.button-group,h1{text-align:center}button,h1{background:linear-gradient(45deg,#667eea,#764ba2)}button,label{font-weight:600}#result,body{padding:20px}#result,textarea:focus{outline:0}#result[contenteditable=true],textarea:focus{border-color:#667eea;box-shadow:0 0 0 3px rgba(102,126,234,.1)}body{font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;max-width:1200px;margin:0 auto;background:linear-gradient(135deg,#667eea 0,#764ba2 100%);min-height:100vh}.input-section,h1{margin-bottom:30px}.container{background:rgba(255,255,255,.95);border-radius:15px;padding:30px;box-shadow:0 20px 40px rgba(0,0,0,.1)}h1{color:#333;font-size:2.5em;-webkit-background-clip:text;-webkit-text-fill-color:transparent}.input-section{display:grid;grid-template-columns:1fr 1fr;gap:20px}.input-group{display:flex;flex-direction:column}label{margin-bottom:8px;color:#555;font-size:1.1em}#result,textarea{font-family:'Courier New',monospace;font-size:14px}textarea{width:100%;height:300px;padding:15px;border:2px solid #e1e5e9;border-radius:10px;resize:vertical;transition:border-color .3s}.button-group{margin:30px 0}button{color:#fff;border:none;padding:15px 30px;font-size:16px;border-radius:25px;cursor:pointer;transition:.3s;margin:0 10px}button:hover{transform:translateY(-2px);box-shadow:0 10px 20px rgba(102,126,234,.3)}.result-section{margin-top:30px}#result{background:#f8f9fa;border:2px solid #e9ecef;border-radius:10px;white-space:pre-wrap;max-height:500px;overflow-y:auto;line-height:1.6;min-height:200px}.new-element{background-color:rgba(255,99,99,.2);padding:2px 4px;border-radius:3px;border-left:3px solid #ff6363}.error,.success{padding:10px;margin:10px 0}.error{color:#dc3545;background:#f8d7da;border:1px solid #f5c6cb;border-radius:5px}.success{color:#155724;background:#d4edda;border:1px solid #c3e6cb;border-radius:5px}@media (max-width:768px){.input-section{grid-template-columns:1fr}.container{padding:20px}h1{font-size:2em}}