/* Copyright (c) 2026 geniuskey and ArtBook contributors.
   Derived from InsureBook/MoneyBook (https://github.com/geniuskey/insurebook), MIT.
   SPDX-License-Identifier: MIT — see ../../LICENSE-MIT. */
/* ==========================================================================
   ArtBook — 서가 공통 스타일 (모든 책이 함께 쓴다)
   색 규칙: UI(글자·테두리·강조·축)는 아래 CSS 변수로만 칠해 테마를 따른다.
   본문 예시 그림(물감, 작품, 견본)의 색은 변수를 쓰지 않고 그 색 그대로 칠해 다크 모드에서도 바뀌지 않게 한다.
   ========================================================================== */
@import url("https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/variable/pretendardvariable-dynamic-subset.min.css");
@import url("https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;600&display=swap");

:root {
  --bg: #f7f6f3;
  --bg-elev: #ffffff;
  --surface: #f0eeea;
  --surface-2: #e5e2dc;
  --border: #dcd8d0;
  --text: #1b1a1f;
  --text-dim: #5d5a66;
  --text-faint: #8f8b98;
  --accent: #b5179e;
  --accent-soft: rgba(181, 23, 158, 0.10);
  --accent-2: #0f7f8a;
  --accent-2-soft: rgba(15, 127, 138, 0.12);
  --ok: #1f9d55;
  --warn: #d98a00;
  --bad: #d64545;
  --grid: rgba(27, 26, 31, 0.08);
  --axis: rgba(27, 26, 31, 0.45);
  --canvas-bg: #ffffff;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 6px 20px rgba(16, 24, 40, 0.06);
  --radius: 14px;
  --radius-sm: 8px;
  --font: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --maxw: 880px;
  --paper: #fbfaf7;     /* 예시 그림의 종이색: 테마와 무관하게 고정 */
  --stage: #808080;     /* 중립 회색 무대: 테마와 무관하게 고정 */
  --nav-h: 58px;
  --on-accent: #ffffff;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111015;
    --bg-elev: #19181f;
    --surface: #211f28;
    --surface-2: #2a2833;
    --border: #34313d;
    --text: #ece9f1;
    --text-dim: #aaa5b5;
    --text-faint: #77728a;
    --accent: #f27ad8;
    --accent-soft: rgba(242, 122, 216, 0.15);
    --accent-2: #4fd1d9;
    --accent-2-soft: rgba(79, 209, 217, 0.14);
    --ok: #3fcf7f;
    --warn: #f5b93a;
    --bad: #ff6b6b;
    --grid: rgba(236, 233, 241, 0.08);
    --axis: rgba(236, 233, 241, 0.45);
    --canvas-bg: #16151b;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 28px rgba(0, 0, 0, 0.35);
    --on-accent: #2b0524;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #111015;
  --bg-elev: #19181f;
  --surface: #211f28;
  --surface-2: #2a2833;
  --border: #34313d;
  --text: #ece9f1;
  --text-dim: #aaa5b5;
  --text-faint: #77728a;
  --accent: #f27ad8;
  --accent-soft: rgba(242, 122, 216, 0.15);
  --accent-2: #4fd1d9;
  --accent-2-soft: rgba(79, 209, 217, 0.14);
  --ok: #3fcf7f;
  --warn: #f5b93a;
  --bad: #ff6b6b;
  --grid: rgba(236, 233, 241, 0.08);
  --axis: rgba(236, 233, 241, 0.45);
  --canvas-bg: #16151b;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 28px rgba(0, 0, 0, 0.35);
  --on-accent: #2b0524;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.75;
  word-break: keep-all;
  overflow-wrap: break-word;
  -webkit-font-smoothing: antialiased;
}
img, svg, canvas, video { max-width: 100%; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, kbd { font-family: var(--mono); font-size: 0.88em; background: var(--surface); padding: 0.1em 0.4em; border-radius: 5px; }
hr { border: 0; border-top: 1px solid var(--border); margin: 48px 0; }
::selection { background: var(--accent-soft); }

/* ------------------------------------------------------------------ Top bar */
.ab-topbar {
  position: sticky; top: 0; z-index: 50;
  height: var(--nav-h);
  display: flex; align-items: center; gap: 12px;
  padding: 0 16px;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.ab-logo { display: flex; align-items: center; gap: 10px; font-weight: 800; color: var(--text); letter-spacing: -0.02em; font-size: 18px; white-space: nowrap; }
.ab-logo:hover { text-decoration: none; }
.ab-logo .mark { width: 28px; height: 28px; flex: none; }
.ab-logo small { font-weight: 500; color: var(--text-dim); font-size: 13px; }
.ab-topbar .spacer { flex: 1; }
.ab-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  height: 36px; padding: 0 12px; border-radius: 10px;
  border: 1px solid var(--border); background: var(--bg-elev); color: var(--text);
  font: inherit; font-size: 14px; cursor: pointer;
}
.ab-btn:hover { border-color: var(--accent); }
.ab-btn.icon { width: 36px; padding: 0; }
.ab-topbar .series-link, .ab-topbar .shelf-link { white-space: nowrap; text-decoration: none; }
@media (max-width: 560px) {
  .ab-topbar .series-link { width: 36px; padding: 0; }
  .ab-topbar .series-link span { display: none; }
}
@media (max-width: 620px) { .ab-topbar .ab-logo small { display: none; } }
@media (max-width: 420px) { .ab-topbar .ab-logo span { display: none; } }
.ab-progress { position: absolute; left: 0; bottom: -1px; height: 2px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); width: 0; }

/* Drawer (chapter list) */
.ab-drawer-backdrop { position: fixed; inset: 0; background: rgba(0,0,0,0.35); z-index: 60; opacity: 0; pointer-events: none; transition: opacity .2s; }
.ab-drawer {
  position: fixed; top: 0; left: 0; bottom: 0; width: min(340px, 88vw); z-index: 61;
  background: var(--bg-elev); border-right: 1px solid var(--border);
  transform: translateX(-102%); transition: transform .25s ease;
  overflow-y: auto; padding: 20px 14px 40px;
}
body.drawer-open .ab-drawer { transform: none; }
body.drawer-open .ab-drawer-backdrop { opacity: 1; pointer-events: auto; }
.ab-drawer h4 { margin: 8px 10px 10px; font-size: 12px; letter-spacing: .12em; color: var(--text-faint); text-transform: uppercase; }
.ab-chlist { list-style: none; margin: 0; padding: 0; }
.ab-chlist a { display: flex; gap: 12px; align-items: baseline; padding: 9px 10px; border-radius: 10px; color: var(--text); line-height: 1.4; }
.ab-chlist a:hover { background: var(--surface); text-decoration: none; }
.ab-chlist a.active { background: var(--accent-soft); color: var(--accent); font-weight: 700; }
.ab-chlist .num { font-family: var(--mono); font-size: 12px; color: var(--text-faint); width: 22px; flex: none; }
.ab-chlist a.active .num { color: var(--accent); }

/* ------------------------------------------------------------------ Layout */
.ab-layout { display: grid; grid-template-columns: minmax(0, 1fr); gap: 40px; max-width: 1240px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 1180px) {
  .ab-layout { grid-template-columns: minmax(0, 1fr) 230px; }
}
.ab-toc { display: none; }
@media (min-width: 1180px) {
  .ab-toc { display: block; position: sticky; top: calc(var(--nav-h) + 28px); align-self: start; max-height: calc(100vh - var(--nav-h) - 56px); overflow-y: auto; padding-top: 48px; font-size: 13.5px; }
  .ab-toc h4 { margin: 0 0 10px; font-size: 11px; letter-spacing: .14em; color: var(--text-faint); }
  .ab-toc a { display: block; padding: 5px 0 5px 12px; border-left: 2px solid var(--border); color: var(--text-dim); line-height: 1.45; }
  .ab-toc a:hover { color: var(--text); text-decoration: none; }
  .ab-toc a.active { border-left-color: var(--accent); color: var(--accent); font-weight: 600; }
}

main.chapter { max-width: var(--maxw); width: 100%; margin: 0 auto; padding: 40px 0 80px; min-width: 0; }
main.chapter > section { margin: 64px 0; }
main.chapter h2 { font-size: 28px; line-height: 1.35; letter-spacing: -0.02em; margin: 0 0 18px; padding-top: 8px; }
main.chapter h2 .h-num { font-family: var(--mono); color: var(--accent); font-size: 0.7em; margin-right: 10px; vertical-align: 0.12em; }
main.chapter h3 { font-size: 20px; margin: 36px 0 12px; letter-spacing: -0.01em; }
main.chapter p { margin: 0 0 16px; }
main.chapter ul, main.chapter ol { padding-left: 1.3em; margin: 0 0 16px; }
main.chapter li { margin: 4px 0; }
strong { font-weight: 700; }
.term { font-weight: 700; color: var(--accent); }
.en { color: var(--text-dim); font-size: 0.9em; }

/* Chapter hero */
.chapter-hero { padding: 24px 0 8px; }
.eyebrow { font-family: var(--mono); font-size: 13px; letter-spacing: .16em; color: var(--accent); font-weight: 600; text-transform: uppercase; }
.chapter-hero h1 { font-size: clamp(32px, 5.4vw, 46px); line-height: 1.2; letter-spacing: -0.03em; margin: 10px 0 16px; }
.lead { font-size: 19px; color: var(--text-dim); line-height: 1.7; }
.objectives { list-style: none; padding: 18px 20px !important; margin: 24px 0 0 !important; background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); display: grid; gap: 6px; }
.objectives::before { content: "이 장에서 배우는 것"; display: block; font-size: 12px; letter-spacing: .1em; color: var(--text-faint); font-weight: 700; margin-bottom: 4px; }
.objectives li { padding-left: 26px; position: relative; margin: 0 !important; }
.objectives li::before { content: ""; position: absolute; left: 4px; top: 0.62em; width: 10px; height: 10px; border-radius: 3px; background: var(--accent); opacity: .85; }

/* ------------------------------------------------------------------ Figures */
figure { margin: 28px 0; }
figure.diagram { background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
figure.diagram svg { display: block; width: 100%; max-width: 620px; margin: 0 auto; height: auto; }
figcaption { font-size: 14px; color: var(--text-dim); margin-top: 12px; line-height: 1.6; }
figcaption b { color: var(--text); }
.fig-row { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* SVG helpers usable inside inline diagrams */
svg .t { fill: var(--text); font-family: var(--font); font-size: 13px; }
svg .t-dim { fill: var(--text-dim); font-family: var(--font); font-size: 12px; }
svg .t-mono { fill: var(--text-dim); font-family: var(--mono); font-size: 11px; }
svg .t-acc { fill: var(--accent); font-family: var(--font); font-size: 13px; font-weight: 700; }
svg .s-line { stroke: var(--text-dim); fill: none; stroke-width: 1.5; }
svg .s-axis { stroke: var(--axis); fill: none; stroke-width: 1.2; }
svg .s-acc { stroke: var(--accent); fill: none; stroke-width: 2; }
svg .f-surface { fill: var(--surface); stroke: var(--border); }
svg .f-elev { fill: var(--bg-elev); stroke: var(--border); }
svg .f-acc { fill: var(--accent); }
svg .f-acc-soft { fill: var(--accent-soft); stroke: var(--accent); }
svg .f-acc2-soft { fill: var(--accent-2-soft); stroke: var(--accent-2); }

/* ------------------------------------------------------------------ Simulator card */
.sim {
  margin: 32px 0;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.sim-head { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; padding: 14px 18px; border-bottom: 1px solid var(--border); background: linear-gradient(90deg, var(--accent-soft), transparent 70%); }
.sim-tag { font-family: var(--mono); font-size: 11px; font-weight: 600; letter-spacing: .12em; color: var(--accent); border: 1px solid var(--accent); border-radius: 999px; padding: 2px 9px; line-height: 1.6; }
.sim-head h3 { margin: 0 !important; font-size: 17px !important; flex: 1; min-width: 180px; }
.sim-body { display: grid; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 820px) {
  .sim-body.side { grid-template-columns: minmax(0, 1fr) 280px; }
  .sim-body.side .sim-controls { border-top: 0; border-left: 1px solid var(--border); }
}
.sim-view { position: relative; background: var(--canvas-bg); min-height: 120px; }
.sim-view canvas { display: block; width: 100%; }
.sim-view .hint { position: absolute; right: 10px; bottom: 8px; font-size: 12px; color: var(--text-faint); pointer-events: none; background: color-mix(in srgb, var(--canvas-bg) 70%, transparent); padding: 2px 8px; border-radius: 6px; }
.overlay-label { position: absolute; pointer-events: none; font-size: 12px; font-weight: 600; color: var(--text); background: color-mix(in srgb, var(--bg-elev) 85%, transparent); border: 1px solid var(--border); padding: 2px 8px; border-radius: 6px; white-space: nowrap; transform: translate(-50%, -50%); }
.sim-controls { padding: 16px 18px; border-top: 1px solid var(--border); display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); align-content: start; }
.sim-body.side .sim-controls { grid-template-columns: 1fr; }
.ctrl { display: grid; gap: 6px; font-size: 14px; }
.ctrl > span { display: flex; justify-content: space-between; gap: 8px; color: var(--text-dim); }
.ctrl output { font-family: var(--mono); color: var(--text); font-weight: 600; font-size: 13px; }
.ctrl select { font: inherit; font-size: 14px; padding: 7px 10px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--text); }
.ctrl-row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.seg { display: inline-flex; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 3px; gap: 2px; flex-wrap: wrap; }
.seg button { font: inherit; font-size: 13px; border: 0; background: transparent; color: var(--text-dim); padding: 5px 11px; border-radius: 7px; cursor: pointer; }
.seg button.on, .seg button[aria-pressed="true"] { background: var(--bg-elev); color: var(--accent); font-weight: 700; box-shadow: 0 1px 3px rgba(0,0,0,.12); }
.btn { font: inherit; font-size: 14px; padding: 8px 14px; border-radius: 9px; border: 1px solid var(--border); background: var(--surface); color: var(--text); cursor: pointer; }
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); font-weight: 600; }
.check { display: flex; gap: 8px; align-items: center; font-size: 14px; color: var(--text-dim); cursor: pointer; }
.check input { accent-color: var(--accent); width: 16px; height: 16px; }

input[type="range"] { -webkit-appearance: none; appearance: none; width: 100%; height: 22px; background: transparent; cursor: pointer; margin: 0; }
input[type="range"]::-webkit-slider-runnable-track { height: 5px; border-radius: 3px; background: linear-gradient(90deg, var(--accent) var(--fill, 50%), var(--surface-2) var(--fill, 50%)); }
input[type="range"]::-moz-range-track { height: 5px; border-radius: 3px; background: var(--surface-2); }
input[type="range"]::-moz-range-progress { height: 5px; border-radius: 3px; background: var(--accent); }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; width: 18px; height: 18px; border-radius: 50%; background: var(--bg-elev); border: 2px solid var(--accent); margin-top: -6.5px; box-shadow: 0 1px 4px rgba(0,0,0,.2); }
input[type="range"]::-moz-range-thumb { width: 14px; height: 14px; border-radius: 50%; background: var(--bg-elev); border: 2px solid var(--accent); }

.sim-readout { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 1px; background: var(--border); border-top: 1px solid var(--border); }
.stat { background: var(--bg-elev); padding: 12px 16px; display: grid; gap: 2px; }
.stat .k { font-size: 12px; color: var(--text-dim); }
.stat .v { font-family: var(--mono); font-size: 18px; font-weight: 600; color: var(--text); font-variant-numeric: tabular-nums; }
.stat .v small { font-size: 12px; color: var(--text-dim); font-weight: 400; margin-left: 2px; }
.sim-note { padding: 12px 18px; font-size: 14px; color: var(--text-dim); border-top: 1px solid var(--border); background: var(--surface); line-height: 1.6; }

/* Legend */
.legend { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 13px; color: var(--text-dim); padding: 10px 18px 0; }
.legend i { display: inline-block; width: 14px; height: 3px; border-radius: 2px; vertical-align: middle; margin-right: 6px; }

/* ------------------------------------------------------------------ Callouts & formula */
.callout { margin: 24px 0; padding: 16px 18px 16px 20px; border-radius: var(--radius-sm); background: var(--accent-soft); border-left: 4px solid var(--accent); font-size: 16px; }
.callout > strong:first-child { display: block; margin-bottom: 4px; }
.callout p:last-child { margin-bottom: 0; }
.callout.tip { background: color-mix(in srgb, var(--ok) 12%, transparent); border-left-color: var(--ok); }
.callout.warn { background: color-mix(in srgb, var(--warn) 14%, transparent); border-left-color: var(--warn); }
.callout.deep { background: var(--accent-2-soft); border-left-color: var(--accent-2); }
.callout.deep > strong:first-child::before { content: "심화 · "; color: var(--accent-2); }
/* 작업실 노트: 현장 작가·디자이너의 실무 요령 */
.callout.studio { background: var(--surface); border: 1px solid var(--border); border-left: 4px solid var(--text-dim); }
.callout.studio > strong:first-child::before { content: "작업실 노트 · "; color: var(--text-dim); }
/* 직접 해 보기: 종이·연필·물감으로 하는 과제 */
.callout.try { background: color-mix(in srgb, var(--ok) 10%, transparent); border-left-color: var(--ok); }
.callout.try > strong:first-child::before { content: "직접 해 보기 · "; color: var(--ok); }
.callout.warn > strong:first-child::before { content: "주의 · "; color: var(--warn); }
.callout ul, .callout ol { margin: 6px 0 0; padding-left: 20px; }

.formula { margin: 22px 0; padding: 14px 18px; background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius-sm); overflow-x: auto; }
.formula .where { font-size: 14px; color: var(--text-dim); margin-top: 6px; }
.katex { font-size: 1.08em; }
/* Leave room for tall fraction glyphs, especially Korean text, inside the scroll area. */
.katex-display { margin: 0.4em 0 !important; padding: 0.5em 0; overflow-x: auto; overflow-y: hidden; }

/* Tables */
.table-wrap { overflow-x: auto; margin: 22px 0; border: 1px solid var(--border); border-radius: var(--radius-sm); }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
th, td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
th { background: var(--surface); font-weight: 700; font-size: 14px; white-space: nowrap; }
tr:last-child td { border-bottom: 0; }
td.num, th.num { text-align: right; font-family: var(--mono); font-variant-numeric: tabular-nums; }

/* Key points summary */
.keypoints { background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 22px; }
.keypoints h2 { font-size: 22px !important; }
.keypoints ol { counter-reset: kp; list-style: none; padding: 0 !important; }
.keypoints li { counter-increment: kp; position: relative; padding-left: 38px; margin: 10px 0 !important; }
.keypoints li::before { content: counter(kp); position: absolute; left: 0; top: 0.1em; width: 26px; height: 26px; border-radius: 8px; background: var(--accent-soft); color: var(--accent); font-weight: 800; font-size: 14px; display: grid; place-items: center; font-family: var(--mono); }

/* ------------------------------------------------------------------ Quiz */
.quiz { display: grid; gap: 16px; }
.quiz-q { background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 20px; }
.quiz-q > p:first-child { font-weight: 700; margin-bottom: 12px; }
.quiz-q .opts { display: grid; gap: 8px; }
.quiz-q button.opt { text-align: left; font: inherit; font-size: 15px; padding: 10px 14px; border-radius: 10px; border: 1px solid var(--border); background: var(--surface); color: var(--text); cursor: pointer; line-height: 1.5; }
.quiz-q button.opt:hover:not(:disabled) { border-color: var(--accent); }
.quiz-q button.opt.right { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 15%, transparent); font-weight: 600; }
.quiz-q button.opt.wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, transparent); }
.quiz-q button.opt:disabled { cursor: default; }
.quiz-exp { display: none; margin-top: 12px; font-size: 15px; color: var(--text-dim); padding: 10px 14px; border-radius: 8px; background: var(--surface); }
.quiz-q.done .quiz-exp { display: block; }

/* ------------------------------------------------------------------ Prev / Next */
.ab-pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; max-width: var(--maxw); margin: 0 auto; padding: 0 0 20px; }
.ab-pager a { display: block; padding: 16px 18px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg-elev); color: var(--text); }
.ab-pager a:hover { border-color: var(--accent); text-decoration: none; }
.ab-pager small { display: block; color: var(--text-faint); font-size: 12px; }
.ab-pager .next { text-align: right; grid-column: 2; }
.ab-foot { border-top: 1px solid var(--border); color: var(--text-faint); font-size: 13px; padding: 28px 16px 40px; text-align: center; }

/* ------------------------------------------------------------------ Home page */
.home-hero { position: relative; overflow: hidden; border-bottom: 1px solid var(--border); }
.home-hero .inner { max-width: 1180px; margin: 0 auto; padding: 72px 16px 64px; display: grid; gap: 40px; align-items: center; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 960px) { .home-hero .inner { grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); } }
.home-hero h1 { font-size: clamp(36px, 6.4vw, 62px); line-height: 1.12; letter-spacing: -0.035em; margin: 14px 0 20px; }
.home-hero h1 .grad { background: linear-gradient(90deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.home-hero p { font-size: 19px; color: var(--text-dim); max-width: 560px; }
.home-hero .cta { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 28px; }
.home-hero .cta a { padding: 12px 20px; border-radius: 12px; font-weight: 700; }
.home-hero .cta a.primary { background: var(--accent); color: var(--on-accent); }
.home-hero .cta a.ghost { border: 1px solid var(--border); color: var(--text); background: var(--bg-elev); }
.home-hero .cta a:hover { text-decoration: none; filter: brightness(1.05); }
.hero-3d { height: 420px; border-radius: 20px; border: 1px solid var(--border); background: radial-gradient(ellipse at 50% 40%, var(--accent-soft), transparent 70%), var(--bg-elev); position: relative; overflow: hidden; box-shadow: var(--shadow); touch-action: none; }
.hero-3d .hint { position: absolute; left: 14px; bottom: 10px; font-size: 12px; color: var(--text-faint); }
.home-section { max-width: 1180px; margin: 0 auto; padding: 64px 16px; }
.home-section h2 { font-size: 30px; letter-spacing: -0.02em; margin: 0 0 8px; }
.home-section > p.sub { color: var(--text-dim); margin: 0 0 32px; }
.ch-grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.ch-card { display: flex; flex-direction: column; gap: 8px; padding: 20px; border-radius: var(--radius); border: 1px solid var(--border); background: var(--bg-elev); color: var(--text); transition: transform .15s, border-color .15s; min-height: 190px; }
.ch-card:hover { text-decoration: none; border-color: var(--accent); transform: translateY(-2px); }
.ch-card .num { font-family: var(--mono); font-size: 12px; color: var(--accent); font-weight: 600; letter-spacing: .1em; }
.ch-card h3 { margin: 0; font-size: 19px; letter-spacing: -0.01em; }
.ch-card p { margin: 0; color: var(--text-dim); font-size: 14.5px; line-height: 1.6; flex: 1; }
.ch-card .tags { display: flex; gap: 6px; flex-wrap: wrap; align-items: center; }
.ch-card .tags span { font-size: 11.5px; padding: 2px 8px; border-radius: 999px; background: var(--surface); color: var(--text-dim); }
.ch-card .tags span.is-sim { background: var(--accent-soft); color: var(--accent); margin: 0; border: 0; box-shadow: none; overflow: visible; }
.ch-card .tags span.d3 { background: var(--accent-2-soft); color: var(--accent-2); }
.flow { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); counter-reset: fl; }
.flow div { counter-increment: fl; padding: 16px; border-radius: 12px; background: var(--bg-elev); border: 1px solid var(--border); font-size: 14.5px; color: var(--text-dim); position: relative; }
.flow div b { display: block; color: var(--text); font-size: 16px; margin-bottom: 4px; }
.flow div::before { content: counter(fl, decimal-leading-zero); font-family: var(--mono); font-size: 12px; color: var(--accent); font-weight: 700; display: block; margin-bottom: 6px; }

/* Glossary */
.gl-search { width: 100%; font: inherit; padding: 12px 16px; border-radius: 12px; border: 1px solid var(--border); background: var(--bg-elev); color: var(--text); margin-bottom: 20px; }
.gl-list { display: grid; gap: 10px; }
.gl-item { padding: 14px 18px; border-radius: 12px; background: var(--bg-elev); border: 1px solid var(--border); }
.gl-item h4 { margin: 0 0 4px; font-size: 16px; }
.gl-item h4 .en { font-weight: 500; margin-left: 6px; }
.gl-item p { margin: 0 !important; font-size: 15px; color: var(--text-dim); }
.gl-item .ch { font-size: 12px; margin-top: 6px; display: inline-block; }

@media (max-width: 640px) {
  body { font-size: 16px; }
  main.chapter { padding-top: 24px; }
  main.chapter h2 { font-size: 24px; }
    .hero-3d { height: 320px; }
  .ab-logo small { display: none; }
  .ab-pager { grid-template-columns: 1fr; }
  .ab-pager .next { grid-column: 1; }
}

/* ------------------------------------------------------------------ 공통 추가 요소 */
svg .s-acc2 { stroke: var(--accent-2); fill: none; stroke-width: 2; }
svg .f-acc2 { fill: var(--accent-2); }
svg .f-ok-soft { fill: color-mix(in srgb, var(--ok) 16%, transparent); stroke: var(--ok); }
svg .f-warn-soft { fill: color-mix(in srgb, var(--warn) 18%, transparent); stroke: var(--warn); }
svg .f-bad-soft { fill: color-mix(in srgb, var(--bad) 14%, transparent); stroke: var(--bad); }
svg .f-bad { fill: var(--bad); }
.pill { display: inline-block; font-size: 12px; padding: 1px 8px; border-radius: 999px; background: var(--surface); color: var(--text-dim); border: 1px solid var(--border); }
/* 스크롤 컨테이너 안의 KaTeX 숨김 MathML(absolute)이 페이지 가로 스크롤을 만들지 않도록 */
.table-wrap, .formula, .sim, figure, .callout, .quiz-q { position: relative; }
/* keep-all에서 '·'로 이어진 긴 토큰이 좁은 화면을 넘지 않도록 */
main.chapter p, main.chapter li, figcaption, .callout, .quiz-exp { overflow-wrap: anywhere; }

svg .s-dash { stroke: var(--text-faint); fill: none; stroke-width: 1.2; stroke-dasharray: 4 3; }
svg .s-bad { stroke: var(--bad); fill: none; stroke-width: 2; }
svg .lbl { fill: var(--text); font-family: var(--font); font-size: 14px; }
svg .lbl-dim { fill: var(--text-dim); font-family: var(--font); font-size: 13px; }
svg .lbl-b { fill: var(--text); font-family: var(--font); font-size: 15px; font-weight: 700; }
svg .lbl-acc { fill: var(--accent); font-family: var(--font); font-size: 14px; font-weight: 700; }
svg .lbl-acc2 { fill: var(--accent-2); font-family: var(--font); font-size: 14px; font-weight: 700; }
svg .lbl-bad { fill: var(--bad); font-family: var(--font); font-size: 14px; font-weight: 700; }

.btn-row { display: flex; flex-wrap: wrap; gap: 6px; }
.btn.sm { padding: 5px 10px; font-size: 13px; }
.btn:disabled { opacity: .45; cursor: default; }
.ok-t { color: var(--ok); } .bad-t { color: var(--bad); } .warn-t { color: var(--warn); }

/* 부 띠 (장 상단, common.js가 삽입. 부의 수는 --n) */
.ab-stages { display: grid; grid-template-columns: repeat(var(--n, 4), minmax(0, 1fr)); gap: 4px; margin: 28px 0 0; }
.ab-stages a, .ab-stages span { position: relative; display: block; padding: 9px 8px 9px 16px; background: var(--surface); color: var(--text-faint); line-height: 1.3; min-width: 0; clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 50%, calc(100% - 9px) 100%, 0 100%, 9px 50%); }
.ab-stages > :first-child { clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 50%, calc(100% - 9px) 100%, 0 100%); padding-left: 10px; border-radius: 8px 0 0 8px; }
.ab-stages a:hover { text-decoration: none; color: var(--text); }
.ab-stages b { display: block; font-size: 13px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.ab-stages small { display: block; font-family: var(--mono); font-size: 10px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; opacity: .8; }
.ab-stages a.done { background: var(--accent-soft); color: var(--accent); }
.ab-stages .cur { background: var(--accent); color: var(--on-accent); }
@media (max-width: 640px) {
  .ab-stages small { display: none; }
  .ab-stages b { font-size: 12.5px; }
}

/* 이어지는 케이스(서윤의 작업 노트): 장마다 한 걸음씩 진전되는 가상의 이야기 */
.casefile { margin: 28px 0; border: 1px solid var(--border); border-left: 4px solid var(--accent-2); border-radius: var(--radius-sm); background: var(--bg-elev); padding: 16px 18px; font-size: 16px; position: relative; }
.casefile > .tag { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; font-family: var(--mono); font-size: 11.5px; font-weight: 600; letter-spacing: .1em; color: var(--accent-2); margin-bottom: 8px; }
.casefile > .tag b { background: var(--accent-2-soft); border-radius: 999px; padding: 2px 9px; }
.casefile h4 { margin: 0 0 6px; font-size: 17px; }
.casefile p { margin: 0 0 10px !important; }
.casefile p:last-child, .casefile ul:last-child { margin-bottom: 0 !important; }
.casefile .clue { display: grid; gap: 1px; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); background: var(--border); border: 1px solid var(--border); border-radius: 8px; overflow: hidden; margin-top: 12px; }
.casefile .clue div { background: var(--surface); padding: 9px 12px; font-size: 13px; color: var(--text-dim); line-height: 1.45; }
.casefile .clue b { display: block; color: var(--text); font-size: 14px; }

[hidden] { display: none !important; }

.sim-view canvas.drag { cursor: grab; touch-action: none; }
.sim-view canvas.drag:active { cursor: grabbing; }

svg .f-ok { fill: var(--ok); } svg .f-warn { fill: var(--warn); } svg .s-ok { stroke: var(--ok); fill: none; stroke-width: 2; }

/* Search in the center of the book menu */
.book-nav-left, .book-nav-right { display: flex; align-items: center; gap: 12px; flex: 1 1 0; min-width: 0; }
.book-nav-left { overflow: hidden; }
.book-nav-left > a { min-width: 0; overflow: hidden; text-overflow: ellipsis; }
.book-nav-right { justify-content: flex-end; }
.book-search { position: relative; flex: 0 1 340px; min-width: 80px; color: var(--text-dim); }
.book-search-icon { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); pointer-events: none; }
.book-search input { display: block; width: 100%; height: 36px; padding: 0 12px 0 37px; border: 1px solid var(--border); border-radius: 10px; background: var(--bg-elev); color: var(--text); font: inherit; font-size: 14px; outline: none; }
.book-search input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.book-search input::placeholder { color: var(--text-faint); }
.book-search-results { display: none; position: absolute; top: calc(100% + 10px); left: 0; width: max(100%, 300px); max-width: min(420px, calc(100vw - 32px)); max-height: min(60vh, 460px); overflow-y: auto; border: 1px solid var(--border); border-radius: 12px; background: var(--bg-elev); box-shadow: var(--shadow); padding: 6px; }
.book-search.open .book-search-results { display: block; }
.book-search-results a { display: block; padding: 9px 11px; border-radius: 8px; color: var(--text); line-height: 1.4; }
.book-search-results a:hover, .book-search-results a:focus { background: var(--accent-soft); text-decoration: none; outline: none; }
.book-search-results strong, .book-search-results small { display: block; }
.book-search-results strong { font-size: 14px; }
.book-search-results small { margin-top: 3px; color: var(--text-dim); font-size: 12px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.book-search-results p { margin: 0; padding: 10px 11px; font-size: 14px; }
@media (max-width: 860px) { .book-nav-left > a small { display: none; } .book-nav-right .series-link span, .book-nav-right .shelf-link span { display: none; } .book-nav-right .series-link, .book-nav-right .shelf-link { width: 36px; padding: 0; } }
@media (max-width: 600px) { .ab-topbar:has(.book-search) .book-nav-left, .ab-topbar:has(.book-search) .book-nav-right { flex: 0 0 auto; } .ab-topbar:has(.book-search) .book-nav-left > a { display: none; } .book-search { flex: 1 1 auto; } .book-search-results { left: 50%; transform: translateX(-50%); } }
@media (max-width: 440px) { .book-nav-right .series-link { display: none; } .book-search input::placeholder { color: transparent; } }

/* Shareable simulator anchor links */
.sim-link { margin-left: auto; flex: 0 0 auto; font: 12px var(--mono); color: var(--text-faint); }
.sim-link:hover, .sim-link:focus-visible { color: var(--accent); text-decoration: none; }
.sim { scroll-margin-top: 1rem; }

/* ------------------------------------------------------------------ ArtBook 미술 도구 */
/* 장 목록의 부 머리와 준비 중인 장 */
.ab-chlist li.part { margin: 14px 10px 4px; font-size: 12px; font-weight: 700; color: var(--text-dim); letter-spacing: .04em; }
.ab-chlist li.part small { font-family: var(--mono); font-weight: 400; color: var(--text-faint); margin-left: 4px; }
.ab-chlist .soon { display: flex; gap: 12px; align-items: baseline; padding: 9px 10px; color: var(--text-faint); line-height: 1.4; }
.ab-chlist .soon em { margin-left: auto; font-style: normal; font-size: 11px; border: 1px solid var(--border); border-radius: 999px; padding: 0 7px; white-space: nowrap; }
.drawer-shelf { display: block; margin: 18px 10px 0; font-size: 14px; }
.ab-pager .soon { display: block; padding: 16px 18px; border: 1px dashed var(--border); border-radius: var(--radius); color: var(--text-faint); }
.ab-pager .soon.next { text-align: right; grid-column: 2; }
@media (max-width: 640px) { .ab-pager .soon.next { grid-column: 1; } }

/* 흑백으로 보기: 선형광 휘도만 남기는 SVG 필터(#ab-luma). 같은 명도의 회색이 된다 */
.ab-mono { filter: url(#ab-luma); }
.mono-toggle { display: inline-flex; align-items: center; gap: 5px; font: 600 12px var(--font); color: var(--text-dim); background: var(--bg-elev); border: 1px solid var(--border); border-radius: 999px; padding: 3px 10px 3px 8px; cursor: pointer; line-height: 1.4; }
.mono-toggle:hover { border-color: var(--accent); color: var(--text); }
.mono-toggle.on { background: var(--text); color: var(--bg); border-color: var(--text); }
.mono-toggle.floating { position: absolute; right: 10px; top: 10px; z-index: 3; box-shadow: var(--shadow); }
.sim-head .mono-toggle { flex: none; }

/* 전/후 비교 */
.compare { position: relative; overflow: hidden; touch-action: pan-y; user-select: none; -webkit-user-select: none; cursor: ew-resize; line-height: 0; }
.compare > .cmp-a, .compare > .cmp-b { line-height: normal; }
.compare > .cmp-b { position: absolute; inset: 0; }
.compare canvas, .compare img { display: block; width: 100%; height: auto; }
.cmp-bar { position: absolute; top: 0; bottom: 0; width: 0; border-left: 2px solid #ffffff; box-shadow: 0 0 0 1px rgba(0,0,0,.35); transform: translateX(-1px); outline: none; }
.cmp-knob { position: absolute; top: 50%; left: 0; width: 34px; height: 34px; transform: translate(-50%, -50%); border-radius: 50%; background: #ffffff; color: #111111; display: grid; place-items: center; box-shadow: 0 2px 8px rgba(0,0,0,.35); }
.cmp-bar:focus-visible .cmp-knob { outline: 3px solid var(--accent); }
.cmp-label { position: absolute; top: 10px; font: 600 12px var(--font); color: #ffffff; background: rgba(0,0,0,.55); padding: 2px 8px; border-radius: 6px; pointer-events: none; transition: opacity .15s; line-height: 1.5; }
.cmp-label.a { left: 10px; } .cmp-label.b { right: 10px; }

/* 작품 그림: 공공 도메인 이미지 + 출처 캡션 */
figure.art-figure { background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; box-shadow: var(--shadow); }
.art-frame { position: relative; background: #2a2a2a; border-radius: 8px; overflow: hidden; line-height: 0; }
.art-frame img, .art-frame canvas { display: block; width: 100%; height: auto; }
.credit { display: block; margin-top: 4px; font-size: 12.5px; color: var(--text-faint); }
.credit a { color: inherit; text-decoration: underline; text-decoration-color: var(--border); }

/* 예시 그림의 무대: 테마와 상관없이 고정된 배경 */
.sim-view.paper { background: var(--paper); }
.sim-view.stage { background: var(--stage); }
figure.diagram.paper { background: var(--paper); }
figure.diagram.paper figcaption { color: #5d5a66; }
figure.diagram.paper figcaption b { color: #1b1a1f; }

/* 색 견본 줄(HTML) */
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0; }
.chip { display: inline-grid; gap: 2px; min-width: 76px; font-size: 12px; color: var(--text-dim); }
.chip i { display: block; height: 44px; border-radius: 8px; box-shadow: inset 0 0 0 1px rgba(0,0,0,.12); }
.chip b { color: var(--text); font-size: 12.5px; }
.chip code { background: none; padding: 0; font-size: 11.5px; }

/* 케이스 인물 소개 */
.persona { display: grid; gap: 18px; grid-template-columns: minmax(0, 1fr); padding: 22px; border-radius: var(--radius); border: 1px solid var(--border); border-left: 4px solid var(--accent-2); background: var(--bg-elev); }
@media (min-width: 760px) { .persona { grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); } }
.persona p { margin: 0 0 10px; color: var(--text-dim); }
.persona p strong { color: var(--text); }

/* 홈: 서가와 책 카드 */
.shelf-grid { display: grid; gap: 18px; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); }
.book-card { display: flex; flex-direction: column; border-radius: var(--radius); border: 1px solid var(--border); background: var(--bg-elev); color: var(--text); overflow: hidden; transition: transform .15s, border-color .15s; }
a.book-card:hover { text-decoration: none; border-color: var(--accent); transform: translateY(-2px); }
.book-card .cover { aspect-ratio: 16 / 10; background: #1d1b26; display: block; }
.book-card .cover svg { display: block; width: 100%; height: 100%; }
.book-card .meta { padding: 16px 18px 18px; display: grid; gap: 6px; flex: 1; align-content: start; }
.book-card .num { font-family: var(--mono); font-size: 12px; color: var(--text-faint); letter-spacing: .08em; }
.book-card h3 { margin: 0; font-size: 19px; letter-spacing: -0.01em; }
.book-card h3 small { font-weight: 500; color: var(--text-dim); font-size: 14px; margin-left: 4px; }
.book-card p { margin: 0; color: var(--text-dim); font-size: 14.5px; line-height: 1.6; }
.book-card .status { justify-self: start; font-size: 12px; font-weight: 700; padding: 2px 9px; border-radius: 999px; background: var(--surface); color: var(--text-dim); }
.book-card .status.published, .book-card .status.writing { background: var(--accent-soft); color: var(--accent); }
.book-card.planned { opacity: .9; }
.book-card.planned .cover { filter: saturate(.35) brightness(.9); }
.book-card .topics { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 4px; }
.book-card .topics span { font-size: 11.5px; padding: 1px 8px; border-radius: 999px; background: var(--surface); color: var(--text-dim); }
.ch-card.soon { opacity: .62; }
.ch-card.soon:hover { transform: none; border-color: var(--border); }
.ch-card .tags span.soon { background: transparent; border: 1px dashed var(--border); }
.disclaimer { font-size: 14px; color: var(--text-dim); }
.credits-list { display: grid; gap: 14px; }
.credits-list .item { display: grid; grid-template-columns: 120px minmax(0, 1fr); gap: 16px; align-items: start; padding: 14px; border: 1px solid var(--border); border-radius: var(--radius-sm); background: var(--bg-elev); }
.credits-list img { width: 120px; height: 90px; object-fit: cover; border-radius: 6px; background: #2a2a2a; }
.credits-list h3 { margin: 0 0 4px; font-size: 16px; }
.credits-list p { margin: 0; font-size: 14px; color: var(--text-dim); line-height: 1.6; }
@media (max-width: 480px) { .credits-list .item { grid-template-columns: 1fr; } .credits-list img { width: 100%; height: 160px; } }