:root {
  --theme-bg: #111827;
  --theme-bg-secondary: #1f2937;
  --theme-border: #374151;
  --theme-text: #e5e7eb;
  --theme-text-secondary: #9ca3af;
  --theme-accent: #3b82f6;
  --theme-accent-hover: #2563eb;
  --theme-shadow-color: rgba(0, 0, 0, 0.3);
}

html {
  height: 100%;
  box-sizing: border-box;
}
*, *:before, *:after {
  box-sizing: inherit;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  margin: 0;
  padding: 0;
  line-height: 1.6;
  font-size: 16px;
  background-color: var(--theme-bg);
  color: var(--theme-text);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

header {
  background-color: var(--theme-bg-secondary);
  color: var(--theme-text);
  padding: 0;
  text-align: center;
  border-bottom: 1px solid var(--theme-border);
  box-shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
  z-index: 10;
}

nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 8px 0;
}

nav ul.menu-principal {
  list-style: none;
  padding: 0 15px;
  margin: 0;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px 12px;
}

nav ul.menu-principal > li {
  position: relative;
  display: inline-block;
}

nav a {
  color: var(--theme-text);
  text-decoration: none;
  padding: 8px 16px;
  display: block;
  transition: color 0.2s ease, background-color 0.2s ease;
  border-radius: 6px;
  font-weight: 500;
}

nav ul.menu-principal > li > a:hover,
nav ul.menu-principal > li > a:focus {
  color: var(--theme-text-white);
  background-color: var(--theme-accent);
  outline: none;
}

nav ul.menu-principal > li:not(:has(ul.sous-menu)) > a {
  padding-right: 16px;
}

nav ul.menu-principal > li:has(ul.sous-menu) > a {
  position: relative;
  padding-right: 30px;
}

nav ul.menu-principal > li:has(ul.sous-menu) > a::after {
  content: '▼';
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.7em;
  color: var(--theme-text-secondary);
  pointer-events: none;
}

nav ul.sous-menu {
  list-style: none;
  padding: 8px 0;
  margin: 0;
  position: absolute;
  top: calc(100% + 5px);
  left: 0;
  background-color: var(--theme-bg-secondary);
  min-width: 200px;
  box-shadow: 0 4px 12px var(--theme-shadow-color);
  display: none;
  z-index: 100;
  border: 1px solid var(--theme-border);
  border-radius: 6px;
}

nav ul.sous-menu li {
  display: block;
  position: relative;
  border: none;
}

nav ul.sous-menu a {
  padding: 8px 20px;
  color: var(--theme-text);
  font-weight: 400;
  transition: color 0.2s ease, background-color 0.2s ease;
  white-space: nowrap;
  text-shadow: none;
  border-radius: 0;
}

nav ul.sous-menu a:hover,
nav ul.sous-menu a:focus {
  background-color: var(--theme-accent);
  color: var(--theme-text-white);
}

nav ul.menu-principal > li:hover > ul.sous-menu,
nav ul.menu-principal > li:focus-within > ul.sous-menu {
  display: block;
}

nav ul.sous-menu ul.sous-menu {
  position: absolute;
  top: 100%;
  left: 0;
  margin-top: -1px;
  min-width: 200px;
  background-color: var(--theme-bg-secondary);
  box-shadow: 0 4px 12px var(--theme-shadow-color);
  border: 1px solid var(--theme-border);
  padding: 8px 0;
  z-index: 101;
  border-radius: 6px;
}

nav ul.sous-menu li:hover > ul.sous-menu,
nav ul.sous-menu li:focus-within > ul.sous-menu {
  display: block;
}

main {
  padding: 30px 25px;
  background-color: var(--theme-bg);
  width: 100%;
  max-width: 960px;
  margin: 30px auto;
  border: none;
  box-shadow: none;
  border-radius: 8px;
  flex-grow: 1;
  background-color: var(--theme-bg-secondary);
  box-shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
}

main .titre-centre {
  color: var(--theme-text);
  text-shadow: none;
  margin-bottom: 1rem;
  font-size: 1.75em;
  font-weight: 600;
  letter-spacing: normal;
}

main p.titre-centre {
  color: var(--theme-text-secondary);
  text-shadow: none;
  font-size: 1.1em;
  margin-bottom: 2rem;
}

footer {
  background-color: var(--theme-bg-secondary);
  color: var(--theme-text-secondary);
  text-align: center;
  padding: 20px 0;
  width: 100%;
  margin-top: auto;
  font-size: 0.9em;
  border-top: 1px solid var(--theme-border);
  box-shadow: none;
}

footer p {
  margin: 0;
  letter-spacing: normal;
}

@media (max-width: 768px) {
  body {
      font-size: 15px;
  }
  nav ul.menu-principal {
      flex-direction: column;
      align-items: stretch;
      padding: 0;
      gap: 0;
  }
  nav ul.menu-principal > li {
      display: block;
      width: 100%;
      text-align: left;
  }
  nav ul.menu-principal > li > a {
      border-bottom: 1px solid var(--theme-border);
      padding: 12px 20px;
      text-align: left;
      border-radius: 0;
  }
  nav ul.menu-principal > li:last-child > a {
      border-bottom: none;
  }
  nav ul.menu-principal > li > a:hover,
  nav ul.menu-principal > li > a:focus {
      color: var(--theme-text-white);
      background-color: var(--theme-accent);
  }

  nav ul.menu-principal > li:has(ul.sous-menu) > a::after {
      right: 20px; 
  }

  nav ul.sous-menu {
      position: static;
      box-shadow: none;
      background-color: rgba(0, 0, 0, 0.15);
      width: 100%;
      display: none;
      border: none;
      padding: 0;
      border-radius: 0;
  }

  nav ul.sous-menu a {
      color: var(--theme-text);
      padding: 10px 30px;
      text-shadow: none;
      border-bottom: 1px solid var(--theme-border);
      border-radius: 0;
  }
  nav ul.sous-menu li:last-child a { border-bottom: none; }

  nav ul.sous-menu a:hover,
  nav ul.sous-menu a:focus {
       background-color: var(--theme-accent);
       color: var(--theme-text-white);
  }

  nav ul.sous-menu ul.sous-menu {
      position: static;
      background-color: rgba(0, 0, 0, 0.25);
      padding-left: 0;
      margin-top: 0;
      box-shadow: none;
      border: none;
      padding: 0;
      border-radius: 0;
  }
  nav ul.sous-menu ul.sous-menu a {
      padding-left: 45px;
      color: var(--theme-text);
       border-bottom: 1px solid var(--theme-border);
  }
    nav ul.sous-menu ul.sous-menu a:hover,
    nav ul.sous-menu ul.sous-menu a:focus {
         background-color: var(--theme-accent);
         color: var(--theme-text-white);
    }

  nav ul.menu-principal > li:hover > ul.sous-menu,
  nav ul.menu-principal > li:focus-within > ul.sous-menu,
  nav ul.sous-menu li:hover > ul.sous-menu,
  nav ul.sous-menu li:focus-within > ul.sous-menu {
      display: block;
  }

  main {
      padding: 20px 15px;
      margin: 15px;
      width: auto;
      max-width: none;
      border-radius: 6px;
  }
  main .titre-centre { font-size: 1.4em; }
  main p.titre-centre { font-size: 1em; }

  footer {
      padding: 15px;
      font-size: 0.85em;
  }
}