:root {
  --bg: #f4f7ff;
  --surface: rgba(255, 255, 255, 0.9);
  --surface-strong: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #4f46e5;
  --primary-soft: rgba(79, 70, 229, 0.14);
  --success: #16a34a;
  --danger: #dc2626;
  --warning: #f59e0b;
  --purple: #8b5cf6;
  --border: rgba(15, 23, 42, 0.1);
  --shadow: 0 18px 45px rgba(15, 23, 42, 0.12);
}

body.dark {
  --bg: #07111f;
  --surface: rgba(15, 23, 42, 0.82);
  --surface-strong: #111c32;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --primary: #7c93ff;
  --primary-soft: rgba(124, 147, 255, 0.16);
  --success: #4ade80;
  --danger: #fb7185;
  --warning: #fbbf24;
  --purple: #c084fc;
  --border: rgba(226, 232, 240, 0.15);
  --shadow: 0 20px 48px rgba(2, 6, 23, 0.42);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(99, 102, 241, 0.2), transparent 26%),
    linear-gradient(135deg, var(--bg) 0%, #eef2ff 100%);
  min-height: 100vh;
  transition: background 0.25s ease, color 0.25s ease;
}

body.dark {
  background: radial-gradient(circle at top left, rgba(67, 56, 202, 0.26), transparent 24%),
    linear-gradient(135deg, var(--bg) 0%, #0f172a 100%);
}

.page-shell {
  min-height: 100vh;
}

.hero-section {
  background: linear-gradient(135deg, rgba(79, 70, 229, 0.96), rgba(15, 23, 42, 0.95));
  color: #fff;
}

.hero-title {
  font-size: clamp(1.8rem, 3vw, 2.7rem);
  font-weight: 800;
  letter-spacing: -0.03em;
}

.eyebrow {
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.3em;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.3rem;
}

.hero-section .eyebrow {
  color: #c7d2fe;
}

.hero-card {
  border-radius: 1.6rem;
  background: linear-gradient(135deg, rgba(255,255,255,0.16), rgba(255,255,255,0.06));
  border: 1px solid rgba(255,255,255,0.16);
  backdrop-filter: blur(12px);
}

.hero-text {
  color: rgba(255,255,255,0.86);
  font-size: 1.02rem;
  line-height: 1.7;
}

.card-glow {
  box-shadow: 0 24px 60px rgba(15, 23, 42, 0.2);
}

.pattern-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.pattern-card,
.info-card,
.card-soft,
.paper-card,
.summary-card,
.question-card,
.review-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 1.2rem;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.pattern-card {
  padding: 1rem;
  color: #fff;
  background: rgba(255,255,255,0.12);
  border-color: rgba(255,255,255,0.16);
}

.pattern-card span {
  display: block;
  font-size: 0.82rem;
  opacity: 0.86;
}

.pattern-card strong {
  display: block;
  font-size: 1.1rem;
  margin-top: 0.35rem;
}

.info-card {
  padding: 1.2rem;
}

.info-card h3,
.section-title {
  font-size: 1.24rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.info-card p,
.result-subtext,
.review-card p,
.question-card p {
  color: var(--muted);
  line-height: 1.7;
  margin-bottom: 0;
}

.paper-card {
  padding: 1.2rem;
}

.paper-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.paper-card ul {
  padding-left: 1rem;
  color: var(--muted);
  line-height: 1.8;
}

.chip,
.timer-pill,
.progress-pill {
  background: var(--primary-soft);
  color: var(--primary);
  border-radius: 999px;
  padding: 0.55rem 0.9rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.quiz-toolbar {
  border-radius: 1.3rem;
}

.question-card {
  padding: 1.2rem;
}

.options-grid {
  display: grid;
  gap: 0.9rem;
}

.option-btn {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 0.95rem;
  padding: 0.9rem 1rem;
  background: var(--surface-strong);
  color: var(--text);
  text-align: left;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.option-btn:hover {
  transform: translateY(-1px);
  border-color: var(--primary);
}

.option-btn.selected {
  border-color: var(--primary);
  box-shadow: inset 0 0 0 2px var(--primary);
}

.option-btn.correct {
  border-color: var(--success);
  background: rgba(22, 163, 74, 0.1);
  color: var(--success);
}

.option-btn.wrong {
  border-color: var(--danger);
  background: rgba(220, 38, 38, 0.1);
  color: var(--danger);
}

.palette-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 0.6rem;
}

.palette-btn {
  border: none;
  border-radius: 0.8rem;
  min-height: 2.8rem;
  font-weight: 700;
  color: #fff;
}

.palette-btn.answered { background: var(--success); }
.palette-btn.not-answered { background: var(--danger); }
.palette-btn.not-visited { background: #64748b; }
.palette-btn.marked { background: var(--purple); }
.palette-btn.current { background: var(--warning); color: #111827; }

.status-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.65rem;
  color: var(--muted);
}

.dot {
  display: inline-block;
  width: 0.8rem;
  height: 0.8rem;
  border-radius: 50%;
  margin-right: 0.45rem;
}

.dot.green { background: var(--success); }
.dot.red { background: var(--danger); }
.dot.gray { background: #64748b; }
.dot.purple { background: var(--purple); }
.dot.orange { background: var(--warning); }

.summary-card {
  padding: 1.2rem;
  border-radius: 1.2rem;
}

.summary-card.primary { background: linear-gradient(135deg, var(--primary), #818cf8); color: #fff; }
.summary-card.success { background: linear-gradient(135deg, var(--success), #34d399); color: #fff; }
.summary-card.danger { background: linear-gradient(135deg, var(--danger), #fb7185); color: #fff; }

.summary-card span {
  display: block;
  opacity: 0.9;
  font-size: 0.92rem;
}

.summary-card strong {
  font-size: 1.5rem;
  margin-top: 0.4rem;
  display: block;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
}

.summary-item {
  padding: 0.9rem 1rem;
  background: var(--surface-strong);
  border-radius: 0.95rem;
  border: 1px solid var(--border);
}

.summary-item strong {
  display: block;
  font-size: 1.15rem;
  margin-top: 0.35rem;
}

.progress-bar-wrap {
  margin-top: 0.7rem;
}

.progress-bar,
.meter-bar {
  width: 100%;
  height: 0.8rem;
  border-radius: 999px;
  background: var(--primary-soft);
  overflow: hidden;
}

.progress-fill,
.meter-fill {
  height: 100%;
  width: 0%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--primary), var(--warning));
  transition: width 0.25s ease;
}

.meter-card {
  padding: 1rem;
  border-radius: 1rem;
  background: var(--surface-strong);
  border: 1px solid var(--border);
}

.topic-item {
  margin-bottom: 0.9rem;
}

.topic-item .topic-label {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.35rem;
  font-weight: 600;
}

.topic-item .progress-bar {
  height: 0.6rem;
}

.review-card {
  padding: 1rem 1.1rem;
  margin-bottom: 1rem;
}

.review-card .review-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 0.8rem;
}

.review-card .status-badge {
  border-radius: 999px;
  padding: 0.4rem 0.7rem;
  font-size: 0.8rem;
  font-weight: 700;
}

.status-badge.correct { background: rgba(22, 163, 74, 0.14); color: var(--success); }
.status-badge.wrong { background: rgba(220, 38, 38, 0.14); color: var(--danger); }
.status-badge.skipped { background: rgba(100, 116, 139, 0.16); color: #64748b; }
.status-badge.flagged { background: rgba(139, 92, 246, 0.14); color: var(--purple); }

.answer-row {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin: 0.45rem 0;
}

.answer-pill {
  padding: 0.45rem 0.7rem;
  border-radius: 999px;
  background: var(--surface-strong);
  border: 1px solid var(--border);
}

.answer-pill.correct {
  color: var(--success);
  border-color: rgba(22, 163, 74, 0.2);
}

.answer-pill.wrong {
  color: var(--danger);
  border-color: rgba(220, 38, 38, 0.2);
}

.filter-btn {
  border: 1px solid var(--border);
  background: var(--surface-strong);
  color: var(--text);
  padding: 0.55rem 0.85rem;
  border-radius: 999px;
}

.filter-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.theme-toggle {
  border: none;
  background: rgba(255,255,255,0.16);
  color: #fff;
  width: 2.7rem;
  height: 2.7rem;
  border-radius: 50%;
}

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

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

.btn-outline-warning {
  color: var(--warning);
  border-color: var(--warning);
}

@media (max-width: 768px) {
  .pattern-grid,
  .summary-grid {
    grid-template-columns: 1fr;
  }

  .palette-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media print {
  .hero-section,
  .theme-toggle,
  .btn,
  .filter-btn,
  .quiz-toolbar {
    display: none !important;
  }

  body {
    background: #fff;
    color: #111;
  }

  .card-soft,
  .summary-card,
  .review-card,
  .question-card {
    box-shadow: none;
    border: 1px solid #ddd;
  }
}