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

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            line-height: 1.6;
            color: #333;
            background-color: #f5f5f5;
        }

        .header-bar {
            background: linear-gradient(to bottom, #ffffff 0%, #f0f0f0 100%);
            border-bottom: 3px solid #638bc8;
            padding: 0;
        }

        .header-container {
            max-width: 1400px;
            margin: 0 auto;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 15px 20px;
        }

        .logo-section a {
            display: inline-block;
            font-size: 24px;
            font-weight: bold;
            color: #638bc8;
            text-decoration: none;
            transition: color 0.3s;
        }

        .logo-section a:hover {
            color: #4a6fa5;
        }

        .nav-section {
            flex-grow: 1;
            text-align: center;
        }

        .nav-tab {
            display: inline-block;
            background-color: #638bc8;
            color: white;
            padding: 10px 25px;
            text-decoration: none;
            border-radius: 5px 5px 0 0;
            font-weight: 600;
            transition: background-color 0.3s;
        }

        .nav-tab:hover {
            background-color: #4a6fa5;
        }

        .header-accent {
            height: 4px;
            background: linear-gradient(to right, #638bc8, #4a6fa5, #638bc8);
        }

        .user-bar {
            background-color: #e8eef7;
            border-bottom: 1px solid #d0d0d0;
            padding: 10px 0;
        }

        .user-container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 20px;
            text-align: right;
            font-size: 14px;
            color: #666;
        }

        .user-container b {
            color: #333;
        }

        .main-container {
            max-width: 1200px;
            margin: 40px auto;
            padding: 0 20px;
        }

        .content-wrapper {
            background-color: white;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
            padding: 50px;
            margin-bottom: 40px;
        }

        h1 {
            font-size: 2.5em;
            color: #2c3e50;
            margin-bottom: 30px;
            padding-bottom: 15px;
            border-bottom: 3px solid #638bc8;
        }

        article h2 {
            font-size: 1.8em;
            color: #34495e;
            margin-top: 30px;
            margin-bottom: 15px;
        }

        article h3 {
            font-size: 1.4em;
            color: #34495e;
            margin-top: 25px;
            margin-bottom: 12px;
        }

        article h4 {
            font-size: 1.2em;
            color: #34495e;
            margin-top: 20px;
            margin-bottom: 10px;
        }

        article p {
            margin-bottom: 20px;
            font-size: 16px;
            color: #555;
            text-align: justify;
        }

        .transition-section {
            background-color: white;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
            padding: 40px 50px;
            margin-bottom: 40px;
        }

        .transition-section p {
            font-size: 16px;
            color: #555;
            margin-bottom: 15px;
            line-height: 1.7;
        }

        .links-section {
            background-color: white;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
            padding: 50px;
        }

        .links-section h2 {
            font-size: 2em;
            color: #2c3e50;
            margin-bottom: 15px;
            padding-bottom: 10px;
            border-bottom: 2px solid #638bc8;
        }

        .links-section h3 {
            font-size: 1.5em;
            color: #34495e;
            margin-top: 35px;
            margin-bottom: 20px;
            padding-left: 10px;
            border-left: 4px solid #638bc8;
        }

        .links-section ul {
            list-style: none;
            column-count: 2;
            column-gap: 40px;
            margin-bottom: 20px;
        }

        .links-section li {
            margin-bottom: 12px;
            break-inside: avoid;
            padding-left: 20px;
            position: relative;
        }

        .links-section li:before {
            content: "→";
            position: absolute;
            left: 0;
            color: #638bc8;
            font-weight: bold;
        }

        .links-section a {
            color: #638bc8;
            text-decoration: none;
            transition: color 0.3s, padding-left 0.3s;
            display: inline-block;
        }

        .links-section a:hover {
            color: #4a6fa5;
            padding-left: 5px;
        }

        @media (max-width: 968px) {
            .header-container {
                flex-direction: column;
                align-items: center;
                gap: 15px;
            }

            .nav-section {
                width: 100%;
            }

            .content-wrapper,
            .transition-section,
            .links-section {
                padding: 30px 25px;
            }

            h1 {
                font-size: 2em;
            }

            .links-section ul {
                column-count: 1;
            }

            .user-container {
                text-align: center;
            }
        }

        @media (max-width: 600px) {
            .main-container {
                margin: 20px auto;
            }

            .content-wrapper,
            .transition-section,
            .links-section {
                padding: 20px 15px;
                border-radius: 5px;
            }

            h1 {
                font-size: 1.6em;
            }

            article h2 {
                font-size: 1.4em;
            }

            article h3 {
                font-size: 1.2em;
            }

            .links-section h2 {
                font-size: 1.5em;
            }

            .links-section h3 {
                font-size: 1.2em;
            }

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