:root{
      --bg:#ffffff;
      --accent:#0b57d0;
      --text:#111;
      --nav-height:64px;
      --transition:300ms;
    }
    *{box-sizing:border-box}
    body{
      margin: 0;
      font-family: 'Inter', sans-serif;
      background-color: #f9f9f9;
      color: #333;
    }
    .main-content h1{
       font-size: 2.8rem;
       color: #1e40af;
       margin-bottom: 1rem;
    }
   

    /* Header / nav bar */
    .site-header{
      height:var(--nav-height);
      display:flex;
      align-items:center;
      justify-content:space-between;
      padding:0 1rem;
      border-bottom:1px solid rgba(0,0,0,.06);
      position:sticky;
      top:0;
      background:linear-gradient(#fff, #fff);
      z-index:100;
      box-shadow: 0 2px 8px rgba(0,0,0,0.05);
      overflow: visible; /* important pour afficher sous-menu */
    }
    .brand{
      display:flex;
      gap:.5rem;
      align-items:center;
      font-weight:700;
      letter-spacing:.3px;
      text-decoration:none;
      color:var(--text);
    }
    .brand .logo{
      width:36px;
      height:36px;
      border-radius:6px;
      background:var(--accent);
      display:inline-block;
    }

    /* Desktop nav links */
    .nav-links {
      overflow: visible; /* important */
    }
    .nav-links ul {
      display: flex;
      gap: 1rem;
      padding: 0;
      margin: 0;
      list-style: none;
      align-items: center;
    }

    .nav-links ul li {
      position: relative;
    }

    .nav-links ul li a {
      text-decoration: none;
      padding: .5rem .7rem;
      border-radius: 6px;
      transition: background var(--transition), transform var(--transition);
      color: var(--text);
      font-weight: 600;
      display: inline-block;
    }

    .nav-links ul li a:hover {
      background: rgba(11, 87, 208, 0.08);
      transform: translateY(-2px);
    }

    /* Sous-menu desktop */
    .nav-links ul li ul {
      position: absolute;
      top: 100%; /* juste sous le parent */
      left: 0;
      background: #fff;
      border-radius: 6px;
      box-shadow: 0 10px 20px rgba(0,0,0,0.1);
      display: none;
      min-width: 180px;
      padding: 0.5rem 0;
      z-index: 9999;
      opacity: 0;
      transform: translateY(10px);
      transition: opacity 0.25s ease, transform 0.25s ease;
    }

    .nav-links ul li ul li a {
      padding: 0.5rem 1rem;
      display: block;
      color: var(--text);
      font-weight: 500;
      white-space: nowrap;
      transition: background var(--transition), color var(--transition);
    }

    .nav-links ul li ul li a:hover {
      background: var(--accent);
      color: white;
    }

    /* Affichage du sous-menu au hover */
    .nav-links ul li:hover > ul {
      display: block;
      opacity: 1;
      transform: translateY(0);
    }

    /* Hamburger button (mobile) */
    .hamburger{
      display:none; /* affiché uniquement sur petit écran */
      width:44px;
      height:44px;
      border-radius:8px;
      border:none;
      background:transparent;
      cursor:pointer;
      align-items:center;
      justify-content:center;
    }
    .hamburger:focus{ outline:2px solid rgba(11,87,208,.2) }

    /* Hamburger icon lines */
    .icon{
      display:inline-block;
      position:relative;
      width:22px;
      height:16px;
    }
    .icon span{
      position:absolute;
      left:0;
      right:0;
      height:2px;
      background:var(--text);
      border-radius:2px;
      transition:transform var(--transition), opacity var(--transition);
    }
    .icon span:nth-child(1){ top:0 }
    .icon span:nth-child(2){ top:7px }
    .icon span:nth-child(3){ top:14px }

    /* Mobile menu (overlay) */
    .mobile-menu{
      position:fixed;
      inset:0 0 0 0;
      display:none;
      align-items:flex-start;
      justify-content:flex-end;
      z-index:90;
      padding:var(--nav-height) 1rem 1rem 1rem;
    }
    .mobile-panel{
      width:280px;
      max-width:90%;
      background:#fff;
      border-radius:10px;
      box-shadow:0 10px 30px rgba(0,0,0,.12);
      padding:1rem;
      transform: translateX(100%);
      transition: transform 0.4s ease, opacity 0.4s ease;
      opacity:0;
    }
    .mobile-menu.open{
      display:flex;
      animation: fadeScaleSlide 0.3s ease forwards;
    }
    .mobile-menu.open .mobile-panel{
      transform: translateX(0);
      opacity:1;
    }

    .mobile-panel a{
      display:block;
      padding:.9rem .6rem;
      text-decoration:none;
      color:var(--text);
      border-radius:8px;
      font-weight:600;
      transition: background 0.3s ease;
    }
    .mobile-panel a:hover {
      background: rgba(11, 87, 208, 0.1);
    }
    .mobile-panel a + a{
      margin-top:.25rem;
    }

    /* Sous-menu mobile accordéon */
    .mobile-submenu {
      display: none;
      padding-left: 1rem;
      margin-top: 0.25rem;
    }
    .mobile-submenu a {
      font-weight: 500;
      font-size: 0.95rem;
    }
    .mobile-panel .has-submenu {
      cursor: pointer;
      position: relative;
      font-weight: 600;
      padding: .9rem .6rem;
      border-radius: 8px;
      user-select: none;
    }
    .mobile-panel .has-submenu::after {
      content: "▸";
      position: absolute;
      right: 1rem;
      font-size: 1.1rem;
      transition: transform 0.3s ease;
    }
    .mobile-panel .has-submenu.open::after {
      content: "▾";
      transform: rotate(0deg);
    }
    .mobile-panel .has-submenu.open + .mobile-submenu {
      display: block;
    }

    /* Transform hamburger into X when open */
    .hamburger.open .icon span:nth-child(1){ transform:translateY(7px) rotate(45deg) }
    .hamburger.open .icon span:nth-child(2){ opacity:0 }
    .hamburger.open .icon span:nth-child(3){ transform:translateY(-7px) rotate(-45deg) }
    /*Bouton Rond Retour en haut */
     #btnTop {
      position: fixed;
      bottom: 30px;
      right: 30px;
      display: none;
      background-color: #f9f9f9;
      color: #007bff;
      border: 2px solid #007bff;
      width: 50px;
      height: 50px;
      border-radius: 50%; /* Cercle parfait */
      cursor: pointer;
      font-size: 0; /* Pas de texte */
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      transition: 
        background-color 0.3s ease,
        color 0.3s ease,
        box-shadow 0.3s ease,
        transform 0.2s ease;
      user-select: none;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 0;
      z-index: 100;
    }

    #btnTop:hover {
      background-color: #007bff;
      color: white;
      box-shadow: 0 8px 20px rgba(0, 123, 255, 0.4);
      transform: translateY(-3px);
    }

    #btnTop svg {
      width: 24px;
      height: 24px;
      fill: currentColor;
      transition: fill 0.3s ease;
    }
    /*Bouton telechargement */
  .app-message p {
  font-size: 1.125rem;
  color: #4b5563;
  max-width: 700px;
  margin: 0 auto 2rem;
}
.app-message {
  margin-top: 1rem;
  font-size: 1.125rem;
  color: #2563eb;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
  font-weight: 600;
}
.sections a.btn{
  text-decoration: none;
}
.btn {
  background: linear-gradient(to right, #2563eb, #1e40af);
  color: white;
  padding: 0.9rem 1.7rem;
  border-radius: 50px;
  font-weight: 600;
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.3);
  transition: all 0.3s ease-in-out;
  margin-bottom: 20px;
}
.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(37, 99, 235, 0.4);
  opacity: 0.95;
}

.section {
      display: flex;
      flex-direction: row-reverse;
      align-items: center;
      justify-content: center;
      gap: 40px;
      padding: 60px;
      background: white;
      max-width: 1200px;
      margin: 50px auto;
      border-radius: 16px;
      box-shadow: 0 6px 20px rgba(0,0,0,0.15);
      opacity: 0;
      transform: translateY(30px);
      transition: opacity 0.8s ease, transform 0.8s ease;
    }

    .section.visible {
      opacity: 1;
      transform: translateY(0);
    }

    .section img {
      width: 400px;
      height: auto;
      border-radius: 16px;
      box-shadow: 0 4px 15px rgba(0,0,0,0.2);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }

    .section img:hover {
      transform: scale(1.05);
      box-shadow: 0 6px 25px rgba(0,0,0,0.25);
    }

    .text {
      max-width: 600px;
      text-align: justify;
    }

    .text h1 {
      color: #0b3d91;
      font-size: 32px;
      margin-bottom: 20px;
    }

    .text p {
      font-size: 18px;
      line-height: 1.9;
      color: #444;
      margin-bottom: 20px;
    }
    .sections {
  padding: 3rem 1rem;
  text-align: center;
}
.section h2 {
  font-size: 2rem;
  color: #0b3d91;
  margin-bottom: 1rem;
}
.section p {
  max-width: 800px;
  margin: auto;
  color: #4b5563;
  font-size: 1.1rem;
}
.sections h2 {
  font-size: 2rem;
  color: #0b3d91;
  margin-bottom: 1rem;
}
.sections p {
  max-width: 800px;
  margin: auto;
  color: #4b5563;
  font-size: 1.1rem;
}

.section p a,
.sections p a{
  text-decoration: none;
  color: #007bff;
  padding: 5px;
}
/* Section contact */
    .contact-section {
      background: white;
      padding: 3rem 1rem;
      margin-top: 3rem;
      border-radius: 12px;
      box-shadow: 0 4px 10px rgba(0,0,0,0.05);
      max-width: 800px;
      margin-left: auto;
      margin-right: auto;
      text-align: center;
    }
    .contact-section h2 {
      color: #1e40af;
      margin-bottom: 1.5rem;
    }
    .contact-info p {
      font-size: 1.2rem;
      margin: 0.7rem 0;
    }
    .contact-info a {
      color: #2563eb;
      text-decoration: none;
    }
    .contact-info a:hover {
      text-decoration: underline;
    }

    /* Responsive breakpoints */
    @media (max-width: 860px){
      .nav-links{ display:none }
      .hamburger{ display:flex }
    }
      /* Animation keyframes */
    @keyframes fadeScaleSlide {
      0% {
        opacity: 0;
        transform: scale(0.95) translateY(-10px);
        pointer-events: none;
      }
      100% {
        opacity: 1;
        transform: scale(1) translateY(0);
        pointer-events: auto;
      }
    }

     /* Main content */
    .main-content {
      text-align: center;
      padding: 50px 20px 80px;
      max-width: 960px;
      margin: auto;
    }

    .card-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 24px;
      margin-top: 36px;
    }

    .card {
      background-color: #fff;
      padding: 28px 24px;
      border-radius: 18px;
      box-shadow: 0 12px 24px rgba(0,0,0,0.05);
      font-weight: 600;
      font-size: 1.1rem;
      user-select: none;
      transition: box-shadow 0.3s ease;
    }

    .card:hover {
      box-shadow: 0 16px 36px rgba(234,76,137,0.3);
    }

    /* Footer */
    .footer {
      text-align: center;
      padding: 22px;
      background-color: #fff;
      margin-top: 80px;
      box-shadow: 0 -4px 12px rgba(0,0,0,0.03);
      font-weight: 500;
      color: #666;
      user-select: none;
    }
    .section {
        flex-direction: column;
        text-align: center;
        padding: 15px; /* réduit l'espace en mobile */
        gap: 20px; /* réduit l'écart entre image et texte */
      }
      .text {
        text-align: center;
        font-size: 16px; /* réduit la taille du texte en mobile */
      }
      .text h1 {
        font-size: 26px; /* titre plus petit en mobile */
      }
      .section img {
        width: 100%;
        max-width: 350px; /* image plus compacte en mobile */
      }