; min-width: 0; width: 100%; accent-color: #2a5c68; cursor: pointer; }
.view-actions { display: flex; gap: 8px; padding-top: 10px; border-top: 1px solid #1f26331a; }
.view-actions button { flex: 1; font-size: 14px; }
.book-view-panel button.is-on { background: #2a5c68; color: #fff; border-color: #2a5c68; }
.book-view-panel button:hover { filter: brightness(.96); }
.book-view-panel :focus-visible,.toolbar :focus-visible { outline: 3px solid #2c6db0; outline-offset: 3px; }
body[data-view="reader"] .desk { cursor: grab; }
body[data-book-orbit="false"] .paper { cursor: auto; }
body[data-book-orbit="true"] .paper,body[data-book-orbit="true"] .cover-hit-area { cursor: grab; touch-action: none; }
body[data-book-gesturing="true"] .desk,body[data-book-gesturing="true"] .paper { cursor: grabbing; }
body[data-book-orbit="true"] .paper button,body[data-book-orbit="true"] .paper input { cursor: pointer; }
@media (max-width: 1050px) {
  body[data-view="reader"] .toolbar { max-width: calc(100vw - 20px); width: max-content; gap: 1px; padding: 5px 6px; }
  body[data-view="reader"] .tool { flex-basis: 52px; width: 52px; min-width: 52px; }
  body[data-view="reader"] .tool-title { min-width: 100px; max-width: 240px; padding: 0 8px; }
  body[data-view="reader"] .tool-title strong { font-size: 18px; }
  body[data-view="reader"] .tool-title small { display: none; }
  body[data-view="reader"] .toolbar-divider { margin: 0 2px; }
}
@media (max-width: 660px) {
  body[data-view="reader"] .toolbar { left: 10px; right: 10px; bottom: 10px; width: auto; transform: none; justify-content: space-between; flex-wrap: wrap; min-height: 106px; padding: 5px; gap: 0; }
  body[data-view="reader"] .tool-title { order: -1; flex: 1 0 100%; width: 100%; max-width: none; min-width: 0; height: 32px; }
  body[data-view="reader"] .tool-title strong { font-size: 17px; }
  body[data-view="reader"] .tool { flex: 1 1 0; width: auto; min-width: 30px; height: 58px; min-height: 58px; border-radius: 8px; }
  body[data-view="reader"] .tool svg { width: 22px; height: 22px; }
  body[data-view="reader"] .tool > small { font-size: 11px; }
  body[data-view="reader"] .toolbar-divider { display: none; }
  .book-view-panel { right: 12px; bottom: 128px; }
  .pb-open { bottom: 138px; }
  body[data-view="reader"] .teacher-panel { z-index: 45; width: min(360px,calc(100vw - 28px)); min-width: 0; bottom: 128px; }
  .pb-menu { bottom: 128px; }
}


/* Native term, list and information block flow. */
body[data-view="reader"] .b-terms { display: grid; gap: 4px; }
body[data-view="reader"] .b-terms > div { display: flex; gap: 12px; }
body[data-view="reader"] .b-terms dt { color: var(--red); min-width: 4.5em; }
body[data-view="reader"] .b-terms dd { margin: 0; }


body[data-view="reader"] .b-box p { margin: 2px 0; }
body[data-view="reader"] .b-box .bx-list { margin: 0; padding-left: 1.55em; font: inherit; line-height: inherit; }
body[data-view="reader"] .b-box .bx-list > li { margin: 1px 0; padding-left: 2px; }
body[data-view="reader"] .b-box .bx-foot { margin-top: 6px !important; }

body[data-view="reader"] .b-formula > .fm-note { margin: 0; }

body[data-view="reader"] .activity-card.bx-act,
body[data-view="reader"] .activity-card.bx-think { --c: var(--green); }
body[data-view="reader"] .activity-card.bx-warn { --c: #b5531a; }
body[data-view="reader"] .activity-card.bx-info {
  --c: var(--tea, #9a6a2c);
  border-width: 0 0 0 6px;
  border-radius: 0 10px 10px 0;
  background: #c99a2e1a;
}
body[data-view="reader"] .activity-card.bx-info > header {
  display: inline-flex;
  margin: 0 10px 0 0;
  vertical-align: 2px;
}
body[data-view="reader"] .activity-card.bx-info p { display: inline; }

/* School identity: white paper, a light green desk, and green interface accents.
   Teaching diagrams/readouts keep their own functional colors; errors stay red. */
:root,
body[data-view="reader"],
body[data-view="shelf"] {
  --brand-green: #155b3f;
  --brand-deep: #123c2d;
  --brand-mid: #2b7955;
  --brand-soft: #e5f1e9;
  --brand-line: #b8d3c1;
  --brand-wash: #f3f9f5;
  --ink: #183c2d;
  --ink2: #3e5e4c;
  --muted: #5b7464;
  --desk: #e5f1e9;
  --paper: #ffffff;
  --paper-deep: #edf4ef;
  --green: #21764d;
  --gold: #84ae94;
}
body[data-view="shelf"] {
  color: var(--ink);
  background: radial-gradient(ellipse at 50% 0,#fff 0,#f7fbf8 48%,#e5f1e9 100%);
}
body[data-view="reader"] {
  background-color: var(--desk);
  background-image: radial-gradient(ellipse at 50% 35%,#f4faf6 0,#e5f1e9 74%,#dcebe1 100%);
}
body :focus-visible { outline-color: var(--brand-mid); }

.school-brand { display: flex; align-items: center; gap: 12px; color: var(--brand-green); text-decoration: none; font-family: var(--sans); }
.brand-logo { display: block; flex: none; width: 48px; height: 48px; object-fit: contain; border-radius: 50%; background: #fff; }
.school-brand .brand-name { display: flex; flex-direction: column; min-width: 0; margin: 0; padding: 0; letter-spacing: 0; text-align: left; }
.school-brand .brand-school { display: block; color: var(--brand-deep); font: 700 17px/1.3 var(--sans); }
.school-brand .brand-product { display: block; margin-top: 2px; color: var(--brand-green); font: 400 14px/1.3 var(--sans); }
.school-brand--reader { position: fixed; z-index: 34; left: 16px; top: 12px; max-width: calc(100vw - 32px); min-height: 58px; padding: 7px 14px 7px 8px; border: 1px solid #c9ddce; border-radius: 14px; background: #fffffff5; box-shadow: 0 3px 14px #16492f12; pointer-events: auto; }
.school-brand--reader .brand-logo { width: 42px; height: 42px; }
.school-brand--reader:hover { background: #f4faf6; border-color: #8fbaa0; }
.school-brand--reader:focus-visible { outline: 3px solid var(--brand-mid); outline-offset: 3px; }
body[data-view="shelf"] .shelf-heading { padding: 44px 20px 8px; }
.school-brand--shelf { position: static; justify-content: center; gap: 20px; width: fit-content; max-width: 100%; margin: 0 auto; padding: 0; background: transparent; }
.school-brand--shelf .brand-logo { width: 84px; height: 84px; border: 1px solid #d3e4d9; box-shadow: 0 3px 12px #16492f0d; }
body[data-view="shelf"] .school-brand--shelf h1.brand-name { display: flex; flex-direction: column; gap: 4px; margin: 0; padding: 0; color: var(--brand-deep); font: inherit; letter-spacing: 0; text-align: left; }
.school-brand--shelf .brand-school { font: 700 clamp(25px,2.5vw,36px)/1.25 var(--serif); letter-spacing: .04em; }
.school-brand--shelf .brand-product { margin: 0; font: 700 clamp(22px,2.4vw,34px)/1.25 var(--sans); letter-spacing: .025em; }
body[data-view="shelf"] .shelf-heading .subtitle { margin-top: 20px; color: var(--muted); }
body[data-view="shelf"] .shelf-heading h1 { color: var(--brand-deep); }
body[data-view="shelf"] .book-cover,
body[data-view="shelf"] .shelf-card:nth-child(even) .book-cover,
body[data-view="shelf"] .shelf-card button:hover .book-cover { padding: 22px 20px 0 30px; background: linear-gradient(90deg,#155b3f 0 9px,#dcebe1 9px 12px,#fff 12px 100%); box-shadow: 0 0 0 1px #bed5c7,0 12px 24px #123c2d1f; }
.cover-school { display: flex; align-items: center; justify-content: center; gap: 8px; margin: 0 0 18px; color: var(--brand-green); font: 700 15px/1.25 var(--sans); letter-spacing: .01em; }
.cover-logo { display: block; flex: none; width: 34px; height: 34px; object-fit: contain; border-radius: 50%; background: #fff; }
body[data-view="shelf"] .cover-label { padding: 26px 8px 22px; color: var(--brand-deep); background: #fff; outline: 1.5px solid #8fbaa0; outline-offset: -12px; }
body[data-view="shelf"] .cover-label h2,
body[data-view="shelf"] .cover-label .edition { color: var(--brand-deep); }
body[data-view="shelf"] .cover-subtitle.cover-product { margin-top: 12px; color: var(--brand-green); font-size: 14px; font-weight: 700; }
body[data-view="shelf"] .cover-footer { left: 30px; right: 20px; color: var(--brand-green); }
body[data-view="shelf"] .chapter-summary { color: #375944; }
body[data-view="shelf"] .chapter-summary b,
body[data-view="shelf"] .chapter-summary strong,
body[data-view="shelf"] .chapter-summary .chapter-num { color: var(--brand-green); }
body[data-view="shelf"] .shelf-footer { color: var(--muted); }

/* Keep all page geometry, font metrics and lesson spacing unchanged. */
body[data-view="reader"] .paper { color: var(--ink); background-color: #fff; background-image: none; }
body[data-view="reader"] .left-page { background-image: linear-gradient(270deg,#234f351a 0,#234f3508 28px,transparent 105px); }
body[data-view="reader"] .right-page { background-image: linear-gradient(90deg,#234f351a 0,#234f3508 28px,transparent 105px); }
body[data-view="reader"] .book-base polygon:nth-of-type(1) { fill: var(--brand-deep); }
body[data-view="reader"] .book-base polygon:nth-of-type(2) { fill: #d8e8dc; }
body[data-view="reader"] .book-base polygon:nth-of-type(3) { fill: #d1e1d5; }
body[data-view="reader"] .book-base polygon:nth-of-type(4) { fill: #fff; }
body[data-view="reader"] .left-page h1,
body[data-view="reader"] .toc-heading,
body[data-view="reader"] .chapter-group h3,
body[data-view="reader"] .fr-title,
body[data-view="reader"] .fr-sub { color: var(--brand-deep); }
body[data-view="reader"] .chapter-no,
body[data-view="reader"] .scene-caption > span { color: #fff; background: var(--brand-green); }
body[data-view="reader"] .left-page .eyebrow > :last-child,
body[data-view="reader"] .b-terms dt,
body[data-view="reader"] .fm-title,
body[data-view="reader"] .fr-how h2,
body[data-view="reader"] .fr-brand,
body[data-view="reader"] .chapter-group h3 > span,
body[data-view="reader"] .lesson-link > span:first-child { color: var(--brand-green); }
body[data-view="reader"] .right-page .eyebrow > :last-child { color: var(--muted); }
body[data-view="reader"] .activity-card { --c: #347a57; }
body[data-view="reader"] .key-card { --c: #155b3f; }
body[data-view="reader"] .activity-card.bx-act,
body[data-view="reader"] .activity-card.bx-think { --c: #28815a; }
body[data-view="reader"] .activity-card.bx-info { --c: #4c795d; background: #eff7f1; }
body[data-view="reader"] .activity-card.bx-warn { --c: #9c6d24; background: #fffaf0; }
body[data-view="reader"] .b-formula { border-color: #84ad94; background: #fff; }
body[data-view="reader"] .prediction { border-color: #80a98e; background: #f1f8f3; }
body[data-view="reader"] .mini-label { color: #fff; background: var(--brand-green); }
body[data-view="reader"] .prediction-tip { color: var(--muted); }
body[data-view="reader"] .choice-row button { color: var(--ink); border-color: #9fbdab; background: #fff; }
body[data-view="reader"] .choice-row button b { background: var(--brand-green); }
body[data-view="reader"] .choice-row button:hover { border-color: var(--brand-green); background: #f6fbf7; }
body[data-view="reader"] .choice-row button.selected { border-color: var(--brand-green); background: #e4f2e9; box-shadow: 0 0 0 3px #9ac7a74d; }
body[data-view="reader"] .choice-row button.correct { border-color: #21764d; background: #e6f5eb; }
body[data-view="reader"] .choice-row button.correct b { background: #21764d; }
body[data-view="reader"] .choice-row button.wrong { border-color: #bb3d3e; background: #fff0f0; box-shadow: none; }
body[data-view="reader"] .choice-row button.wrong b { background: #bb3d3e; }
body[data-view="reader"] .answer-content { border-color: #71a684; background: #fff; }
body[data-view="reader"] .answer-content > strong { color: var(--brand-green); }
body[data-view="reader"] .answer-sheet,
body[data-view="reader"] .answer-wrap:has(.revealed) > .answer-sheet { color: var(--brand-deep); background: repeating-linear-gradient(0deg,#62836c09 0 2px,transparent 2px 34px),linear-gradient(#f5fcf7,#dfeee4); box-shadow: 0 5px 12px #234e3424,inset 0 0 0 2px #94b49f70; }
body[data-view="reader"] .answer-sheet > strong { color: var(--brand-deep); }
body[data-view="reader"] .scene-controls { background: #f9fcf9f5; box-shadow: 0 0 0 1.5px #b9d1c2; }
body[data-view="reader"] .pb-btn,
body[data-view="reader"] .pb-toggle,
body[data-view="reader"] .pb-select select,
body[data-view="reader"] .parameter,
body[data-view="reader"] .pb-slider { color: var(--brand-deep); background: #fff; border-color: #719f80; }
body[data-view="reader"] .pb-btn:hover,
body[data-view="reader"] .pb-toggle:hover,
body[data-view="reader"] .scene-actions button:hover { background: #edf7f0; }
body[data-view="reader"] .pb-btn.is-primary { color: #fff; border-color: var(--brand-green); background: var(--brand-green); }
body[data-view="reader"] .pb-toggle.is-on,
body[data-view="reader"] .scene-actions label:has(input:checked) { background: #e2f2e8; }
body[data-view="reader"] .pb-toggle i,
body[data-view="reader"] .scene-actions input { border-color: var(--brand-green); }
body[data-view="reader"] .pb-toggle.is-on i,
body[data-view="reader"] .scene-actions input:checked { background: var(--brand-green); }
body[data-view="reader"] input[type="range"] { accent-color: var(--brand-green); }
body[data-view="reader"] .readout { background: #fff; }
body[data-view="reader"] .lesson-link small { background: #347a57; }
body[data-view="reader"] .lesson-link small.coming { color: #5b7464; background: #eaf1ec; }
body[data-view="reader"] .lesson-link:hover { background: #eaf5ed; }
.frontis-school-logo { position: absolute; left: 0; top: 10px; width: 56px; height: 56px; object-fit: contain; border-radius: 50%; background: #fff; }
body[data-view="reader"] .pg-frontis .fr-top { align-self: flex-end; max-width: calc(100% - 76px); color: var(--muted); font-size: 20px; line-height: 1.3; letter-spacing: .08em; text-align: center; }

body[data-view="reader"] .toolbar { background: #fffffff5; box-shadow: 0 6px 24px #133c2a24,0 0 0 1px #bfd7c6; }
body[data-view="reader"] .tool,
body[data-view="reader"] .tool[data-action="play"],
body[data-view="reader"] .tool-title,
body[data-view="reader"] .tool-title em { color: var(--brand-green); }
body[data-view="reader"] .tool:hover:not(:disabled),
body[data-view="reader"] .tool-title:hover { background: #edf6f0; }
body[data-view="reader"] .tool.active { color: #fff; background: var(--brand-green); }
body[data-view="reader"] .tool.active:hover:not(:disabled) { color: #fff; background: #104b34; }
body[data-view="reader"] .tool.answer-next { color: var(--brand-green); background: #e4f3e9; box-shadow: inset 0 0 0 2px #8bb69a; }
body[data-view="reader"] .toolbar-divider { background: #cbded1; }
.book-view-panel { color: var(--ink); border-color: #b7d1c0; background: #fff; box-shadow: 0 10px 28px #123c2d26; }
.book-view-panel h2 { color: var(--brand-deep); }
.book-view-panel button { color: var(--brand-green); border-color: #b8d1c1; background: #f1f8f3; }
.book-view-panel button.is-on { color: #fff; border-color: var(--brand-green); background: var(--brand-green); }
.book-view-panel .view-close { background: transparent; }
.book-view-panel :focus-visible,
body[data-view="reader"] .toolbar :focus-visible { outline-color: var(--brand-mid); }
.view-actions { border-color: #d7e6dc; }
body[data-view="reader"] .teacher-panel { top: 82px; border-left-color: #3f8d61; background: #fafffb; box-shadow: 0 6px 20px #123c2d26; }
body[data-view="reader"] .teacher-panel > header { color: var(--brand-deep); background: #fafffb; }
body[data-view="reader"] .teacher-panel > header button:hover { background: #e6f2ea; }
body[data-view="reader"] .teacher-panel > header em,
body[data-view="reader"] .teacher-panel h4,
body[data-view="reader"] .teacher-panel h3,
body[data-view="reader"] .tn-goal b { color: var(--brand-green); }
body[data-view="reader"] .teacher-keys { border-top-color: #a8c8b3; color: var(--muted); }
body[data-view="reader"] .teacher-keys kbd,
kbd { color: var(--brand-deep); border-color: #a7c5b2; background: #f0f8f2; }
.pb-menu { color: var(--ink); background: #fff; box-shadow: 0 10px 28px #123c2d26,0 0 0 1px #c3d9cb; }
.pb-menu hr { border-top-color: #d4e4d9; }
.mi:hover { background: #eff7f2; }
.mi i { background: #ccdcd1; }
.mi.is-on i { background: var(--brand-green); }
.hp-card { color: var(--ink); background: #fff; box-shadow: 0 20px 50px #123c2d40; }
.hp-card header { color: var(--brand-deep); border-bottom-color: #86ad94; }
.hp-cols h3 { color: var(--brand-green); }
dialog.pb-help::backdrop { background: #123c2d66; }
body[data-view="reader"] #toast { background: #154f38f5; }
.pb-open { color: #fff; background: var(--brand-green); box-shadow: 0 6px 20px #123c2d38; }
.scene-error { color: #ad373b; }

@media (max-width: 660px) {
  body[data-view="shelf"] .shelf-heading { padding: 26px 16px 6px; }
  .school-brand--shelf { gap: 12px; }
  .school-brand--shelf .brand-logo { width: 60px; height: 60px; }
  .school-brand--shelf .brand-school { font-size: 23px; }
  .school-brand--shelf .brand-product { font-size: 21px; }
  body[data-view="shelf"] .shelf-heading .subtitle { margin-top: 16px; font-size: 15px; line-height: 1.6; }
  .school-brand--reader { left: 8px; top: 7px; gap: 8px; min-height: 42px; max-width: calc(100vw - 16px); padding: 4px 10px 4px 5px; border-radius: 11px; box-shadow: 0 2px 8px #16492f12; }
  .school-brand--reader .brand-logo { width: 30px; height: 30px; }
  .school-brand--reader .brand-school { font-size: 12px; line-height: 1.25; }
  .school-brand--reader .brand-product { margin-top: 1px; font-size: 11px; line-height: 1.2; }
  body[data-view="reader"] .teacher-panel { top: 59px; }
}
@media (max-width: 380px) {
  .school-brand--shelf { gap: 9px; }
  .school-brand--shelf .brand-logo { width: 52px; height: 52px; }
  .school-brand--shelf .brand-school { font-size: 20px; }
  .school-brand--shelf .brand-product { font-size: 18px; }
}