:root {
  --bg: #f5f6f8;
  --surface: #ffffff;
  --surface-2: #f0f2f5;
  --border: #d0d5dd;
  --text: #1a1d21;
  --muted: #5c6570;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --radius: 10px;
  --font: "Segoe UI", system-ui, -apple-system, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

/* ——— Навигация лабораторных ——— */
.site-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.25rem;
  padding: 0.85rem 1.5rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.site-nav__home {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
}

.site-nav__home:hover {
  color: var(--accent-hover);
}

.site-nav__title {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
}

.site-nav__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-left: auto;
}

.site-nav__links a {
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  font-size: 0.88rem;
  color: var(--muted);
  text-decoration: none;
  border: 1px solid transparent;
}

.site-nav__links a:hover {
  color: var(--text);
  background: var(--surface-2);
}

.site-nav__links a.is-active {
  color: var(--accent);
  background: #eff6ff;
  border-color: #bfdbfe;
  font-weight: 600;
}

/* ——— Главная страница ——— */
.home {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
}

.home h1 {
  margin: 0 0 0.5rem;
  font-size: 1.75rem;
  font-weight: 600;
}

.home__meta {
  margin: 0 0 2rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.lab-grid {
  display: grid;
  gap: 1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.lab-card {
  display: block;
  padding: 1.25rem 1.35rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.lab-card:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.12);
}

.lab-card h2 {
  margin: 0 0 0.35rem;
  font-size: 1.1rem;
  color: var(--accent);
}

.lab-card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--muted);
}

.lab-card--soon {
  opacity: 0.65;
  pointer-events: none;
}

/* ——— Заглушка лабораторной ——— */
.lab-stub {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.lab-stub h1 {
  margin: 0 0 0.75rem;
  font-size: 1.5rem;
}

.lab-stub p {
  margin: 0;
  color: var(--muted);
}