/*
  Studentsponsor Landing Page – style.css
  - Klare Farbpalette: Blau (Akzent), Weiß, dezente Grautöne
  - Responsives Layout mit Flexbox/Grid
  - Gut lesbare Typografie (Inter), ausreichende Abstände
*/

:root {
  --bg: #f7f9fc;
  --text: #0f172a;        /* sehr dunkles Blau/Grau */
  --muted: #64748b;       /* gedämpftes Grau/Blau */
  --card: #ffffff;        /* Weiß */
  --border: #e2e8f0;      /* zartes Grau */
  --accent: #2563eb;      /* Akzent-Blau */
  --accent-weak: #dbeafe; /* helles Blau für Hintergründe */
}

/* Basis */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  line-height: 1.5;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 16px;
}

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; font-weight: 600; border-radius: 10px; transition: transform .06s ease, box-shadow .2s ease; }
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-sm { padding: 8px 12px; font-size: 14px; }
.btn-lg { padding: 12px 18px; font-size: 16px; }

.btn-accent { background: var(--accent); color: #fff; box-shadow: 0 6px 14px rgba(37,99,235,.25); }
.btn-accent:hover { box-shadow: 0 8px 18px rgba(37,99,235,.35); }

.btn-outline { border: 2px solid var(--border); color: var(--text); background: transparent; }
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }

/* Header / Navigation */
.site-header {
  position: sticky; top: 0; z-index: 10; 
  backdrop-filter: saturate(1.2) blur(6px);
  background: rgba(255,255,255,.7);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-weight: 700; letter-spacing: .2px; }
.menu { display: none; gap: 18px; align-items: center; }
.menu a { color: var(--muted); }
.menu a:hover { color: var(--text); }

@media (min-width: 860px) {
  .menu { display: flex; }
}

/* Hero */
.hero { padding: 64px 0; background: linear-gradient(180deg, #ffffff 0%, #f7f9fc 100%); }
.hero-inner { display: grid; grid-template-columns: 1fr; gap: 24px; align-items: center; }
.hero-text h1 { font-size: clamp(28px, 4vw, 44px); line-height: 1.15; margin: 0 0 12px; }
.hero-text .lead { color: var(--muted); margin: 0 0 18px; font-size: clamp(16px, 2.2vw, 18px); }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; }

/* Hero Visual – Laptop Mockup */
.hero-visual { display: grid; place-items: center; }
.laptop { width: min(520px, 95%); aspect-ratio: 16 / 10; background: #0b1220; border-radius: 14px; padding: 14px; box-shadow: 0 20px 60px rgba(2, 6, 23, .25); }
.screen { width: 100%; height: 100%; background: #0e1628; border-radius: 8px; position: relative; overflow: hidden; }
.banner { position: absolute; top: 0; left: 0; right: 0; height: 46px; background: var(--accent); color: #fff; display: flex; align-items: center; justify-content: center; font-weight: 600; letter-spacing: .2px; }
.content-lines { position: absolute; inset: 60px 18px 18px; display: grid; gap: 10px; }
.content-lines span { display: block; height: 10px; background: #1f2a44; border-radius: 6px; }
.content-lines span:nth-child(1) { width: 80%; }
.content-lines span:nth-child(2) { width: 60%; }
.content-lines span:nth-child(3) { width: 70%; }
.content-lines span:nth-child(4) { width: 50%; }
.base { width: 60%; height: 8px; background: #cbd5e1; border-radius: 0 0 10px 10px; margin: 10px auto 0; }

@media (min-width: 900px) {
  .hero-inner { grid-template-columns: 1.1fr 1fr; }
}

/* Sections */
.section { padding: 56px 0; }
.section.alt { background: #ffffff; }
.section-title { font-size: 24px; margin: 0 0 18px; }
.muted { color: var(--muted); }

/* Features */
.features-grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
.feature-card { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 16px; display: grid; gap: 8px; }
.feature-card .icon { font-size: 26px; }

@media (min-width: 860px) {
  .features-grid { grid-template-columns: repeat(3, 1fr); }
}

/* Bullet Lists */
.bullet-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; }
.bullet-list li { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 10px 12px; }

/* CTA */
.cta { background: linear-gradient(180deg, #eef2ff 0%, #ffffff 100%); }
.cta-inner { text-align: center; }
.cta .btn { margin: 6px; }

/* Footer */
.site-footer { background: #0b1220; color: #cbd5e1; padding-top: 28px; }
.footer-grid { display: grid; grid-template-columns: 1fr; gap: 20px; padding: 12px 0 20px; }
.footer-links { list-style: none; padding: 0; margin: 8px 0 0; display: grid; gap: 8px; }
.footer-links a { color: #cbd5e1; }
.footer-links a:hover { color: #ffffff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.12); padding: 12px 0 18px; text-align: center; font-size: 14px; }

@media (min-width: 860px) {
  .footer-grid { grid-template-columns: 1.2fr .8fr .8fr; }
}