:root {
            --primary-color: #552392;
            --accent-color: #E4405F;
            --bg-color: #ffffff;
            --text-color: #333333;
            --card-bg: #ffffff;
            --border-color: rgba(0,0,0,0.1);
            --footer-bg: rgba(0,0,0,0.05);
        }

        [data-theme="dark"] {
            --primary-color: #552392;
            --accent-color: #ff4757;
            --bg-color: #1a1a1a;
            --text-color: #ffffff;
            --card-bg: #2d2d2d;
            --border-color: rgba(255,255,255,0.1);
            --footer-bg: rgba(255,255,255,0.05);
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            -webkit-tap-highlight-color: transparent;
            transition: background-color 0.3s, color 0.3s;
        }

        body {
            font-family: 'Segoe UI', sans-serif;
            background-color: var(--bg-color);
            color: var(--text-color);
            font-size: 0.9rem;
            min-height: 100vh;
            position: relative;
            display: flex;
            flex-direction: column;
        }

        .control-group {
            position: fixed;
            top: 1rem;
            right: 1rem;
            display: flex;
            gap: 0.5rem;
            z-index: 1000;
        }

        .theme-switcher,
        .lang-switcher {
            background: var(--primary-color);
            color: white;
            border: none;
            padding: 0.5rem 1rem;
            border-radius: 25px;
            cursor: pointer;
            display: flex;
            align-items: center;
            gap: 0.5rem;
            backdrop-filter: blur(5px);
            font-size: 0.9rem;
        }

        nav {
            background: var(--primary-color);
            padding: 1rem;
            color: white;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }

        nav h1 {
            font-size: 1.5rem;
            text-align: center;
        }

        .container {
            max-width: 1200px;
            margin: 1rem auto;
            padding: 0 1rem 1rem; /* 增加底部内边距 */
            flex: 1; /* 占据剩余空间 */
        }

        .domain-group {
            margin: 0.1rem 0;
        }

        .group-title {
            color: var(--primary-color);
            border-left: 4px solid var(--accent-color);
            padding-left: 1rem;
            margin: 1.5rem 0;
            font-size: 1.4rem;
        }

        .domain-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 1.5rem;
            padding: 1rem;
        }

        .domain-card {
            position: relative;
            overflow: visible;
            border-radius: 10px;
            background: transparent;
            cursor: pointer;
        }

        .domain-card::before {
            content: '';
            position: absolute;
            top: -1px;
            left: -1px;
            right: -1px;
            bottom: -1px;
            background: linear-gradient(90deg, #ff6b6b 25%, #4ecdc4 50%, #45b7d1 75%);
            background-size: 400% 100%;
            animation: borderMarquee 5s linear infinite;
            z-index: 0;
            border-radius: 11px;
        }

        @keyframes borderMarquee {
            0% { background-position: 200% 50%; }
            100% { background-position: -100% 50%; }
        }

        .domain-card-inner {
            position: relative;
            z-index: 1;
            background: var(--card-bg);
            border-radius: 10px;
            margin: 1px;
            padding: 1.5rem;
            box-shadow: 0 3px 10px var(--border-color);
        }

        .domain-name {
            font-size: 1.2rem;
            color: var(--text-color);
            margin-bottom: 0.5rem;
        }

        .price-tag {
            background: var(--accent-color);
            color: white;
            border-radius: 20px;
            font-weight: bold;
            position: absolute;
            z-index: 2;
            box-shadow: 0 2px 5px rgba(0,0,0,0.2);
            white-space: nowrap;
        }

        .btn-register {
            background: var(--primary-color);
            color: white;
            border: none;
            padding: 0.5rem 1.5rem;
            border-radius: 5px;
            cursor: pointer;
            min-width: 100px;
            transition: transform 0.2s;
            font-size: 0.9rem;
        }

        .btn-register:active {
            transform: scale(0.95);
        }

        .alert-modal {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.5);
            justify-content: center;
            align-items: center;
            z-index: 999;
        }

        .alert-content {
            background: var(--card-bg);
            padding: 2rem;
            border-radius: 10px;
            text-align: center;
            box-shadow: 0 0 20px var(--border-color);
            max-width: 300px;
            color: var(--text-color);
            font-size: 0.9rem;
        }

        .close-btn {
            background: var(--accent-color);
            color: white;
            border: none;
            padding: 0.5rem 1.5rem;
            border-radius: 5px;
            cursor: pointer;
            margin-top: 1rem;
        }

       .footer-section {
    position: relative;
    margin-top: auto;
    width: 100%;
-    background: var(--footer-bg);
+    background: transparent;
}


        .custom-link {
            text-align: center;
            padding: 0.5rem;
            border-bottom: 1px solid var(--border-color);
        }

        .custom-link a {
            color: var(--primary-color);
            text-decoration: none;
            transition: opacity 0.3s;
        }

        .custom-link a:hover {
            opacity: 0.8;
        }

        .custom-link a strong {
            font-weight: bold;
        }

        .copyright {
            padding: 0.5rem;
            text-align: center;
            font-size: 0.85rem;
            color: var(--text-color);
        }

        .renewal-card {
            background: var(--card-bg) !important;
            border-radius: 10px;
            padding: 1.5rem;
            box-shadow: 0 3px 10px var(--border-color);
            position: relative;
        }

        .renewal-price {
            font-size: 1.1rem;
            color: var(--accent-color);
            font-weight: bold;
        }

        @media (max-width: 768px) {
            nav {
                padding-top: 3.5rem;
                min-height: 4rem;
            }
            .control-group {
                top: 1rem;
                right: 1rem;
                flex-direction: column;
                gap: 0.3rem;
            }
            .theme-switcher span {
                display: none;
            }
            .price-tag {
                padding: 0.2rem 1rem;
                font-size: 0.8rem;
                top: -12px;
                right: -15px;
            }
            .container {
                padding: 0.1rem 0.1rem; /* 移动端减少间距 */
            }
            .domain-grid {
                display: grid !important;
                grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
                gap: 1rem;
            }
            .domain-card-inner {
                padding: 1rem;
            }
            .domain-name {
                font-size: 1.1rem;
                margin-bottom: 0.3rem;
            }
            .btn-register {
                padding: 0.4rem 1.2rem;
                font-size: 0.85rem;
            }
            .copyright {
                padding: 0.5rem;
            }
        }

        @media (min-width: 769px) {
            .price-tag {
                padding: 0.3rem 1rem;
                font-size: 0.9rem;
                top: -15px;
                right: -18px;
            }
        }
        
        /* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.3s, transform 0.3s;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.show {
    opacity: 1;
}

.back-to-top:hover {
    transform: scale(1.1);
    background: var(--accent-color);
}

.back-to-top:focus {
    background: var(--accent-color); /* 焦点时改变背景色 */
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.5); /* 添加白色阴影作为焦点提示 */
}