/* 添加返回顶部样式 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: rgba(0, 243, 255, 0.9);
    border: none;
    border-radius: 10px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(0,243,255,0.3);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top i {
    color: var(--primary-color);
    font-size: 1.2rem;
    transition: transform 0.3s ease;
}

.back-to-top:hover {
    background: var(--accent-color);
    transform: translateY(-3px);
}

.back-to-top:active {
    transform: scale(0.95);
}

@media (max-width: 768px) {
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}