header {
    display: flex;
    gap: 10px;
    padding: 15px;
    background: rgba(0, 0, 0, 0.25);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
}

/* buttons inside header */
header .btn {
    transition: 0.2s;
}

header .btn:hover {
    transform: translateY(-2px);
}

/* admin button special style */
.btn.admin-btn {
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
}