/* ===== 全局重置 & 字体 ===== */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        /* 设置基准字号：10px = 1rem */
        html {
            font-size: 62.5%; /* 1rem = 10px */
        }

        body {
            font-family: 'Inter', sans-serif;
            background-color: #ffffff;
            color: #1e293b;
            line-height: 1.5;
            scroll-behavior: smooth;
            font-size: 1.6rem; /* 16px */
        }

        .container {
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 24px;
        }

        .section {
            padding: 80px 0;
        }
        .bg-light {
            background-color: #f8fafc;
        }
        .bg-white {
            background-color: #ffffff;
        }
        .section-title {
            font-size: 3.2rem; /* 32px */
            font-weight: 700;
            text-align: center;
            margin-bottom: 16px;
            letter-spacing: -0.02em;
        }
        .section-sub {
            text-align: center;
            color: #475569;
            max-width: 700px;
            margin: 0 auto 48px auto;
            font-size: 1.8rem; /* 18px */
        }

        /* 按钮样式 */
        .btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 12px 28px;
            border-radius: 40px;
            font-weight: 600;
            transition: all 0.25s ease;
            cursor: pointer;
            border: none;
            font-size: 1.6rem; /* 16px */
            text-decoration: none;
        }
        .btn-primary {
            background: #0f3b5f;
            color: white;
            box-shadow: 0 4px 8px rgba(15, 59, 95, 0.2);
        }
        .btn-primary:hover {
            background: #0a2c48;
            transform: translateY(-2px);
        }
        .btn-outline {
            background: transparent;
            border: 1.5px solid #0f3b5f;
            color: #0f3b5f;
        }
        .btn-outline:hover {
            background: #eef2ff;
            border-color: #0a2c48;
            color: #0a2c48;
        }
        .btn-cta {
            background: #f97316;
            color: white;
            box-shadow: 0 4px 12px rgba(249, 115, 22, 0.25);
        }
        .btn-cta:hover {
            background: #ea580c;
            transform: translateY(-2px);
        }

        /* 卡片网格 */
        .grid-3 {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 32px;
            margin-top: 16px;
        }
        .grid-2 {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 40px;
        }
        .feature-card {
            background: #ffffff;
            border-radius: 28px;
            padding: 32px 24px;
            transition: all 0.3s ease;
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.02);
            border: 1px solid #eef2f6;
            text-align: center;
        }
        .feature-card:hover {
            transform: translateY(-6px);
            border-color: #cbdde6;
            box-shadow: 0 20px 30px -12px rgba(0, 0, 0, 0.1);
        }
        .feature-icon {
            font-size: 4.0rem; /* 40px */
            background: #eef2ff;
            width: 70px;
            height: 70px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            border-radius: 30px;
            color: #0f3b5f;
            margin-bottom: 24px;
        }
        .feature-card h3 {
            font-size: 2.4rem; /* 24px */
            font-weight: 700;
            margin-bottom: 12px;
        }
        .feature-card p {
            color: #475569;
            font-size: 1.5rem; /* 15px */
        }

        .two-col {
            display: flex;
            flex-wrap: wrap;
            gap: 48px;
            align-items: center;
        }
        .two-col > div {
            flex: 1;
        }
        .smart-list {
            list-style: none;
            margin-top: 24px;
        }
        .smart-list li {
            margin-bottom: 16px;
            display: flex;
            align-items: center;
            gap: 12px;
            font-size: 1.6rem; /* 16px */
        }
        .smart-list li i {
            color: #0f3b5f;
            font-size: 1.9rem; /* 19px */
            width: 28px;
        }
        .badge {
            background: #eef2ff;
            color: #0f3b5f;
            border-radius: 40px;
            padding: 4px 14px;
            font-size: 1.3rem; /* 13px */
            font-weight: 600;
            display: inline-block;
            margin-top: 12px;
        }

        /* 作品仓库预览 */
        .code-showcase {
            background: linear-gradient(145deg, #f1f5f9, #ffffff);
            border-radius: 32px;
            padding: 24px;
        }
        .project-card {
            background: white;
            border-radius: 24px;
            padding: 16px;
            margin-top: 16px;
            display: flex;
            gap: 16px;
            align-items: center;
            box-shadow: 0 4px 6px -2px rgba(0,0,0,0.05);
        }
        .project-icon {
            width: 48px;
            height: 48px;
            background: #eef2ff;
            border-radius: 20px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #0f3b5f;
            font-size: 2.4rem; /* 24px */
        }

        /* 等级测评卡片 */
        .level-card {
            background: white;
            border-radius: 28px;
            padding: 24px;
            border: 1px solid #e2e8f0;
        }
        .level-progress {
            margin: 20px 0;
        }
        .progress-label {
            display: flex;
            justify-content: space-between;
            margin-bottom: 6px;
        }
        .progress-bar-bg {
            background: #e2e8f0;
            border-radius: 20px;
            height: 8px;
            overflow: hidden;
        }
        .progress-fill {
            background: #0f3b5f;
            width: 65%;
            height: 8px;
            border-radius: 20px;
        }

        /* 教具管理展示 */
        .inventory-row {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            margin-top: 20px;
        }
        .inventory-item {
            background: #f8fafc;
            border-radius: 20px;
            padding: 12px 20px;
            flex: 1;
            text-align: center;
        }

        /* 案例卡片 */
        .case-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 30px;
        }
        .case-card {
            background: white;
            border-radius: 28px;
            padding: 24px;
            border: 1px solid #edf2f7;
        }
        .case-card .quote {
            font-size: 1.6rem; /* 16px */
            color: #334155;
            margin: 16px 0;
            line-height: 1.5;
        }
        .case-card .org {
            font-weight: 800;
            color: #0f172a;
            font-size: 1.5rem; /* 15px */
        }
        .case-card .stat {
            color: #f97316;
            font-weight: 700;
            font-size: 1.5rem; /* 15px */
        }

        /* 表单 */
        .form-card {
            background: linear-gradient(135deg, #f0f9ff 0%, #ffffff 100%);
            border-radius: 40px;
            padding: 48px 40px;
            box-shadow: 0 20px 35px -12px rgba(0, 0, 0, 0.08);
            border: 1px solid #d9e6f2;
        }
        .form-row {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            margin-top: 32px;
        }
        .input-group {
            flex: 1;
            min-width: 200px;
        }
        .input-group input {
            width: 100%;
            padding: 14px 20px;
            border-radius: 60px;
            border: 1px solid #cbd5e1;
            font-size: 1.6rem; /* 16px */
            background: white;
        }
        .input-group input:focus {
            outline: none;
            border-color: #0f3b5f;
            box-shadow: 0 0 0 3px rgba(15,59,95,0.2);
        }

        /* 导航 + 底部 */
        .navbar {
            background: white;
            padding: 16px 0;
            border-bottom: 1px solid #edf2f7;
            position: sticky;
            top: 0;
            z-index: 50;
            background: rgba(255,255,255,0.96);
        }
        .nav-flex {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .logo {
            font-size: 2.6rem; /* 26px */
            font-weight: 800;
            color: #1e293b;
        }
        .logo span {
            color: #0f3b5f;
        }
        .nav-links {
            display: flex;
            gap: 32px;
            align-items: center;
        }
        .nav-links a {
            text-decoration: none;
            color: #334155;
            font-weight: 500;
            font-size: 1.5rem; /* 15px */
        }
        .nav-links a:hover {
            color: #0f3b5f;
        }
        @media (max-width: 700px) {
            .nav-links { display: none; }
            .navbar .btn-outline { display: none; }
        }

        .footer {
            background-color: #0f172a;
            color: #cbd5e1;
            padding: 48px 0 24px;
        }
        .footer-links {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 32px;
            margin-bottom: 32px;
        }
        .footer-col {
            min-width: 140px;
        }
        .footer-col h4 {
            color: white;
            font-weight: 600;
            margin-bottom: 16px;
            font-size: 1.6rem; /* 16px */
        }
        .footer-col a {
            display: block;
            color: #94a3b8;
            text-decoration: none;
            margin-bottom: 10px;
            font-size: 1.4rem; /* 14px */
        }
        .footer-col a:hover {
            color: #f97316;
        }
        .copyright {
            text-align: center;
            border-top: 1px solid #1e293b;
            padding-top: 28px;
            font-size: 1.4rem; /* 14px */
        }
        .hero {
            padding: 150px 0 60px;
            background: linear-gradient(120deg, #ffffff 0%, #eff6ff 100%);
        }
        .hero h1 {
            font-size: 4.8rem; /* 48px */
            font-weight: 800;
            letter-spacing: -0.02em;
            line-height: 1.2;
            margin-bottom: 20px;
        }
        .hero .highlight {
            color: #f97316;
        }
        .hero-buttons {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            margin: 32px 0 16px;
        }
        .hero-sub {
            font-size: 1.9rem; /* 19px */
            color: #475569;
            margin: 24px 0 0;
        }
        @media (max-width: 768px) {
            .section { padding: 60px 0; }
            .hero h1 { font-size: 3.6rem; }
            .section-title { font-size: 2.8rem; }
            .form-card { padding: 32px 24px; }
        }