:root {
  --bg-page: #f3f5ff;
  --bg-panel: #ffffff;
  --accent: #4f46e5;
  --accent-soft: rgba(79, 70, 229, 0.1);
  --accent-strong: #4338ca;
  --text-main: #111827;
  --text-muted: #6b7280;
  --border-soft: #e5e7eb;
  --chip-bg: #eef2ff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Nunito", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  background: radial-gradient(circle at top left, #e0f2fe 0, var(--bg-page) 40%, #eef2ff 100%);
  color: var(--text-main);
}

.page-shell {
  max-width: 1120px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

@media (min-width: 992px) {
  .page-shell {
    padding-top: 2.5rem;
  }
}

.hero-card {
  background: linear-gradient(135deg, #eef2ff, #e0f2fe);
  border-radius: 1.4rem;
  padding: 1.75rem 1.75rem 1.5rem;
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.18);
  border: 1px solid rgba(148, 163, 184, 0.4);
  position: relative;
  overflow: hidden;
}

.hero-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 120% 0%, rgba(79, 70, 229, 0.22), transparent 55%);
  pointer-events: none;
}

.hero-title {
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: 1.6rem;
  margin-bottom: 0.25rem;
}

@media (min-width: 768px) {
  .hero-title {
    font-size: 1.9rem;
  }
}

.hero-subtitle {
  margin: 0;
  font-size: 0.95rem;
  color: var(--text-muted);
  max-width: 40rem;
}

.hero-badges {
  margin-top: 0.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.hero-badge {
  font-size: 0.75rem;
  padding: 0.18rem 0.65rem;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.06);
  color: var(--text-muted);
  border: 1px solid rgba(148, 163, 184, 0.3);
  backdrop-filter: blur(6px);
}

.hero-badge strong {
  font-weight: 700;
  color: var(--accent-strong);
}

.hero-pill {
  position: absolute;
  right: 1.4rem;
  top: 1.4rem;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.82);
  color: #e5e7eb;
  font-size: 0.76rem;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: 1px solid rgba(148, 163, 184, 0.7);
}

.hero-pill-dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: #22c55e;
  box-shadow: 0 0 0 6px rgba(34, 197, 94, 0.28);
}

@media (max-width: 576px) {
  .hero-pill {
    position: static;
    margin-top: 0.9rem;
  }
}

.panel {
  margin-top: 1.5rem;
  padding: 1rem 1.1rem 1.3rem;
  border-radius: 1.2rem;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(209, 213, 219, 0.7);
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.12);
}

.filter-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.form-control,
.form-select {
  border-radius: 999px;
  border: 1px solid #d1d5db;
  font-size: 0.9rem;
  padding-inline: 1rem;
}

.form-control:focus,
.form-select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.25);
}

.quick-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.5rem;
}

.quick-chip {
  border-radius: 999px;
  border: 1px dashed rgba(148, 163, 184, 0.9);
  padding: 0.15rem 0.75rem;
  font-size: 0.8rem;
  background: rgba(249, 250, 251, 0.9);
  color: var(--text-muted);
  cursor: pointer;
  transition: background 0.15s, transform 0.08s, box-shadow 0.12s;
}

.quick-chip:hover {
  background: #e5e7eb;
  box-shadow: 0 0 0 1px rgba(148, 163, 184, 0.6);
  transform: translateY(-1px);
}

.year-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-top: 1.8rem;
  margin-bottom: 0.8rem;
}

.year-title {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 700;
}

.year-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.class-card {
  border-radius: 1rem;
  border: 1px solid var(--border-soft);
  background: var(--bg-panel);
  margin-bottom: 1rem;
  box-shadow: 0 9px 24px rgba(15, 23, 42, 0.08);
  transition: transform 0.12s ease-out, box-shadow 0.12s ease-out, border-color 0.12s;
}

.class-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 32px rgba(15, 23, 42, 0.12);
  border-color: rgba(129, 140, 248, 0.9);
}

.class-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.25rem;
}

.class-name {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.class-tag {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.75rem;
  border-radius: 999px;
  background: var(--chip-bg);
  color: var(--accent-strong);
  font-weight: 700;
}

.class-meta-badges {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.chip {
  border-radius: 999px;
  padding: 0.15rem 0.7rem;
  font-size: 0.75rem;
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  color: var(--text-muted);
  white-space: nowrap;
}

.chip-strong {
  background: var(--accent-soft);
  border-color: rgba(129, 140, 248, 0.9);
  color: var(--accent-strong);
  font-weight: 600;
}

.toggle-btn {
  border-radius: 999px;
  border: 1px solid #d1d5db;
  background: #f9fafb;
  font-size: 0.78rem;
  padding: 0.15rem 0.65rem;
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s, transform 0.08s, box-shadow 0.12s;
}

.toggle-btn:hover {
  background: #e5e7eb;
  border-color: #9ca3af;
  box-shadow: 0 0 0 1px rgba(148, 163, 184, 0.7);
  transform: translateY(-1px);
}

.toggle-icon {
  font-size: 0.8rem;
  display: inline-block;
  transition: transform 0.12s;
}

.toggle-icon.open {
  transform: rotate(90deg);
}

.lessons-list {
  margin: 0;
  padding-left: 0;
  list-style: none;
  margin-top: 0.35rem;
}

.lesson-item {
  padding: 0.35rem 0;
  border-top: 1px dashed #e5e7eb;
}

.lesson-item:first-child {
  border-top: none;
}

.lesson-link {
  text-decoration: none;
  font-weight: 600;
  font-size: 0.92rem;
  color: #111827;
  display: inline-flex;
  align-items: baseline;
  gap: 0.3rem;
}

.lesson-link:hover {
  color: var(--accent-strong);
  text-decoration: underline;
}

.lesson-meta {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.05rem;
}

.lesson-meta span + span::before {
  content: "•";
  margin: 0 0.35rem;
  color: #d1d5db;
}

.lessons-collapsed-text {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.alert {
  border-radius: 0.9rem;
  border-width: 1px;
  font-size: 0.88rem;
}

.alert-info {
  background: #e0f2fe;
  border-color: #7dd3fc;
  color: #0f172a;
}

.alert-warning {
  background: #fef3c7;
  border-color: #fbbf24;
}

.alert-danger {
  background: #fee2e2;
  border-color: #f87171;
}

@media (max-width: 575.98px) {
  .class-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .class-meta-badges {
    width: 100%;
    justify-content: space-between;
  }
}