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

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            background-color: #87CEFA;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 20px;
        }

        .container {
            width: 100%;
            max-width: 800px;
            min-height: 540px;
            background: white;
            border-radius: 20px;
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
            display: flex;
            flex-direction: column;
            overflow: hidden;
        }

        .header {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 10px;
            text-align: center;
            flex-shrink: 0;
        }

        .header h1 {
            font-size: 24px;
            font-weight: 600;
            letter-spacing: 1px;
        }

        .nav {
            display: flex;
            justify-content: space-around;
            padding: 15px 20px;
            background: #f8f9fa;
            border-bottom: 1px solid #e9ecef;
            flex-shrink: 0;
        }

        .nav-item {
            flex: 1;
            text-align: center;
            padding: 12px 15px;
            margin: 0 5px;
            background: white;
            border-radius: 10px;
            cursor: pointer;
            transition: all 0.3s ease;
            font-size: 18px;
            font-weight: bold;
            color: #495057;
            border: 2px solid transparent;
        }

        .nav-item:hover {
            background: #667eea;
            color: white;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
        }

        .nav-item.active {
            background: #667eea;
            color: white;
        }

        .content {
            flex: 1;
            padding: 25px 30px 20px 30px;
            position: relative;
        }

        .content.centered {
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .initial-content {
            text-align: center;
        }

        .initial-message {
            color: #6c757d;
            text-align: center;
            font-size: 16px;
            line-height: 1.8;
            margin-bottom: 5px;
        }

        .initial-message:nth-child(1) {
            font-size: 18px;
            margin-bottom: 15px;
            color: #495057;
        }

        .initial-message:nth-child(2) {
            font-size: 16px;
            margin-bottom: 10px;
        }

        .initial-message:nth-child(3) {
            font-size: 15px;
            margin-bottom: 15px;
        }

        .random-btn {
            background: none;
            border: none;
            color: #667eea;
            font-size: 18px;
            cursor: pointer;
            text-decoration: none;
            transition: all 0.3s ease;
            padding: 5px;
            border-radius: 4px;
            display: inline-block;
        }

        .random-btn:hover {
            color: #764ba2;
            transform: translateY(-2px);
        }

        .article-container {
            width: 100%;
        }

        .article-list {
            list-style: none;
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 16px 24px;
        }

        .article-item {
            padding-left: 22px;
            position: relative;
            transition: all 0.3s ease;
        }

        .article-item::before {
            content: '';
            position: absolute;
            left: 0;
            top: 12px;
            width: 6px;
            height: 6px;
            background: #667eea;
            border-radius: 50%;
            transition: all 0.3s ease;
        }

        .article-item:hover::before {
            transform: scale(1.5);
            background: #764ba2;
        }

        .article-item:hover {
            transform: translateX(5px);
        }

        .article-link {
            text-decoration: none;
            color: #495057;
            display: block;
            font-size: 18px; 
            white-space: nowrap; 
            line-height: 1.6;
            transition: color 0.3s ease;
        }

        .article-link:hover {
            color: #667eea;
        }

        .more-btn-wrapper {
            text-align: right;
            margin-top: 10px;
            padding-top: 0px;
            grid-column: 1 / -1;
        }

        .more-btn {
            display: inline-block;
            padding: 3px 3px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            text-decoration: none;
            border-radius: 20px;
            font-size: 14px;
            transition: all 0.3s ease;
            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
        }

        .more-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
        }

        .footer {
            background: #f8f9fa;
            padding: 15px 20px;
            text-align: center;
            color: #6c757d;
            font-size: 14px;
            border-top: 1px solid #e9ecef;
            flex-shrink: 0;
        }

        @media (max-width: 800px) and (orientation: portrait) {
            body {
                background-color: #f5f7fa;
            }
            
            .container {
                max-width: 480px;
                min-height: 540px;
            }

            .article-list {
                grid-template-columns: 1fr;
                gap: 16px;
            }

            .content {
                padding: 25px 25px 20px 25px;
            }

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

            .nav {
                padding: 15px 15px;
            }

            .nav-item {
                font-size: 16px;
                font-weight: bold;
                padding: 10px 10px;
                margin: 0 4px;
            }

            .article-link {
                font-size: 16px; 
            }

            .article-item::before {
                top: 10px; 
            }

            .initial-message:nth-child(1) {
                font-size: 16px;
            }

            .initial-message:nth-child(2),
            .initial-message:nth-child(3) {
                font-size: 15px;
            }

            .random-btn {
                font-size: 16px;
            }
        }

        @media (max-width: 800px) and (orientation: landscape) {
            body {
                padding: 15px;
                background-color: #f5f7fa;
            }

            .container {
                max-width: 100%;
                min-height: 400px;
                max-height: calc(100vh - 30px);
            }

            .content {
                overflow-y: auto;
            }

            .article-list {
                grid-template-columns: repeat(2, 1fr);
                gap: 12px 20px;
            }

            .header {
                padding: 8px;
            }

            .header h1 {
                font-size: 22px;
            }

            .nav {
                padding: 12px 20px;
            }

            .nav-item {
                font-size: 16px;
                font-weight: bold;
                padding: 10px 12px;
                margin: 0 4px;
            }

            .content {
                padding: 20px 25px 15px 25px;
            }

            .more-btn {
                padding: 4px 10px;
                font-size: 13px;
            }
            
            .article-link {
                font-size: 16px; 
                line-height: 1.5;
            }

            .article-item {
                padding-left: 20px;
            }

            .article-item::before {
                top: 10px; 
                width: 5px;
                height: 5px;
            }

            .footer {
                padding: 10px 20px;
                font-size: 11px;
            }

            .more-btn-wrapper {
                margin-top: 15px;
                padding-top: 12px;
            }

            .initial-message:nth-child(1) {
                font-size: 16px;
            }

            .initial-message:nth-child(2),
            .initial-message:nth-child(3) {
                font-size: 14px;
            }

            .random-btn {
                font-size: 15px;
            }

            .content::-webkit-scrollbar {
                width: 6px;
            }

            .content::-webkit-scrollbar-track {
                background: #f1f1f1;
                border-radius: 10px;
            }

            .content::-webkit-scrollbar-thumb {
                background: #667eea;
                border-radius: 10px;
            }

            .content::-webkit-scrollbar-thumb:hover {
                background: #764ba2;
            }
        }

        @media (max-width: 480px) and (orientation: portrait) {
            body {
                padding: 15px;
                background-color: #f5f7fa;
            }

            .container {
                max-width: 100%;
                border-radius: 20px;
                min-height: 540px;
            }

            .header {
                padding: 10px;
            }

            .nav {
                padding: 15px 10px;
            }

            .nav-item {
                font-size: 14px;
                font-weight: bold;
                padding: 10px 8px;
                margin: 0 3px;
            }

            .content {
                padding: 25px 20px;
            }
            
            .more-btn {
                padding: 4px 10px;
                font-size: 12px;
            }

            .article-link {
                font-size: 15px; 
            }

            .article-item::before {
                top: 9px; 
            }

            .initial-message:nth-child(1) {
                font-size: 15px;
            }

            .initial-message:nth-child(2),
            .initial-message:nth-child(3) {
                font-size: 13px;
            }

            .random-btn {
                font-size: 15px;
            }
        }

        @media (max-width: 360px) and (orientation: portrait) {
            body {
                padding: 10px;
                background-color: #f5f7fa;
            }

            .nav-item {
                font-size: 13px;
                font-weight: bold;
                padding: 8px 5px;
                margin: 0 2px;
            }

            .content {
                padding: 20px 15px;
            }
            
            .more-btn {
                padding: 3px 8px;
                font-size: 11px;
            }

            .article-link {
                font-size: 14px; 
            }

            .article-item::before {
                top: 8px; 
            }

            .initial-message:nth-child(1) {
                font-size: 14px;
            }

            .initial-message:nth-child(2),
            .initial-message:nth-child(3) {
                font-size: 12px;
            }

            .random-btn {
                font-size: 14px;
            }
        }