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

        body {
            font-family: 'Open Sans', Arial, sans-serif;
            color: #333;
            line-height: 1.6;
            background-color: #f8f9fa;
        }

        .header-top {
            background-color: #222;
            color: #fff;
            padding: 12px 0;
            font-size: 13px;
        }

        .header-top .container {
            max-width: 1140px;
            margin: 0 auto;
            padding: 0 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .header-main {
            background-color: #fff;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            position: sticky;
            top: 0;
            z-index: 100;
        }

        .header-main .container {
            max-width: 1140px;
            margin: 0 auto;
            padding: 0 20px;
        }

        .logo {
            padding: 20px 0;
            text-align: center;
        }

        .logo h1 {
            font-size: 32px;
            color: #4db2ec;
            font-weight: 600;
        }

        nav {
            background-color: #fff;
            border-top: 1px solid #e6e6e6;
        }

        nav ul {
            list-style: none;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
        }

        nav ul li {
            margin: 0;
        }

        nav ul li a {
            display: block;
            padding: 18px 24px;
            color: #111;
            text-decoration: none;
            font-size: 14px;
            font-weight: 500;
            transition: all 0.3s ease;
            position: relative;
        }

        nav ul li a:hover {
            color: #4db2ec;
        }

        nav ul li a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 0;
            height: 3px;
            background-color: #4db2ec;
            transition: width 0.3s ease;
        }

        nav ul li a:hover::after {
            width: 80%;
        }

        main {
            max-width: 1140px;
            margin: 40px auto;
            padding: 0 20px;
        }

        article {
            background-color: #fff;
            padding: 40px;
            margin-bottom: 40px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.05);
            border-radius: 4px;
        }

        h1 {
            font-size: 36px;
            line-height: 1.3;
            color: #111;
            margin-bottom: 30px;
            font-weight: 600;
        }

        article h2 {
            font-size: 28px;
            color: #111;
            margin: 35px 0 20px;
            font-weight: 600;
        }

        article h3 {
            font-size: 22px;
            color: #111;
            margin: 30px 0 15px;
            font-weight: 600;
        }

        article h4 {
            font-size: 18px;
            color: #111;
            margin: 25px 0 12px;
            font-weight: 600;
        }

        article p {
            font-size: 16px;
            line-height: 1.8;
            color: #444;
            margin-bottom: 20px;
        }

        article ul, article ol {
            margin: 20px 0 20px 25px;
        }

        article li {
            margin-bottom: 10px;
            font-size: 16px;
            line-height: 1.8;
            color: #444;
        }

        .transition-section {
            background-color: #fff;
            padding: 35px 40px;
            margin-bottom: 40px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.05);
            border-radius: 4px;
        }

        .transition-section p {
            font-size: 16px;
            line-height: 1.8;
            color: #444;
            margin-bottom: 15px;
        }

        .transition-section p:last-child {
            margin-bottom: 0;
        }

        .links-section {
            background-color: #fff;
            padding: 40px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.05);
            border-radius: 4px;
            margin-bottom: 40px;
        }

        .links-section h2 {
            font-size: 28px;
            color: #111;
            margin-bottom: 25px;
            font-weight: 600;
        }

        .links-section h3 {
            font-size: 20px;
            color: #111;
            margin: 30px 0 15px;
            font-weight: 600;
        }

        .links-section h3:first-of-type {
            margin-top: 0;
        }

        .links-section ul {
            list-style: none;
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 12px 30px;
            margin-bottom: 30px;
        }

        .links-section ul li {
            position: relative;
            padding-left: 20px;
        }

        .links-section ul li::before {
            content: '→';
            position: absolute;
            left: 0;
            color: #4db2ec;
            font-weight: bold;
        }

        .links-section ul li a {
            color: #4db2ec;
            text-decoration: none;
            font-size: 15px;
            line-height: 1.6;
            transition: color 0.3s ease;
        }

        .links-section ul li a:hover {
            color: #222;
            text-decoration: underline;
        }

        footer {
            background-color: #222;
            color: #fff;
            padding: 30px 0;
            margin-top: 60px;
        }

        footer .container {
            max-width: 1140px;
            margin: 0 auto;
            padding: 0 20px;
            text-align: center;
        }

        footer p {
            font-size: 14px;
            color: #999;
        }

        @media (max-width: 1018px) {
            h1 {
                font-size: 32px;
            }

            article h2 {
                font-size: 24px;
            }

            article h3 {
                font-size: 20px;
            }

            nav ul li a {
                padding: 16px 18px;
                font-size: 13px;
            }

            .links-section ul {
                gap: 10px 20px;
            }
        }

        @media (max-width: 767px) {
            .header-top {
                display: none;
            }

            .logo h1 {
                font-size: 24px;
            }

            nav ul {
                flex-direction: column;
            }

            nav ul li {
                border-bottom: 1px solid #e6e6e6;
            }

            nav ul li:last-child {
                border-bottom: none;
            }

            nav ul li a {
                padding: 14px 20px;
                text-align: left;
            }

            nav ul li a::after {
                display: none;
            }

            main {
                margin: 20px auto;
            }

            article, .transition-section, .links-section {
                padding: 25px 20px;
                margin-bottom: 20px;
            }

            h1 {
                font-size: 28px;
                margin-bottom: 20px;
            }

            article h2 {
                font-size: 22px;
            }

            article h3 {
                font-size: 18px;
            }

            article p, article li, .transition-section p {
                font-size: 15px;
            }

            .links-section ul {
                grid-template-columns: 1fr;
                gap: 10px;
            }

            .links-section h2 {
                font-size: 24px;
            }

            .links-section h3 {
                font-size: 18px;
            }
        }