/* 返回顶部组件样式 - 简化版 */

/* 基础容器样式 */
.back-to-top-component {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    pointer-events: none;
}

/* 显示状态 */
.back-to-top-component.show {
    opacity: 0.5;
    visibility: visible;
    pointer-events: auto;
}

/* 按钮样式 */
.back-to-top-btn {
    width: 100%;
    height: 100%;
    border: 1px solid #000000;
    background-color: rgba(255, 255, 255, 0.5);
    color: #000000;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    transition: all 0.3s ease;
    outline: none;
    border-radius: 0;
}

.back-to-top-btn:hover {
    background-color: rgba(255, 255, 255, 0.7);
    transform: translateY(-2px);
}

.back-to-top-btn:active {
    background-color: rgba(255, 255, 255, 0.8);
    transform: translateY(0);
}

.back-to-top-btn:focus {
    outline: 2px solid #007bff;
    outline-offset: 2px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .back-to-top-component {
        bottom: 15px;
        right: 15px;
        width: 45px;
        height: 45px;
    }
    
    .back-to-top-btn {
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .back-to-top-component {
        bottom: 10px;
        right: 10px;
        width: 40px;
        height: 40px;
    }
    
    .back-to-top-btn {
        font-size: 14px;
    }
}

/* 触摸设备优化 */
@media (hover: none) and (pointer: coarse) {
    .back-to-top-btn:hover {
        transform: none;
    }
    
    .back-to-top-btn:active {
        transform: scale(0.95);
    }
}