/* Dazwischen – Webseite. Nur Systemschriften, keine externen Ressourcen (DSGVO). */
:root {
  --blue: #3b6ef5;
  --blue-dark: #2c50cf;
  --green: #1f9d55;
  --amber: #f2a900;
  --bg: #f7f7fb;
  --card: #ffffff;
  --text: #1c1c24;
  --muted: #5d5d6e;
  --line: #e3e3ec;
  --radius: 16px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #13131a;
    --card: #1d1d27;
    --text: #f1f1f6;
    --muted: #a3a3b5;
    --line: #2d2d3a;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
a { color: var(--blue); }
img { max-width: 100%; height: auto; }
.wrap { max-width: 920px; margin: 0 auto; padding: 0 20px; }

/* Kopfzeile */
header.top { padding: 18px 0; }
header.top .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); font-weight: 800; letter-spacing: 1.5px; }
.brand img { width: 36px; height: 36px; border-radius: 9px; }
nav.top a { color: var(--muted); text-decoration: none; margin-left: 16px; font-size: 15px; }
nav.top a:hover { color: var(--text); }

/* Startseite */
.hero { text-align: center; padding: 40px 0 24px; }
.hero img.icon { width: 112px; height: 112px; border-radius: 26px; box-shadow: 0 10px 30px rgba(59, 110, 245, .35); }
.hero h1 { font-size: clamp(34px, 7vw, 54px); margin: 18px 0 6px; letter-spacing: 2px; }
.hero p.lead { font-size: clamp(18px, 3vw, 22px); color: var(--muted); margin: 0 auto 26px; max-width: 580px; }
.btn {
  display: inline-block; background: var(--blue); color: #fff; text-decoration: none;
  padding: 14px 28px; border-radius: 999px; font-weight: 700; font-size: 18px;
  box-shadow: 0 6px 18px rgba(59, 110, 245, .35);
}
.btn:hover { background: var(--blue-dark); }
.stores { margin-top: 14px; color: var(--muted); font-size: 15px; }

/* Beispiel-Rätsel */
.demo { max-width: 360px; margin: 34px auto 0; display: grid; gap: 10px; }
.demo .bound { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 8px; text-align: center; }
.demo .bound small { display: block; font-size: 11px; letter-spacing: 1.2px; color: var(--muted); }
.demo .bound b { font-size: 26px; letter-spacing: 8px; }
.demo .bound b span { color: var(--green); }
.demo .cells { display: flex; justify-content: center; gap: 6px; }
.demo .cells i { width: 46px; height: 52px; display: flex; align-items: center; justify-content: center; font-style: normal; font-weight: 800; font-size: 24px; border: 2px solid var(--line); border-radius: 10px; background: var(--card); }
.demo .cells i:first-child { border-color: var(--green); background: rgba(31, 157, 85, .12); }

/* Abschnitte */
section { padding: 30px 0; }
h2 { font-size: 26px; margin: 0 0 16px; }
.cards { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); font-size: 16px; }
.num { display: inline-flex; width: 30px; height: 30px; border-radius: 50%; background: var(--blue); color: #fff; align-items: center; justify-content: center; font-weight: 700; margin-bottom: 8px; }
.levels { display: flex; flex-wrap: wrap; gap: 10px; }
.levels span { background: var(--card); border: 1px solid var(--line); border-radius: 999px; padding: 8px 16px; font-weight: 600; }
.levels span b { color: var(--blue); }

/* Textseiten */
main.text { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; margin: 10px auto 30px; }
main.text h1 { margin-top: 0; font-size: 30px; }
main.text h2 { font-size: 20px; margin: 28px 0 8px; }
main.text p, main.text li { color: var(--text); }
.note { background: rgba(242, 169, 0, .15); border-radius: 10px; padding: 10px 14px; font-size: 15px; }
details { border-bottom: 1px solid var(--line); padding: 12px 0; }
summary { font-weight: 600; cursor: pointer; }

/* Fußzeile */
footer { padding: 28px 0 40px; color: var(--muted); font-size: 14px; text-align: center; }
footer a { color: var(--muted); margin: 0 8px; }

@media (max-width: 520px) {
  nav.top a { margin-left: 10px; font-size: 14px; }
  main.text { padding: 20px; }
}