:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #5a5a5a;
  --accent: #1f4fd8;
  --border: #e4e4e4;
  --max-width: 760px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --text: #eaeaea;
    --muted: #a3a3a3;
    --accent: #7aa2ff;
    --border: #2a2d33;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  border-bottom: 1px solid var(--border);
}

.site-nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.brand {
  font-weight: 600;
  color: var(--text);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

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

.lang-toggle {
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.15rem 0.5rem;
  font-size: 0.85rem;
}

.content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.25rem 3rem;
}

.profile {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.profile img {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}

.profile-intro h1 {
  margin: 0 0 0.25rem;
}

.profile-intro p {
  margin: 0;
  color: var(--muted);
}

h1 { font-size: 1.75rem; }
h2 {
  font-size: 1.2rem;
  margin-top: 2.25rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.35rem;
}

.course-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.course-list li {
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--border);
}

.course-list a {
  font-weight: 600;
  color: var(--text);
}

.course-list p {
  margin: 0.25rem 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.other-courses {
  color: var(--muted);
}

.back-link {
  font-size: 0.9rem;
}

.course-summary {
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid var(--border);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 2.5rem;
  color: var(--muted);
  font-size: 0.85rem;
}

.footer-note {
  margin-top: 0.25rem;
}

table {
  border-collapse: collapse;
  width: 100%;
  margin: 1rem 0;
}

th, td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  text-align: left;
}

th {
  background: rgba(127, 127, 127, 0.08);
}