/* ========================================
   页脚样式 - ilovepdf 风格
   ======================================== */

.footer {
    background: #1f2937;
    color: #9ca3af;
    margin-top: 80px;
}

.footer .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 60px 20px 20px;
}

/* 页脚内容区 */
.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    color: white;
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 16px;
}

.footer-section p {
    font-size: 14px;
    line-height: 1.8;
    color: #9ca3af;
}

.footer-contact {
    margin-top: 8px;
}

.footer-contact a {
    color: #a31e22;
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-contact a:hover {
    color: #dc2626;
    text-decoration: underline;
}

.footer-section a {
    color: #9ca3af;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: #a31e22;
}

/* 页脚链接列表 */
.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    display: inline-block;
    padding: 4px 0;
}

/* 社交链接 */
.social-links {
    display: flex;
    gap: 16px;
    margin-top: 16px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: #374151;
    border-radius: 8px;
    color: #9ca3af;
    text-decoration: none;
    font-size: 18px;
    transition: all 0.3s ease;
}

.social-link:hover {
    background: #a31e22;
    color: white;
    transform: translateY(-2px);
}

/* 页脚底部 */
.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 24px;
    text-align: center;
    font-size: 14px;
}

.footer-bottom p {
    margin: 4px 0;
    color: #6b7280;
}

.footer-bottom a {
    color: #9ca3af;
    text-decoration: none;
    margin: 0 8px;
    transition: color 0.3s ease;
}

.footer-bottom a:hover {
    color: #a31e22;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #a31e22 0%, #d32f2f 100%);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 20px;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(163, 30, 34, 0.3);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 25px rgba(163, 30, 34, 0.4);
}

.back-to-top:active {
    transform: translateY(-2px);
}

/* ========================================
   响应式设计
   ======================================== */

@media (max-width: 768px) {
    .footer .container {
        padding: 40px 20px 20px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
        margin-bottom: 32px;
    }
    
    .footer-section h3 {
        font-size: 16px;
    }
    
    .footer-section p,
    .footer-section a {
        font-size: 13px;
    }
    
    .footer-bottom {
        font-size: 12px;
    }
    
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: 18px;
    }
}

@media (max-width: 480px) {
    .footer .container {
        padding: 30px 16px 16px;
    }
    
    .social-links {
        gap: 12px;
    }
    
    .social-link {
        width: 36px;
        height: 36px;
        font-size: 16px;
    }
    
    .back-to-top {
        bottom: 16px;
        right: 16px;
        width: 40px;
        height: 40px;
        font-size: 16px;
    }
}