:root {
  color-scheme: light;
  --ink: #22283a;
  --paper: #eef1f7;
  --card: #f8faff;
  --accent: #2e4a8a;
  --accent-2: #3d4c6b;
  --seal: #33478f;
  --line: #cdd6ea;
  --muted: #5f6b85;
  --correct: #3a7d5c;
  --wrong: #c0432f;
  --history: #8a4f2d;
  --geography: #246b5a;
  --civics: #315b8a;
  --integrated: #6b4b8a;
  --gradient: linear-gradient(135deg, #141a2e 0%, #233163 45%, #2e4a8a 100%);
  font-family: "Songti TC", "Noto Serif TC", "PMingLiU", serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(ellipse at top left, rgb(46 74 138 / 5%), transparent 55%),
    radial-gradient(ellipse at bottom right, rgb(35 49 99 / 6%), transparent 55%),
    var(--paper);
  line-height: 1.75;
}
body, button, input, select, textarea { font-family: inherit; }
a { color: var(--seal); text-underline-offset: 3px; text-decoration-color: rgb(51 71 143 / 40%); }
a:hover { text-decoration-color: var(--seal); }
button { cursor: pointer; }
img { max-width: 100%; height: auto; }
[hidden] { display: none !important; }

.skip-link {
  position: fixed;
  left: -100vw;
  top: 8px;
  z-index: 100;
}
.skip-link:focus {
  left: 8px;
  padding: 8px 12px;
  color: var(--ink);
  background: white;
}
.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;
}

.check-link {
  position: fixed;
  top: calc(env(safe-area-inset-top, 0px) + 10px);
  right: 10px;
  z-index: 60;
  padding: 5px 12px;
  color: #eef2fb;
  background: rgb(30 36 54 / 78%);
  border: 1px solid rgb(255 255 255 / 20%);
  border-radius: 14px;
  font-size: .8rem;
  text-decoration: none;
  opacity: .82;
  backdrop-filter: blur(3px);
}

.font-size-control {
  position: fixed;
  right: 10px;
  bottom: calc(env(safe-area-inset-bottom, 0px) + 22px);
  z-index: 20;
  display: flex;
  gap: 4px;
  padding: 6px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: 0 1px 6px rgb(42 31 24 / 20%);
  transition: opacity .15s ease;
}
.font-size-control.folded { opacity: .62; }
.font-size-control.folded .font-option { display: none; }
.font-size-control button {
  min-width: 36px;
  min-height: 36px;
  color: var(--ink);
  background: #f4f6fc;
  border: 1px solid var(--line);
  border-radius: 6px;
}
html.font-large body { font-size: 1.15rem; }
html.font-xlarge body { font-size: 1.3rem; }

.hero-header {
  position: relative;
  min-height: 120px;
  overflow: hidden;
  color: #f4ecdc;
  text-align: center;
  background: var(--gradient);
}
.hero-image {
  display: block;
  width: 100%;
  max-height: 260px;
  object-fit: cover;
  object-position: center 30%;
}
.hero-text {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  padding: 40px 16px 12px;
  background: linear-gradient(180deg, transparent 0%, rgb(27 22 17 / 72%) 55%, rgb(27 22 17 / 88%) 100%);
}
.hero-text h1 {
  margin: 0;
  font-size: 1.55rem;
  letter-spacing: .2em;
  text-shadow: 0 1px 10px rgb(0 0 0 / 55%);
}
.hero-text p {
  margin: 4px 0 0;
  font-size: .85rem;
  opacity: .92;
  text-shadow: 0 1px 6px rgb(0 0 0 / 50%);
}

.page-wrap, main {
  width: min(860px, calc(100% - 32px));
  margin: 0 auto;
  padding: 16px 0 48px;
}
.panel, .question-card, .notice {
  position: relative;
  padding: 16px;
  margin-bottom: 16px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 4px 16px 4px 16px;
  box-shadow: 0 1px 3px rgb(42 31 24 / 8%);
}
.panel h2, .session-bar h2 {
  margin: 0;
  padding-left: 8px;
  color: var(--accent);
  border-left: 4px solid var(--seal);
  font-size: 1.05rem;
}
.notice { padding: 12px 14px; }
.draft-notice { color: #8a4f00; background: #fff8df; border-color: #d59d47; }

.intro-box {
  padding: 12px 14px;
  margin-bottom: 16px;
  color: var(--accent-2);
  background: #e8edf8;
  border-left: 3px solid var(--seal);
  border-radius: 0 8px 8px 0;
  font-size: .88rem;
}
.intro-box h2 {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: .92rem;
  line-height: 1.55;
}
.intro-box b { color: var(--ink); }
.intro-toggle { display: none; margin-left: 6px; }
.intro-box.collapsed .intro-rest { display: none; }

.quick-start {
  padding: 16px;
  margin-bottom: 16px;
  color: #f4ecdc;
  text-align: center;
  background: var(--gradient);
  border-radius: 4px 16px 4px 16px;
}
.quick-start p {
  margin: 8px 0 0;
  font-size: .82rem;
  opacity: .87;
}

.tool-row, .session-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.text-toggle {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  padding: 2px 4px;
  color: var(--accent-2);
  background: transparent;
  border: 0;
  font-size: .82rem;
}
.filter-summary {
  margin: 6px 0 10px;
  color: var(--muted);
  font-size: .9rem;
}
.filter-hint {
  margin: 2px 0 10px;
  color: var(--muted);
  font-size: .85rem;
}
.filter-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
}
label {
  display: grid;
  gap: 4px;
  color: var(--muted);
  font-size: .88rem;
  font-weight: 700;
}
select, input, textarea {
  width: 100%;
  min-height: 44px;
  padding: 7px 9px;
  color: var(--ink);
  background: #f4f6fc;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 16px;
}
.microcopy {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: .8rem;
}
.filter-options {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  padding-top: 12px;
  margin-top: 12px;
  border-top: 1px dashed var(--line);
}
.filter-options label {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 44px;
  color: var(--ink);
  font-weight: 400;
}
.filter-options input {
  width: 18px;
  min-height: 18px;
  accent-color: var(--seal);
}
.button-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
}
.more-row {
  padding-top: 10px;
  border-top: 1px dashed var(--line);
}
.button {
  min-height: 44px;
  padding: 10px 22px;
  color: var(--ink);
  background: #e2e9f5;
  border: 1px solid var(--accent-2);
  border-radius: 4px 12px 4px 12px;
  font-size: 1rem;
}
.button.primary { color: #fff9ec; background: var(--seal); border-color: var(--seal); }
.button.outline { color: var(--seal); background: transparent; border: 1.5px solid var(--seal); font-weight: 700; }
.button.ghost { color: var(--muted); background: transparent; border-color: var(--line); }
.button.danger { color: var(--wrong); border-color: var(--wrong); }
.compact-row .button { padding: 8px 14px; font-size: .88rem; }
.quick-button {
  padding: 14px 30px;
  font-size: 1.1rem;
  box-shadow: 0 2px 8px rgb(0 0 0 / 25%);
}
.button:disabled { cursor: default; opacity: .4; }
.button:focus-visible, .option:focus-visible, .text-toggle:focus-visible, .font-size-control button:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

.history-panel { margin-top: 16px; }
.history-row {
  display: grid;
  grid-template-columns: 9em 1fr auto;
  gap: 10px;
  align-items: center;
  padding: 7px 0;
  border-bottom: 1px solid var(--line);
  font-size: .85rem;
}
.history-row:last-child { border-bottom: 0; }
.history-bar {
  height: 10px;
  overflow: hidden;
  background: #d9e0f0;
  border-radius: 6px;
}
.history-bar i { display: block; height: 100%; background: var(--correct); }
.history-empty { color: var(--muted); font-size: .86rem; }
.paper-panel { margin-top: 16px; }
.paper-question-list {
  display: grid;
  gap: 7px;
  max-height: 440px;
  padding: 10px;
  margin-top: 12px;
  overflow-y: auto;
  background: #eef2fb;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.paper-question-list label {
  display: grid;
  grid-template-columns: 22px 1fr auto;
  gap: 8px;
  align-items: start;
  padding: 8px;
  color: var(--ink);
  background: var(--card);
  border-radius: 6px;
  font-weight: 400;
}
.paper-question-list input { width: 18px; min-height: 18px; }
.paper-question-list small { color: var(--muted); white-space: nowrap; }

.session { margin-top: 28px; }
.session-bar {
  position: sticky;
  top: 0;
  z-index: 5;
  padding: 10px 0;
  margin-bottom: 12px;
  background: rgb(238 241 247 / 94%);
  border-bottom: 2px solid var(--seal);
  backdrop-filter: blur(8px);
}
.session-bar p { margin: 0; font-weight: 700; }
.session-status {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 8px 14px;
}
.session-status #timerText { color: var(--wrong); }
.submit-session { padding: 7px 16px; font-size: .88rem; }
.option.selected {
  color: var(--seal);
  background: #dce6f8;
  border: 2px solid var(--seal);
}
.print-only { display: none; }
.question-card { margin-bottom: 14px; }
.question-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 8px; }
.tag {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 1px 8px;
  background: #e3e9f6;
  border-radius: 4px 10px 4px 10px;
  font-size: .78rem;
  font-weight: 700;
}
.tag.history { color: white; background: var(--history); }
.tag.geography { color: white; background: var(--geography); }
.tag.civics { color: white; background: var(--civics); }
.tag.integrated { color: white; background: var(--integrated); }
.group-material, .material {
  padding: 10px 12px;
  margin: 10px 0;
  overflow-x: auto;
  background: #eef2fb;
  border-left: 3px solid var(--seal);
  border-radius: 0 8px 8px 0;
}
.group-material h3 { margin: 0 0 6px; color: var(--accent); font-size: 1rem; }
.group-material p { margin: 0; }
.question-stem { margin-bottom: 10px; font-size: 1rem; font-weight: 700; }
.question-image, .group-image {
  display: block;
  max-height: 680px;
  margin: 12px auto;
  object-fit: contain;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.options { display: grid; gap: 8px; margin-top: 12px; }
.option {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 8px;
  width: 100%;
  min-height: 44px;
  padding: 11px 12px;
  color: var(--ink);
  text-align: left;
  background: #f4f6fc;
  border: 1px solid var(--line);
  border-radius: 10px;
  transition: transform .12s ease, box-shadow .12s ease;
}
.option:hover:not([disabled]) { transform: translateY(-1px); border-color: var(--accent); box-shadow: 0 2px 8px rgb(42 31 24 / 14%); }
.option.correct { color: var(--correct); background: #eef3e6; border-color: var(--correct); }
.option.wrong { color: var(--wrong); background: #f7e9e5; border-color: var(--wrong); }
.option[disabled] { cursor: default; opacity: 1; }
.feedback, .rubric {
  padding: 10px 12px;
  margin-top: 10px;
  background: #e8edf8;
  border-radius: 0 8px 8px 0;
}
.feedback.correct { border-left: 3px solid var(--correct); }
.feedback.wrong { border-left: 3px solid var(--wrong); }
.explanation { margin: 8px 0 0; color: var(--accent-2); font-size: .88rem; }
.official-stats { margin-top: 12px; }
.official-stats summary { color: var(--accent-2); cursor: pointer; font-weight: 700; }
.stat-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin-top: 8px; }
.stat-grid div { padding: 8px; background: #eef2fb; border-radius: 8px; }
.analysis-table, .material table { width: 100%; margin-top: 8px; border-collapse: collapse; }
.analysis-table th, .analysis-table td, .material th, .material td { padding: 6px; text-align: center; border: 1px solid #b8c2d8; }
.material caption { margin-bottom: 5px; text-align: left; font-weight: 700; }
.constructed-box textarea { min-height: 120px; resize: vertical; }
.rubric { white-space: pre-wrap; }
.source-warning { color: #8a4f00; font-size: .8rem; }

.site-footer {
  padding: 18px 16px 48px;
  color: var(--muted);
  text-align: center;
  font-size: .78rem;
}
.site-footer p { margin: 2px 0; }
.site-footer nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px 18px; margin-top: 8px; }

/* 內頁沿用同一套色彩，但保留簡潔標頭。 */
.site-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 2rem;
  padding: 32px max(24px, calc((100vw - 860px) / 2));
  color: #f4ecdc;
  background: var(--gradient);
  border-bottom: 4px solid var(--seal);
}
.site-header h1 { margin: 0; letter-spacing: .12em; }
.site-header p { margin: 4px 0 0; }
.site-header nav { display: flex; flex-wrap: wrap; gap: 16px; }
.site-header a { color: white; }
.eyebrow { margin: 0; color: #d7e1f7; font-size: .78rem; font-weight: 800; letter-spacing: .14em; }

@media (max-width: 600px) {
  .hero-header h1 { font-size: 1.25rem; letter-spacing: .1em; }
  .hero-image { max-height: 230px; }
  .page-wrap, main { width: min(100% - 20px, 860px); padding-top: 10px; }
  .intro-toggle { display: inline-flex; }
  .filter-grid { grid-template-columns: 1fr; }
  .button-row { gap: 8px; }
  .button-row .button { flex: 1 1 auto; padding: 10px 16px; font-size: .95rem; }
  .quick-button { padding: 14px 18px !important; font-size: 1.02rem !important; }
  .tool-row, .session-bar { align-items: flex-start; }
  .history-row { grid-template-columns: 7em 1fr; }
  .history-row strong { grid-column: 2; }
  .session-status { justify-content: flex-start; }
  .paper-question-list label { grid-template-columns: 22px 1fr; }
  .paper-question-list small { grid-column: 2; }
  .site-header { align-items: start; flex-direction: column; }
  .site-footer { padding-bottom: 92px; }
}

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

@media print {
  .no-print, .site-footer, .site-header, .hero-header, .session-bar { display: none !important; }
  body { color: black; background: white; }
  main { width: 100%; margin: 0; padding: 0; }
  .question-card { break-inside: avoid; border-radius: 0; box-shadow: none; }
  body.printing-paper > :not(main),
  body.printing-paper main > :not(#paperPrintArea) { display: none !important; }
  body.printing-paper #paperPrintArea { display: block !important; width: 100%; margin: 0; }
  .print-question {
    break-inside: avoid;
    padding: 0 0 14px;
    margin-bottom: 14px;
    border-bottom: 1px solid #999;
  }
  .print-question h3 { margin: 0 0 6px; font-size: 1rem; }
  .print-options { margin: 6px 0 0; padding-left: 24px; }
  .print-answer-key { break-before: page; }
}