:root {
  --primary: #4f46e5;
  --primary-dark: #3730a3;
  --bg: #f4f4fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --good: #16a34a;
  --bad: #dc2626;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  height: 100%;
  overscroll-behavior-y: none;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
  -webkit-user-select: none;
  user-select: none;
}

input, textarea {
  -webkit-user-select: text;
  user-select: text;
}

button, a { touch-action: manipulation; }

#app {
  max-width: 480px;
  margin: 0 auto;
  height: 100dvh;
  height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  position: relative;
}

.topbar {
  flex: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: calc(env(safe-area-inset-top) + 14px) 16px 14px;
  background: var(--bg);
  border-bottom: 1px solid rgba(0,0,0,0.04);
  z-index: 5;
}
.topbar-actions { display: flex; gap: 2px; }

.app-content {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-y: contain;
  padding: 16px 16px calc(env(safe-area-inset-bottom) + 16px);
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.bottom-nav {
  flex: none;
  display: flex;
  background: var(--card);
  border-top: 1px solid #e5e7eb;
  padding: 6px 8px calc(env(safe-area-inset-bottom) + 6px);
  z-index: 5;
}
.nav-tab {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  border: none;
  background: none;
  padding: 8px 4px;
  border-radius: 12px;
  color: var(--muted);
  cursor: pointer;
}
.nav-tab .nav-icon { font-size: 22px; line-height: 1; }
.nav-tab .nav-label { font-size: 11px; font-weight: 600; }
.nav-tab.active { color: var(--primary); }
.nav-tab.active .nav-icon { transform: scale(1.08); }
.nav-tab:active { background: #f3f4f6; }

#practiceMode, #chatMode {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.topic-card {
  background: var(--card);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}
.topic-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 10px;
}
.topic-btn {
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  background: #fafafa;
  padding: 12px 8px;
  font-size: 14px;
  cursor: pointer;
  text-align: center;
  line-height: 1.4;
}
.topic-btn:active { background: #eef2ff; border-color: var(--primary); }
.topic-btn .topic-vi { display: block; font-size: 12px; color: var(--muted); }

.chat-panel {
  background: var(--card);
  border-radius: 16px;
  padding: 12px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.chat-topic-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
}
.link-btn {
  background: none;
  border: none;
  color: var(--primary);
  font-size: 13px;
  cursor: pointer;
  padding: 4px;
}
.chat-log {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 55vh;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 4px 2px;
  -webkit-overflow-scrolling: touch;
}
.chat-msg {
  max-width: 85%;
  padding: 9px 12px;
  border-radius: 14px;
  font-size: 14px;
  line-height: 1.5;
  white-space: pre-wrap;
  word-break: break-word;
}
.chat-msg.user {
  align-self: flex-end;
  background: var(--primary);
  color: #fff;
  border-bottom-right-radius: 4px;
}
.chat-msg.teacher {
  align-self: flex-start;
  background: #f3f4f6;
  color: var(--text);
  border-bottom-left-radius: 4px;
}
.chat-msg.typing { color: var(--muted); font-style: italic; }

.chat-msg-wrap {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
  max-width: 90%;
}
.chat-translation {
  font-size: 12.5px;
  color: var(--muted);
  padding: 0 4px;
  line-height: 1.4;
}
.suggestion-chip {
  display: block;
  text-align: left;
  background: #eef2ff;
  border: 1px dashed #c7d2fe;
  border-radius: 12px;
  padding: 8px 10px;
  font-size: 13px;
  color: var(--primary-dark);
  cursor: pointer;
  max-width: 100%;
}
.suggestion-chip b { color: var(--primary); }
.suggestion-chip .suggestion-vi { display: block; color: var(--muted); font-size: 12px; margin-top: 2px; }
.suggestion-chip:active { background: #e0e7ff; }
.chat-input-row {
  display: flex;
  gap: 8px;
  align-items: center;
}
.chat-input-row input {
  flex: 1;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid #d1d5db;
  font-size: 16px;
  min-width: 0;
  -webkit-user-select: text;
  user-select: text;
}
.chat-mic-btn {
  width: 56px;
  height: 56px;
  flex: none;
  border-radius: 50%;
  border: none;
  background: var(--primary);
  color: #fff;
  font-size: 24px;
  cursor: pointer;
  box-shadow: 0 3px 10px rgba(79,70,229,0.35);
  transition: transform 0.15s, background 0.15s;
}
.chat-mic-btn.recording {
  background: var(--bad);
  transform: scale(1.08);
  box-shadow: 0 0 0 7px rgba(220,38,38,0.15);
  animation: chat-mic-pulse 1.2s ease-in-out infinite;
}
@keyframes chat-mic-pulse {
  0%, 100% { box-shadow: 0 0 0 6px rgba(220,38,38,0.15); }
  50% { box-shadow: 0 0 0 12px rgba(220,38,38,0.08); }
}
.chat-mic-hint {
  font-size: 12px;
  color: var(--muted);
  text-align: center;
}
.chat-send-btn { flex: none; width: auto; padding: 10px 16px; font-size: 13px; }

.stats-card {
  background: var(--card);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}
.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.stat-box {
  background: #f8f8fd;
  border-radius: 14px;
  padding: 14px 10px;
  text-align: center;
}
.stat-value { font-size: 26px; font-weight: 700; color: var(--primary); }
.stat-label { font-size: 12px; color: var(--muted); margin-top: 2px; }

.notebook-card {
  background: var(--card);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}
.idiom-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 10px;
}
.idiom-card {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 12px;
  padding: 12px;
}
.idiom-phrase { font-weight: 700; font-size: 15px; color: #92400e; }
.idiom-meaning { font-size: 14px; margin-top: 4px; }
.idiom-example { font-size: 13px; color: var(--muted); margin-top: 4px; font-style: italic; }
.idiom-topic {
  display: inline-block;
  margin-top: 6px;
  font-size: 11px;
  color: var(--primary);
  background: #eef2ff;
  padding: 2px 8px;
  border-radius: 999px;
}
.idiom-empty { text-align: center; color: var(--muted); font-size: 14px; padding: 20px 0; }

/* Word drill */
.word-drill-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.word-drill-chip {
  display: flex;
  align-items: center;
  gap: 6px;
  background: #fee2e2;
  color: #991b1b;
  border: none;
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 13px;
  cursor: pointer;
}
.word-drill-chip .miss-count {
  background: #991b1b;
  color: #fff;
  border-radius: 999px;
  font-size: 10px;
  padding: 1px 6px;
}

/* Banners */
.banner {
  display: flex;
  align-items: center;
  gap: 8px;
  border-radius: 14px;
  padding: 10px 12px;
  font-size: 13px;
}
.reminder-banner { background: #fff7ed; color: #9a3412; border: 1px solid #fed7aa; }
.quote-banner { background: #eef2ff; color: #3730a3; border: 1px solid #c7d2fe; }
.quote-text { flex: 1; line-height: 1.4; }
.banner-close, .banner-icon-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 14px;
  color: inherit;
  padding: 2px 4px;
  flex: none;
}
#reminderBanner { justify-content: space-between; }
#reminderText { flex: 1; }

/* Shadowing toggle */
.sentence-label-row { display: flex; align-items: center; justify-content: space-between; }
.shadow-toggle {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  color: var(--muted);
  cursor: pointer;
}
.shadow-toggle input { accent-color: var(--primary); }
.shadow-hint {
  font-size: 12px;
  color: var(--primary);
  background: #eef2ff;
  border-radius: 10px;
  padding: 8px 10px;
  margin: -6px 0 12px;
}

/* Custom topic input */
.custom-topic-row { display: flex; gap: 8px; margin-top: 10px; }
.custom-topic-row input {
  flex: 1;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid #d1d5db;
  font-size: 16px;
  min-width: 0;
}
.chat-topic-actions { display: flex; gap: 4px; }

/* Roadmap */
.roadmap-card, .roadmap-session {
  background: var(--card);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  margin-top: 12px;
}
.roadmap-day-btn {
  aspect-ratio: 1;
  border: none;
  border-radius: 10px;
  background: #f3f4f6;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}
.roadmap-day-btn.unlocked { background: #eef2ff; color: var(--primary); }
.roadmap-day-btn.completed { background: var(--primary); color: #fff; }
.roadmap-day-btn.locked { cursor: not-allowed; opacity: 0.6; }

.dictation-progress { font-size: 13px; color: var(--muted); margin: 10px 0; text-align: center; }
.dictation-card { display: flex; flex-direction: column; gap: 10px; }
.dictation-card input {
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid #d1d5db;
  font-size: 16px;
}
.dictation-feedback {
  margin-top: 12px;
  background: #f8f8fd;
  border-radius: 12px;
  padding: 10px 12px;
  font-size: 14px;
}
.dictation-feedback .df-score { font-weight: 700; }
.dictation-day-result {
  margin-top: 12px;
  text-align: center;
  background: #eef2ff;
  border-radius: 12px;
  padding: 14px;
  font-size: 14px;
}

/* Backup + account */
.backup-row { display: flex; gap: 10px; }
#accountArea .btn { margin-bottom: 8px; width: 100%; flex: none; }
#accountStatus { margin-top: 4px; }
.topbar h1 { font-size: 20px; margin: 0; }

.icon-btn {
  background: none;
  border: none;
  font-size: 22px;
  cursor: pointer;
  padding: 6px;
}

.avatar-wrap {
  position: relative;
  background: var(--card);
  border-radius: 20px;
  height: 260px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
  overflow: hidden;
}

.avatar-face { width: 200px; height: 200px; }
#avatar3d { width: 100%; height: 100%; }
.hidden { display: none !important; }

.status-badge {
  position: absolute;
  bottom: 10px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,0.55);
  color: #fff;
  font-size: 12px;
  padding: 4px 12px;
  border-radius: 999px;
}

.sentence-card, .record-card, .result-card, .model-load-card {
  background: var(--card);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.06);
}

.sentence-label { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: .04em; }
.target-sentence { font-size: 22px; font-weight: 600; margin: 8px 0 14px; line-height: 1.4; }

.sentence-actions { display: flex; gap: 10px; }

.btn {
  flex: 1;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 12px;
  padding: 12px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
}
.btn:active { background: var(--primary-dark); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-secondary { background: #e5e7eb; color: var(--text); }
.btn-secondary:active { background: #d1d5db; }

.record-card { display: flex; flex-direction: column; align-items: center; gap: 10px; }

.mic-btn {
  width: 84px;
  height: 84px;
  border-radius: 50%;
  border: none;
  background: var(--primary);
  color: #fff;
  font-size: 34px;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(79,70,229,0.4);
  transition: transform 0.15s, background 0.15s;
}
.mic-btn.recording {
  background: var(--bad);
  transform: scale(1.08);
  box-shadow: 0 0 0 8px rgba(220,38,38,0.15);
}
.mic-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.mic-hint { font-size: 13px; color: var(--muted); }

.result-row { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 8px; gap: 10px; }
.heard-text { font-weight: 600; text-align: right; }
.score-text { font-weight: 700; font-size: 18px; }
.score-good { color: var(--good); }
.score-bad { color: var(--bad); }

.word-diff { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.word-diff span {
  padding: 3px 8px;
  border-radius: 8px;
  font-size: 14px;
}
.word-ok { background: #dcfce7; color: #166534; }
.word-miss { background: #fee2e2; color: #991b1b; }

.model-load-card { text-align: center; font-size: 13px; color: var(--muted); }
.progress-bar { height: 6px; background: #e5e7eb; border-radius: 4px; margin-top: 8px; overflow: hidden; }
.progress-fill { height: 100%; width: 0%; background: var(--primary); transition: width 0.2s; }

.modal {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  z-index: 50;
}
.modal-content {
  background: #fff;
  border-radius: 20px 20px 0 0;
  padding: 20px;
  width: 100%;
  max-width: 480px;
}
.modal-content h2 { margin-top: 0; }
.modal-content { max-height: 85dvh; overflow-y: auto; padding-bottom: calc(env(safe-area-inset-bottom) + 20px); }
.field-label { display: block; font-size: 13px; color: var(--muted); margin: 14px 0 6px; }
.modal-content input[type="text"],
.modal-content input[type="password"],
.modal-content select {
  width: 100%;
  padding: 10px;
  border-radius: 10px;
  border: 1px solid #d1d5db;
  font-size: 16px;
  -webkit-user-select: text;
  user-select: text;
  background: #fff;
}
.modal-content input[type="range"] { width: 100%; }
.hint-text { font-size: 12px; color: var(--muted); }
.modal-actions { display: flex; gap: 10px; margin-top: 16px; }