/* Back to top button styles */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-gradient);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.3s ease, transform 0.3s ease;
    z-index: 1000;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

/* Light mode back-to-top button */
body:not(.dark-theme) .back-to-top {
    background: var(--primary-gradient);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

body:not(.dark-theme) .back-to-top:hover {
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.15);
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.3);
}

.back-to-top i {
    font-size: 20px;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-5px);
    }
    60% {
        transform: translateY(-3px);
    }
}