/*
 * TheChess.Art — Courses listing + lesson view
 */

.courses {
  max-width: 1440px;
  margin: 0 auto;
  padding: 60px 32px 80px;
}

.courses__head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 24px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}
.courses__head h1 {
  font-family: var(--font-serif);
  font-size: clamp(36px, 4vw, 56px);
  line-height: 1;
}
.courses__head p {
  color: var(--primary-dim);
  font-size: 14px;
  line-height: 1.6;
  max-width: 440px;
}

.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.course-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 28px 24px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  min-height: 260px;
  transition: border-color var(--t-fast), transform var(--t-fast);
  text-decoration: none;
  color: inherit;
  overflow: hidden;
}
.course-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--course-accent, var(--accent));
}
.course-card:hover { border-color: var(--course-accent, var(--accent)); transform: translateY(-3px); }
.course-card__tier {
  position: absolute;
  top: 16px;
  right: 16px;
  padding: 3px 8px;
  font-size: 9px;
  letter-spacing: var(--letter-widest);
  text-transform: uppercase;
  border: 1px solid var(--line);
  border-radius: 2px;
  color: var(--secondary);
}
.course-card__tier.is-premium {
  color: var(--course-accent, var(--accent));
  border-color: var(--course-accent, var(--accent));
}
.course-card__level {
  font-size: 10px;
  letter-spacing: var(--letter-widest);
  text-transform: uppercase;
  color: var(--secondary);
  margin-bottom: 10px;
}
.course-card__title {
  font-family: var(--font-serif);
  font-size: 24px;
  line-height: 1.1;
  margin-bottom: 12px;
}
.course-card__summary {
  flex: 1;
  color: var(--primary-dim);
  font-size: 13px;
  line-height: 1.6;
  margin-bottom: 22px;
}
.course-card__meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 11px;
  letter-spacing: var(--letter-wide);
  color: var(--secondary);
  text-transform: uppercase;
}
.course-card__meta .cta { color: var(--course-accent, var(--accent)); }

/* Lesson viewer */
.lesson {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 18px;
  padding: 18px 24px 24px;
  height: calc(100vh - 57px);
  overflow: hidden;
}
.lesson__main { display: flex; flex-direction: column; gap: 16px; min-height: 0; }
.lesson__side { display: flex; flex-direction: column; gap: 16px; min-height: 0; }

.lesson__panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.lesson__eyebrow {
  font-size: 10px;
  letter-spacing: var(--letter-widest);
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 6px;
}
.lesson__title {
  font-family: var(--font-serif);
  font-size: 28px;
  line-height: 1.1;
  margin-bottom: 10px;
}
.lesson__intro {
  color: var(--primary-dim);
  line-height: 1.6;
  font-size: 14px;
}

.lesson__stepper {
  display: flex;
  gap: 8px;
  margin-top: 18px;
  flex-wrap: wrap;
}
.lesson__stepper button {
  padding: 8px 12px;
  font-size: 11px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  color: var(--secondary);
  border-radius: var(--radius-sm);
  transition: all var(--t-fast);
}
.lesson__stepper button:hover { color: var(--primary); border-color: var(--secondary); }
.lesson__stepper button.is-active {
  color: var(--body);
  background: var(--accent);
  border-color: var(--accent);
  font-weight: 700;
}

.lesson__step-title {
  font-family: var(--font-serif);
  font-size: 18px;
  margin-top: 20px;
  margin-bottom: 8px;
}
.lesson__step-body {
  color: var(--primary-dim);
  line-height: 1.6;
  font-size: 13px;
  flex: 1;
  overflow-y: auto;
}

.lesson__nav {
  display: flex;
  gap: 10px;
  margin-top: 16px;
}

.lesson__board-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  min-height: 0;
}
.lesson__board {
  aspect-ratio: 1 / 1;
  max-height: 100%;
  max-width: 100%;
  position: relative;
}
.lesson__board canvas {
  width: 100%;
  height: 100%;
  border: 1px solid var(--muted);
  border-radius: var(--radius-sm);
}

.lesson__heatmap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  min-height: 0;
}
.lesson__heatmap .heatmap-wrap {
  aspect-ratio: 1 / 1;
  max-width: 100%;
  max-height: 100%;
  position: relative;
}
.lesson__heatmap canvas {
  width: 100%;
  height: 100%;
  background: #181818;
  border-radius: var(--radius-sm);
}

@media (max-width: 1100px) {
  .lesson { grid-template-columns: 1fr; height: auto; overflow: auto; }
}