:root {
            --i0yps4-primary: #0078d4;
            --i0yps4-secondary: #2b579a;
            --i0yps4-accent: #00a4ef;
            --i0yps4-bg-light: #f3f2f1;
            --i0yps4-text-main: #323130;
            --i0yps4-text-muted: #605e5c;
            --i0yps4-white: #ffffff;
            --i0yps4-success: #107c10;
            --i0yps4-shadow: 0 4px 20px rgba(0,0,0,0.08);
            --i0yps4-radius: 12px;
        }

        * {
            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;
            color: var(--i0yps4-text-main);
            background-color: var(--i0yps4-bg-light);
            line-height: 1.6;
            overflow-x: hidden;
        }

        /* 导航栏 */
        .i0yps4-navbar {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(10px);
            z-index: 1000;
            border-bottom: 1px solid rgba(0,0,0,0.05);
            padding: 0 5vw;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            height: 70px;
        }

        .i0yps4-logo {
            display: flex;
            align-items: center;
            min-width: 0;
        }

        .i0yps4-logo img {
            height: 40px;
            width: auto;
        }

        .i0yps4-nav-menu {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 16px;
            min-width: 0;
        }

        .i0yps4-nav-item a {
            text-decoration: none;
            color: var(--i0yps4-text-main);
            font-size: 14px;
            font-weight: 500;
            padding: 8px 12px;
            border-radius: 6px;
            transition: all 0.3s ease;
            white-space: nowrap;
        }

        .i0yps4-nav-item a:hover {
            color: var(--i0yps4-primary);
            background: rgba(0, 120, 212, 0.05);
        }

        .i0yps4-nav-item a.i0yps4-active {
            color: var(--i0yps4-primary);
            background: rgba(0, 120, 212, 0.1);
            font-weight: 700;
        }

        /* Hero下载区 */
        .i0yps4-hero {
            padding: 140px 5vw 80px;
            background: linear-gradient(135deg, #ffffff 0%, #eef5ff 100%);
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            align-items: center;
            gap: 48px;
        }

        .i0yps4-hero-content {
            flex: 1;
            min-width: 320px;
            max-width: 600px;
            word-break: break-word;
        }

        .i0yps4-hero-title {
            font-size: clamp(2rem, 4vw + 1rem, 3.5rem);
            line-height: 1.2;
            color: var(--i0yps4-secondary);
            margin-bottom: 24px;
            font-weight: 800;
        }

        .i0yps4-hero-subtitle {
            font-size: clamp(1rem, 2vw + 0.5rem, 1.25rem);
            color: var(--i0yps4-text-muted);
            margin-bottom: 32px;
            line-height: 1.8;
        }

        .i0yps4-main-download-card {
            background: var(--i0yps4-white);
            padding: 40px;
            border-radius: var(--i0yps4-radius);
            box-shadow: var(--i0yps4-shadow);
            width: 100%;
            max-width: 440px;
            min-width: 0;
            border: 1px solid rgba(0,0,0,0.05);
            text-align: center;
        }

        .i0yps4-btn-primary {
            display: inline-block;
            background: linear-gradient(45deg, var(--i0yps4-primary), var(--i0yps4-accent));
            color: white;
            padding: 18px 48px;
            border-radius: 50px;
            text-decoration: none;
            font-size: 1.2rem;
            font-weight: 700;
            box-shadow: 0 10px 20px rgba(0, 120, 212, 0.3);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            margin-bottom: 16px;
        }

        .i0yps4-btn-primary:hover {
            transform: translateY(-3px);
            box-shadow: 0 15px 30px rgba(0, 120, 212, 0.4);
        }

        .i0yps4-version-info {
            font-size: 0.9rem;
            color: var(--i0yps4-text-muted);
        }

        /* 下载列表区 */
        .i0yps4-download-grid {
            padding: 64px 5vw;
            max-width: 1100px;
            margin: 0 auto;
        }

        .i0yps4-section-label {
            text-align: center;
            margin-bottom: 48px;
        }

        .i0yps4-section-label h2 {
            font-size: 2rem;
            color: var(--i0yps4-secondary);
            margin-bottom: 12px;
        }

        .i0yps4-grid-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 24px;
        }

        .i0yps4-download-item {
            background: var(--i0yps4-white);
            padding: 32px;
            border-radius: var(--i0yps4-radius);
            transition: transform 0.3s ease;
            display: flex;
            flex-direction: column;
            border-bottom: 4px solid transparent;
            word-break: break-word;
        }

        .i0yps4-download-item:hover {
            transform: translateY(-8px);
            border-bottom-color: var(--i0yps4-primary);
        }

        .i0yps4-item-title {
            font-size: 1.4rem;
            margin-bottom: 16px;
            color: var(--i0yps4-secondary);
        }

        .i0yps4-item-desc {
            font-size: 0.95rem;
            color: var(--i0yps4-text-muted);
            margin-bottom: 24px;
            flex-grow: 1;
        }

        .i0yps4-btn-outline {
            display: inline-block;
            padding: 10px 24px;
            border: 2px solid var(--i0yps4-primary);
            color: var(--i0yps4-primary);
            text-decoration: none;
            border-radius: 8px;
            font-weight: 600;
            text-align: center;
            transition: all 0.3s ease;
        }

        .i0yps4-btn-outline:hover {
            background: var(--i0yps4-primary);
            color: white;
        }

        /* 校验码区 */
        .i0yps4-checksum-section {
            background: #f8f9fa;
            padding: 64px 5vw;
        }

        .i0yps4-checksum-table-wrapper {
            max-width: 1100px;
            margin: 0 auto;
            overflow-x: auto;
            background: white;
            padding: 24px;
            border-radius: var(--i0yps4-radius);
            box-shadow: 0 2px 10px rgba(0,0,0,0.03);
        }

        .i0yps4-checksum-table {
            width: 100%;
            border-collapse: collapse;
            min-width: 600px;
        }

        .i0yps4-checksum-table th, .i0yps4-checksum-table td {
            padding: 16px;
            text-align: left;
            border-bottom: 1px solid #eee;
            word-break: break-all;
        }

        .i0yps4-checksum-table th {
            color: var(--i0yps4-secondary);
            font-weight: 700;
        }

        /* 安装指南 */
        .i0yps4-guide-section {
            padding: 96px 5vw;
            max-width: 1100px;
            margin: 0 auto;
        }

        .i0yps4-steps {
            display: flex;
            flex-wrap: wrap;
            gap: 32px;
            counter-reset: step;
        }

        .i0yps4-step-card {
            flex: 1;
            min-width: 240px;
            position: relative;
            padding: 24px;
            background: white;
            border-radius: var(--i0yps4-radius);
            word-break: break-word;
        }

        .i0yps4-step-card::before {
            counter-increment: step;
            content: counter(step);
            position: absolute;
            top: -20px;
            left: 20px;
            width: 40px;
            height: 40px;
            background: var(--i0yps4-primary);
            color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 50%;
            font-weight: bold;
            font-size: 1.2rem;
        }

        .i0yps4-step-card h3 {
            margin-top: 16px;
            margin-bottom: 12px;
        }

        /* 页脚 */
        .i0yps4-footer {
            background: #201f1e;
            color: #d2d0ce;
            padding: 64px 5vw 32px;
            margin-top: 96px;
        }

        .i0yps4-footer-content {
            max-width: 1100px;
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 48px;
            border-bottom: 1px solid #323130;
            padding-bottom: 48px;
        }

        .i0yps4-footer-brand {
            min-width: 200px;
        }

        .i0yps4-footer-brand h2 {
            color: white;
            margin-bottom: 16px;
        }

        .i0yps4-footer-links {
            display: flex;
            flex-wrap: wrap;
            gap: 64px;
        }

        .i0yps4-footer-group h4 {
            color: white;
            margin-bottom: 20px;
            font-size: 1.1rem;
        }

        .i0yps4-footer-group ul {
            list-style: none;
        }

        .i0yps4-footer-group ul li {
            margin-bottom: 10px;
        }

        .i0yps4-footer-group ul li a {
            color: #d2d0ce;
            text-decoration: none;
            transition: color 0.3s;
        }

        .i0yps4-footer-group ul li a:hover {
            color: var(--i0yps4-accent);
        }

        .i0yps4-footer-bottom {
            max-width: 1100px;
            margin: 32px auto 0;
            text-align: center;
            font-size: 0.85rem;
        }

        /* 响应式调整 */
        @media (max-width: 768px) {
            .i0yps4-navbar {
                height: auto;
                padding: 10px 5vw;
            }
            .i0yps4-nav-menu {
                width: 100%;
                justify-content: center;
                padding: 10px 0;
            }
            .i0yps4-hero {
                padding-top: 180px;
                text-align: center;
            }
            .i0yps4-hero-content {
                max-width: 100%;
            }
            .i0yps4-main-download-card {
                max-width: 100%;
            }
            .i0yps4-grid-container {
                grid-template-columns: 1fr;
            }
        }