:root {
  --bg: #fbfbfc;
  --text: #0f172a;
  --muted: #6b7280;
  --accent: #0b63ff;
  --container: 1100px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

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

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 28px;
}

.main {
  padding-top: 110px;
}

section {
  margin-bottom: 4rem;
  scroll-margin-top: 110px;
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--bg);
  border-bottom: 1px solid rgba(15,23,42,0.06);
  z-index: 1000;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-title {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 700;
}

.nav a {
  margin-left: 16px;
  color: inherit;
  text-decoration: none;
  font-weight: 600;
}

.nav a:hover { text-decoration: underline; }

/* Home */
.home-grid {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
}

.home-photo-wrap { max-width: 360px; }

.home-photo {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 10px;
}

.home-about { flex: 1 1 320px; }

/* Typography */
h2 { font-size: 1.5rem; margin-bottom: 1rem; }
h3 { margin-top: 1.75rem; margin-bottom: 0.25rem; }
p { margin-bottom: 0.75rem; }

.small-muted { color: var(--muted); }

ul { margin-left: 1.1rem; }
li { margin-bottom: 0.35rem; }

/* Links */
a { color: inherit; text-decoration: none; }
a:hover, a:focus { text-decoration: underline; }

.course-link { font-weight: 600; }

/* Buttons */
.button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  background: #111827;
  color: #fff;
  border-radius: 6px;
  font-weight: 600;
}

.button:hover {
  background: var(--accent);
  text-decoration: none;
}

.button-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* Footer */
.site-footer {
  border-top: 1px solid rgba(15,23,42,0.06);
  padding: 18px 0;
  text-align: center;
  color: var(--muted);
}

/* Responsive */
@media (max-width: 880px) {
  .home-grid { flex-direction: column; }
  .nav a { margin-left: 10px; }
}