/* Gemeinsames Stylesheet für ph.carstenfalk.de (Übersichtsseiten).
   Aufbau wie bei ma8.carstenfalk.de, Akzentfarbe Blau für Physik. */
:root {
  --bg: #f5f7fb;
  --panel: #ffffff;
  --ink: #1b2433;
  --muted: #5d687a;
  --line: #dfe4ee;
  --accent: #2f55d4;
  --accent-ink: #2442a8;
  --accent-soft: #dfe6fb;
  --north: #d7263d;
  --south: #1e9a55;
  --radius: 16px;
  --shadow: 0 1px 2px rgba(27, 36, 51, .05), 0 10px 24px rgba(27, 36, 51, .08);
  --font: "Avenir Next", "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
}
* { box-sizing: border-box; }
html { color-scheme: light; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 1080px; margin: 0 auto; padding: 20px 20px 48px; }

.top { display: flex; align-items: center; justify-content: space-between; gap: 14px; flex-wrap: wrap; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: inherit; text-decoration: none; }
.brand .logo {
  width: 38px; height: 38px; border-radius: 11px;
  background: var(--accent); color: #fff;
  display: grid; place-items: center;
  font-weight: 900; font-size: 15px; letter-spacing: -.3px;
}
.crumbs { font-size: .95rem; color: var(--muted); }
.crumbs a { color: var(--accent-ink); font-weight: 700; text-decoration: none; }
.crumbs a:hover { text-decoration: underline; }

h1 { font-size: clamp(1.9rem, 4vw, 2.6rem); line-height: 1.15; margin: .7em 0 .25em; }
.lead { color: var(--muted); font-size: 1.1rem; max-width: 62ch; margin: 0 0 28px; }

/* Abschnitt je Klasse */
.klasse { display: flex; align-items: baseline; gap: 12px; margin: 34px 0 14px; font-size: 1.35rem; }
.klasse .sub { font-size: .95rem; font-weight: 600; color: var(--muted); }

/* Karten-Übersicht */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 18px; }
.card {
  position: relative;
  display: flex; flex-direction: column; gap: 10px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  color: inherit; text-decoration: none;
  box-shadow: var(--shadow);
  transition: transform .15s ease, box-shadow .15s ease;
}
.card:hover, .card:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 2px 4px rgba(27, 36, 51, .06), 0 18px 34px rgba(27, 36, 51, .12);
  outline: none;
}
.card:focus-visible { box-shadow: 0 0 0 3px var(--accent-soft), 0 18px 34px rgba(27, 36, 51, .12); }
.card .icon {
  width: 58px; height: 58px; border-radius: 15px;
  display: grid; place-items: center;
  font-size: 30px; font-weight: 800;
  background: var(--accent-soft); color: var(--accent-ink);
}
.card .icon svg { width: 46px; height: 46px; }
.card h2 { margin: 4px 0 0; font-size: 1.3rem; line-height: 1.2; }
.card p { margin: 0; color: var(--muted); }
.card .meta { margin-top: auto; padding-top: 6px; font-size: .85rem; font-weight: 700; color: var(--accent-ink); }
.hinweis-leer { color: var(--muted); font-style: italic; margin-top: 24px; }

footer {
  margin-top: 56px; padding-top: 16px;
  border-top: 1px solid var(--line);
  color: var(--muted); font-size: .85rem;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px;
}
@media (prefers-reduced-motion: reduce) { .card { transition: none; } .card:hover { transform: none; } }