/* Rechenraumschiff – Seite. Hell, ruhig, klar. Dunkel folgt der Systemeinstellung. */
:root {
  --bg: #ffffff;
  --bg-alt: #f5f5f7;
  --card: #ffffff;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: #d2d2d7;
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --accent-ink: #ffffff;
  --nav: rgba(255, 255, 255, .8);
  --shadow: 0 20px 50px rgba(0, 0, 0, .16);
  --frame: #1d1d1f;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-alt: #1d1d1f;
    --card: #2c2c2e;
    --ink: #f5f5f7;
    --muted: #a1a1a6;
    --line: #424245;
    --accent: #2997ff;
    --accent-hover: #4aa8ff;
    --accent-ink: #ffffff;
    --nav: rgba(0, 0, 0, .72);
    --shadow: 0 20px 50px rgba(0, 0, 0, .6);
    --frame: #3a3a3c;
  }
}

* { box-sizing: border-box; }
html { background: var(--bg); scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.5;
  font-size: 1.0625rem;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { width: min(1020px, 100% - 40px); margin: 0 auto; }
section { padding: 88px 0; }
section.alt { background: var(--bg-alt); }
h1, h2, h3 { margin: 0 0 14px; letter-spacing: -.022em; }
h1 { font-size: clamp(2.6rem, 8vw, 4.6rem); line-height: 1.04; font-weight: 700; letter-spacing: -.035em; }
h2 { font-size: clamp(1.9rem, 5vw, 2.8rem); line-height: 1.1; font-weight: 700; text-align: center; margin-bottom: 44px; }
h3 { font-size: 1.3rem; font-weight: 600; line-height: 1.2; }
p { margin: 0 0 14px; }
.eyebrow { color: var(--accent); font-weight: 600; font-size: .9rem; letter-spacing: .01em; margin-bottom: 8px; }
.lead { font-size: clamp(1.15rem, 2.6vw, 1.5rem); line-height: 1.35; color: var(--muted); max-width: 30em; margin: 0 auto 28px; letter-spacing: -.01em; }
.fine { color: var(--muted); font-size: .9rem; }

/* Navigation */
.top {
  position: sticky; top: 0; z-index: 10;
  background: var(--nav);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(128, 128, 128, .2);
}
.top .wrap { display: flex; align-items: center; justify-content: space-between; height: 104px; }
.brand { display: flex; align-items: center; gap: 18px; font-weight: 600; font-size: 2rem; letter-spacing: -.02em; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand img { width: 52px; height: 52px; border-radius: 14px; }
.top nav a { color: var(--ink); opacity: .8; font-size: .85rem; margin-left: 24px; }
.top nav a:hover { opacity: 1; text-decoration: none; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 0 26px; border-radius: 980px;
  font: inherit; font-weight: 500; font-size: 1.0625rem; cursor: pointer; border: 0;
  background: var(--bg-alt); color: var(--ink);
}
.btn:hover { text-decoration: none; filter: brightness(.97); }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { background: var(--accent-hover); filter: none; }
.btn-disabled { opacity: .45; cursor: default; pointer-events: none; }
.link-more { font-size: 1.0625rem; }
.link-more::after { content: " ›"; }
.cta { display: flex; flex-wrap: wrap; gap: 14px 28px; justify-content: center; align-items: center; }

/* Hero */
.hero { text-align: center; padding: 72px 0 0; overflow: hidden; }
.hero h1 { margin-bottom: 16px; }
.hero .cta { margin-bottom: 14px; }
.phones { display: flex; justify-content: center; align-items: flex-start; gap: 0; margin-top: 56px; height: clamp(360px, 62vw, 560px); overflow: hidden; }
.phone {
  width: clamp(150px, 26vw, 250px);
  border-radius: clamp(22px, 4vw, 36px); border: 6px solid var(--frame); overflow: hidden;
  box-shadow: var(--shadow); background: var(--frame); flex: none;
}
.phones .phone:nth-child(1) { transform: translate(18%, 36px) scale(.9); }
.phones .phone:nth-child(3) { transform: translate(-18%, 36px) scale(.9); }
.phones .phone:nth-child(2) { z-index: 1; }

/* Karten */
.grid { display: grid; gap: 20px; grid-template-columns: repeat(3, 1fr); }
.card { background: var(--card); border-radius: 22px; padding: 30px 28px 32px; }
section.alt .card { background: var(--card); }
section:not(.alt) .card { background: var(--bg-alt); }
.card p { color: var(--muted); margin: 0; }
.card .eyebrow { margin-bottom: 10px; }
.card ul { margin: 0; padding-left: 1.15em; color: var(--muted); }
.card li { padding: 2px 0; }
.steps .num { display: block; font-size: 2.6rem; font-weight: 700; letter-spacing: -.03em; color: var(--accent); line-height: 1; margin-bottom: 14px; }
.quote { max-width: 720px; margin: 0 auto; text-align: center; font-size: clamp(1.3rem, 3.4vw, 1.8rem); line-height: 1.35; letter-spacing: -.015em; font-weight: 500; }
.quote small { display: block; margin-top: 16px; font-size: 1rem; color: var(--muted); font-weight: 400; }

/* Preise */
.plans { display: grid; gap: 20px; grid-template-columns: 1fr 1fr; max-width: 780px; margin: 0 auto; }
.plan { background: var(--card); border-radius: 22px; padding: 34px 30px; display: flex; flex-direction: column; border: 1px solid var(--line); }
section.alt .plan { border-color: transparent; }
.plan.pro, section.alt .plan.pro { border: 2px solid var(--accent); }
.plan h3 { margin-bottom: 4px; }
.price { font-size: 2.8rem; font-weight: 700; letter-spacing: -.03em; margin: 2px 0 20px; line-height: 1.1; }
.price small { display: block; font-size: .95rem; color: var(--muted); font-weight: 400; letter-spacing: 0; margin-top: 2px; }
.plan ul { list-style: none; padding: 0; margin: 0 0 26px; flex: 1; border-top: 1px solid var(--line); }
.plan li { padding: 11px 0; border-bottom: 1px solid var(--line); font-size: .98rem; }
.plan li.no { color: var(--muted); }
.plan .btn { width: 100%; }

/* FAQ */
.faq { max-width: 740px; margin: 0 auto; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); padding: 20px 0; }
.faq summary { cursor: pointer; font-weight: 600; font-size: 1.1rem; list-style: none; display: flex; justify-content: space-between; gap: 20px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-weight: 300; font-size: 1.6rem; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq details p { margin: 12px 0 0; color: var(--muted); }

/* Fuß */
footer { background: var(--bg-alt); padding: 28px 0 40px; color: var(--muted); font-size: .85rem; border-top: 1px solid var(--line); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 10px 28px; justify-content: space-between; }
footer a { color: var(--muted); margin-right: 22px; }
footer a:hover { color: var(--ink); }

/* Rechtstexte */
.legal { max-width: 720px; padding: 56px 0 90px; }
.legal h1 { font-size: clamp(2rem, 6vw, 3rem); margin-bottom: 28px; }
.legal h2 { text-align: left; font-size: 1.35rem; margin: 34px 0 10px; }
.legal p, .legal li { color: var(--muted); }
.legal ul { padding-left: 22px; }

@media (max-width: 800px) {
  section { padding: 60px 0; }
  .hero { padding-top: 48px; }
  .grid, .plans { grid-template-columns: 1fr; }
  .top { position: static; }
  .top .wrap { height: 88px; }
  .brand { font-size: 1.6rem; gap: 12px; }
  .brand img { width: 44px; height: 44px; border-radius: 12px; }
  .top nav a:not(:last-child) { display: none; }
  .phones .phone:nth-child(1), .phones .phone:nth-child(3) { display: none; }
  .phone { width: min(62vw, 250px); }
  .phones { height: auto; max-height: 540px; }
}

/* Übungsblätter */
.tool { max-width: 860px; padding: 56px 0 80px; }
.tool h1 { font-size: clamp(2rem, 6vw, 3rem); }
.tool .lead { margin: 0 0 8px; max-width: none; }
.controls { display: flex; flex-wrap: wrap; gap: 14px; align-items: end; margin: 22px 0 30px; }
.controls label { display: grid; gap: 6px; font-weight: 500; font-size: .9rem; color: var(--muted); }
.controls select { font: inherit; font-size: 1rem; color: var(--ink); background: var(--bg-alt); padding: 0 14px; border-radius: 12px; border: 1px solid var(--line); min-height: 48px; }
.sheet { background: #fff; color: #111; border-radius: 14px; border: 1px solid var(--line); padding: 32px 36px; }
.sheet h2 { text-align: left; font-size: 1.5rem; margin: 0 0 6px; color: #111; }
.sheet .foot b { color: #111; }
.sheet .meta { display: flex; justify-content: space-between; gap: 20px; margin: 14px 0 22px; font-weight: 700; }
.sheet .meta span { flex: 1; border-bottom: 2px solid #111; padding-bottom: 2px; }
.tasks { list-style: none; counter-reset: t; padding: 0; margin: 0; columns: 2; column-gap: 40px; }
.tasks li { counter-increment: t; break-inside: avoid; padding: 9px 0; font-size: 1.25rem; font-weight: 700; display: flex; gap: 10px; }
.tasks li::before { content: counter(t) "."; width: 2em; color: #777; font-weight: 600; }
.blank { display: inline-block; min-width: 3.2em; border-bottom: 2px solid #111; margin: 0 .1em; }
.solutions { margin-top: 34px; padding-top: 16px; border-top: 3px dashed #bbb; }
.solutions h3 { font-size: 1.1rem; color: #111; }
.solutions .tasks li { font-size: 1.05rem; padding: 4px 0; }
.foot { margin-top: 22px; font-size: .95rem; color: #555; }
@media (max-width: 640px) { .tasks { columns: 1; } .sheet { padding: 20px; } }
@media print {
  body { background: #fff !important; }
  .top, .noprint, footer { display: none !important; }
  .tool { width: 100%; max-width: none; padding: 0; margin: 0; }
  .sheet { border-radius: 0; padding: 0; }
  .solutions { break-before: page; border-top: 0; margin-top: 0; padding-top: 0; }
}

/* Themenseiten */
.intro { max-width: 720px; }
.intro p { font-size: 1.15rem; line-height: 1.45; color: var(--muted); margin: 0 0 12px; letter-spacing: -.01em; }
.prose { max-width: 720px; margin-top: 56px; }
.prose h2 { text-align: left; font-size: 1.5rem; margin: 30px 0 10px; }
.prose p, .prose li { color: var(--muted); }
.prose ul { padding-left: 22px; }
.prose li { padding: 3px 0; }
.related { list-style: none; padding: 0; }
.related li { padding: 6px 0; border-bottom: 1px solid var(--line); }
.related li:last-child { border-bottom: 0; }