:root {
  --bg: #10192b;
  --panel: #1a2a44;
  --panel-soft: #14253a;
  --accent: #3ee6d1;
  --accent-warm: #ffb648;
  --text: #eef3fc;
  --text-dim: #93a8c4;
  --locked: #3a4658;
  --locked-fg: #6b7a91;
  --correct: #3ecf8e;
  --wrong: #ff6b6b;

  --strand-number: #3ee6d1;
  --strand-algebra: #7c9cff;
  --strand-geometry: #ffb648;
  --strand-pattern: #ff8fb1;
  --strand-data: #a8e05f;

  --font-sans: "PingFang TC", "Microsoft JhengHei", sans-serif;
  --font-mono-num: "SF Mono", "Roboto Mono", ui-monospace, monospace;

  --fs-title: 1.75rem;
  --fs-node: 1rem;
  --fs-stem: 1.25rem;
  --fs-option: 1rem;
  --fs-caption: 0.8125rem;
  --lh-body: 1.5;

  --radius-card: 16px;
  --radius-badge: 999px;
  --shadow-glow: 0 8px 20px -4px rgba(62, 230, 209, 0.3);

  font-family: var(--font-sans);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: var(--lh-body);
}

/* ---------- 版面骨架 ---------- */

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: var(--panel);
  border-bottom: 1px solid var(--locked);
}

.topbar h1 { margin: 0; font-size: var(--fs-title); color: var(--accent); }
.topbar nav button {
  margin-left: 8px;
  min-height: 44px;
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
}
.topbar nav button:hover { background: var(--accent); color: var(--bg); }

main { padding: 24px; max-width: 960px; margin: 0 auto; }

.view { display: none; }
.view.active { display: block; }

@media (max-width: 600px) {
  main { padding: 12px; }
  .topbar { padding: 12px; }
  .topbar h1 { font-size: 1.3rem; }
}

/* ---------- 技能樹：路徑地圖 ---------- */

.strand { margin-bottom: 32px; }
.strand-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-left: 10px;
  border-left: 4px solid var(--strand-color, var(--accent-warm));
  margin-bottom: 10px;
}
.strand-name { color: var(--strand-color, var(--accent-warm)); font-weight: bold; }
.strand-soon-banner {
  border-radius: var(--radius-card);
  border: 1px dashed var(--strand-color, var(--locked));
  background: var(--panel-soft);
  padding: 16px;
  color: var(--text-dim);
}
.strand-soon-banner .soon-title { color: var(--strand-color, var(--text-dim)); font-weight: bold; margin-bottom: 4px; }
.strand-soon-banner .soon-tip { font-size: var(--fs-caption); margin-top: 6px; opacity: 0.85; }

.skill-map { position: relative; }
.skill-map svg { width: 100%; display: block; overflow: visible; }

.map-path { fill: none; stroke: var(--locked); stroke-width: 1.5; stroke-dasharray: 4 4; opacity: 0.6; }
.map-path.path-active { stroke: var(--strand-color, var(--accent)); stroke-width: 3; stroke-dasharray: none; opacity: 1; }

.map-node { cursor: pointer; }
.map-node circle.node-ring-bg { fill: none; stroke: var(--locked); stroke-width: 3; opacity: 0.4; }
.map-node circle.node-ring-progress {
  fill: none;
  stroke: var(--strand-color, var(--accent));
  stroke-width: 3;
  stroke-linecap: round;
  transform: rotate(-90deg);
  transform-origin: center;
  transition: stroke-dashoffset 0.4s ease;
}
.map-node circle.node-body { fill: var(--panel); stroke: var(--locked); stroke-width: 2; }
.map-node.state-unlocked circle.node-body { stroke: var(--strand-color, var(--accent)); filter: drop-shadow(0 0 6px var(--strand-color, var(--accent))); }
.map-node.state-unlocked.is-frontier circle.node-body { animation: pulse-ring 1.8s infinite; }
.map-node.state-locked { opacity: 0.55; cursor: not-allowed; }
.map-node.state-mastered circle.node-body { fill: var(--panel-soft); stroke: gold; stroke-width: 3; }
.map-node .node-star { fill: gold; font-size: 12px; }
.map-node .node-label { fill: var(--text); font-size: 12px; text-anchor: middle; }
.map-node .node-lock-icon { fill: var(--locked-fg); font-size: 14px; text-anchor: middle; }

.map-mascot {
  position: absolute;
  width: 84px;
  height: 84px;
  transform: translate(-50%, -125%);
  pointer-events: none;
  animation: float 2.4s ease-in-out infinite;
}
.map-mascot img { width: 100%; height: 100%; object-fit: contain; }

.node-suggested-tip {
  position: absolute;
  background: var(--accent);
  color: var(--bg);
  font-size: var(--fs-caption);
  font-weight: bold;
  padding: 4px 10px;
  border-radius: var(--radius-badge);
  white-space: nowrap;
  transform: translate(-50%, -420%);
  pointer-events: none;
}

.lock-reason { font-size: var(--fs-caption); color: var(--locked-fg); margin-top: 4px; max-width: 130px; text-align: center; }

@keyframes pulse-ring {
  0%, 100% { filter: drop-shadow(0 0 4px var(--strand-color, var(--accent))); }
  50% { filter: drop-shadow(0 0 12px var(--strand-color, var(--accent))); }
}
@keyframes float {
  0%, 100% { margin-top: 0; }
  50% { margin-top: -6px; }
}

/* ---------- 首次使用教學貼紙 ---------- */

.tip-bubble {
  position: fixed;
  bottom: 24px;
  right: 24px;
  max-width: 260px;
  background: var(--panel);
  border: 2px solid var(--accent);
  border-radius: var(--radius-card);
  padding: 14px 16px;
  box-shadow: var(--shadow-glow);
  z-index: 50;
}
.tip-bubble button {
  margin-top: 8px;
  background: var(--accent);
  border: none;
  color: var(--bg);
  padding: 6px 12px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: bold;
}

/* ---------- 測驗畫面 ---------- */

.quiz-progressbar {
  display: flex;
  gap: 4px;
  margin-bottom: 16px;
}
.quiz-progressbar .seg {
  flex: 1;
  height: 6px;
  border-radius: 3px;
  background: var(--locked);
  overflow: hidden;
}
.quiz-progressbar .seg.filled { background: var(--accent); animation: segment-fill 0.3s; }

.streak-badge {
  display: inline-block;
  background: var(--accent-warm);
  color: var(--bg);
  font-weight: bold;
  padding: 2px 10px;
  border-radius: var(--radius-badge);
  margin-left: 8px;
  animation: badge-pop 0.3s;
}

.q-card {
  background: var(--panel);
  border-radius: var(--radius-card);
  padding: 20px;
  margin-bottom: 16px;
  border-left: 4px solid var(--locked);
  transition: box-shadow 0.3s;
}
.q-card.type-basic-mastery { border-left-color: var(--strand-color, var(--accent)); }
.q-card.type-concept-id { background: var(--panel-soft); }
.q-card.type-error-diagnosis { border-left-color: var(--wrong); }
.q-card.type-context-application { border-left-color: var(--accent-warm); }
.q-card.streak-active { animation: streak-glow 1.5s infinite alternate; }

.q-type { color: var(--accent-warm); font-size: var(--fs-caption); margin-bottom: 8px; font-weight: bold; }
.q-stem { font-size: var(--fs-stem); margin-bottom: 14px; }
.q-scenario {
  color: var(--text-dim);
  margin-bottom: 8px;
  background: var(--panel-soft);
  border-radius: 10px;
  padding: 10px 12px;
}
.q-wrong-solution {
  background: #2a1f1f;
  border: 1px dashed var(--wrong);
  border-radius: 8px;
  font-family: var(--font-mono-num);
  padding: 10px 12px;
  margin-bottom: 14px;
}
.q-wrong-solution::before { content: "⚠ 病歷："; color: var(--wrong); font-family: var(--font-sans); font-weight: bold; }

.q-options { display: flex; flex-direction: column; gap: 8px; }
.type-concept-id .q-options { flex-direction: row; }
.type-concept-id .q-option { flex: 1; text-align: center; font-weight: bold; }

.q-option {
  min-height: 44px;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--locked);
  background: #1d2c44;
  color: var(--text);
  cursor: pointer;
  text-align: left;
  font-size: var(--fs-option);
}
.q-option:hover:not(:disabled) { border-color: var(--accent); }
.q-option:disabled { cursor: default; }
.q-correct { border-color: var(--correct) !important; background: #16352a !important; animation: pulse-glow 0.5s ease-out; }
.q-correct::before { content: "✓ "; color: var(--correct); font-weight: bold; }
.q-wrong { border-color: var(--wrong) !important; background: #3a1f1f !important; animation: shake-x 0.3s; }
.q-wrong::before { content: "✕ "; color: var(--wrong); font-weight: bold; }

.q-explain { margin-top: 14px; padding-top: 10px; border-top: 1px dashed var(--locked); color: var(--text-dim); }

.q-mascot-react {
  position: absolute;
  width: 48px;
  height: 48px;
  top: 12px;
  right: 12px;
}
.q-mascot-react img { width: 100%; height: 100%; object-fit: contain; }
.q-mascot-react.react-happy img { animation: mascot-cheer 0.4s; }
.q-mascot-react.react-sad img { animation: mascot-sad 0.4s; }

.q-next {
  min-height: 44px;
  margin-top: 10px;
  padding: 10px 18px;
  border-radius: 10px;
  border: none;
  background: var(--accent);
  color: var(--bg);
  cursor: pointer;
  font-weight: bold;
}

@keyframes pulse-glow {
  0% { box-shadow: 0 0 0 rgba(62, 207, 142, 0); }
  50% { box-shadow: 0 0 20px var(--correct); }
  100% { box-shadow: 0 0 0 rgba(62, 207, 142, 0); }
}
@keyframes shake-x {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}
@keyframes mascot-cheer {
  0% { transform: scale(1) rotate(0); }
  50% { transform: scale(1.15) rotate(-5deg); }
  100% { transform: scale(1) rotate(0); }
}
@keyframes mascot-sad {
  0% { transform: scale(1) rotate(0); }
  100% { transform: scale(0.95) rotate(3deg); }
}
@keyframes streak-glow {
  from { box-shadow: 0 0 6px var(--accent-warm); }
  to { box-shadow: 0 0 16px var(--accent-warm); }
}
@keyframes badge-pop {
  0% { transform: scale(1.3); }
  100% { transform: scale(1); }
}
@keyframes segment-fill {
  0% { transform: scaleY(1); }
  50% { transform: scaleY(1.6); }
  100% { transform: scaleY(1); }
}

/* ---------- 過關總結儀式 ---------- */

.q-summary {
  background: var(--panel);
  border-radius: var(--radius-card);
  padding: 24px;
  margin-bottom: 16px;
  text-align: center;
}
.summary-mascot { width: 96px; height: 96px; margin: 0 auto 12px; animation: mascot-victory-bounce 0.6s; }
.summary-mascot img { width: 100%; height: 100%; object-fit: contain; }
.summary-stars { margin: 10px 0; font-size: 1.8rem; }
.summary-stars .star { opacity: 0.25; display: inline-block; }
.summary-stars .star.lit { opacity: 1; animation: star-pop 0.3s; }
.summary-reports { display: flex; gap: 10px; justify-content: center; margin-top: 14px; flex-wrap: wrap; }
.summary-reports .report-tile {
  background: var(--panel-soft);
  border-radius: 10px;
  padding: 10px 16px;
  min-width: 100px;
}
.badge-unlock { margin-top: 14px; color: var(--accent-warm); font-weight: bold; animation: badge-reveal 0.4s; }

@keyframes mascot-victory-bounce {
  0% { transform: translateY(-20px); opacity: 0; }
  60% { transform: translateY(4px); opacity: 1; }
  100% { transform: translateY(0); }
}
@keyframes star-pop {
  0% { transform: scale(0); }
  70% { transform: scale(1.3); }
  100% { transform: scale(1); }
}
@keyframes badge-reveal {
  0% { transform: scale(0.7); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

/* ---------- 儀表板 ---------- */

.dash-summary, .dash-badges, .dash-errorbook, .dash-leaderboard {
  background: var(--panel);
  border-radius: var(--radius-card);
  padding: 18px;
  margin-bottom: 16px;
}
.badge-row { padding: 6px 0; color: var(--text-dim); }
.badge-row.got { color: var(--accent-warm); }
.errorbook-row, .leaderboard-row { padding: 6px 0; border-bottom: 1px solid var(--locked); }

.dash-name { display: flex; align-items: center; gap: 10px; }
.dash-name input {
  min-height: 44px;
  background: #1d2c44;
  border: 1px solid var(--locked);
  border-radius: 8px;
  color: var(--text);
  padding: 8px 10px;
}

@media (max-width: 600px) {
  .summary-reports { flex-direction: column; }
}