:root {
  --bg: #f8fafc;
  --text: #0f172a;
  --accent: #2563eb;
  --accent-hover: #1e40af;
  --accent-contrast: #ffffff;
  --muted: #6b7280;
  --radius: 12px;
  --shadow: 0 6px 18px rgba(0,0,0,0.08);
  font-size: 16px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* Skip-Link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 8px;
  z-index: 100;
}
.skip-link:focus {
  top: 10px;
}

/* Header & Navigation */
.site-header {
  background: #fff;
  border-bottom: 1px solid #e5e7eb;
  padding: 0.5rem 1rem;
}
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1100px;
  margin: 0 auto;
}
.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--accent);
  text-decoration: none;
}
.nav-list {
  display: flex;
  gap: 1rem;
  list-style: none;
  padding: 0;
  margin: 0;
}
.nav-list a {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
}
.nav-list a:hover,
.nav-list a:focus {
  color: var(--accent);
  text-decoration: underline;
}

/* Burger Menü */
.nav-toggle {
  display: none;
  font-size: 1.5rem;
  background: none;
  border: none;
  cursor: pointer;
}

/* Hero */
.hero {
  text-align: center;
  padding: 4rem 1rem;
}
.hero h1 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}
.hero .subtitle {
  color: var(--muted);
  margin-bottom: 1.5rem;
}

/* Features */
.features {
  padding: 3rem 1rem;
  max-width: 1100px;
  margin: 0 auto;
}
.features .grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}
.features article {
  background:#fff;
  border-radius: var(--radius);
  padding:1rem;
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}
.features article:hover,
.features article:focus {
  transform: translateY(-4px);
  box-shadow: 0 10px 24px rgba(0,0,0,0.12);
  outline: 3px solid #93c5fd;
}
.feature-section {
  margin-top: 1.5rem;
}
.hidden {
  display: none;
}

/* Kontaktformular */
.contact {
  padding: 3rem 1rem;
  max-width: 700px;
  margin: 0 auto;
}
.contact form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.contact input,
.contact textarea {
  padding: 0.75rem;
  border: 1px solid #d1d5db;
  border-radius: var(--radius);
  font-size: 1rem;
}
.contact input:focus,
.contact textarea:focus {
  outline: 3px solid #93c5fd;
  border-color: var(--accent);
}

/* Download */
.download {
  text-align: center;
  padding: 3rem 1rem;
}
.download .actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius);
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow);
}
.btn:hover,
.btn:focus {
  background: var(--accent-hover);
}

/* Footer */
.footer {
  background: #f1f5f9;
  text-align: center;
  padding: 1rem;
  font-size: 0.9rem;
  color: var(--muted);
}

/* Fortschrittsbalken */
.bar-container {
  background: #e5e7eb;
  border-radius: var(--radius);
  overflow: hidden;
  height: 20px;
  margin-top: 8px;
}
.bar {
  background: var(--accent);
  height: 100%;
  width: 0%;
  transition: width 0.3s ease;
}

/* Responsive Navigation */
@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }
  .nav-list {
    display: none;
    flex-direction: column;
    gap: 0.75rem;
    margin-top: 1rem;
    background: #fff;
    padding: 1rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
  }
  .nav-list.show {
    display: flex;
  }
}