/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #d3d3d3; /* Gris clair moderne */
    position: sticky; 
    top: 0;
    font-family: 'Poppins', Arial, Helvetica, sans-serif; 
    z-index: 1000;
    box-shadow: 0px 1px 7px 0px rgba(0, 0, 0, 0.2); 
    padding: 0 1.5em;
    height: 60px; 
}

/* Logo */
.logo {
    height: 45px; 
    margin-left: 0.2em;
    border-radius: 0.3em;
    transition: transform 0.3s ease, background-color 0.5s ease;
}

.logo:hover {
    transform: scale(1.1);
    transition-duration: 0.5s;
}

/* Menu */
h3 {
    display: flex;
    justify-content: center;
    gap: 9em;
    flex-grow: 1;
    font-size: 100%; 
    font-weight: 500; 
}

h3 a {
    color: #333; 
    text-decoration: none;
    padding: 0.5em 1em; 
    border-radius: 0.5em;
    background-color: rgba(255, 255, 255, 0.4); 
    transition: transform 0.3s ease, background-color 0.5s ease, box-shadow 0.3s ease;
}

h3 a:hover,
h3 a.active {
    background-color: rgba(255, 255, 255, 0.6); 
    transform: scale(1.1); 
    box-shadow: 0px 4px 15px rgba(0, 0, 0, 0.1); /* Ombre */
}