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

/* DA 29 Challenge : fond clair, touches de bleu */
:root {
  --bg: #f7f7fa;
  --surface: #fff;
  --card-border: #e8e8ec;
  --text: #1a1a1f;
  --text-secondary: #1a1a1f;
  --text-tertiary: #1a1a1f;
  --muted: #1a1a1f;
  --accent: #2563eb;
  --accent-light: #dbeafe;
  --max-width: 720px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, 'DM Sans', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  background: var(--surface);
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--card-border);
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}

nav a {
  color: var(--text);
  text-decoration: none;
  font-size: 0.95rem;
  padding: 0.35rem 0.6rem;
  border-radius: 8px;
  transition: background 0.2s, color 0.2s;
}

nav a:hover {
  background: var(--accent-light);
  color: var(--accent);
}

.logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--accent);
}

main {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
  width: 100%;
}

h1 {
  font-size: clamp(1.75rem, 5vw, 2.25rem);
  margin-bottom: 0.5rem;
  font-weight: 700;
  color: var(--text);
}

h2 {
  font-size: 1.35rem;
  margin: 2rem 0 0.75rem;
  font-weight: 600;
  color: var(--accent);
}

h3 {
  font-size: 1.1rem;
  margin: 1.25rem 0 0.5rem;
  font-weight: 600;
  color: var(--text);
}

p {
  margin-bottom: 1rem;
  color: var(--text);
}

.lead {
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 2rem;
}

a[href^="mailto"] {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

a[href^="mailto"]:hover {
  text-decoration: underline;
}

footer {
  background: var(--surface);
  padding: 1.25rem 1.5rem;
  border-top: 1px solid var(--card-border);
  text-align: center;
  font-size: 0.9rem;
  color: var(--text);
}

footer a {
  color: var(--accent);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* Page d'accueil */
.hero {
  text-align: center;
  padding: 3rem 0 2rem;
}

.hero h1 {
  margin-bottom: 0.75rem;
}

.cta {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.6rem 1.25rem;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 10px;
  font-weight: 600;
  transition: opacity 0.2s, transform 0.2s;
  box-shadow: 0 1px 3px rgba(37, 99, 235, 0.25);
}

.cta:hover {
  opacity: 0.92;
  transform: translateY(-1px);
}

/* Listes */
ul, ol {
  margin: 0 0 1rem 1.25rem;
  color: var(--text);
}

li {
  margin-bottom: 0.35rem;
}

/* Responsive */
@media (max-width: 480px) {
  header, main {
    padding-left: 1rem;
    padding-right: 1rem;
  }
  .hero {
    padding: 2rem 0 1.5rem;
  }
}