header {
    position: sticky;
    top: 0;
    background: rgba(31, 42, 68, 0.9);
    padding: 1rem 2rem;
    z-index: 100; /* Ensure header stays above content */
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
}

.nav-menu {
    transition: transform 0.3s ease-in-out;
}

nav ul li a {
    color: #E8ECEF;
    text-decoration: none;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: #34C759;
}

.btn-signin {
    background: #34C759;
    padding: 0.5rem 1rem;
    border-radius: 5px;
}

.hamburger {
    display: none;
    font-size: 2rem;
    cursor: pointer;
}