.container {
            max-width: 1000px;
            margin: 0 auto;
            background: white;
            border-radius: 12px;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
            overflow: hidden;
            border: 1px solid #eaeaea;
        }
        
        .header {
            background: linear-gradient(135deg, #4a6fa5, #3a5a80);
            color: white;
            padding: 30px;
            text-align: center;
        }
        
        .header h1 {
            font-size: 2.2em;
            margin-bottom: 10px;
        }
        
        .header p {
            opacity: 0.9;
            font-size: 1.1em;
        }
        
        .content {
            padding: 30px;
            display: grid;
            grid-template-columns: 1fr auto 1fr;
            gap: 25px;
            align-items: start;
        }
        
        .input-section, .output-section {
            display: flex;
            flex-direction: column;
        }
        
        .control-section {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 20px 0;
        }
        
        .section-title {
            font-size: 1.2em;
            font-weight: bold;
            margin-bottom: 10px;
            color: #2c3e50;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        textarea {
            width: 100%;
            height: 250px;
            padding: 15px;
            border: 2px solid #e0e0e0;
            border-radius: 8px;
            font-size: 16px;
            resize: vertical;
            font-family: inherit;
            transition: border-color 0.3s;
            background: #fafafa;
        }
        
        textarea:focus {
            outline: none;
            border-color: #4a6fa5;
            background: white;
        }
        
        .char-count {
            text-align: right;
            margin-top: 5px;
            color: #666;
            font-size: 14px;
        }
        
        .controls {
            display: flex;
            flex-direction: column;
            gap: 15px;
            margin-top: 15px;
        }
        
        .conversion-type {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        
        .conversion-option {
            display: flex;
            align-items: center;
            padding: 12px;
            border: 2px solid #e0e0e0;
            border-radius: 8px;
            cursor: pointer;
            transition: all 0.3s;
            background: white;
        }
        
        .conversion-option:hover {
            border-color: #4a6fa5;
            background: #f5f7fa;
        }
        
        .conversion-option.active {
            border-color: #4a6fa5;
            background: #edf2f7;
        }
        
        .conversion-option input {
            margin-right: 10px;
        }
        
        .action-buttons {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        
        button {
            padding: 12px 20px;
            border: none;
            border-radius: 8px;
            font-size: 16px;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s;
        }
        
        .convert-btn {
            background: linear-gradient(135deg, #4a6fa5, #3a5a80);
            color: white;
        }
        
        .convert-btn:hover {
            background: linear-gradient(135deg, #3a5a80, #4a6fa5);
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(74, 111, 165, 0.3);
        }
        
        .copy-btn {
            background: linear-gradient(135deg, #5a9367, #4a7a56);
            color: white;
        }
        
        .copy-btn:hover {
            background: linear-gradient(135deg, #4a7a56, #5a9367);
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(90, 147, 103, 0.3);
        }
        
        .switch-btn {
            background: #e67e22;
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 20px;
            margin: 20px 0;
        }
        
        .switch-btn:hover {
            background: #d35400;
            transform: rotate(180deg);
        }
        
        .result-box {
            background: #f8f9fa;
            border-radius: 8px;
            padding: 20px;
            min-height: 250px;
            border: 2px dashed #c8d1d9;
        }
        
        .result-text {
            line-height: 1.6;
            white-space: pre-wrap;
            word-wrap: break-word;
        }
        
        .loading {
            display: none;
            text-align: center;
            padding: 20px;
        }
        
        .spinner {
            border: 4px solid #f3f3f3;
            border-top: 4px solid #4a6fa5;
            border-radius: 50%;
            width: 40px;
            height: 40px;
            animation: spin 1s linear infinite;
            margin: 0 auto 10px;
        }
        
        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }
        
        .examples {
            margin-top: 20px;
            padding: 15px;
            background: #f0f5ff;
            border-radius: 8px;
            border-left: 4px solid #4a6fa5;
        }
        
        .examples h3 {
            margin-bottom: 10px;
            color: #2c3e50;
        }
        
        .example-item {
            padding: 8px;
            margin: 5px 0;
            background: white;
            border-radius: 5px;
            cursor: pointer;
            transition: background 0.3s;
            border: 1px solid #e0e0e0;
        }
        
        .example-item:hover {
            background: #e3ecf7;
            border-color: #4a6fa5;
        }
        
        .footer {
            text-align: center;
            padding: 20px;
            background: #f5f7fa;
            color: #666;
            border-top: 1px solid #eaeaea;
        }
        
        .footer a {
            color: #4a6fa5;
            text-decoration: none;
        }
        
        .footer a:hover {
            text-decoration: underline;
        }
        
        @media (max-width: 768px) {
            .content {
                grid-template-columns: 1fr;
                grid-template-rows: auto auto auto;
            }
            
            .control-section {
                order: 3;
                flex-direction: row;
                justify-content: center;
                gap: 20px;
            }
            
            .switch-btn {
                margin: 0;
            }
        }