/* 返回顶部按钮样式 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: #12c2e9;
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    z-index: 1000;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(18, 194, 233, 0.3);
}

.back-to-top:hover {
    background-color: #0ea5c7;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(18, 194, 233, 0.4);
}

.back-to-top:active {
    transform: translateY(0);
}

.back-to-top.show {
    display: flex;
}

.back-to-top::before {
    content: '↑';
    font-weight: bold;
}

/* 移动端适配 */
@media (max-width: 768px) {
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: 16px;
    }
}