/* 暗黑简洁主题 - 底部样式（极简扁平设计） */

/* ========== 底部样式 ========== */
.footer {
    background: #1f2833;
    color: #CCCCCC;
    padding: 25px 0;
    border-top: 1px solid #2a3441;
}

.footer-container {
    max-width: 2000px;
    margin: 0 auto;
    padding: 0 20px;
}

.footer-bottom {
    text-align: center;
}

.copyright {
    color: #a0a8b0;
    font-size: 13px;
}

.beian-link {
    color: #a0a8b0;
    text-decoration: none;
    transition: color 0.2s;
}

.beian-link:hover {
    color: #5dade2;
}

/* ========== 返回顶部按钮 ========== */
.back-to-top {
    position: fixed;
    bottom: 25px;
    right: 25px;
    width: 44px;
    height: 44px;
    background: #5dade2;
    color: white;
    border: none;
    border-radius: 2px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s, visibility 0.2s;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}

.back-to-top svg {
    width: 24px;
    height: 24px;
}

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

.back-to-top:hover {
    background: #4a9bc7;
}

/* ========== 响应式设计 ========== */
@media (max-width: 768px) {
    .footer {
        padding: 18px 0;
    }
    
    .footer-container {
        padding: 0 5%;
    }
    
    .copyright {
        font-size: 12px;
        line-height: 1.5;
        text-align: center;
    }
    
    .beian-link {
        font-size: 12px;
    }
    
    .back-to-top {
        width: 40px;
        height: 40px;
        bottom: 18px;
        right: 12px;
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    }
    
    .back-to-top svg {
        width: 20px;
        height: 20px;
    }
}