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

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
            min-height: 100vh;
            color: #333;
        }

        #container {
            max-width: 2400px;
            margin: 0 auto;
            padding: 20px;
        }

        container {
            display: flex;
            justify-content: space-between;
            }

        header {
            background: white;
            padding: 20px 20px;
            border-radius: 12px;
            box-shadow: 0 4px 20px rgba(0,0,0,0.1);
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 30px;
        }

        header h1 {
            font-size: 32px;
            color: #1e3c72;
            display: flex;
            align-items: center;
            gap: 10px;
            cursor: pointer;
            transition: color 0.3s ease;
        }

        header h1:hover {
            color: #667eea;
        }

        header input[type="submit"] {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            padding: 10px 24px;
            border-radius: 8px;
            font-size: 14px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
        }


        header input[type="submit"]:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
        }

        header input[type="submit"]:active {
            transform: translateY(0);
        }

        main {
            background: white;
            padding: 30px;
            border-radius: 12px;
            box-shadow: 0 4px 20px rgba(0,0,0,0.1);
            min-height: 400px;
            margin: 0 auto;
        }

        button {
            width: 100%;
            padding: 14px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            border-radius: 8px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: transform 0.2s, box-shadow 0.2s;

        button:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 20px rgba(102, 126, 234, 0.4);
        }

        button:active {
            transform: translateY(0);
        }