:root {
  --bg: #0a0a0a;
  --surface: #141414;
  --surface-2: #1c1c1c;
  --border: #2a2a2a;
  --gold: #d4af37;
  --gold-bright: #e8c252;
  --gold-dim: #8a7128;
  --text: #f2f2f2;
  --text-muted: #8a8a8a;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* ---------- Top bar ---------- */
.topbar {
  background: linear-gradient(180deg, #0d0d0d 0%, #0a0a0a 100%);
  position: sticky;
  top: 0;
  z-index: 10;
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 32px;
}

.progress-bar {
  margin: 0 32px 16px;
  height: 8px;
  background: #1a1a1a;
  border-radius: 999px;
  overflow: hidden;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.6);
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #8a7128 0%, #d4af37 40%, #f5d56e 65%, #d4af37 100%);
  box-shadow: 0 0 14px rgba(212, 175, 55, 0.55), 0 0 4px rgba(255, 213, 110, 0.7);
  border-radius: 999px;
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.brand { display: flex; align-items: center; gap: 14px; }

.brand-logo {
  height: 36px;
  width: 36px;
  display: block;
  filter: drop-shadow(0 0 18px rgba(212, 175, 55, 0.25));
}

.brand-mark {
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  font-size: 22px;
  letter-spacing: -0.5px;
  color: #fff;
}

.brand-divider {
  width: 1px;
  height: 20px;
  background: var(--border);
  margin: 0 4px;
}

.brand-sub {
  font-size: 11px;
  letter-spacing: 3px;
  color: var(--text-muted);
  text-transform: uppercase;
  font-weight: 500;
}

.progress {
  font-size: 12px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--gold);
  padding: 6px 14px;
  border: 1px solid var(--gold-dim);
  border-radius: 999px;
}

/* ---------- Layout ---------- */
.layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  min-height: calc(100vh - 70px);
}

/* ---------- Sidebar ---------- */
.sidebar {
  border-right: 1px solid var(--border);
  background: #0c0c0c;
  padding: 24px 16px;
  overflow-y: auto;
}

.lesson-link {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 14px;
  margin-bottom: 6px;
  border-radius: 10px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background 0.15s ease, border-color 0.15s ease;
  color: var(--text);
  user-select: none;
}

.lesson-link:hover {
  background: var(--surface);
}

.lesson-link.active {
  background: var(--surface-2);
  border-color: var(--gold-dim);
}

.lesson-num {
  flex: 0 0 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--gold-dim);
  color: var(--gold);
  font-weight: 600;
  font-size: 14px;
  background: #0a0a0a;
}

.lesson-link.active .lesson-num {
  background: var(--gold);
  color: #0a0a0a;
  border-color: var(--gold);
}

.lesson-link.done .lesson-num {
  background: var(--gold-dim);
  color: #0a0a0a;
  border-color: var(--gold-dim);
}

.lesson-link.done .lesson-num::before {
  content: "✓";
}
.lesson-link.done .lesson-num span { display: none; }

.lesson-label {
  font-size: 14px;
  font-weight: 500;
  line-height: 1.3;
}

.lesson-meta {
  font-size: 11px;
  letter-spacing: 1.5px;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 2px;
}

/* ---------- Content ---------- */
.content {
  padding: 48px 56px 80px;
  max-width: 1000px;
  width: 100%;
}

.lesson-eyebrow {
  font-size: 12px;
  letter-spacing: 4px;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 12px;
}

.lesson-title {
  font-family: 'Inter', sans-serif;
  font-size: 52px;
  font-weight: 800;
  margin: 0 0 16px;
  letter-spacing: -1.5px;
  line-height: 1.05;
}

.lesson-title em {
  font-family: 'Cormorant Garamond', serif;
  font-weight: 600;
  font-style: italic;
  color: var(--gold);
  letter-spacing: 0;
}

.lesson-desc {
  color: var(--text-muted);
  font-size: 16px;
  line-height: 1.6;
  margin-bottom: 32px;
  max-width: 720px;
}

.video-wrap {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%;
  background: #000;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 0 0 1px rgba(212, 175, 55, 0.08), 0 20px 60px rgba(0,0,0,0.5);
}

.video-wrap iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.video-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 14px;
  letter-spacing: 2px;
  text-transform: uppercase;
}

/* ---------- Resources ---------- */
.resources {
  margin-top: 40px;
}

.section-heading {
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

.resource-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.resource {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  text-decoration: none;
  font-size: 15px;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.resource:hover {
  border-color: var(--gold);
  transform: translateY(-1px);
}

.resource-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: #0a0a0a;
  border: 1px solid var(--gold-dim);
  color: var(--gold);
  font-size: 16px;
}

.resource-label { flex: 1; }

.resource-arrow {
  color: var(--gold);
  font-size: 18px;
  opacity: 0.6;
}

.resources-empty {
  color: var(--text-muted);
  font-size: 14px;
  font-style: italic;
}

/* ---------- Actions ---------- */
.actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 22px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  cursor: pointer;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  transition: all 0.15s ease;
  font-family: inherit;
}

.btn:hover { border-color: var(--gold); color: var(--gold); }

.btn-primary {
  background: var(--gold);
  color: #0a0a0a;
  border-color: var(--gold);
}
.btn-primary:hover {
  background: var(--gold-bright);
  border-color: var(--gold-bright);
  color: #0a0a0a;
}

.btn[disabled] {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-complete.done {
  background: var(--gold-dim);
  color: #0a0a0a;
  border-color: var(--gold-dim);
}

/* ---------- Responsive ---------- */
@media (max-width: 880px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 16px;
    display: flex;
    gap: 8px;
    overflow-x: auto;
  }
  .lesson-link {
    flex: 0 0 auto;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 10px 12px;
    min-width: 110px;
    margin-bottom: 0;
  }
  .lesson-label { font-size: 12px; }
  .lesson-meta { display: none; }
  .content { padding: 32px 20px 60px; }
  .lesson-title { font-size: 32px; }
  .topbar-inner { padding: 14px 20px; }
  .progress-bar { margin: 0 20px 12px; height: 6px; }
  .brand-mark { font-size: 18px; }
  .brand-logo { height: 30px; width: 30px; }
  .brand-divider { display: none; }
  .brand-sub { display: none; }
  .lesson-title { font-size: 34px; letter-spacing: -1px; }
}