:root {
  --bg: #f8f9fa;
  --surface: #ffffff;
  --surface-2: #f1f3f5;
  --text: #1a1d21;
  --text-secondary: #5a6470;
  --text-tertiary: #8a95a1;
  --accent: #2563eb;
  --accent-light: #3b82f6;
  --accent-dark: #1d4ed8;
  --danger: #ef4444;
  --success: #10b981;
  --warning: #f59e0b;
  --border: #e2e8f0;
  --shadow: 0 4px 16px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.1);
  --radius: 16px;
  --radius-sm: 10px;
  --transition: 0.2s ease;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --surface: #1e293b;
  --surface-2: #162032;
  --text: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-tertiary: #64748b;
  --accent: #3b82f6;
  --accent-light: #60a5fa;
  --accent-dark: #2563eb;
  --border: #334155;
  --shadow: 0 4px 16px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.4);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
}

/* Utility */
.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 20px;
}

.hidden { display: none !important; }

.text-center { text-align: center; }
.text-secondary { color: var(--text-secondary); }
.text-tertiary { color: var(--text-tertiary); }

.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), opacity var(--transition);
  background: var(--accent);
  color: #fff;
  white-space: nowrap;
  flex-shrink: 0;
  box-sizing: border-box;
}

.btn:hover {
  opacity: 0.92;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(37,99,235,0.25);
}

.btn:active { transform: translateY(0); }

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1.5px solid var(--border);
}

.btn-ghost:hover { background: var(--surface-2); box-shadow: none; }

.btn-danger { background: var(--danger); }
.btn-success { background: var(--success); }

.card {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px;
  transition: background var(--transition), box-shadow var(--transition);
  overflow-wrap: break-word;
  word-wrap: break-word;
  min-width: 0;
}

.card + .card { margin-top: 20px; }

input[type="text"],
textarea {
  width: 100%;
  padding: 14px 16px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  line-height: 1.5;
  resize: vertical;
  transition: border-color var(--transition), box-shadow var(--transition);
}

input[type="text"]:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
}

select {
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-size: 0.95rem;
  cursor: pointer;
}

/* Header */
.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(var(--surface), 0.7);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}

[data-theme="dark"] .app-header {
  background: rgba(30, 41, 59, 0.7);
}

.app-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  padding-bottom: 14px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.2rem;
  letter-spacing: -0.4px;
  color: var(--text);
  text-decoration: none;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent), var(--accent-light));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  border: 1.5px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: background var(--transition), color var(--transition);
}

.theme-toggle:hover {
  background: var(--surface-2);
  color: var(--accent);
}

/* Dashboard */
.dashboard-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 14px;
  margin-bottom: 28px;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 18px 14px;
  text-align: center;
  transition: background var(--transition), border-color var(--transition);
}

.stat-value {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-top: 6px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

.section-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Category Grid */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 12px;
  margin-bottom: 28px;
}

.category-card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 18px 14px;
  cursor: pointer;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
  text-align: center;
}

.category-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.category-card.selected {
  border-color: var(--accent);
  background: rgba(37,99,235,0.06);
}

.category-card .cat-emoji {
  font-size: 1.6rem;
  margin-bottom: 8px;
}

.category-card .cat-name {
  font-weight: 700;
  font-size: 0.88rem;
  color: var(--text);
  line-height: 1.3;
}

.category-card .cat-count {
  font-size: 0.78rem;
  color: var(--text-tertiary);
  margin-top: 4px;
}

/* Difficulty selector */
.difficulty-row {
  display: flex;
  gap: 8px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.diff-btn {
  padding: 8px 16px;
  border: 1.5px solid var(--border);
  border-radius: 20px;
  background: var(--surface);
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}

.diff-btn:hover { border-color: var(--accent); color: var(--accent); }
.diff-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* Simulator */
.sim-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.sim-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.badge-easy { background: rgba(16,185,129,0.12); color: var(--success); }
.badge-medium { background: rgba(245,158,11,0.12); color: var(--warning); }
.badge-hard { background: rgba(239,68,68,0.12); color: var(--danger); }

.timer-display {
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  font-size: 1.3rem;
  color: var(--accent);
  transition: color var(--transition);
}

.timer-display.warning { color: var(--warning); }
.timer-display.danger { color: var(--danger); }

.objection-box {
  background: var(--surface-2);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 22px 20px;
  font-size: 1.35rem;
  font-weight: 600;
  line-height: 1.45;
  margin-bottom: 20px;
  color: var(--text);
  transition: background var(--transition);
}

.response-area {
  margin-bottom: 16px;
}

.response-area textarea {
  min-height: 160px;
  font-size: 1.05rem;
}

/* Voice typing bar */
.voice-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
  flex-wrap: wrap;
}

.voice-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1.5px solid var(--border);
  border-radius: 24px;
  background: var(--surface);
  color: var(--text-secondary);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  user-select: none;
  -webkit-user-select: none;
}

.voice-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(37,99,235,0.05);
}

.voice-btn.listening {
  background: var(--danger);
  color: #fff;
  border-color: var(--danger);
  animation: pulse-ring 1.2s infinite;
}

.voice-btn.listening:hover {
  background: #dc2626;
  color: #fff;
}

.voice-icon {
  font-size: 1.2rem;
  line-height: 1;
}

.voice-label {
  font-size: 0.88rem;
}

.voice-status {
  font-size: 0.84rem;
  color: var(--text-tertiary);
  font-weight: 500;
  line-height: 1.3;
}

@keyframes pulse-ring {
  0% { box-shadow: 0 0 0 0 rgba(239,68,68,0.4); }
  70% { box-shadow: 0 0 0 10px rgba(239,68,68,0); }
  100% { box-shadow: 0 0 0 0 rgba(239,68,68,0); }
}

.sim-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
}

/* Feedback */
.score-circle-wrap {
  display: flex;
  align-items: center;
  gap: 22px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.score-ring {
  position: relative;
  width: 130px;
  height: 130px;
  flex-shrink: 0;
}

.score-ring svg {
  transform: rotate(-90deg);
  width: 100%;
  height: 100%;
}

.score-ring-bg { fill: none; stroke: var(--border); stroke-width: 8; }
.score-ring-fill {
  fill: none;
  stroke: var(--accent);
  stroke-width: 8;
  stroke-linecap: round;
  transition: stroke-dasharray 1s ease;
}

.score-text {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.score-number {
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--accent);
  line-height: 1;
}

.score-label-text {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

.score-breakdown {
  flex: 1;
  min-width: 220px;
}

.breakdown-item {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.breakdown-item span { font-size: 0.88rem; color: var(--text-secondary); min-width: 110px; }

.breakdown-bar {
  flex: 1;
  height: 10px;
  background: var(--surface-2);
  border-radius: 5px;
  overflow: hidden;
}

.breakdown-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-light));
  border-radius: 5px;
  transition: width 0.8s ease;
}

.stars {
  display: flex;
  gap: 4px;
  font-size: 1.4rem;
  margin-bottom: 14px;
}

.star { color: #e2e8f0; transition: color var(--transition); }
[data-theme="dark"] .star { color: #334155; }
.star.filled { color: #fbbf24; }

.feedback-panel {
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 18px;
  margin-bottom: 18px;
}

.feedback-title {
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.feedback-list {
  list-style: none;
}

.feedback-list li {
  padding: 6px 0;
  font-size: 0.92rem;
  color: var(--text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.feedback-list li::before {
  content: attr(data-icon);
  flex-shrink: 0;
  font-size: 1rem;
}

.model-answer {
  background: rgba(37,99,235,0.05);
  border: 1px solid rgba(37,99,235,0.18);
  border-radius: var(--radius-sm);
  padding: 18px;
  margin-bottom: 18px;
}

.model-answer-title {
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--accent);
  margin-bottom: 8px;
}

.model-answer-text {
  font-size: 1rem;
  color: var(--text);
  line-height: 1.55;
  font-style: italic;
}

/* Settings */
.settings-section h3 {
  font-size: 1rem;
  margin-bottom: 12px;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.form-row { margin-bottom: 16px; }
.form-row label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text);
}

.danger-zone { border-top: 1px solid var(--border); padding-top: 20px; margin-top: 24px; }

/* Animations */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-in {
  animation: fadeInUp 0.35s ease both;
}

/* ─── Mobile Optimizations ─── */
@media (max-width: 600px) {
  .container { padding: 12px 14px; }

  .card {
    padding: 18px 16px;
    border-radius: 14px;
  }

  .app-header .container {
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .logo { font-size: 1.05rem; }
  .logo-icon { width: 28px; height: 28px; }

  /* Dashboard */
  .dashboard-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-bottom: 18px;
  }
  .stat-card { padding: 14px 8px; }
  .stat-value { font-size: 1.5rem; }
  .stat-label { font-size: 0.72rem; }

  .category-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-bottom: 18px;
  }
  .category-card { padding: 14px 8px; }
  .category-card .cat-emoji { font-size: 1.4rem; }
  .category-card .cat-name { font-size: 0.82rem; }
  .category-card .cat-count { font-size: 0.72rem; }

  .section-title { font-size: 1rem; margin-bottom: 12px; }

  /* Simulator */
  .objection-box {
    font-size: 1.1rem;
    padding: 16px 14px;
    margin-bottom: 14px;
  }

  .sim-header { margin-bottom: 12px; }
  .timer-display { font-size: 1.1rem; }
  .sim-badge { font-size: 0.7rem; padding: 3px 8px; }

  .response-area { margin-bottom: 12px; }
  .response-area textarea {
    min-height: 120px;
    font-size: 1rem;
    padding: 12px 14px;
  }

  .sim-actions {
    flex-direction: column;
    gap: 8px;
  }
  .sim-actions .btn {
    width: 100%;
    padding: 12px 16px;
    font-size: 0.95rem;
  }

  /* Voice bar */
  .voice-bar {
    flex-wrap: nowrap;
    margin-top: 8px;
  }
  .voice-btn {
    padding: 12px 20px;
    font-size: 1rem;
    gap: 8px;
    min-height: 48px;
    min-width: 160px;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
  }
  .voice-icon { font-size: 1.2rem; }
  .voice-label { font-size: 0.9rem; }
  .voice-status {
    font-size: 0.85rem;
    max-width: 100%;
  }

  /* Feedback */
  .score-circle-wrap {
    flex-direction: column;
    align-items: center;
    gap: 14px;
    margin-bottom: 18px;
  }
  .score-ring { width: 110px; height: 110px; }
  .score-number { font-size: 1.8rem; }
  .score-label-text { font-size: 0.72rem; }
  .score-breakdown { min-width: unset; width: 100%; }
  .breakdown-item span { font-size: 0.82rem; min-width: 90px; }
  .breakdown-fill { transition: width 0.6s ease; }

  .stars { font-size: 1.2rem; margin-bottom: 10px; }

  .feedback-panel { padding: 14px; margin-bottom: 14px; }
  .feedback-title { font-size: 0.85rem; }
  .feedback-list li { font-size: 0.88rem; padding: 5px 0; }

  .model-answer { padding: 14px; margin-bottom: 14px; }
  .model-answer-title { font-size: 0.72rem; }
  .model-answer-text { font-size: 0.95rem; }

  /* Settings */
  .settings-section h3 { font-size: 0.9rem; }
  .form-row label { font-size: 0.85rem; }
  .diff-btn { padding: 6px 12px; font-size: 0.85rem; }
}