.lessons-page {
  position: relative;
  z-index: 1;
  padding: 48px 0 80px;
}

.lessons-header {
  max-width: 560px;
  margin-bottom: 32px;
}

.lessons-header h1 {
  font-family: "Instrument Serif", Georgia, serif;
  font-size: clamp(2.2rem, 4vw, 3rem);
  font-weight: 400;
  margin: 8px 0 12px;
  letter-spacing: -0.02em;
}

.lessons-sub {
  color: var(--text-soft);
  line-height: 1.55;
  margin: 0;
}

.lessons-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 28px;
}

.lessons-filters {
  flex-wrap: wrap;
}

.lessons-count {
  font-size: 0.85rem;
  color: var(--text-faint);
  margin: 0;
}

.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.lesson-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 22px 20px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--bg-card);
  box-shadow: var(--shadow);
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.lesson-card:hover {
  border-color: color-mix(in srgb, var(--accent) 40%, var(--line));
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
}

.lesson-card-placeholder {
  opacity: 0.9;
  border-style: dashed;
  box-shadow: none;
  background: color-mix(in srgb, var(--bg-card) 80%, transparent);
}

.lesson-card-placeholder:hover {
  transform: none;
  box-shadow: none;
  border-color: var(--text-faint);
}

.lesson-card-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-soft);
  color: var(--accent);
  transition: background 0.2s, color 0.2s;
}

.lesson-card:not(.lesson-card-placeholder):hover .lesson-card-icon {
  background: var(--accent);
  color: #fff;
}

[data-theme="dark"] .lesson-card:not(.lesson-card-placeholder):hover .lesson-card-icon {
  color: #0c0b0a;
}

.lesson-meta {
  font-size: 0.75rem;
  color: var(--text-faint);
  margin: 0 0 6px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.lesson-title {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 6px;
  line-height: 1.3;
}

.lesson-desc {
  font-size: 0.88rem;
  color: var(--text-soft);
  margin: 0;
  line-height: 1.45;
}

.lesson-card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
  padding-top: 4px;
}

.btn-sm {
  padding: 8px 14px;
  font-size: 0.82rem;
}

.lesson-soon {
  font-size: 0.8rem;
  color: var(--text-faint);
}

.lessons-empty {
  text-align: center;
  padding: 48px 16px;
  color: var(--text-soft);
}

.lessons-empty-hint {
  font-size: 0.85rem;
  color: var(--text-faint);
  max-width: 420px;
  margin: 8px auto 0;
}

.lessons-empty code,
.lessons-howto code {
  font-size: 0.85em;
  padding: 1px 6px;
  border-radius: 4px;
  background: var(--line);
}

.lessons-howto {
  margin-top: 48px;
  padding: 24px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--surface, rgba(255, 255, 255, 0.03));
}

.lessons-howto h2 {
  font-size: 1.1rem;
  margin: 0 0 12px;
}

.lessons-howto ol {
  margin: 0 0 12px;
  padding-left: 1.25rem;
  color: var(--text-soft);
  line-height: 1.6;
}

.lessons-howto-note {
  margin: 0;
  font-size: 0.85rem;
  color: var(--text-faint);
}

.nav-link.active {
  color: var(--text);
  font-weight: 600;
}

@media (max-width: 640px) {
  .lessons-page {
    padding: 32px 0 56px;
  }
  .lessons-grid {
    grid-template-columns: 1fr;
  }
}

.lesson-card-icon-math {
  font-family: "Instrument Serif", Georgia, serif;
  font-size: 1.5rem;
  line-height: 1;
}