header {
    position: sticky;
    top: 0;
    backdrop-filter: saturate(140%) blur(6px);
    background: var(--green-2);
    border-bottom: 1px solid var(--green);
    z-index: 10;
    color: white;
    line-height: 1.5;
    font-size: 1.5em;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    padding: 14px;
}

nav ul {
    display: flex;
    gap: 6px;
    list-style: none;
    margin: 0;
    padding: 0;
}
nav a {
    display: inline-block;
    padding: 0 12px;
    border-radius: 10px;
    color: inherit;
    text-decoration: none;
    border: 1px solid transparent;
}
nav a:hover { background: var(--yellow); }


/* Burger Menu Button (hidden by default) */
.burger-menu {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Mobile Styles */
@media (max-width: 768px) {
    .topbar {
        justify-content: space-between;
        flex-wrap: wrap;
    }

    .burger-menu {
        display: block;
    }

    nav {
        width: 100%;
        display: none; /* Hidden by default on mobile */
    }

    nav.active {
        display: block;
    }

    nav ul {
        flex-direction: column;
        gap: 0;
        width: 100%;
    }

    nav a {
        display: block;
        width: 100%;
        border-radius: 0;
        text-align: center;
        padding: 15px 0;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
}