:root {
            --i0yps4-primary: #0056b3;
            --i0yps4-secondary: #ff8c00;
            --i0yps4-accent: #eef4ff;
            --i0yps4-text: #2d3436;
            --i0yps4-text-light: #636e72;
            --i0yps4-bg: #ffffff;
            --i0yps4-card-bg: #f8f9fa;
            --i0yps4-border: #dfe6e9;
            --i0yps4-code-bg: #2d3436;
            --i0yps4-radius: 12px;
            --i0yps4-gap: 8px;
        }

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

        body {
            font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
            color: var(--i0yps4-text);
            line-height: 1.8;
            background-color: var(--i0yps4-bg);
            word-break: keep-all;
            overflow-x: hidden;
        }

        /* Typography */
        h1, h2, h3 {
            line-height: 1.3;
            white-space: normal;
            word-break: break-word;
            margin-bottom: calc(var(--i0yps4-gap) * 3);
        }

        p {
            margin-bottom: calc(var(--i0yps4-gap) * 2);
            word-break: break-word;
            overflow-wrap: break-word;
        }

        /* Layout */
        .i0yps4-container {
            max-width: 1100px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* Header & Nav */
        .i0yps4-header {
            position: sticky;
            top: 0;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid var(--i0yps4-border);
            padding: 16px 0;
        }

        .i0yps4-nav-wrapper {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
        }

        .i0yps4-logo {
            min-width: 0;
            flex: 0 0 auto;
        }

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

        .i0yps4-nav {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 20px;
        }

        .i0yps4-nav li {
            min-width: 0;
        }

        .i0yps4-nav a {
            text-decoration: none;
            color: var(--i0yps4-text);
            font-weight: 500;
            font-size: 15px;
            transition: color 0.3s;
        }

        .i0yps4-nav a:hover, .i0yps4-nav a.active {
            color: var(--i0yps4-primary);
        }

        /* Hero Section */
        .i0yps4-hero {
            padding: 96px 0 64px;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            text-align: center;
            border-radius: 0 0 40px 40px;
        }

        .i0yps4-hero h1 {
            font-size: clamp(2rem, 5vw + 1rem, 3.5rem);
            color: var(--i0yps4-primary);
            font-weight: 800;
        }

        .i0yps4-hero p {
            font-size: clamp(1rem, 2vw + 0.5rem, 1.25rem);
            max-width: 800px;
            margin: 0 auto 32px;
            color: var(--i0yps4-text-light);
        }

        /* Diagnostic Section */
        .i0yps4-section {
            padding: 64px 0;
        }

        .i0yps4-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
            gap: 32px;
            margin-top: 48px;
        }

        .i0yps4-card {
            background: var(--i0yps4-card-bg);
            border: 1px solid var(--i0yps4-border);
            border-radius: var(--i0yps4-radius);
            padding: 32px;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            display: flex;
            flex-direction: column;
            min-width: 0;
        }

        .i0yps4-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 12px 24px rgba(0,0,0,0.05);
        }

        .i0yps4-card-icon {
            font-size: 40px;
            margin-bottom: 24px;
        }

        .i0yps4-card h3 {
            color: var(--i0yps4-primary);
            font-size: 1.5rem;
        }

        /* Tutorial Content */
        .i0yps4-tutorial-box {
            background: #fff;
            border-left: 5px solid var(--i0yps4-secondary);
            padding: 32px;
            margin: 48px 0;
            box-shadow: 0 4px 12px rgba(0,0,0,0.03);
            border-radius: 0 var(--i0yps4-radius) var(--i0yps4-radius) 0;
        }

        .i0yps4-step {
            display: flex;
            flex-wrap: wrap;
            gap: 24px;
            margin-bottom: 40px;
            align-items: flex-start;
        }

        .i0yps4-step-num {
            flex: 0 0 50px;
            height: 50px;
            background: var(--i0yps4-primary);
            color: #fff;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            font-size: 20px;
        }

        .i0yps4-step-content {
            flex: 1;
            min-width: 280px;
        }

        .i0yps4-code-block {
            background: var(--i0yps4-code-bg);
            color: #e0e0e0;
            padding: 20px;
            border-radius: 8px;
            font-family: "Consolas", monospace;
            font-size: 14px;
            margin: 16px 0;
            overflow-x: auto;
        }

        /* CTA Section */
        .i0yps4-cta {
            background: var(--i0yps4-primary);
            color: #fff;
            padding: 80px 0;
            text-align: center;
            border-radius: 40px;
            margin: 64px 24px;
        }

        .i0yps4-btn {
            display: inline-block;
            padding: 16px 40px;
            background: var(--i0yps4-secondary);
            color: #fff;
            text-decoration: none;
            border-radius: 30px;
            font-weight: bold;
            transition: background 0.3s;
            margin-top: 24px;
        }

        .i0yps4-btn:hover {
            background: #e67e00;
        }

        /* Footer */
        .i0yps4-footer {
            background: #f1f2f6;
            padding: 64px 0 32px;
            border-top: 1px solid var(--i0yps4-border);
        }

        .i0yps4-footer-grid {
            display: flex;
            flex-wrap: wrap;
            gap: 48px;
            justify-content: space-between;
        }

        .i0yps4-footer-brand {
            flex: 1;
            min-width: 240px;
        }

        .i0yps4-footer-brand h2 {
            color: var(--i0yps4-primary);
            margin-bottom: 16px;
        }

        .i0yps4-footer-links {
            display: flex;
            flex-wrap: wrap;
            gap: 48px;
        }

        .i0yps4-footer-col {
            min-width: 140px;
        }

        .i0yps4-footer-col h4 {
            margin-bottom: 20px;
            color: var(--i0yps4-text);
        }

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

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

        .i0yps4-footer-col a {
            text-decoration: none;
            color: var(--i0yps4-text-light);
            font-size: 14px;
        }

        .i0yps4-copyright {
            margin-top: 48px;
            padding-top: 24px;
            border-top: 1px solid #ddd;
            text-align: center;
            font-size: 14px;
            color: var(--i0yps4-text-light);
        }

        /* Responsive */
        @media (max-width: 768px) {
            .i0yps4-nav {
                display: none; /* Simple mobile hide for brevity, normally a hamburger */
            }
            .i0yps4-grid {
                grid-template-columns: 1fr;
            }
            .i0yps4-hero {
                padding: 64px 0 48px;
            }
        }