/* ====================
   乌发族模块 - （优化版）
   ==================== */
        :root {
            --primary-color: #1a73e8;
            --secondary-color: #34a853;
            --accent-color: #ea4335;
            --text-color: #333;
            --bg-color: #f8f9fa;
            --card-bg: #ffffff;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
            line-height: 1.6;
            color: var(--text-color);
            background-color: var(--bg-color);
            padding: 20px;
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .header {
            text-align: center;
            padding: 30px 0;
            background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
            color: white;
            border-radius: 15px;
            margin-bottom: 30px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        
        .header h1 {
            font-size: 2.8rem;
            margin-bottom: 10px;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
        }
        
        .header .subtitle {
            font-size: 1.2rem;
            opacity: 0.9;
            max-width: 800px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        .search-box {
            max-width: 600px;
            margin: 25px auto;
            padding: 0 20px;
        }
        
        .search-box input {
            width: 100%;
            padding: 15px 20px;
            border: none;
            border-radius: 50px;
            font-size: 1.1rem;
            box-shadow: 0 4px 15px rgba(0,0,0,0.1);
            transition: all 0.3s ease;
        }
        
        .search-box input:focus {
            outline: none;
            box-shadow: 0 4px 20px rgba(26, 115, 232, 0.3);
            transform: translateY(-2px);
        }
        
        .tip-text {
            text-align: center;
            color: #666;
            font-size: 0.9rem;
            margin-top: 10px;
            font-style: italic;
        }
        
        .categories {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 25px;
            margin: 40px 0;
        }
        
        .category-card {
            background: var(--card-bg);
            border-radius: 12px;
            padding: 25px;
            box-shadow: 0 6px 20px rgba(0,0,0,0.08);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border-left: 5px solid var(--primary-color);
        }
        
        .category-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 12px 25px rgba(0,0,0,0.15);
        }
        
        .category-card h2 {
            color: var(--primary-color);
            margin-bottom: 20px;
            font-size: 1.5rem;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .category-card h2::before {
            content: "✦";
            font-size: 1.8rem;
        }
        
        .site-list {
            list-style: none;
        }
        
        .site-item {
            margin-bottom: 15px;
            padding-bottom: 15px;
            border-bottom: 1px solid #eee;
        }
        
        .site-item:last-child {
            border-bottom: none;
            margin-bottom: 0;
            padding-bottom: 0;
        }
        
        .site-link {
            display: flex;
            justify-content: space-between;
            align-items: center;
            text-decoration: none;
            color: var(--text-color);
            padding: 8px 0;
            transition: color 0.3s ease;
        }
        
        .site-link:hover {
            color: var(--primary-color);
        }
        
        .site-name {
            font-weight: 500;
            font-size: 1.05rem;
        }
        
        .site-desc {
            color: #666;
            font-size: 0.9rem;
            margin-top: 3px;
        }
        
        .visit-btn {
            background: var(--primary-color);
            background: #0d5bb5;/* 底部导航小按钮默认颜色 */
            color: white;
            border: none;
            padding: 6px 15px;
            border-radius: 20px;
            font-size: 0.85rem;
            cursor: pointer;
            transition: background 0.3s ease;
            white-space: nowrap;
        }
        
        .visit-btn:hover {
            background: #ff0000;/* 底部导航小按钮点击变色 */
        }
        
        .footer {
            text-align: center;
            margin-top: 50px;
            padding: 25px;
            background: #f1f3f4;
            border-radius: 10px;
            color: #666;
        }
        
        .safety-tips {
            background: #fff8e1;
            border: 1px solid #ffd54f;
            border-radius: 8px;
            padding: 20px;
            margin: 30px 0;
        }
        
        .safety-tips h3 {
            color: #f57c00;
            margin-bottom: 10px;
        }
        
        @media (max-width: 768px) {
            body {
                padding: 15px;
            }
            
            .header h1 {
                font-size: 2.2rem;
            }
            
            .categories {
                grid-template-columns: 1fr;
            }
            
            .category-card {
                padding: 20px;
            }
        }

    /* ========== 四角圆润foot版块代码 ========== */
.footer-custom {
    background-color: #1f2937; /* 对应 button-group 效果 */
    color: white;
    padding: 3rem 1rem;
    margin-top: 4rem;
    text-align: center;
    /*  */
    border-radius: 0.75rem; /* 中等圆角，推荐使用。对应 Tailwind CSS 中的 rounded-lg 或 rounded-xl */
    /* 如果想更圆润一点，可以使用下面这行：*/
    /* border-radius: 1rem; */
}

.button-group {
    display: flex;
    justify-content: center;
    gap: 1.5rem; /* 按钮间距 */
    flex-wrap: wrap; /* 在小屏幕上自动换行 */
    margin-top: 1rem;
}

/* 确保按钮链接不换行 */
.button-group .site-link {
    display: inline-block;
}
    /* ====================================== */
	
/* 优化后的返回顶部按钮 */
.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: linear-gradient(135deg, #ff00ff, #c400c4); /* 渐变背景 */
  color: white;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 10px rgba(0,0,0,0.2);
  opacity: 0;
  transition: 
    opacity 0.3s,
    transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1),
    box-shadow 0.3s,
    background 0.3s;
  z-index: 1000;
  
  /* 修复黑圈问题 - 开始 */
  outline: none;
  border: none;
  /* 修复黑圈问题 - 结束 */
}

/* 修复聚焦/激活时的黑圈问题 */
.scroll-top:focus,
.scroll-top:active {
  outline: none !important;
  border: none !important;
  box-shadow: 0 8px 16px rgba(0,0,0,0.25) !important; /* 保持悬停时的阴影效果 */
}

/* 悬停效果 */
.scroll-top:hover {
  background: linear-gradient(135deg, #e500e5, #a800a8); /* 加深渐变 */
  transform: translateY(-5px) scale(1.02); /* 上浮+放大 */
  box-shadow: 0 8px 16px rgba(0,0,0,0.25); /* 增强阴影 */
}

/* 按下效果 */
.scroll-top:active {
  transform: translateY(2px) scale(0.98); /* 下沉+缩小 */
  box-shadow: 0 2px 4px rgba(0,0,0,0.15); /* 减弱阴影 */
}

/* 显示状态 */
.scroll-top.visible {
  opacity: 1;
}

/* 箭头动画 */
.scroll-top::after {
  content: "↑";
  color: white;
  font-size: 24px;
  font-weight: bold;
  transition: transform 0.2s ease;
}

/* 悬停时箭头微动 */
.scroll-top:hover::after {
  transform: translateY(-2px);
}