/* Configuration globale */
body { 
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; 
    line-height: 1.6; 
    margin: 0; 
    color: #333;
    background-image: url('estl-pano.jpg');
    background-size: cover;
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
}

header { 
    background: rgba(0, 74, 153, 0.9); 
    color: white; 
    padding: 2.5rem; 
    text-align: center; 
}

.main-logo {
    max-width: 120px;
    margin-bottom: 1rem;
}

/* Menu fixe (Sticky) */
nav { 
    background: rgba(244, 244, 244, 0.98); 
    padding: 1rem; 
    text-align: center; 
    border-bottom: 2px solid #ddd;
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav a { 
    margin: 0 15px; 
    text-decoration: none; 
    color: #004a99; 
    font-weight: bold; 
    transition: color 0.3s;
}

nav a:hover { color: #002a55; text-decoration: underline; }

/* Contenu Principal */
section { 
    max-width: 800px; 
    margin: 3rem auto; 
    padding: 2.5rem; 
    background: rgba(255, 255, 255, 0.95); 
    box-shadow: 0 4px 15px rgba(0,0,0,0.2); 
    border-radius: 10px;
}

/* Éléments spéciaux */
.btn { 
    display: inline-block; 
    background: #004a99; 
    color: white !important; 
    padding: 12px 24px; 
    text-decoration: none; 
    border-radius: 5px; 
    margin-top: 15px;
    transition: background 0.3s;
}

.btn:hover { background: #00356b; }

.highlight {
    background: #f0f7ff;
    border-left: 5px solid #004a99;
    padding: 15px;
    margin: 20px 0;
}

.box {
    background: #fff;
    border: 2px dashed #004a99;
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    margin: 20px 0;
}

footer { 
    text-align: center; 
    padding: 2rem; 
    color: white; 
    background: rgba(0,0,0,0.7);
    font-size: 0.9rem;
}