/* ==========================================================================
   iPAS AIAP 題庫 — 設計系統
   風格：專業 SaaS dashboard（資料密集、克制的色彩、清楚的層級）
   每個顏色都走 token，明暗兩套主題各定義一次；元件不寫死顏色。
   ========================================================================== */

:root {
  color-scheme: light;

  --bg: #ffffff;
  --bg-canvas: #f6f7f9;
  --surface: #ffffff;
  --surface-2: #f3f4f6;
  --surface-3: #e9ebef;
  --border: #e4e7ec;
  --border-strong: #d0d5dd;

  --text: #101828;
  --text-2: #475467;
  --text-3: #667085;

  --brand: #2563eb;
  --brand-hover: #1d4ed8;
  --brand-fg: #ffffff;
  --brand-soft: #eff4ff;
  --brand-border: #b8d0ff;

  --ok: #067647;
  --ok-soft: #ecfdf3;
  --ok-border: #a9e5c3;
  --bad: #b42318;
  --bad-soft: #fef3f2;
  --bad-border: #f5b7b1;
  --warn: #b54708;
  --warn-soft: #fffaeb;
  --warn-border: #f5d18a;

  --shadow-sm: 0 1px 2px rgba(16, 24, 40, 0.06);
  --shadow-md: 0 4px 12px -2px rgba(16, 24, 40, 0.08), 0 2px 4px -2px rgba(16, 24, 40, 0.04);
  --shadow-lg: 0 12px 28px -6px rgba(16, 24, 40, 0.12), 0 4px 8px -4px rgba(16, 24, 40, 0.06);

  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 14px;

  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC",
    "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;

  --nav-h: 60px;
  --page-max: 1180px;

  /* footer 固定用的中性深色，不隨明暗主題變 */
  --ink: #16202e;
  --ink-deep: #0e1622;
  --ink-accent: #7fb0ff;
}

[data-theme="dark"] {
  color-scheme: dark;

  --bg: #101216;
  --bg-canvas: #0a0c0f;
  --surface: #16191f;
  --surface-2: #1d2129;
  --surface-3: #262b34;
  --border: #272c35;
  --border-strong: #363c47;

  --text: #e9ebef;
  --text-2: #a3abb8;
  --text-3: #8b93a0;

  --brand: #6aa1ff;
  --brand-hover: #85b3ff;
  --brand-fg: #0a0c0f;
  --brand-soft: #16233d;
  --brand-border: #2c4373;

  --ok: #56cc8b;
  --ok-soft: #10261a;
  --ok-border: #235f3c;
  --bad: #f4796d;
  --bad-soft: #2a1614;
  --bad-border: #6b2c26;
  --warn: #e3ab48;
  --warn-soft: #271d0b;
  --warn-border: #6b5321;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 14px 34px -8px rgba(0, 0, 0, 0.62);
}

/* --------------------------------------------------------------- 基礎 */

*,
*::before,
*::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg-canvas);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  margin: 0;
  font-weight: 600;
  letter-spacing: -0.011em;
  color: var(--text);
}
h1 { font-size: 24px; line-height: 1.3; }
h2 { font-size: 16px; }
h3 { font-size: 14.5px; }
p { margin: 0; }

/* button 預設吃系統 buttontext，深色主題下會變成黑字，一定要明確給色 */
button {
  font: inherit;
  color: var(--text);
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 2px;
  border-radius: var(--r-sm);
}

.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--text-2); font-size: 13px; }
.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;
}

.icon { width: 18px; height: 18px; flex: none; stroke-width: 1.75; }
.icon-sm { width: 15px; height: 15px; }

/* --------------------------------------------------------------- 版面骨架 */

.topbar {
  position: sticky; top: 0; z-index: 30;
  height: var(--nav-h);
  display: flex; align-items: center; gap: 18px;
  padding: 0 22px;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(1.6) blur(12px);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex; align-items: center; gap: 10px;
  color: var(--text); font-weight: 600; font-size: 14.5px;
  padding: 6px 8px 6px 6px; border-radius: var(--r-md);
}
.brand:hover { background: var(--surface-2); }
.brand .logo {
  width: 30px; height: 30px; border-radius: 9px; flex: none;
  background: var(--brand); color: #fff; display: grid; place-items: center;
}
.brand .logo svg { width: 24px; height: 24px; display: block; }

.nav { display: flex; gap: 2px; margin-left: 8px; }
/* display:flex 會蓋掉 [hidden] 的 display:none，要明確加回來 */
.nav[hidden] { display: none; }
.navbtn {
  display: inline-flex; align-items: center; gap: 7px;
  height: 36px; padding: 0 13px; border-radius: var(--r-md);
  color: var(--text-2); font-size: 14px; font-weight: 500;
  transition: background 0.15s, color 0.15s;
}
.navbtn:hover { background: var(--surface-2); color: var(--text); }
.navbtn.active { background: var(--brand-soft); color: var(--brand-hover); }
.navbtn.active .icon { stroke-width: 2.1; }

.topbar-right { margin-left: auto; display: flex; align-items: center; gap: 8px; }

.iconbtn {
  display: grid; place-items: center;
  width: 36px; height: 36px; border-radius: var(--r-md);
  color: var(--text-2); border: 1px solid var(--border); background: var(--surface);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.iconbtn:hover { background: var(--surface-2); color: var(--text); border-color: var(--border-strong); }

main {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: 28px 22px 96px;
}
.stack { display: flex; flex-direction: column; gap: 18px; }
.row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }

/* --------------------------------------------------------------- 面板 */

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-sm);
}
.panel-head {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}
.panel-head .titles { display: flex; flex-direction: column; gap: 2px; }
.panel-head .titles p { color: var(--text-2); font-size: 13px; }
.panel-head .spacer { margin-left: auto; }
.panel-body { padding: 20px; }

/* --------------------------------------------------------------- 統計卡 */

.kpi-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.kpi {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 16px 18px; box-shadow: var(--shadow-sm);
  display: flex; flex-direction: column; gap: 3px;
}
.kpi .kpi-top { display: flex; align-items: center; gap: 7px; color: var(--text-2); }
.kpi .kpi-top .icon { width: 15px; height: 15px; }
.kpi .kpi-label { font-size: 12.5px; font-weight: 500; letter-spacing: 0.01em; }
.kpi .kpi-value {
  font: 600 28px/1.2 var(--font-sans);
  letter-spacing: -0.02em; font-variant-numeric: tabular-nums; color: var(--text);
}
.kpi .kpi-sub { font-size: 12.5px; color: var(--text-3); }

/* --------------------------------------------------------------- 科目卡 */

.subject-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }

.subject-card {
  display: flex; align-items: center; gap: 16px; text-align: left; width: 100%;
  padding: 16px 18px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg);
  color: var(--text);
  transition: border-color 0.15s, box-shadow 0.15s, background 0.15s;
}
.subject-card:hover {
  border-color: var(--brand-border);
  box-shadow: var(--shadow-md);
}
.subject-card .sc-main { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 5px; }
.subject-card .sc-tags { display: flex; align-items: center; gap: 7px; }
.subject-card .sc-name {
  font-size: 15px; font-weight: 600; color: var(--text);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.subject-card .sc-meta { font-size: 12.5px; color: var(--text-2); }
.subject-card .sc-go { color: var(--text-3); transition: color 0.15s, transform 0.15s; }
.subject-card:hover .sc-go { color: var(--brand); transform: translateX(2px); }

.ring { position: relative; width: 52px; height: 52px; flex: none; }
.ring svg { transform: rotate(-90deg); display: block; }
.ring .ring-bg { stroke: var(--surface-3); }
.ring .ring-fg { stroke: var(--brand); stroke-linecap: round; transition: stroke-dasharray 0.5s ease; }
.ring .ring-txt {
  position: absolute; inset: 0; display: grid; place-items: center;
  font: 600 12px/1 var(--font-mono); color: var(--text-2);
}

/* --------------------------------------------------------------- 標籤 */

.badge {
  display: inline-flex; align-items: center; gap: 5px;
  height: 21px; padding: 0 8px; border-radius: 999px;
  font-size: 11.5px; font-weight: 500; letter-spacing: 0.01em;
  background: var(--surface-2); color: var(--text-2);
  border: 1px solid var(--border);
  white-space: nowrap;
}
.badge.code { font-family: var(--font-mono); font-size: 11px; }
.badge.brand { background: var(--brand-soft); color: var(--brand); border-color: var(--brand-border); }
.badge.ok { background: var(--ok-soft); color: var(--ok); border-color: var(--ok-border); }
.badge.bad { background: var(--bad-soft); color: var(--bad); border-color: var(--bad-border); }
.badge.warn { background: var(--warn-soft); color: var(--warn); border-color: var(--warn-border); }

/* --------------------------------------------------------------- 表單控制 */

.builder { display: flex; flex-direction: column; gap: 22px; }
.field { display: flex; flex-direction: column; gap: 9px; }
.field > .field-label {
  font-size: 12.5px; font-weight: 600; color: var(--text-2);
  letter-spacing: 0.02em;
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  display: inline-flex; align-items: center; gap: 7px;
  min-height: 36px; padding: 6px 14px;
  border: 1px solid var(--border); border-radius: 999px;
  background: var(--surface); color: var(--text); font-size: 13.5px;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.chip:hover:not(:disabled) { border-color: var(--border-strong); background: var(--surface-2); }
.chip.on {
  background: var(--brand); border-color: var(--brand); color: var(--brand-fg); font-weight: 500;
}
.chip.on .chip-n { background: color-mix(in srgb, var(--brand-fg) 22%, transparent); color: inherit; }
.chip:disabled { opacity: 0.45; cursor: not-allowed; }
.chip-n {
  font: 500 11px/1 var(--font-mono); padding: 3px 6px; border-radius: 5px;
  background: var(--surface-2); color: var(--text-3);
}

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 40px; padding: 0 18px; border-radius: var(--r-md);
  font-size: 14px; font-weight: 500; white-space: nowrap;
  border: 1px solid transparent;
  transition: background 0.15s, border-color 0.15s, color 0.15s, box-shadow 0.15s;
}
.btn-primary { background: var(--brand); color: var(--brand-fg); box-shadow: var(--shadow-sm); }
.btn-primary:hover:not(:disabled) { background: var(--brand-hover); }
.btn-primary:disabled { opacity: 0.45; cursor: not-allowed; box-shadow: none; }
.btn-ghost { background: var(--surface); border-color: var(--border); color: var(--text); }
.btn-ghost:hover:not(:disabled) { background: var(--surface-2); border-color: var(--border-strong); }
.btn-ghost.on { background: var(--warn-soft); border-color: var(--warn-border); color: var(--warn); }
.btn-ghost.danger:hover { border-color: var(--bad-border); color: var(--bad); background: var(--bad-soft); }
.btn-lg { min-height: 44px; padding: 0 22px; font-size: 15px; }

/* --------------------------------------------------------------- 作答 */

.quizbar {
  display: flex; align-items: center; gap: 14px;
  padding: 12px 16px;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); box-shadow: var(--shadow-sm);
}
.quizbar .qb-meta {
  display: flex; align-items: baseline; gap: 6px;
  font-size: 13px; color: var(--text-2); white-space: nowrap;
}
.quizbar .qb-meta b {
  font: 600 15px/1 var(--font-mono); color: var(--text); font-variant-numeric: tabular-nums;
}
.track { flex: 1; height: 6px; border-radius: 999px; background: var(--surface-3); overflow: hidden; min-width: 60px; }
.track > i { display: block; height: 100%; background: var(--brand); border-radius: 999px; transition: width 0.3s ease; }
.timer {
  display: inline-flex; align-items: center; gap: 6px;
  font: 600 13.5px/1 var(--font-mono); color: var(--text-2);
  padding: 6px 10px; border-radius: var(--r-sm); background: var(--surface-2);
  font-variant-numeric: tabular-nums;
}
.timer.warn { color: var(--bad); background: var(--bad-soft); }

.qcard {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); box-shadow: var(--shadow-sm);
  overflow: hidden;
}
.qcard-head {
  display: flex; flex-wrap: wrap; gap: 7px; align-items: center;
  padding: 13px 22px; border-bottom: 1px solid var(--border); background: var(--surface-2);
}
.qcard-body { padding: 22px; }

.shared {
  margin-bottom: 18px; padding: 14px 16px;
  background: var(--brand-soft); border: 1px solid var(--brand-border);
  border-radius: var(--r-md);
  font-size: 14px; line-height: 1.7; color: var(--text);
}
.shared::before {
  content: "題組共用敘述";
  display: block; margin-bottom: 6px;
  font-size: 11px; font-weight: 600; letter-spacing: 0.06em;
  color: var(--brand);
}
.shared:empty { display: none; }

.stem { font-size: 16.5px; line-height: 1.8; color: var(--text); margin-bottom: 18px; }

.figs { display: flex; flex-direction: column; gap: 12px; margin-bottom: 18px; }
.figs:empty { display: none; }
.figs figure { margin: 0; }
.figs img {
  display: block; max-width: 100%; border-radius: var(--r-md);
  border: 1px solid var(--border-strong); background: #fff; cursor: zoom-in;
}
.figs figcaption {
  margin-top: 5px; font-size: 11.5px; color: var(--text-3);
  display: flex; align-items: center; gap: 5px;
}

.options { display: flex; flex-direction: column; gap: 10px; }
.opt {
  display: flex; align-items: flex-start; gap: 13px; text-align: left; width: 100%;
  padding: 14px 16px; border-radius: var(--r-md);
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  font-size: 14.5px; line-height: 1.65;
  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
}
.opt:hover:not(:disabled) { border-color: var(--brand-border); background: var(--brand-soft); }
.opt .key {
  flex: none; display: grid; place-items: center;
  width: 26px; height: 26px; border-radius: 7px;
  background: var(--surface-2); border: 1px solid var(--border);
  font: 600 12.5px/1 var(--font-mono); color: var(--text-2);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.opt .mark { margin-left: auto; flex: none; display: none; }
.opt.picked { border-color: var(--brand); background: var(--brand-soft); }
.opt.picked .key { background: var(--brand); border-color: var(--brand); color: var(--brand-fg); }
.opt.correct { border-color: var(--ok-border); background: var(--ok-soft); }
.opt.correct .key { background: var(--ok); border-color: var(--ok); color: #fff; }
.opt.correct .mark { display: block; color: var(--ok); }
.opt.wrong { border-color: var(--bad-border); background: var(--bad-soft); }
.opt.wrong .key { background: var(--bad); border-color: var(--bad); color: #fff; }
.opt.wrong .mark { display: block; color: var(--bad); }
.opt:disabled { cursor: default; }

.qactions {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--border);
}
.kbd-hint { margin-left: auto; display: flex; align-items: center; gap: 6px; color: var(--text-3); font-size: 12px; }
kbd {
  display: inline-grid; place-items: center; min-width: 20px; height: 20px; padding: 0 5px;
  font: 500 11px/1 var(--font-mono);
  background: var(--surface-2); border: 1px solid var(--border);
  border-bottom-width: 2px; border-radius: 5px; color: var(--text-2);
}

/* --------------------------------------------------------------- 解析 */

.feedback { margin-top: 22px; }
.feedback:empty { display: none; }
/* 有解析時，按鈕區的上緣分隔線省略，避免兩條線疊在一起 */
.feedback:not(:empty) + .qactions { border-top: none; padding-top: 8px; }

.verdict {
  display: flex; align-items: center; gap: 10px;
  padding: 13px 16px; border-radius: var(--r-md); margin-bottom: 14px;
  font-size: 14.5px; font-weight: 600;
}
.verdict.ok { background: var(--ok-soft); border: 1px solid var(--ok-border); color: var(--ok); }
.verdict.bad { background: var(--bad-soft); border: 1px solid var(--bad-border); color: var(--bad); }
.verdict .v-sub { margin-left: auto; font-weight: 400; font-size: 13px; opacity: 0.85; }

.explain { border: 1px solid var(--border); border-radius: var(--r-md); overflow: hidden; }
.explain section { padding: 16px 18px; border-bottom: 1px solid var(--border); }
.explain section:last-child { border-bottom: none; }
.explain h4 {
  display: flex; align-items: center; gap: 7px;
  margin-bottom: 9px; font-size: 11.5px; font-weight: 600;
  letter-spacing: 0.06em; color: var(--text-3);
}
.explain .body { font-size: 14.5px; line-height: 1.85; color: var(--text); }

.oa-list { display: flex; flex-direction: column; gap: 10px; }
.oa { display: flex; gap: 11px; font-size: 14px; line-height: 1.7; color: var(--text-2); }
.oa .oa-key {
  flex: none; display: grid; place-items: center;
  width: 22px; height: 22px; border-radius: 6px;
  font: 600 11.5px/1 var(--font-mono);
  background: var(--surface-2); color: var(--text-3); border: 1px solid var(--border);
}
.oa.is-ans { color: var(--text); }
.oa.is-ans .oa-key { background: var(--ok-soft); color: var(--ok); border-color: var(--ok-border); }

.callout {
  display: flex; gap: 10px; padding: 12px 14px; border-radius: var(--r-md);
  font-size: 13.5px; line-height: 1.7;
}
.callout .icon { margin-top: 2px; }
.callout.warn { background: var(--warn-soft); border: 1px solid var(--warn-border); color: var(--text); }
.callout.warn .icon { color: var(--warn); }
.callout.info { background: var(--surface-2); border: 1px solid var(--border); color: var(--text-2); }

.kw { display: flex; flex-wrap: wrap; gap: 6px; }

.empty {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  padding: 34px 20px; text-align: center; color: var(--text-3);
}
.empty .icon { width: 26px; height: 26px; }
.empty p { font-size: 13.5px; }

/* --------------------------------------------------------------- 成績 */

.result-hero { display: flex; align-items: center; gap: 26px; flex-wrap: wrap; padding: 24px; }
.score-ring { position: relative; width: 108px; height: 108px; flex: none; }
.score-ring svg { transform: rotate(-90deg); display: block; }
.score-ring .sr-bg { stroke: var(--surface-3); }
.score-ring .sr-fg { stroke-linecap: round; transition: stroke-dasharray 0.7s ease; }
.score-ring.pass .sr-fg { stroke: var(--ok); }
.score-ring.fail .sr-fg { stroke: var(--bad); }
.score-ring .sr-txt {
  position: absolute; inset: 0; display: grid; place-items: center;
  grid-auto-rows: min-content; align-content: center;
}
.score-ring .sr-num { font: 600 30px/1 var(--font-sans); letter-spacing: -0.02em; }
.score-ring.pass .sr-num { color: var(--ok); }
.score-ring.fail .sr-num { color: var(--bad); }
.score-ring .sr-unit { font-size: 11px; color: var(--text-3); }

.result-facts { display: flex; flex-direction: column; gap: 6px; }
.result-facts .rf-title { font-size: 17px; font-weight: 600; }
.result-facts .rf-line { font-size: 13.5px; color: var(--text-2); }

.review { display: flex; flex-direction: column; }
.rev {
  display: flex; gap: 13px; align-items: flex-start; width: 100%; text-align: left;
  padding: 13px 20px; border-bottom: 1px solid var(--border);
  color: var(--text); transition: background 0.15s;
}
.rev:last-child { border-bottom: none; }
.rev:hover { background: var(--surface-2); }
.rev .rev-i { flex: none; width: 24px; font: 500 12px/1.6 var(--font-mono); color: var(--text-3); }
.rev .rev-txt { flex: 1; min-width: 0; font-size: 14px; line-height: 1.6; }
.rev .rev-line {
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.rev .rev-state { flex: none; display: flex; align-items: center; gap: 6px; font-size: 12px; }
.rev.ok .rev-state { color: var(--ok); }
.rev.bad .rev-state { color: var(--bad); }
.rev-body { margin-top: 14px; display: none; }
.rev.open .rev-body { display: block; }
.rev .chev { transition: transform 0.2s; }
.rev.open .chev { transform: rotate(90deg); }

/* --------------------------------------------------------------- 圖表 */

.bars { display: flex; flex-direction: column; gap: 12px; }
.bar-row { display: grid; grid-template-columns: 74px 1fr 96px; gap: 12px; align-items: center; }
.bar-row .b-code { font: 500 11.5px/1 var(--font-mono); color: var(--text-3); }
.bar-row .b-name {
  grid-column: 2 / 4; font-size: 13px; color: var(--text-2);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.bar-row .b-track { height: 9px; border-radius: 999px; background: var(--surface-3); overflow: hidden; }
.bar-row .b-track > i {
  display: block; height: 100%; border-radius: 999px;
  background: var(--brand); transition: width 0.5s ease;
}
.bar-row .b-track > i.hi { background: var(--ok); }
.bar-row .b-track > i.mid { background: var(--warn); }
.bar-row .b-track > i.lo { background: var(--bad); }
.bar-row .b-num {
  text-align: right; font: 500 12.5px/1 var(--font-mono);
  color: var(--text-2); font-variant-numeric: tabular-nums;
}

.spark { width: 100%; height: 110px; display: block; overflow: visible; }
.spark .sp-line { fill: none; stroke: var(--brand); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.spark .sp-area { fill: var(--brand); opacity: 0.1; }
.spark .sp-dot { fill: var(--surface); stroke: var(--brand); stroke-width: 2; }
.spark .sp-grid { stroke: var(--border); stroke-width: 1; stroke-dasharray: 3 3; }
.spark .sp-lbl { fill: var(--text-3); font: 10px var(--font-mono); }

.legend { display: flex; gap: 14px; flex-wrap: wrap; font-size: 12px; color: var(--text-2); }
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.legend i { width: 9px; height: 9px; border-radius: 3px; display: inline-block; }

/* --------------------------------------------------------------- 工作區（左欄＋右區） */

.workspace {
  display: grid; grid-template-columns: 264px minmax(0, 1fr); gap: 18px;
  align-items: stretch; /* 左欄高度跟著右區走，兩側對齊 */
}

.rail {
  display: flex; flex-direction: column;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); box-shadow: var(--shadow-sm); overflow: hidden;
}
.rail-head {
  padding: 13px 16px; border-bottom: 1px solid var(--border);
  font-size: 12px; font-weight: 600; letter-spacing: 0.06em; color: var(--text-3);
}
.rail-list { flex: 1; padding: 8px; display: flex; flex-direction: column; gap: 4px; overflow-y: auto; }

.rail-item {
  display: flex; flex-direction: column; gap: 3px; align-items: flex-start; justify-content: center;
  width: 100%; text-align: left; padding: 11px 12px; border-radius: var(--r-md);
  color: var(--text); transition: background 0.15s, color 0.15s;
}
.rail-list.even .rail-item { flex: 1; min-height: 64px; }
.rail-item:hover { background: var(--surface-2); }
.rail-item.on { background: var(--brand-soft); }
.rail-item .ri-top {
  display: flex; align-items: center; gap: 6px;
  font: 600 10.5px/1 var(--font-mono); letter-spacing: 0.05em; color: var(--text-3);
}
.rail-item.on .ri-top { color: var(--brand); }
.rail-item .ri-name { font-size: 13.5px; font-weight: 500; line-height: 1.45; }
.rail-item.on .ri-name { color: var(--brand-hover); }
.rail-item .ri-bar {
  width: 100%; height: 4px; margin-top: 4px; border-radius: 999px;
  background: var(--surface-3); overflow: hidden;
}
.rail-item .ri-bar > i { display: block; height: 100%; background: var(--brand); border-radius: 999px; }
.rail-item .ri-meta { font-size: 11.5px; color: var(--text-3); }

/* 教材章節樹 */
.rail-group { margin-top: 4px; }
.rail-group:first-child { margin-top: 0; }
.rail-subject {
  display: flex; align-items: center; gap: 7px; width: 100%; text-align: left;
  padding: 9px 12px; border-radius: var(--r-md);
  font-size: 13px; font-weight: 600; color: var(--text);
  transition: background 0.15s;
}
.rail-subject:hover { background: var(--surface-2); }
.rail-subject .chev { margin-left: auto; color: var(--text-3); transition: transform 0.2s; }
.rail-subject.open .chev { transform: rotate(90deg); }
.rail-subject .rs-code { font: 600 10.5px/1 var(--font-mono); color: var(--text-3); }
.rail-sections { display: none; flex-direction: column; gap: 1px; padding: 2px 0 6px 10px; }
.rail-subject.open + .rail-sections { display: flex; }
.rail-sec {
  width: 100%; text-align: left; padding: 7px 11px; border-radius: var(--r-sm);
  font-size: 12.5px; line-height: 1.5; color: var(--text-2);
  border-left: 2px solid var(--border);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.rail-sec:hover { background: var(--surface-2); color: var(--text); }
.rail-sec.on { background: var(--brand-soft); color: var(--brand-hover); border-left-color: var(--brand); font-weight: 500; }

.workarea { min-width: 0; display: flex; flex-direction: column; gap: 18px; }

/* 科目介紹 */
.workarea > .panel.info-card { display: flex; flex-direction: column; }
.workarea > .panel.setup-card { flex: 1; display: flex; flex-direction: column; }
.workarea > .panel.setup-card > .panel-body { flex: 1; }

.subject-hero { padding: 22px 24px; border-bottom: 1px solid var(--border); }
.subject-hero .sh-top { display: flex; align-items: center; gap: 8px; margin-bottom: 9px; }
.subject-hero .sh-top .spacer { margin-left: auto; }
.info-btn {
  display: inline-flex; align-items: center; gap: 6px;
  height: 32px; padding: 0 12px; border-radius: 999px;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text-2); font-size: 12.5px; font-weight: 500;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}
.info-btn:hover { border-color: var(--brand-border); color: var(--brand); background: var(--brand-soft); }
.subject-hero h1 { font-size: 22px; margin-bottom: 8px; }
.subject-hero p { font-size: 14px; line-height: 1.8; color: var(--text-2); max-width: 720px; }
.subject-facts {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px;
  background: var(--border); border-top: 1px solid var(--border);
}
.subject-facts div { background: var(--surface); padding: 14px 18px; }
.subject-facts b {
  display: block; font: 600 20px/1.3 var(--font-sans);
  letter-spacing: -0.02em; font-variant-numeric: tabular-nums;
}
.subject-facts span { font-size: 12px; color: var(--text-3); }

.topic-list { display: flex; flex-direction: column; gap: 7px; }
.topic-row {
  display: grid; grid-template-columns: 66px minmax(0, 1fr) auto; gap: 11px; align-items: center;
  font-size: 13px;
}
.topic-row .t-code { font: 500 11px/1 var(--font-mono); color: var(--text-3); }
.topic-row .t-name { color: var(--text-2); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.topic-row .t-n { font: 500 11.5px/1 var(--font-mono); color: var(--text-3); }

/* 章節閱讀區 */
.reader { padding: 26px 30px; }
.reader-head { margin-bottom: 20px; padding-bottom: 16px; border-bottom: 1px solid var(--border); }
.reader-head .rh-crumb {
  display: flex; align-items: center; gap: 7px; margin-bottom: 8px;
  font-size: 12px; color: var(--text-3);
}
.reader-head h1 { font-size: 21px; }
.reader-nav {
  display: flex; gap: 10px; margin-top: 26px; padding-top: 18px;
  border-top: 1px solid var(--border);
}
.reader-nav .btn { flex: 1; justify-content: flex-start; }
.reader-nav .btn.next { justify-content: flex-end; }
.reader-nav .rn-label { display: flex; flex-direction: column; align-items: flex-start; gap: 2px; }
.reader-nav .rn-label small { font-size: 11px; color: var(--text-3); }
.reader-nav .btn.next .rn-label { align-items: flex-end; }

.md { font-size: 14.5px; line-height: 1.85; color: var(--text); }
.md > *:first-child { margin-top: 0; }
.md h1 { font-size: 20px; margin: 26px 0 10px; }
.md h2 {
  font-size: 16.5px; margin: 28px 0 10px; padding-bottom: 7px;
  border-bottom: 1px solid var(--border);
}
.md h3 { font-size: 14.5px; margin: 20px 0 8px; }
.md p { margin: 0 0 12px; }
.md ul { margin: 0 0 12px; padding-left: 20px; }
.md li { margin-bottom: 5px; }
.md blockquote {
  margin: 0 0 14px; padding: 10px 14px;
  border-left: 3px solid var(--brand-border); background: var(--surface-2);
  border-radius: 0 var(--r-sm) var(--r-sm) 0; color: var(--text-2);
}
.md code {
  font: 12.5px var(--font-mono); padding: 2px 5px; border-radius: 5px;
  background: var(--surface-2); border: 1px solid var(--border); color: var(--text);
}
.md .table-wrap { overflow-x: auto; margin: 0 0 16px; }
.md table { border-collapse: collapse; width: 100%; font-size: 13.5px; }
.md th, .md td {
  border: 1px solid var(--border); padding: 8px 11px; text-align: left; vertical-align: top;
}
.md th { background: var(--surface-2); font-weight: 600; color: var(--text); white-space: nowrap; }
.md strong { font-weight: 600; color: var(--text); }


/* --------------------------------------------------------------- 404 */

.notfound { max-width: 520px; margin: 0 auto; padding: 72px 0 96px; text-align: center; }
.notfound .nf-code {
  font: 600 60px/1 var(--font-mono); letter-spacing: -0.03em;
  color: var(--brand); opacity: 0.28; margin-bottom: 14px;
}
.notfound h1 { font-size: 24px; margin-bottom: 12px; }
.notfound .nf-text {
  font-size: 14.5px; line-height: 1.9; color: var(--text-2); margin-bottom: 26px;
}

/* --------------------------------------------------------------- 文件頁（FAQ 等靜態內容） */

.doc {
  max-width: 760px; margin: 0 auto; padding: 12px 0 40px;
}
.doc-crumb { font-size: 13px; color: var(--text-3); margin-bottom: 14px; }
.doc h1 { font-size: 26px; line-height: 1.35; margin-bottom: 14px; }
.doc-lead {
  font-size: 15.5px; line-height: 1.9; color: var(--text-2);
  padding-bottom: 26px; margin-bottom: 8px; border-bottom: 1px solid var(--border);
}
.doc .qa { padding: 22px 0; border-bottom: 1px solid var(--border); }
.doc .qa h2 { font-size: 17px; margin-bottom: 10px; }
.doc .qa p { font-size: 14.5px; line-height: 1.95; color: var(--text-2); }
.doc-cta { padding-top: 28px; }

/* --------------------------------------------------------------- footer */

.site-footer {
  margin-top: 64px;
  background: var(--ink-deep);
  color: rgba(255, 255, 255, 0.72);
  font-size: 14px;
}
.footer-main {
  max-width: var(--page-max); margin: 0 auto; padding: 56px 22px;
  display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 44px;
}
.footer-brand { display: flex; align-items: center; gap: 12px; }
.footer-brand .fb-name { font-size: 15px; font-weight: 600; color: #fff; }
.footer-brand .fb-sub { display: block; font-size: 12px; color: var(--ink-accent); }
.footer-logo {
  width: 40px; height: 40px; border-radius: 11px; flex: none;
  background: var(--brand); color: #fff; display: grid; place-items: center;
}
.footer-logo svg { width: 32px; height: 32px; display: block; }
.footer-desc {
  margin-top: 16px; max-width: 380px;
  font-size: 13.5px; line-height: 1.9; color: rgba(255, 255, 255, 0.62);
}
.footer-meta { margin-top: 20px; display: flex; flex-direction: column; gap: 9px; }
.footer-meta p {
  display: flex; align-items: center; gap: 9px;
  font-size: 13px; color: rgba(255, 255, 255, 0.62);
}
.footer-meta .icon { color: var(--ink-accent); width: 16px; height: 16px; }
.footer-col h4 {
  margin-bottom: 15px; font-size: 12.5px; font-weight: 600;
  letter-spacing: 0.08em; color: rgba(255, 255, 255, 0.92);
}
.footer-col ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 11px; }
.footer-col a, .footer-col button {
  display: inline-block; padding: 4px 0;
  font-size: 13.5px; color: rgba(255, 255, 255, 0.62);
  transition: color 0.15s; text-align: left;
}
.footer-col a:hover, .footer-col button:hover { color: var(--ink-accent); text-decoration: none; }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.08); }
.footer-bottom .inner {
  max-width: var(--page-max); margin: 0 auto; padding: 20px 22px;
  display: flex; align-items: center; justify-content: space-between; gap: 14px; flex-wrap: wrap;
  font-size: 12.5px; color: rgba(255, 255, 255, 0.58); /* 0.45 只有 4.43:1，不到 WCAG 門檻 */
}
.footer-bottom a {
  color: rgba(255, 255, 255, 0.78); display: inline-block; padding: 5px 2px;
}

@media (max-width: 900px) {
  .features { grid-template-columns: 1fr; }
  .footer-main { grid-template-columns: 1fr; gap: 32px; padding: 40px 18px; }
}

/* --------------------------------------------------------------- 堆疊累積圖 */

.stack-chart { display: flex; flex-direction: column; gap: 14px; }
.stack-bar {
  display: flex; width: 100%; height: 30px; border-radius: 8px; overflow: hidden;
  background: var(--surface-2); gap: 2px; /* 2px 縫隙讓相鄰色塊分開 */
}
.stack-seg {
  position: relative; height: 100%; min-width: 3px;
  display: grid; place-items: center;
  font: 500 11.5px/1 var(--font-mono); color: #fff;
  transition: filter 0.15s;
}
.stack-seg:first-child { border-radius: 8px 0 0 8px; }
.stack-seg:last-child { border-radius: 0 8px 8px 0; }
.stack-seg:hover { filter: brightness(1.08); }
.stack-seg span { text-shadow: 0 1px 2px rgba(0, 0, 0, 0.35); pointer-events: none; }

.stack-legend { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.stack-legend .lg {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--text-2);
}
.stack-legend .lg i { width: 10px; height: 10px; border-radius: 3px; flex: none; }
.stack-legend .lg b { color: var(--text); font-weight: 600; }
.stack-legend .lg .lg-code { font: 500 11px/1 var(--font-mono); color: var(--text-3); }

.topic-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.topic-table th, .topic-table td {
  padding: 9px 10px; border-bottom: 1px solid var(--border); text-align: left; vertical-align: middle;
}
.topic-table th {
  font-size: 11.5px; font-weight: 600; letter-spacing: 0.04em;
  color: var(--text-3); border-bottom-color: var(--border-strong);
}
.topic-table td.num { text-align: right; font: 500 12.5px/1 var(--font-mono); color: var(--text-2); }
.topic-table .dot { display: inline-block; width: 8px; height: 8px; border-radius: 3px; margin-right: 8px; }
.topic-table .code { font: 500 11.5px/1 var(--font-mono); color: var(--text-3); }
.topic-table tbody tr:last-child td { border-bottom: none; }
.topic-table .acc-hi { color: var(--ok); }
.topic-table .acc-mid { color: var(--warn); }
.topic-table .acc-lo { color: var(--bad); }

/* --------------------------------------------------------------- 彈窗 */

.modal-backdrop {
  position: fixed; inset: 0; z-index: 55;
  background: rgba(8, 12, 20, 0.55); backdrop-filter: blur(3px);
  display: grid; place-items: center; padding: 28px;
  animation: fade 0.14s ease;
}
.modal {
  width: min(720px, 100%); max-height: 82vh; display: flex; flex-direction: column;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); box-shadow: var(--shadow-lg);
  animation: pop 0.16s ease;
}
@keyframes pop { from { opacity: 0; transform: translateY(6px) scale(0.99); } to { opacity: 1; transform: none; } }
.modal-head {
  display: flex; align-items: flex-start; gap: 12px;
  padding: 18px 20px; border-bottom: 1px solid var(--border);
}
.modal-head .titles { display: flex; flex-direction: column; gap: 3px; }
.modal-head .titles p { font-size: 13px; color: var(--text-2); }
.modal-head .closebtn { margin-left: auto; }
.modal-body { padding: 18px 20px; overflow-y: auto; }

/* --------------------------------------------------------------- 其他 */

.sourcebox { font-size: 13.5px; color: var(--text-2); line-height: 1.9; }

.lightbox {
  position: fixed; inset: 0; z-index: 60; padding: 32px;
  background: rgba(8, 10, 14, 0.86);
  display: grid; place-items: center; cursor: zoom-out;
  animation: fade 0.15s ease;
}
.lightbox img {
  max-width: 100%; max-height: 100%;
  background: #fff; border-radius: var(--r-md); box-shadow: var(--shadow-lg);
}
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

.toast {
  position: fixed; left: 50%; bottom: 26px; transform: translateX(-50%);
  z-index: 70; display: flex; align-items: center; gap: 9px;
  padding: 11px 17px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--border);
  box-shadow: var(--shadow-lg); font-size: 13.5px; color: var(--text);
  animation: rise 0.18s ease;
}
@keyframes rise { from { opacity: 0; transform: translate(-50%, 8px); } to { opacity: 1; transform: translate(-50%, 0); } }

/* --------------------------------------------------------------- 響應式 */

@media (max-width: 900px) {
  .kpi-grid { grid-template-columns: repeat(2, 1fr); }
  .subject-facts { grid-template-columns: repeat(2, 1fr); }
  .workspace { grid-template-columns: 1fr; }
  .reader { padding: 20px 18px; }

  /* 直向排列時，左欄若照桌機那樣展開會吃掉整個首屏，
     改成一列可橫向捲動的科目按鈕，內容區直接接在下面。 */
  .rail { flex-direction: row; align-items: center; padding: 8px; gap: 8px; }
  .rail-head {
    padding: 0 4px 0 6px; border-bottom: none; flex: none;
    font-size: 11px; white-space: nowrap;
  }
  .rail-list {
    flex-direction: row; padding: 0; gap: 8px;
    overflow-x: auto; scrollbar-width: none; -webkit-overflow-scrolling: touch;
  }
  .rail-list::-webkit-scrollbar { display: none; }
  .rail-list.even .rail-item { flex: 0 0 auto; min-height: 44px; }
  .rail-item {
    flex-direction: row; align-items: center; gap: 7px; width: auto;
    padding: 9px 14px; border-radius: 999px;
    border: 1px solid var(--border); white-space: nowrap;
  }
  .rail-item.on { border-color: var(--brand); }
  .rail-item .ri-top { font-size: 10px; }
  .rail-item .ri-name { font-size: 13px; }
  .rail-item .ri-bar, .rail-item .ri-meta { display: none; }

  /* 教材章節樹在手機上限高，不然整頁都是目錄 */
  .rail.notes-rail { flex-direction: column; align-items: stretch; padding: 0; }
  .rail.notes-rail .rail-head { padding: 12px 16px; border-bottom: 1px solid var(--border); }
  .rail.notes-rail .rail-list {
    flex-direction: column; padding: 8px; max-height: 46vh; overflow-y: auto;
  }
}

@media (max-width: 680px) {
  main { padding: 18px 14px 80px; }
  .topbar { padding: 0 12px; gap: 8px; }
  .brand .brandtext { display: none; }
  .navbtn { padding: 0 10px; gap: 0; }
  .navbtn .navtext { display: none; }
  .qcard-body { padding: 16px; }
  .bar-row { grid-template-columns: 62px 1fr 74px; }
  .kbd-hint { display: none; }
  .result-hero { gap: 18px; padding: 18px; }
}

/* 觸控裝置與平板：可點元素放大到 WCAG 建議的 44x44 */
@media (pointer: coarse), (max-width: 900px) {
  .btn, .chip, .iconbtn, .navbtn, .brand { min-height: 44px; }
  .iconbtn, .navbtn, .brand { min-width: 44px; }
  .footer-col a, .footer-col button { padding: 9px 0; }
  .footer-col ul { gap: 4px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}