/* primzahltest.de — style.css
   Farbwelt: Weiß, Dunkelblau, Hellblau, dezentes Grün/Rot.
   Brand-Accent: #E8452B (Byte.at). Mobile First. */

:root{
  --navy:#0f2a4a;
  --navy-700:#163d68;
  --blue:#2f6fb0;
  --blue-100:#e8f1fb;
  --blue-50:#f4f9ff;
  --accent:#E8452B;
  --accent-700:#c5371f;
  --green:#1f8a4c;
  --green-100:#e6f5ec;
  --red:#c0392b;
  --red-100:#fdecea;
  --amber:#b8730a;
  --ink:#16202c;
  --muted:#5a6b7b;
  --line:#dde5ee;
  --bg:#ffffff;
  --card:#ffffff;
  --radius:14px;
  --shadow:0 1px 2px rgba(15,42,74,.06),0 6px 20px rgba(15,42,74,.07);
  --maxw:1080px;
  --font:'Segoe UI',system-ui,-apple-system,Roboto,Helvetica,Arial,sans-serif;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;font-family:var(--font);color:var(--ink);background:var(--bg);
  line-height:1.65;font-size:17px;-webkit-font-smoothing:antialiased;
}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}

/* Skip link & focus */
.skip{position:absolute;left:-999px;top:0;background:var(--navy);color:#fff;padding:10px 16px;z-index:200}
.skip:focus{left:8px;top:8px}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px}

/* Header */
header.site{background:var(--navy);color:#fff;position:sticky;top:0;z-index:100}
.nav{display:flex;align-items:center;justify-content:space-between;height:60px}
.brand{display:flex;align-items:center;gap:9px;color:#fff;font-weight:700;font-size:1.12rem}
.brand:hover{text-decoration:none}
.brand .mark{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:8px;
  background:var(--accent);color:#fff;font-weight:800;font-size:.95rem}
.menu-btn{display:inline-flex;background:transparent;border:1px solid rgba(255,255,255,.35);
  color:#fff;border-radius:8px;padding:8px 12px;font-size:1rem;cursor:pointer}
nav.primary ul{display:none}
nav.primary.open ul{display:flex}
nav.primary ul{list-style:none;margin:0;padding:0;flex-direction:column;gap:2px;
  position:absolute;left:0;right:0;top:60px;background:var(--navy-700);padding:8px 20px 14px}
nav.primary a{color:#eaf2fb;display:block;padding:9px 6px;border-bottom:1px solid rgba(255,255,255,.08)}
@media(min-width:920px){
  .menu-btn{display:none}
  nav.primary ul{display:flex !important;flex-direction:row;position:static;background:transparent;
    padding:0;gap:4px;flex-wrap:wrap;justify-content:flex-end}
  nav.primary a{border:0;padding:8px 11px;border-radius:8px;font-size:.95rem}
  nav.primary a:hover{background:var(--navy-700);text-decoration:none}
}

/* Breadcrumbs */
.crumbs{font-size:.85rem;color:var(--muted);padding:12px 0 0}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:6px;margin:0;padding:0}
.crumbs li::after{content:"›";margin-left:6px;color:var(--line)}
.crumbs li:last-child::after{content:""}

/* Hero */
.hero{background:linear-gradient(170deg,var(--navy) 0%,var(--navy-700) 100%);color:#fff;
  padding:40px 0 46px;margin-top:0}
.hero.hero-bg{position:relative;background-color:var(--navy);
  background-image:linear-gradient(180deg,rgba(15,42,74,.80),rgba(15,42,74,.90)),url("https://primzahltest.de/primzahl2.png");
  background-size:cover;background-position:center center;background-repeat:no-repeat}
.hero h1{font-size:1.9rem;line-height:1.2;margin:.2em 0 .35em;letter-spacing:-.01em;
  text-shadow:0 1px 12px rgba(0,0,0,.25)}
.hero p.sub{font-size:1.08rem;color:#e3edf8;max-width:60ch;margin:0 0 1.2em}
.hero .eyebrow{display:inline-block;background:var(--accent);color:#fff;font-weight:700;
  font-size:.72rem;letter-spacing:.08em;text-transform:uppercase;padding:5px 11px;border-radius:999px}
@media(min-width:760px){.hero h1{font-size:2.5rem}.hero.hero-bg{padding:56px 0 60px}}

/* Buttons */
.btn{display:inline-block;border:0;cursor:pointer;font:inherit;font-weight:700;
  padding:13px 22px;border-radius:10px;text-align:center;transition:transform .05s,background .15s}
.btn:hover{text-decoration:none}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:var(--accent-700)}
.btn-secondary{background:#fff;color:var(--navy);border:2px solid #fff}
.btn-secondary:hover{background:var(--blue-50)}
.btn-ghost{background:var(--blue-100);color:var(--navy)}
.btn-ghost:hover{background:#dbe9fa}
.cta-row{display:flex;flex-wrap:wrap;gap:12px}

/* Sections & cards */
main{padding:14px 0 10px}
section.block{padding:30px 0;border-top:1px solid var(--line)}
section.block:first-of-type{border-top:0}
h2{font-size:1.5rem;line-height:1.25;margin:.2em 0 .5em;color:var(--navy)}
h3{font-size:1.15rem;margin:1.1em 0 .4em;color:var(--navy-700)}
p,li{color:var(--ink)}
.lead{font-size:1.08rem;color:var(--muted)}
.grid{display:grid;gap:16px}
@media(min-width:680px){.grid.cols-2{grid-template-columns:1fr 1fr}
  .grid.cols-3{grid-template-columns:repeat(3,1fr)}}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:18px 18px;box-shadow:var(--shadow)}
.card h3{margin-top:0}
.card .more{font-weight:600}

/* Answer box (GEO/AI-Overview) */
.answerbox{background:var(--blue-50);border:1px solid var(--line);border-left:4px solid var(--accent);
  border-radius:10px;padding:16px 18px;margin:0 0 18px}
.answerbox strong{color:var(--navy)}

/* Tool UI */
.tool{background:var(--blue-50);border:1px solid var(--line);border-radius:var(--radius);
  padding:20px;box-shadow:var(--shadow)}
.tool label{display:block;font-weight:700;margin:0 0 8px;color:var(--navy)}
.tool .field{display:flex;flex-wrap:wrap;gap:10px}
.tool input[type=number],.tool input[type=text]{flex:1 1 200px;min-width:0;font:inherit;
  font-size:1.15rem;padding:14px 14px;border:2px solid var(--line);border-radius:10px;background:#fff}
.tool input:focus{border-color:var(--blue);outline:none}
.tool .hint{font-size:.85rem;color:var(--muted);margin:8px 0 0}
.result{margin-top:16px;border-radius:10px;padding:16px 18px;display:none}
.result.show{display:block}
.result.is-prime{background:var(--green-100);border:1px solid #bfe2cd}
.result.not-prime{background:var(--red-100);border:1px solid #f3c3bd}
.result.neutral{background:#fff;border:1px solid var(--line)}
.result .verdict{font-size:1.25rem;font-weight:800;margin:0 0 6px}
.result.is-prime .verdict{color:var(--green)}
.result.not-prime .verdict{color:var(--red)}
.result .err{color:var(--red);font-weight:700}
.kv{margin:8px 0 0;font-size:.97rem}
.kv b{color:var(--navy)}
.pillrow{display:flex;flex-wrap:wrap;gap:6px;margin-top:6px}
.pill{background:#fff;border:1px solid var(--line);border-radius:999px;padding:3px 10px;font-size:.9rem}
.pill.prime{border-color:var(--accent);color:var(--accent-700);font-weight:700}

/* Tables */
.tablewrap{overflow-x:auto}
table.data{border-collapse:collapse;width:100%;font-size:.95rem;background:#fff}
table.data caption{text-align:left;font-weight:700;color:var(--navy);margin-bottom:8px}
table.data th,table.data td{border:1px solid var(--line);padding:8px 10px;text-align:left}
table.data th{background:var(--blue-100);color:var(--navy)}
table.prime-grid td{text-align:center;padding:7px 4px;font-variant-numeric:tabular-nums}
table.prime-grid td.p{background:var(--green-100);font-weight:700;color:var(--green)}

/* Number grid (1..100) */
.numgrid{display:grid;grid-template-columns:repeat(10,1fr);gap:4px;max-width:560px;font-size:.85rem}
.numgrid span{display:grid;place-items:center;aspect-ratio:1/1;border-radius:7px;
  background:#fff;border:1px solid var(--line);font-variant-numeric:tabular-nums}
.numgrid span.p{background:var(--accent);color:#fff;border-color:var(--accent);font-weight:700}

/* FAQ */
.faq details{border:1px solid var(--line);border-radius:10px;margin:0 0 10px;background:#fff;overflow:hidden}
.faq summary{cursor:pointer;padding:14px 16px;font-weight:700;color:var(--navy);list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";float:right;color:var(--accent);font-weight:800}
.faq details[open] summary::after{content:"–"}
.faq .a{padding:0 16px 14px;color:var(--ink)}

/* Copybox */
.copybox{margin-top:12px}
.copybox textarea{width:100%;min-height:90px;font-family:ui-monospace,Menlo,Consolas,monospace;
  font-size:.9rem;border:1px solid var(--line);border-radius:10px;padding:12px;resize:vertical}

/* Quiz */
.quiz .q{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px;margin-bottom:14px}
.quiz .opt{display:block;width:100%;text-align:left;background:var(--blue-50);border:1px solid var(--line);
  border-radius:10px;padding:11px 14px;margin:7px 0;cursor:pointer;font:inherit}
.quiz .opt:hover{background:var(--blue-100)}
.quiz .opt.correct{background:var(--green-100);border-color:#bfe2cd;font-weight:700}
.quiz .opt.wrong{background:var(--red-100);border-color:#f3c3bd}
.quiz .explain{margin-top:8px;font-size:.95rem;color:var(--muted)}
.quiz-score{font-weight:800;color:var(--navy);font-size:1.1rem}

/* Author / meta */
.authorbox{display:flex;gap:14px;align-items:flex-start;background:var(--blue-50);
  border:1px solid var(--line);border-radius:12px;padding:16px}
.authorbox .av{flex:0 0 46px;width:46px;height:46px;border-radius:50%;background:var(--accent);
  color:#fff;display:grid;place-items:center;font-weight:800}
.meta{font-size:.85rem;color:var(--muted);margin-top:6px}

/* Related links */
.related ul{list-style:none;padding:0;margin:0;display:grid;gap:8px}
@media(min-width:680px){.related ul{grid-template-columns:1fr 1fr}}
.related a{display:block;background:#fff;border:1px solid var(--line);border-radius:10px;padding:12px 14px}
.related a:hover{border-color:var(--accent);text-decoration:none}

/* Footer */
footer.site{background:var(--navy);color:#cfe0f2;margin-top:30px;padding:34px 0 24px}
footer.site h4{color:#fff;font-size:.95rem;margin:0 0 10px}
footer.site ul{list-style:none;padding:0;margin:0}
footer.site li{margin:6px 0}
footer.site a{color:#cfe0f2}
footer.site a:hover{color:#fff}
.foot-grid{display:grid;gap:24px 32px}
@media(min-width:680px){.foot-grid{grid-template-columns:1.6fr 1fr 1fr 1fr}}
.foot-brand .brand{margin-bottom:12px}
.foot-desc{color:#cfe0f2;font-size:.92rem;max-width:42ch;margin:0}
.foot-legal{display:flex;flex-wrap:wrap;align-items:center;gap:8px 18px;
  margin:26px 0 0;border-top:1px solid rgba(255,255,255,.12);padding-top:18px}
.foot-legal-label{color:#fff;font-weight:700;font-size:.9rem}
.foot-legal a{color:#cfe0f2;font-size:.92rem}
.foot-legal a:hover{color:#fff}
.foot-catch{font-size:.85rem;color:#aac3df;margin:18px 0 0}
.foot-catch a{color:#fff;text-decoration:underline}
.foot-bottom{border-top:1px solid rgba(255,255,255,.12);margin-top:16px;padding-top:16px;
  font-size:.85rem}
.foot-bottom a{color:#cfe0f2}
.foot-bottom a:hover{color:#fff}

.note{font-size:.85rem;color:var(--muted)}
hr.soft{border:0;border-top:1px solid var(--line);margin:24px 0}

@media (prefers-reduced-motion:reduce){
  *{animation:none !important;transition:none !important;scroll-behavior:auto !important}
}

/* Cookie-Banner (Info-Hinweis, trackingfrei) */
.cookie-banner{position:fixed;left:0;right:0;bottom:0;z-index:300;
  background:var(--navy);color:#eaf2fb;box-shadow:0 -4px 20px rgba(0,0,0,.2)}
.cookie-banner[hidden]{display:none}
.cookie-inner{max-width:var(--maxw);margin:0 auto;padding:14px 20px;
  display:flex;flex-wrap:wrap;gap:14px;align-items:center;justify-content:space-between}
.cookie-inner p{margin:0;font-size:.9rem;flex:1 1 320px;color:#eaf2fb}
.cookie-inner a{color:#fff;text-decoration:underline}
.cookie-inner .btn{flex:0 0 auto}