header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 30px;
    background: white;
    border-bottom: 2px solid #4f46e5;
}

header img {
    height: 50px;
    width: auto;
}

header h1 {
    margin: 0;
    margin-left: 15px;
    font-size: 1.8em;
    color: #4f46e5;
    flex: 1;
}

header nav a {
    margin-left: 20px;
    text-decoration: none;
    color: #333;
    font-weight: 500;
}

header nav a:hover {
    color: #4f46e5;
    text-decoration: underline;
}

.marge_50px {
    margin-left: 50px;
}