/* ============================================================
   LESSONS.CSS — styles for lessons.html only.
   Loaded in addition to style.css and pages.css.
   You never need to edit this file when adding new lessons.
   ============================================================ */

/* === CURRENT LESSON === */
.current-lesson {
  background: var(--color-white);
}

.current-lesson-inner {
  background: linear-gradient(135deg, var(--color-accent-light) 0%, var(--color-mist) 60%, #e4f3f7 100%);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  padding: var(--space-lg);
  position: relative;
  overflow: hidden;
}

.current-lesson-inner::before {
  content: '';
  position: absolute;
  top: -60px; right: -60px;
  width: 240px; height: 240px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(74,171,186,0.15) 0%, transparent 70%);
  pointer-events: none;
}

.current-lesson-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary-dark);
  background: var(--color-white);
  border: 1px solid var(--color-border);
  padding: 0.3rem 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-md);
}

.current-lesson-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: center;
}

.current-lesson-icon {
  max-width: 120px;
  margin-inline: auto;
  filter: drop-shadow(0 8px 20px rgba(44,62,69,0.12));
}

.current-lesson-icon svg {
  width: 100%;
  display: block;
}

.current-lesson-text h2 {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  margin-bottom: var(--space-sm);
  margin-top: var(--space-xs);
}

.current-lesson-text p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
  max-width: 60ch;
  line-height: 1.8;
}

.current-lesson-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: var(--space-sm);
}

.current-lesson-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.current-lesson-actions .btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.lesson-filesize {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}

/* === LESSON TAGS === */
.lesson-tag {
  display: inline-block;
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.2rem 0.65rem;
  border-radius: var(--radius-full);
  background: var(--color-mist);
  color: var(--color-primary-dark);
  font-weight: 500;
}

.lesson-tag--alt {
  background: #d4eef5;
  color: #145f6e;
}

.lesson-tag--c {
  background: #ddf0f4;
  color: #1a6070;
}

.lesson-tag--d {
  background: #b8dfe8;
  color: #145f6e;
}

.lesson-date {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}

/* === ARCHIVE === */
.lessons-archive { background: var(--color-bg); }

/* Filter bar */
.lessons-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: var(--space-sm);
}

/* Reuse .filter-btn from pages.css */

/* Sort bar */
.lessons-sort-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}

.sort-label {
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.sort-btn {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.06em;
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--color-border);
  color: var(--color-text-muted);
  background: var(--color-white);
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.sort-btn:hover,
.sort-btn.active {
  background: var(--color-bg-alt);
  border-color: var(--color-primary);
  color: var(--color-primary-dark);
}

.sort-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Category heading */
.category-heading {
  font-family: var(--font-heading);
  font-size: clamp(1.3rem, 2.5vw, 1.75rem);
  font-weight: 300;
  color: var(--color-text);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1.5px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.category-heading-label {
  position: relative;
}

.lesson-category {
  margin-bottom: var(--space-xl);
}

.lesson-category:last-child { margin-bottom: 0; }

/* Lesson grid */
.lessons-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

/* Lesson card */
.lesson-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  padding: var(--space-md);
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: var(--space-md);
  align-items: start;
  transition: box-shadow var(--transition), transform var(--transition);
}

.lesson-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.lesson-card-icon {
  width: 56px;
  flex-shrink: 0;
  filter: drop-shadow(0 3px 8px rgba(44,62,69,0.1));
}

.lesson-card-icon svg {
  width: 100%;
  display: block;
}

.lesson-card-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.4rem;
}

.lesson-card-body h4 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: 0.4rem;
  line-height: 1.3;
}

.lesson-card-body p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.65;
  margin-bottom: var(--space-sm);
  max-width: 55ch;
}

.lesson-download-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-primary-dark);
  transition: color var(--transition);
  letter-spacing: 0.02em;
}

.lesson-download-link:hover { color: var(--color-primary); }

.lesson-download-link .lesson-filesize {
  font-weight: 400;
  margin-left: 0.2rem;
}

/* === RESPONSIVE === */
@media (min-width: 640px) {
  .lessons-grid { grid-template-columns: 1fr 1fr; }
}

@media (min-width: 768px) {
  .current-lesson-grid {
    grid-template-columns: 140px 1fr;
    gap: var(--space-xl);
  }

  .current-lesson-icon { max-width: none; margin: 0; }
}

@media (min-width: 1024px) {
  .lessons-grid { grid-template-columns: 1fr 1fr 1fr; }
}