:root {
  --bg: #faf6f0;
  --card: #ffffff;
  --ink: #2b2420;
  --muted: #8a7f74;
  --accent: #d96b3a;
  --accent-soft: #f3d9c8;
  --correct: #4c9a6a;
  --wrong: #cf5252;
  --border: #ece2d6;
  font-family: -apple-system, "PingFang SC", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

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

.app-header {
  padding: 20px 24px 12px;
  text-align: center;
  position: relative;
}
.app-header h1 { margin: 0; font-size: 1.6rem; }
.tagline { margin: 4px 0 0; color: var(--muted); font-size: 0.9rem; }

.ghost-btn, .primary-btn {
  border-radius: 999px;
  padding: 8px 16px;
  font-size: 0.85rem;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--ink);
}
.ghost-btn { position: absolute; right: 20px; top: 20px; }
.ghost-btn:hover { border-color: var(--accent); color: var(--accent); }

.primary-btn {
  background: var(--accent);
  color: white;
  border: none;
  font-size: 1rem;
  padding: 10px 24px;
}
.primary-btn:hover { opacity: 0.9; }

.layout {
  display: flex;
  gap: 20px;
  max-width: 920px;
  margin: 10px auto 40px;
  padding: 0 20px;
  align-items: flex-start;
  flex-wrap: wrap;
}

.scene-panel {
  flex: 2;
  min-width: 320px;
  background: var(--card);
  border-radius: 18px;
  border: 1px solid var(--border);
  padding: 24px;
}

.scene-progress {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 16px;
}
.scene-progress .dot {
  flex: 1;
  height: 5px;
  border-radius: 999px;
  background: var(--border);
  transition: background 0.3s ease;
}
.scene-progress .dot.done { background: var(--correct); }
.scene-progress .dot.active { background: var(--accent); }

.scene-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 18px;
}
.avatar {
  font-size: 2.4rem;
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-soft);
  border-radius: 50%;
}
.scene-head h2 { margin: 0; font-size: 1.15rem; }
.scene-subtitle { margin: 2px 0 0; color: var(--muted); font-size: 0.85rem; }

.dialogue-bubble {
  background: #fdf8f3;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  margin-bottom: 20px;
}
.npc-en-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}
.npc-en { margin: 0; font-size: 1.15rem; font-weight: 600; }
.npc-zh { margin: 0; color: var(--muted); font-size: 0.9rem; }

.audio-btn {
  flex: none;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1.5px solid var(--border);
  background: var(--card);
  font-size: 0.95rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 0.15s, transform 0.15s;
}
.audio-btn:hover { border-color: var(--accent); }
.audio-btn:active { transform: scale(0.92); }
.audio-btn.playing { border-color: var(--accent); color: var(--accent); }

.choices {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.choice-btn {
  text-align: left;
  padding: 13px 16px;
  border-radius: 12px;
  border: 1.5px solid var(--border);
  background: var(--card);
  font-size: 1rem;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}
.choice-btn:hover:not(:disabled) {
  border-color: var(--accent);
  background: var(--accent-soft);
}
.choice-btn:disabled { cursor: default; opacity: 0.6; }
.choice-btn.wrong {
  border-color: var(--wrong);
  background: #fbe9e9;
  opacity: 1;
}
.choice-btn.correct {
  border-color: var(--correct);
  background: #e6f4ea;
  opacity: 1;
}
.choice-btn.shake {
  animation: shake 0.35s ease;
}
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(5px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(3px); }
}

.xp-float {
  position: fixed;
  font-weight: 700;
  color: var(--correct);
  font-size: 1rem;
  pointer-events: none;
  animation: xp-rise 0.9s ease-out forwards;
  z-index: 50;
}
@keyframes xp-rise {
  0% { transform: translateY(0); opacity: 0; }
  15% { opacity: 1; }
  100% { transform: translateY(-40px); opacity: 0; }
}

.hint {
  min-height: 1.2em;
  margin-top: 14px;
  color: var(--wrong);
  font-size: 0.88rem;
  opacity: 0;
  transition: opacity 0.2s;
}
.hint.visible { opacity: 1; }

.sidebar {
  flex: 1;
  min-width: 240px;
  background: var(--card);
  border-radius: 18px;
  border: 1px solid var(--border);
  padding: 22px;
}
.sidebar h3 { margin: 0 0 14px; font-size: 1rem; }

.skill-row {
  margin-bottom: 14px;
}
.skill-label { font-size: 0.88rem; margin-bottom: 5px; }
.skill-bar {
  background: var(--border);
  border-radius: 999px;
  height: 8px;
  overflow: hidden;
}
.skill-bar-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 999px;
  transition: width 0.3s ease;
}
.skill-xp { font-size: 0.75rem; color: var(--muted); margin-top: 3px; text-align: right; }

.stat-row {
  display: flex;
  justify-content: space-between;
  font-size: 0.88rem;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  margin-top: 10px;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(43, 36, 32, 0.5);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.overlay.visible { display: flex; }

.flashback-card {
  background: var(--card);
  border-radius: 18px;
  padding: 28px;
  max-width: 380px;
  width: 100%;
  text-align: center;
}
.flashback-label { color: var(--muted); font-size: 0.85rem; margin: 0 0 6px; }
.flashback-zh { font-size: 1.4rem; font-weight: 700; margin: 0 0 18px; }
.flashback-feedback { min-height: 1.4em; margin-top: 14px; font-size: 0.9rem; }

.end-screen {
  max-width: 480px;
  margin: 60px auto;
  text-align: center;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 40px 30px;
}
.end-screen h2 { margin-top: 0; }
#end-summary p { margin: 8px 0; color: var(--ink); }

.hidden { display: none; }

@media (max-width: 640px) {
  .layout { flex-direction: column; }
  .ghost-btn { position: static; display: inline-block; margin-top: 10px; }
}