:root {
  --primary: #1a73e8;
  --primary-dark: #0d47a1;
  --bg: #f8f9fa;
  --bg-card: #ffffff;
  --text: #212529;
  --text-muted: #6c757d;
  --border: #dee2e6;
  --accent-red: #dc3545;
  --accent-green: #198754;
  --accent-orange: #fd7e14;
  --accent-purple: #6f42c1;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; color: var(--primary-dark); }

nav {
  background: #0d1117;
  color: #fff;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  gap: 2rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,.15);
}
nav .logo {
  font-size: 1.25rem;
  font-weight: 700;
  padding: 1rem 0;
  white-space: nowrap;
  color: #58a6ff;
}
nav .logo span { color: #fff; }
nav ul {
  list-style: none;
  display: flex;
  gap: .25rem;
  flex-wrap: wrap;
}
nav ul li a {
  color: #c9d1d9;
  padding: .75rem .75rem;
  display: block;
  font-size: .875rem;
  border-radius: 6px;
  transition: background .15s;
}
nav ul li a:hover, nav ul li a.active {
  background: rgba(255,255,255,.08);
  color: #fff;
  text-decoration: none;
}

.hero {
  background: linear-gradient(135deg, #0d1117 0%, #161b22 50%, #0d47a1 100%);
  color: #fff;
  padding: 4rem 2rem;
  text-align: center;
}
.hero h1 { font-size: 2.5rem; margin-bottom: 1rem; }
.hero p { font-size: 1.15rem; max-width: 700px; margin: 0 auto 2rem; color: #c9d1d9; }

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.75rem;
  transition: box-shadow .2s, transform .2s;
}
.card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,.08);
  transform: translateY(-2px);
}
.card h3 { margin-bottom: .5rem; font-size: 1.1rem; }
.card p { color: var(--text-muted); font-size: .95rem; }
.card .icon { font-size: 2rem; margin-bottom: .75rem; display: block; }
.card a.btn {
  display: inline-block;
  margin-top: 1rem;
  padding: .5rem 1rem;
  background: var(--primary);
  color: #fff;
  border-radius: 6px;
  font-size: .875rem;
  font-weight: 600;
}
.card a.btn:hover { background: var(--primary-dark); text-decoration: none; }

h1 { font-size: 2rem; margin-bottom: 1rem; }
h2 { font-size: 1.5rem; margin: 2rem 0 1rem; padding-bottom: .5rem; border-bottom: 2px solid var(--primary); }
h3 { font-size: 1.2rem; margin: 1.5rem 0 .75rem; }
p, li { margin-bottom: .5rem; }
ul, ol { padding-left: 1.5rem; margin-bottom: 1rem; }

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: .9rem;
  background: var(--bg-card);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 1px 4px rgba(0,0,0,.06);
}
th, td { padding: .75rem 1rem; text-align: left; border-bottom: 1px solid var(--border); }
th { background: #0d1117; color: #fff; font-weight: 600; }
tr:last-child td { border-bottom: none; }
tr:hover td { background: #f1f3f5; }

.callout {
  background: #e7f1ff;
  border-left: 4px solid var(--primary);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 8px 8px 0;
}
.callout.warning { background: #fff3cd; border-color: var(--accent-orange); }
.callout.danger { background: #f8d7da; border-color: var(--accent-red); }

.badge {
  display: inline-block;
  padding: .2rem .6rem;
  border-radius: 12px;
  font-size: .75rem;
  font-weight: 600;
  color: #fff;
}
.badge.red { background: var(--accent-red); }
.badge.green { background: var(--accent-green); }
.badge.orange { background: var(--accent-orange); }
.badge.purple { background: var(--accent-purple); }
.badge.blue { background: var(--primary); }

.checklist { list-style: none; padding-left: 0; }
.checklist li { padding: .4rem 0; padding-left: 1.75rem; position: relative; }
.checklist li::before { content: "\2610"; position: absolute; left: 0; color: var(--primary); font-weight: bold; }

.level { padding: 1.25rem; border-radius: 8px; margin: 1rem 0; border-left: 4px solid; }
.level.decouverte { border-color: var(--accent-green); background: #d1e7dd; }
.level.intermediaire { border-color: var(--accent-orange); background: #fff3cd; }
.level.avance { border-color: var(--accent-red); background: #f8d7da; }
.level h3 { margin-top: 0; }

footer {
  background: #0d1117;
  color: #8b949e;
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
  font-size: .875rem;
}
footer a { color: #58a6ff; }

@media (max-width: 768px) {
  nav { flex-direction: column; padding: .75rem 1rem; gap: .5rem; }
  nav ul { gap: 0; }
  .hero { padding: 2.5rem 1rem; }
  .hero h1 { font-size: 1.75rem; }
  .container { padding: 1.5rem 1rem; }
}