/* 基础变量与重置 */
        :root {
            --ucchpb-primary: #FF7139;
            --ucchpb-primary-hover: #e65a2b;
            --ucchpb-dark: #20123A;
            --ucchpb-bg: #f9f9fb;
            --ucchpb-text: #15141a;
            --ucchpb-text-muted: #5b5b66;
            --ucchpb-card-bg: rgba(255, 255, 255, 0.95);
            --ucchpb-gradient: linear-gradient(135deg, #FF9400 0%, #FF271E 100%);
            --ucchpb-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
            --ucchpb-radius: 16px;
            --ucchpb-container-width: 1100px;
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--ucchpb-bg);
            color: var(--ucchpb-text);
            line-height: 1.6;
            overflow-x: hidden;
            word-break: break-word;
        }

        /* 导航系统 */
        .ucchpb-header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid rgba(0, 0, 0, 0.05);
            transition: all 0.3s ease;
        }

        .ucchpb-nav-container {
            max-width: var(--ucchpb-container-width);
            margin: 0 auto;
            padding: 0 24px;
            height: 72px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
        }

        .ucchpb-logo {
            flex: 0 0 auto;
            display: flex;
            align-items: center;
            min-width: 0;
        }

        .ucchpb-logo img {
            height: 40px;
            width: auto;
        }

        .ucchpb-nav-menu {
            display: flex;
            list-style: none;
            gap: 24px;
            flex-wrap: wrap;
            min-width: 0;
        }

        .ucchpb-nav-link {
            text-decoration: none;
            color: var(--ucchpb-text-muted);
            font-weight: 500;
            font-size: 14px;
            transition: color 0.2s;
            white-space: nowrap;
        }

        .ucchpb-nav-link:hover {
            color: var(--ucchpb-primary);
        }

        .ucchpb-nav-link.active {
            color: var(--ucchpb-primary);
            position: relative;
        }

        .ucchpb-nav-link.active::after {
            content: '';
            position: absolute;
            bottom: -8px;
            left: 0;
            width: 100%;
            height: 2px;
            background: var(--ucchpb-primary);
        }

        /* 独特Hero/登录区域布局 */
        .ucchpb-hero {
            padding: 140px 24px 80px;
            background: radial-gradient(circle at top right, #fff5f0 0%, #f9f9fb 50%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .ucchpb-main-grid {
            display: flex;
            flex-wrap: wrap;
            max-width: var(--ucchpb-container-width);
            width: 100%;
            gap: 64px;
            align-items: center;
        }

        .ucchpb-content-side {
            flex: 1;
            min-width: 320px;
        }

        .ucchpb-title {
            font-size: clamp(2rem, 4vw + 0.5rem, 3.5rem);
            font-weight: 800;
            line-height: 1.1;
            margin-bottom: 24px;
            color: var(--ucchpb-dark);
            word-break: keep-all;
        }

        .ucchpb-subtitle {
            font-size: clamp(1rem, 1.5vw + 0.5rem, 1.25rem);
            color: var(--ucchpb-text-muted);
            margin-bottom: 48px;
            max-width: 500px;
        }

        /* 登录卡片设计 */
        .ucchpb-login-side {
            flex: 0 0 420px;
            min-width: 320px;
        }

        .ucchpb-login-card {
            background: var(--ucchpb-card-bg);
            padding: 48px;
            border-radius: var(--ucchpb-radius);
            box-shadow: var(--ucchpb-shadow);
            border: 1px solid rgba(255, 255, 255, 0.8);
            position: relative;
            overflow: hidden;
        }

        .ucchpb-login-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 4px;
            background: var(--ucchpb-gradient);
        }

        .ucchpb-form-group {
            margin-bottom: 24px;
        }

        .ucchpb-label {
            display: block;
            font-size: 14px;
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--ucchpb-dark);
        }

        .ucchpb-input {
            width: 100%;
            padding: 14px 16px;
            border: 2px solid #e0e0e6;
            border-radius: 8px;
            font-size: 16px;
            transition: all 0.2s;
            outline: none;
        }

        .ucchpb-input:focus {
            border-color: var(--ucchpb-primary);
            background: #fff;
            box-shadow: 0 0 0 4px rgba(255, 113, 57, 0.1);
        }

        .ucchpb-btn-primary {
            width: 100%;
            padding: 16px;
            background: var(--ucchpb-primary);
            color: white;
            border: none;
            border-radius: 8px;
            font-size: 16px;
            font-weight: 700;
            cursor: pointer;
            transition: transform 0.2s, background 0.2s;
            margin-top: 8px;
        }

        .ucchpb-btn-primary:hover {
            background: var(--ucchpb-primary-hover);
            transform: translateY(-2px);
        }

        /* 隐私防御武器库 Section */
        .ucchpb-section {
            padding: 96px 24px;
            max-width: var(--ucchpb-container-width);
            margin: 0 auto;
        }

        .ucchpb-section-header {
            text-align: center;
            margin-bottom: 64px;
        }

        .ucchpb-grid-3 {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 32px;
        }

        .ucchpb-feature-card {
            background: white;
            padding: 40px;
            border-radius: var(--ucchpb-radius);
            transition: all 0.3s ease;
            border: 1px solid #f0f0f4;
        }

        .ucchpb-feature-card:hover {
            transform: translateY(-8px);
            box-shadow: var(--ucchpb-shadow);
        }

        .ucchpb-feature-icon {
            width: 48px;
            height: 48px;
            background: #fff0eb;
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 24px;
            font-size: 24px;
            color: var(--ucchpb-primary);
        }

        .ucchpb-feature-title {
            font-size: 20px;
            font-weight: 700;
            margin-bottom: 16px;
            color: var(--ucchpb-dark);
        }

        .ucchpb-feature-list {
            list-style: none;
            font-size: 14px;
            color: var(--ucchpb-text-muted);
        }

        .ucchpb-feature-list li {
            margin-bottom: 8px;
            padding-left: 20px;
            position: relative;
        }

        .ucchpb-feature-list li::before {
            content: '✓';
            position: absolute;
            left: 0;
            color: var(--ucchpb-primary);
            font-weight: bold;
        }

        /* 页脚 */
        .ucchpb-footer {
            background: var(--ucchpb-dark);
            color: white;
            padding: 64px 24px;
            text-align: center;
        }

        .ucchpb-footer-brand {
            font-size: 24px;
            font-weight: 800;
            margin-bottom: 24px;
            letter-spacing: -0.5px;
        }

        .ucchpb-footer-links {
            display: flex;
            justify-content: center;
            gap: 32px;
            flex-wrap: wrap;
            margin-bottom: 32px;
        }

        .ucchpb-footer-link {
            color: #a0a0b0;
            text-decoration: none;
            font-size: 14px;
            transition: color 0.2s;
        }

        .ucchpb-footer-link:hover {
            color: white;
        }

        .ucchpb-copyright {
            font-size: 13px;
            color: #6b6b7b;
        }

        /* 响应式适配 */
        @media (max-width: 768px) {
            .ucchpb-nav-menu {
                display: none; /* 简化移动端，实际开发中应使用汉堡菜单 */
            }
            .ucchpb-main-grid {
                flex-direction: column;
                gap: 48px;
            }
            .ucchpb-content-side, .ucchpb-login-side {
                flex: 1 1 100%;
                min-width: 0;
            }
            .ucchpb-title {
                text-align: center;
            }
            .ucchpb-subtitle {
                text-align: center;
                margin-left: auto;
                margin-right: auto;
            }
        }