:root {
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-elevated: #334155;
  --text: #f8fafc;
  --text-muted: #94a3b8;
  --primary: #38bdf8;
  --primary-hover: #0ea5e9;
  --success: #22c55e;
  --success-bg: rgba(34, 197, 94, 0.14);
  --danger: #ef4444;
  --danger-bg: rgba(239, 68, 68, 0.14);
  --warning: #f59e0b;
  --warning-bg: rgba(245, 158, 11, 0.15);
  --border: #334155;
  --radius: 12px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Inter, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
}

.app-header {
  background: rgba(30, 41, 59, 0.9);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
}

.header-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0.9rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  cursor: pointer;
}

.brand-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, #38bdf8, #6366f1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.25rem;
  color: #fff;
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
}

.brand-subtitle {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

.view {
  display: none;
}

.view.active {
  display: block;
}

.btn {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 0.55rem 1rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.btn-sm {
  padding: 0.35rem 0.75rem;
  font-size: 0.82rem;
}

.btn-primary {
  background: var(--primary);
  color: #0f172a;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text);
  border-color: var(--border);
}

.btn-secondary:hover {
  background: #475569;
}

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: var(--border);
}

.btn-ghost:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.05);
}

.stats-banner {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(175px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.stat-value {
  font-size: 1.65rem;
  font-weight: 700;
  color: var(--primary);
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.15rem;
  flex-wrap: wrap;
}

.subjects-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.subject-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.35rem;
}

.subject-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.subject-title {
  font-size: 1.2rem;
  font-weight: 700;
}

.quizzes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1rem;
}

.quiz-card {
  background: rgba(15, 23, 42, 0.55);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.15rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1rem;
}

.quiz-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.quiz-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.quiz-stats-strip {
  background: rgba(255, 255, 255, 0.03);
  border-radius: 8px;
  padding: 0.6rem 0.75rem;
  font-size: 0.82rem;
  display: flex;
  justify-content: space-between;
  color: var(--text-muted);
}

.quiz-card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
}

.badge-subject {
  background: rgba(56, 189, 248, 0.15);
  color: var(--primary);
}

.badge-mode {
  background: rgba(99, 102, 241, 0.2);
  color: #a5b4fc;
}

/* QUIZ PLAYER */
.quiz-top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.1rem;
  flex-wrap: wrap;
}

.quiz-controls-meta {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  flex-wrap: wrap;
}

.toggle-inline {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.86rem;
  color: var(--text-muted);
  cursor: pointer;
}

.progress-wrapper {
  margin-bottom: 1.25rem;
}

.progress-info {
  display: flex;
  justify-content: space-between;
  font-size: 0.86rem;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.progress-bar-track {
  height: 8px;
  background: var(--bg-card);
  border-radius: 999px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, #38bdf8, #6366f1);
  transition: width 0.2s ease;
}

.question-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem;
  margin-bottom: 1.25rem;
}

.question-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.8rem;
}

.question-num-badge {
  background: var(--bg-elevated);
  color: var(--primary);
  font-weight: 700;
  font-size: 0.82rem;
  padding: 0.25rem 0.65rem;
  border-radius: 6px;
}

.question-review-badge {
  background: var(--warning-bg);
  color: var(--warning);
  font-size: 0.76rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
}

.question-stem {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
}

.options-list {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.option-btn {
  width: 100%;
  text-align: left;
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.9rem 1.1rem;
  color: var(--text);
  font-size: 0.96rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.85rem;
  transition: all 0.15s ease;
}

.option-btn:hover:not(:disabled) {
  border-color: var(--primary);
  background: rgba(56, 189, 248, 0.08);
}

.option-letter {
  width: 30px;
  height: 30px;
  border-radius: 7px;
  background: var(--bg-elevated);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.86rem;
  flex-shrink: 0;
}

.option-btn.selected {
  border-color: var(--primary);
  background: rgba(56, 189, 248, 0.15);
}

.option-btn.correct {
  border-color: var(--success);
  background: var(--success-bg);
}

.option-btn.correct .option-letter {
  background: var(--success);
  color: #0f172a;
}

.option-btn.incorrect {
  border-color: var(--danger);
  background: var(--danger-bg);
}

.option-btn.incorrect .option-letter {
  background: var(--danger);
  color: #fff;
}

.feedback-box {
  margin-top: 1.1rem;
  padding: 0.9rem 1.1rem;
  border-radius: 8px;
  font-size: 0.9rem;
}

.feedback-box.correct {
  background: var(--success-bg);
  border: 1px solid var(--success);
  color: #86efac;
}

.feedback-box.incorrect {
  background: var(--danger-bg);
  border: 1px solid var(--danger);
  color: #fca5a5;
}

.hidden {
  display: none !important;
}

.player-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.6rem;
}

.question-navigator-panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem;
}

.question-navigator-panel h4 {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.navigator-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.nav-dot {
  width: 36px;
  height: 36px;
  border-radius: 7px;
  border: 1px solid var(--border);
  background: rgba(15, 23, 42, 0.65);
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
}

.nav-dot.current {
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.25);
}

.nav-dot.answered-correct {
  background: var(--success-bg);
  border-color: var(--success);
  color: #86efac;
}

.nav-dot.answered-incorrect {
  background: var(--danger-bg);
  border-color: var(--danger);
  color: #fca5a5;
}

.nav-dot.answered-neutral {
  background: rgba(56, 189, 248, 0.2);
  border-color: var(--primary);
  color: var(--text);
}

/* RESULTS & BROWSE */
.results-summary-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  margin-bottom: 2rem;
}

.results-score-circle {
  margin: 1.5rem auto;
}

.score-big {
  font-size: 3rem;
  font-weight: 800;
  color: var(--primary);
}

.score-sub {
  font-size: 1rem;
  color: var(--text-muted);
}

.results-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.filter-pills {
  display: flex;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.pill {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
  font-size: 0.82rem;
  cursor: pointer;
}

.pill.active {
  background: var(--primary);
  color: #0f172a;
  border-color: var(--primary);
  font-weight: 600;
}

.breakdown-list {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.breakdown-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.15rem;
}

.breakdown-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.55rem;
}

.breakdown-options {
  margin-top: 0.75rem;
  display: grid;
  gap: 0.4rem;
}

.breakdown-opt {
  padding: 0.45rem 0.75rem;
  border-radius: 6px;
  font-size: 0.88rem;
  background: rgba(15, 23, 42, 0.5);
  border: 1px solid transparent;
}

.breakdown-opt.is-correct {
  border-color: var(--success);
  background: var(--success-bg);
  color: #86efac;
  font-weight: 600;
}

.breakdown-opt.user-wrong {
  border-color: var(--danger);
  background: var(--danger-bg);
  color: #fca5a5;
}

.review-note-banner {
  margin-top: 0.65rem;
  padding: 0.5rem 0.75rem;
  background: var(--warning-bg);
  border-left: 3px solid var(--warning);
  color: #fcd34d;
  font-size: 0.82rem;
  border-radius: 4px;
}

.validation-summary-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem;
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
}

.browse-controls, .form-grid {
  display: flex;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.input-select, .input-text, .input-textarea {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  font-size: 0.9rem;
}

.input-textarea {
  width: 100%;
  font-family: monospace;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-bottom: 1rem;
  flex: 1;
}

.text-muted {
  color: var(--text-muted);
  font-size: 0.88rem;
}