/* 基础设置 */
.site-footer {
    background-color: #333333; /* 深灰色背景 */
    color: #ffffff;
    padding: 4.167vw 5vw 2.083vw 5vw; /* 80px 192px 40px */
    font-family: "Microsoft YaHei", sans-serif;
    position: relative;
}

/* 上部布局 */
.footer-main {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 3.125vw; /* 60px */
}

.footer-column h3 {
    font-size: 0.938vw; /* 18px */
    font-weight: 400;
    margin-bottom: 2.083vw; /* 40px */
    color: rgba(255,255,255,0.8);
}

/* 联系方式详情 */
.contact-content {
    display: flex;
    gap: 3vw;
}

.address {
    font-size: 0.833vw; /* 16px */
    line-height: 1.6;
    color: rgba(255,255,255,0.7);
}

.details {
    list-style: none;
    padding: 0;
    margin: 0;
    font-size: 0.833vw;
    display: flex;
    gap: 2vw;
    align-items: center;
}

.details li {
    display: flex;
    align-items: center;
    gap: 0.5vw;
}

/* 二维码区域 */
.qr-box img, .qr-item img {
    width: 6.25vw; /* 120px */
    height: 6.25vw;
    background: #fff;
    padding: 0.2vw;
}

.social-qr-group {
    display: flex;
    gap: 2vw;
}

.qr-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.8vw;
    font-size: 0.729vw; /* 14px */
}

/* 分割线 */
.footer-divider {
    border: none;
    border-top: 1px solid rgba(255,255,255,0.1);
    margin-bottom: 2.083vw;
}

/* 底部导航 */
.footer-bottom {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.footer-nav {
    display: flex;
    gap: 5vw;
}

.footer-nav a {
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    font-size: 0.938vw; /* 18px */
    transition: color 0.3s;
}

.footer-nav a:hover {
    color: #ffffff;
}

/* 返回顶部按钮 */
.back-to-top {
    position: absolute;
    right: 0;
    bottom: -0.5vw;
    width: 3.125vw; /* 60px */
    height: 3.125vw;
    background-color: #444444;
    border: 1px solid #666;
    border-radius: 4px;
    color: #fff;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.3s;
}

.back-to-top:hover {
    background-color: #555555;
    border-color: #ffffff; /* 模拟图片中的红框高亮感 */
}