:root {
  color-scheme: dark;
  --bg: #0e0d0a;
  --bg-alt: #18170f;
  --panel: #1c1b15;
  --panel-2: #211f17;
  --border: #2f2b20;
  --border-strong: #454033;
  --text: #f0e9d8;
  --text-dim: #b2ac9e;
  --text-muted: #858073;
  --accent: #d4a373;
  --accent-bright: #e6c197;
  --good: #4ade80;
  --warn: #fbbf24;
  --bad: #f87171;
  --info: #93c5fd;
  --image-stage: #030405;
  --image-border: #343943;
  --stage-panel: #0d1014;
  --stage-warm: #241d15;
  --stage-info: #101a26;
  --stage-good: #0d2117;
  --r-panel: 14px;
  --r-control: 9px;
  --focus: 0 0 0 3px color-mix(in srgb, var(--accent) 42%, transparent);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Noto Sans TC", "PingFang TC", "Heiti TC", -apple-system, BlinkMacSystemFont, sans-serif;
  font-size: 17px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
button, input { font: inherit; }
a { color: var(--accent-bright); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
img { max-width: 100%; }
::selection { color: var(--text); background: color-mix(in srgb, var(--accent) 25%, transparent); }

.skip {
  position: fixed;
  left: 12px;
  top: -80px;
  z-index: 100;
  padding: 8px 12px;
  color: var(--text);
  background: var(--panel-2);
  border: 1px solid var(--accent);
  border-radius: var(--r-control);
}
.skip:focus { top: 12px; }

.site-head {
  position: sticky;
  top: 0;
  z-index: 30;
  background: color-mix(in srgb, var(--bg) 94%, transparent);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}
.site-head-in {
  width: min(1080px, calc(100% - 40px));
  min-height: 62px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  color: var(--text);
  text-decoration: none;
  font-family: "Iowan Old Style", "Noto Serif TC", Georgia, serif;
  font-size: 20px;
  font-weight: 700;
}
.brand em { color: var(--accent-bright); font-style: normal; }
.head-meta, .eyebrow, .section-label, .chapter-meta, .visual-tag, .quiz-num {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 10.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
}
.head-meta { color: var(--text-muted); white-space: nowrap; }

.reading-shell {
  width: min(760px, calc(100% - 40px));
  margin: 0 auto;
  padding: 54px 0 96px;
}
.hub-shell {
  width: min(1060px, calc(100% - 40px));
  margin: 0 auto;
  padding: 60px 0 96px;
}
.chapter-section { margin: 58px 0; scroll-margin-top: 84px; }
.chapter-section:first-child { margin-top: 0; }

.eyebrow, .section-label, .chapter-meta { color: var(--accent); margin: 0 0 12px; }
h1, h2 {
  font-family: "Iowan Old Style", "Noto Serif TC", Georgia, serif;
  color: var(--text);
  letter-spacing: -.015em;
}
h1 {
  margin: 14px 0 20px;
  font-size: clamp(36px, 6vw, 44px);
  line-height: 1.22;
}
h1 .accent { color: var(--accent-bright); }
h2 {
  margin: 0 0 18px;
  font-size: clamp(26px, 4vw, 30px);
  line-height: 1.35;
}
h3 { margin: 0 0 10px; font-size: 19px; line-height: 1.5; }
p { margin: 14px 0; }
strong { color: var(--text); font-weight: 700; }
.promise {
  margin: 0;
  color: var(--text-dim);
  font-size: 19px;
  line-height: 1.75;
}
.promise strong { color: var(--accent-bright); }

.chapter-progress {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 24px;
}
.chapter-progress span { width: 36px; height: 3px; background: var(--border-strong); border-radius: 99px; }
.chapter-progress span.on { background: var(--accent); }

.prompt-box, .plain-box, .trap-box, .takeaway, .image-decision {
  border: 1px solid var(--border);
  border-left: 4px solid var(--info);
  border-radius: var(--r-control);
  background: var(--panel);
  padding: 18px 20px;
}
.prompt-box .t, .plain-box .t, .trap-box .t, .image-decision .t {
  margin: 0 0 8px;
  font-family: "SFMono-Regular", Consolas, monospace;
  color: var(--info);
  font-size: 10.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
}
.prompt-box p:last-child, .plain-box p:last-child, .trap-box p:last-child, .image-decision p:last-child { margin-bottom: 0; }
.plain-box { border-left-color: var(--accent); background: linear-gradient(180deg, var(--panel-2), var(--panel)); }
.plain-box .t { color: var(--accent-bright); }
.trap-box { border-left-color: var(--bad); }
.trap-box .t { color: var(--bad); }
.image-decision { border-left-color: var(--text-muted); background: var(--bg-alt); }
.image-decision .t { color: var(--text-muted); }
.takeaway {
  border-left-color: var(--accent);
  color: var(--text);
  background: color-mix(in srgb, var(--accent) 12%, var(--panel));
  font-size: 18px;
}
.takeaway strong { color: var(--accent-bright); }

.reasoning {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: reason;
  display: grid;
  gap: 14px;
}
.reasoning li {
  position: relative;
  padding: 15px 18px 15px 58px;
  color: var(--text-dim);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-control);
  counter-increment: reason;
}
.reasoning li::before {
  content: counter(reason, decimal-leading-zero);
  position: absolute;
  left: 18px;
  top: 15px;
  color: var(--accent);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 12px;
  font-weight: 700;
}

.flow {
  margin: 18px 0 0;
  padding: 14px 16px;
  overflow-x: auto;
  color: var(--text-dim);
  background: var(--bg-alt);
  border-left: 2px solid var(--accent);
  border-radius: 6px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 13px;
  line-height: 1.75;
  white-space: pre-wrap;
}

.pathway-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.pathway-card { padding: 16px; background: var(--stage-panel); border: 1px solid var(--image-border); border-radius: var(--r-control); }
.pathway-card .path-name { display: block; margin-bottom: 8px; color: var(--accent-bright); font: 700 18px/1.3 "SFMono-Regular", Consolas, monospace; }
.pathway-card p { margin: 0; color: var(--text-dim); font: 500 14px/1.75 "SFMono-Regular", Consolas, monospace; }
.pathway-card .arrow { color: var(--accent); }
.mobile-map { display: none; }

.visual-stage {
  margin: 24px 0;
  overflow: hidden;
  color: var(--text);
  background: var(--image-stage);
  border: 1px solid var(--image-border);
  border-radius: var(--r-panel);
}
.visual-stage svg, .visual-stage > img {
  display: block;
  width: 100%;
  height: auto;
  background: var(--image-stage);
}
.visual-stage figcaption {
  padding: 12px 15px 14px;
  color: var(--text-dim);
  background: var(--image-stage);
  border-top: 1px solid var(--image-border);
  font-size: 13px;
  line-height: 1.65;
}
.visual-tag { display: block; margin-bottom: 4px; color: var(--accent); }
.visual-breakout {
  position: relative;
  left: 50%;
  width: min(980px, calc(100vw - 32px));
  transform: translateX(-50%);
}

.pathway-svg .panel-shape { fill: var(--stage-panel); stroke: var(--image-border); stroke-width: 2; }
.pathway-svg .accent-shape { fill: var(--stage-warm); stroke: var(--accent); stroke-width: 2; }
.pathway-svg .info-shape { fill: var(--stage-info); stroke: var(--info); stroke-width: 2; }
.pathway-svg .good-shape { fill: var(--stage-good); stroke: var(--good); stroke-width: 2; }
.pathway-svg .svg-title { fill: var(--text); font: 700 25px -apple-system, "PingFang TC", sans-serif; }
.pathway-svg .svg-head { fill: var(--accent-bright); font: 700 19px -apple-system, "PingFang TC", sans-serif; }
.pathway-svg .svg-body { fill: var(--text-dim); font: 500 15px -apple-system, "PingFang TC", sans-serif; }
.pathway-svg .svg-small { fill: var(--text-muted); font: 500 13px -apple-system, "PingFang TC", sans-serif; }
.pathway-svg .svg-line { fill: none; stroke: var(--accent); stroke-width: 3; marker-end: url(#study-arrow); }
.pathway-svg .svg-line-info { fill: none; stroke: var(--info); stroke-width: 3; marker-end: url(#study-arrow-info); }

.lab {
  margin-top: 22px;
  padding: 20px;
  background: var(--bg-alt);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-panel);
}
.lab h3 { color: var(--text); }
.lab > p { color: var(--text-dim); }
.choice-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin-top: 16px; }
.choice-row button, .quiz-options button, .complete-btn, .zoom-btn {
  border: 1px solid var(--border-strong);
  border-radius: var(--r-control);
  background: var(--panel);
  color: var(--text-dim);
  cursor: pointer;
  transition: border-color .16s ease, color .16s ease, transform .16s ease, background .16s ease;
}
.choice-row button { min-height: 48px; padding: 10px 12px; }
.choice-row button:hover, .quiz-options button:hover, .complete-btn:hover, .zoom-btn:hover { border-color: var(--accent); color: var(--text); }
.choice-row button:focus-visible, .quiz-options button:focus-visible, .complete-btn:focus-visible, .zoom-btn:focus-visible, a:focus-visible { outline: none; box-shadow: var(--focus); }
.choice-row button.correct, .quiz-options button.correct { border-color: var(--good); color: var(--good); background: color-mix(in srgb, var(--good) 10%, var(--panel)); }
.choice-row button.wrong, .quiz-options button.wrong { border-color: var(--bad); color: var(--bad); background: color-mix(in srgb, var(--bad) 10%, var(--panel)); }
.lab-result { min-height: 31px; margin: 14px 0 0; padding-top: 12px; color: var(--text-dim); border-top: 1px solid var(--border); }
.lab-result.good { color: var(--good); }
.lab-result.bad { color: var(--bad); }

.real-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.real-card {
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-panel);
}
.real-frame {
  position: relative;
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  background: var(--image-stage);
  cursor: zoom-in;
}
.real-frame img { display: block; width: 100%; height: auto; background: var(--image-stage); }
.zoom-btn {
  position: absolute;
  right: 8px;
  bottom: 8px;
  padding: 5px 8px;
  color: var(--text);
  background: color-mix(in srgb, var(--image-stage) 88%, transparent);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 10px;
}
.real-card-body { padding: 14px 15px 16px; }
.real-card h3 { font-size: 16px; }
.look-list { margin: 0; padding-left: 18px; color: var(--text-dim); font-size: 14px; line-height: 1.65; }
.look-list li + li { margin-top: 7px; }
.boundary { color: var(--warn); }
.source-line { margin: 12px 0 0; color: var(--text-muted); font-size: 11.5px; line-height: 1.55; }

.local-atlas {
  padding: 20px;
  background: var(--bg-alt);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-panel);
}
.local-atlas > h2 { margin-bottom: 10px; }
.local-atlas > p { color: var(--text-dim); }
.atlas-links { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 18px; }
.atlas-links a, .atlas-links > article {
  display: grid;
  gap: 6px;
  padding: 16px;
  color: var(--text);
  text-decoration: none;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-control);
}
.atlas-links a:hover { border-color: var(--accent); }
.atlas-links span { color: var(--accent); font: 600 10.5px/1.4 "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; }
.atlas-links strong { color: var(--text); }
.atlas-links small { color: var(--text-dim); font-size: 13px; line-height: 1.6; }

.worked {
  padding: 20px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-panel);
}
.worked-stem {
  padding: 13px 15px;
  color: var(--text);
  background: var(--bg-alt);
  border-left: 3px solid var(--warn);
  border-radius: 6px;
}
.worked .reasoning { margin-top: 16px; }
.worked .reasoning li { background: var(--panel-2); }

.recall-list { display: grid; gap: 10px; }
.recall-item {
  padding: 13px 15px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-control);
}
.recall-item b { color: var(--accent-bright); }

.quiz { display: grid; gap: 16px; }
.quiz-q { padding: 18px; background: var(--panel); border: 1px solid var(--border); border-radius: var(--r-panel); }
.quiz-head { display: flex; gap: 12px; align-items: baseline; }
.quiz-num { color: var(--accent); flex: none; }
.quiz-head h3 { margin: 0; font-size: 17px; }
.quiz-options { display: grid; gap: 8px; margin-top: 14px; }
.quiz-options button { width: 100%; padding: 10px 13px; text-align: left; font-size: 15px; }
.quiz-explain { margin: 12px 0 0; padding: 11px 13px; color: var(--text-dim); background: var(--bg-alt); border-left: 3px solid var(--accent); border-radius: 6px; font-size: 14px; }
.quiz-explain[hidden] { display: none; }

.complete-row { display: flex; justify-content: space-between; gap: 14px; align-items: center; margin-top: 34px; }
.complete-btn { padding: 10px 16px; color: var(--text); }
.complete-btn.done { border-color: var(--good); color: var(--good); }
.chapter-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 56px; padding-top: 24px; border-top: 1px solid var(--border); }
.chapter-nav a { padding: 14px 16px; color: var(--text-dim); text-decoration: none; background: var(--panel); border: 1px solid var(--border); border-radius: var(--r-control); }
.chapter-nav a:last-child { text-align: right; }
.chapter-nav a:hover { color: var(--text); border-color: var(--accent); }

.hub-hero { max-width: 760px; margin-bottom: 60px; }
.hub-lead { color: var(--text-dim); font-size: 19px; max-width: 62ch; }
.hub-principles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 26px; }
.complete-launch { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 24px; margin: 0 0 58px; padding: 24px 26px; background: color-mix(in srgb, var(--accent) 10%, var(--panel)); border: 1px solid var(--border-strong); border-left: 4px solid var(--accent); border-radius: var(--r-panel); }
.complete-launch h2 { margin-bottom: 8px; }
.complete-launch p { margin: 0; color: var(--text-dim); }
.complete-launch a { display: inline-flex; min-height: 44px; align-items: center; justify-content: center; padding: 10px 14px; color: var(--bg); background: var(--accent-bright); border: 1px solid var(--accent-bright); border-radius: var(--r-control); font-weight: 750; text-decoration: none; white-space: nowrap; }
.complete-launch a:hover { background: var(--accent); border-color: var(--accent); }
.principle { padding: 18px; background: var(--panel); border: 1px solid var(--border); border-radius: var(--r-panel); }
.principle .n { color: var(--accent); font-family: "SFMono-Regular", Consolas, monospace; font-size: 11px; }
.principle h2 { margin: 8px 0; font-family: inherit; font-size: 17px; }
.principle p { margin: 0; color: var(--text-dim); font-size: 14px; }
.chapter-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.chapter-card { display: flex; min-height: 280px; flex-direction: column; padding: 20px; color: inherit; text-decoration: none; background: var(--panel); border: 1px solid var(--border); border-radius: var(--r-panel); transition: border-color .18s ease, transform .18s ease; }
.chapter-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.chapter-card h2 { margin: 14px 0 10px; font-family: inherit; font-size: 20px; line-height: 1.45; }
.chapter-card p { margin: 0; color: var(--text-dim); font-size: 14px; }
.chapter-card .card-foot { margin-top: auto; padding-top: 18px; display: flex; justify-content: space-between; gap: 10px; color: var(--text-muted); font-family: "SFMono-Regular", Consolas, monospace; font-size: 10px; text-transform: uppercase; }
.chapter-card.done { border-color: color-mix(in srgb, var(--good) 55%, var(--border)); }
.chapter-card.done .card-state { color: var(--good); }
.role-tag { align-self: flex-start; padding: 4px 8px; border-radius: 999px; color: var(--accent-bright); border: 1px solid var(--border-strong); font-family: "SFMono-Regular", Consolas, monospace; font-size: 10px; letter-spacing: .08em; text-transform: uppercase; }
.preserve-note { margin-top: 46px; padding: 18px 20px; color: var(--text-dim); background: var(--bg-alt); border: 1px solid var(--border); border-radius: var(--r-panel); }

dialog.image-dialog {
  width: min(1120px, calc(100vw - 32px));
  max-height: calc(100vh - 32px);
  padding: 0;
  overflow: hidden;
  color: var(--text);
  background: var(--image-stage);
  border: 1px solid var(--image-border);
  border-radius: var(--r-panel);
}
dialog.image-dialog::backdrop { background: color-mix(in srgb, var(--image-stage) 88%, transparent); }
.dialog-head { display: flex; justify-content: space-between; gap: 12px; align-items: center; padding: 12px 14px; border-bottom: 1px solid var(--image-border); }
.dialog-head strong { font-size: 15px; }
.dialog-head button { padding: 6px 10px; color: var(--text); background: transparent; border: 1px solid var(--image-border); border-radius: var(--r-control); cursor: pointer; }
.dialog-stage { max-height: calc(100vh - 110px); overflow: auto; display: grid; place-items: center; background: var(--image-stage); }
.dialog-stage img { display: block; max-width: 100%; height: auto; background: var(--image-stage); }

.site-foot { border-top: 1px solid var(--border); }
.site-foot-in { width: min(1080px, calc(100% - 40px)); margin: 0 auto; padding: 20px 0; display: flex; justify-content: space-between; gap: 12px; color: var(--text-muted); font-family: "SFMono-Regular", Consolas, monospace; font-size: 10px; letter-spacing: .1em; text-transform: uppercase; }

/* 縮寫在各章首次出現時已直接寫出全名；虛線只用來提示可停留查英文全名。 */
.acronym-first-use {
  color: var(--text);
  font-weight: 650;
  text-decoration-line: underline;
  text-decoration-style: dotted;
  text-decoration-color: color-mix(in srgb, var(--accent) 58%, transparent);
  text-decoration-thickness: 1px;
  text-underline-offset: .18em;
}

.anki-route-card { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 10px 16px; margin-top: 16px; padding: 16px; background: var(--bg-alt); border: 1px solid var(--border); border-radius: var(--r-control); }
.anki-route-card strong { color: var(--text); }
.anki-route-card p { margin: 4px 0 0; color: var(--text-dim); font-size: 13px; }
.anki-route-card button { min-height: 42px; padding: 8px 14px; color: var(--text); background: var(--panel-2); border: 1px solid var(--border-strong); border-radius: var(--r-control); cursor: pointer; }
.anki-route-card button:hover { color: var(--accent-bright); border-color: var(--accent); }
.anki-route-state { grid-column: 1 / -1; }
.anki-route-state.is-connected { color: var(--good); }

@media (max-width: 760px) {
  body { font-size: 17px; }
  .site-head-in, .reading-shell, .hub-shell, .site-foot-in { width: min(100% - 32px, 760px); }
  .anki-route-card { grid-template-columns: 1fr; }
  .anki-route-card button { width: 100%; }
  .anki-route-state { grid-column: 1; }
  .reading-shell { padding-top: 38px; }
  .head-meta { display: none; }
  .choice-row, .real-grid, .hub-principles, .chapter-grid, .pathway-grid { grid-template-columns: 1fr; }
  .complete-launch { grid-template-columns: 1fr; padding: 20px; }
  .complete-launch a { width: 100%; white-space: normal; }
  .atlas-links { grid-template-columns: 1fr; }
  .chapter-card { min-height: 0; }
  .visual-breakout { width: calc(100vw - 20px); }
  .complete-row { align-items: stretch; flex-direction: column; }
  .chapter-nav { grid-template-columns: 1fr; }
  .chapter-nav a:last-child { text-align: left; }
  .pathway-svg .svg-title { font-size: 23px; }
  .pathway-svg .svg-head { font-size: 18px; }
  .pathway-svg .svg-body { font-size: 14px; }
  .visual-stage .desktop-map { display: none; }
  .mobile-map { display: grid; padding: 14px; }
}

@media print {
  :root {
    --bg: #ffffff;
    --bg-alt: #f5f2ec;
    --panel: #faf8f4;
    --panel-2: #f3efe7;
    --border: #ddd6c8;
    --border-strong: #c9c0b0;
    --text: #1c1a14;
    --text-dim: #545044;
    --text-muted: #716b60;
    --accent: #9b6638;
    --accent-bright: #7c4e28;
  }
  .site-head, .complete-row, .chapter-nav, .zoom-btn, dialog { display: none !important; }
  .reading-shell { padding-top: 24px; }
  .visual-breakout { left: auto; width: 100%; transform: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation: none !important; transition: none !important; }
}