:root {
  --navy: #0b2545;
  --navy-light: #13345e;
  --steel: #4a6fa5;
  --sky: #7fa8d9;
  --accent: #f2a541;
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --text: #1a2433;
  --text-muted: #5b6b7d;
  --border: #e1e6ec;
  --success: #2e8b57;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

header.site-header {
  background: linear-gradient(135deg, var(--navy) 0%, var(--navy-light) 100%);
  color: #fff;
  padding: 2.5rem 1.5rem 2rem;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.75rem;
  color: var(--sky);
  font-weight: 600;
  margin: 0 0 0.5rem;
}

header.site-header h1 {
  margin: 0 0 0.5rem;
  font-size: 2rem;
}

header.site-header p {
  margin: 0;
  color: #cfe0f5;
  max-width: 60ch;
  line-height: 1.5;
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.catalog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.course-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}

.course-card:hover {
  box-shadow: 0 6px 20px rgba(11, 37, 69, 0.1);
  transform: translateY(-2px);
}

.course-icon {
  width: 42px;
  height: 42px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--steel), var(--sky));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
}

.course-card h3 {
  margin: 0;
  font-size: 1.1rem;
}

.course-card p.description {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.5;
  flex-grow: 1;
}

.course-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
}

.badge {
  display: inline-block;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.badge.not-attempted {
  background: #eef1f5;
  color: var(--text-muted);
}

.badge.incomplete {
  background: #fdf1de;
  color: #a5690b;
}

.badge.completed,
.badge.passed {
  background: #e4f4ea;
  color: var(--success);
}

.btn {
  display: inline-block;
  text-decoration: none;
  background: var(--navy);
  color: #fff;
  padding: 0.55rem 1rem;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  text-align: center;
  border: none;
  cursor: pointer;
}

.btn:hover {
  background: var(--navy-light);
}

.btn.secondary {
  background: transparent;
  color: var(--navy);
  border: 1px solid var(--border);
}

.btn.secondary:hover {
  background: #eef1f5;
}

.empty-state {
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem;
  text-align: center;
  color: var(--text-muted);
  margin-top: 1.5rem;
}

.empty-state code {
  background: #eef1f5;
  padding: 0.1rem 0.4rem;
  border-radius: 4px;
}

/* Player page */

.player-header {
  background: var(--navy);
  color: #fff;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.player-header .back-link {
  color: #cfe0f5;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
}

.player-header .back-link:hover {
  color: #fff;
}

.player-header h2 {
  margin: 0;
  font-size: 1.1rem;
  flex-grow: 1;
}

.player-frame-wrap {
  width: 100%;
  height: calc(100vh - 64px);
  background: #000;
}

.player-frame-wrap iframe {
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

.status-line {
  padding: 2rem 1.5rem;
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
  color: var(--text-muted);
}

footer.site-footer {
  text-align: center;
  padding: 2rem 1.5rem 3rem;
  color: var(--text-muted);
  font-size: 0.85rem;
}