*{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh}.app{max-width:1400px;margin:0 auto;padding:2rem}header{text-align:center;color:#fff;margin-bottom:2rem}header h1{font-size:2.5rem;margin-bottom:.5rem;text-shadow:2px 2px 4px rgba(0,0,0,.2)}header p{font-size:1.1rem;opacity:.95}main.side-by-side{display:grid;grid-template-columns:1fr 1fr;gap:2rem;margin-bottom:2rem}.column{background:#fff;border-radius:12px;padding:2rem;box-shadow:0 10px 40px #0003}.column h2{color:#667eea;margin-bottom:1.5rem;font-size:1.5rem;text-align:center;padding-bottom:1rem;border-bottom:2px solid #f0f0f0}.column h3{color:#667eea;margin-bottom:.8rem;margin-top:1.5rem;font-size:1.1rem}.column h3:first-of-type{margin-top:0}.upload-section,.message-section,.action-section{margin-bottom:1.5rem}input[type=file]{display:none}.upload-button{display:inline-block;padding:.75rem 1.5rem;background:#667eea;color:#fff;border-radius:6px;cursor:pointer;font-size:1rem;transition:background .3s}.upload-button:hover{background:#5568d3}.preview{margin-top:1rem;text-align:center}.preview img{max-width:100%;max-height:250px;border-radius:8px;box-shadow:0 4px 12px #0000001a}.capacity{margin-top:.5rem;color:#666;font-size:.9rem}textarea{width:100%;padding:.75rem;border:2px solid #e0e0e0;border-radius:6px;font-size:1rem;font-family:inherit;resize:vertical;transition:border-color .3s}textarea:focus{outline:none;border-color:#667eea}.char-count{margin-top:.5rem;color:#666;font-size:.9rem}.action-section{text-align:center}.action-button{width:100%;padding:1rem 2rem;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;border-radius:8px;font-size:1.1rem;font-weight:600;cursor:pointer;transition:transform .2s,box-shadow .3s;box-shadow:0 4px 15px #667eea66}.action-button:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 20px #667eea80}.action-button:active:not(:disabled){transform:translateY(0)}.action-button:disabled{opacity:.6;cursor:not-allowed}.message{padding:1rem;border-radius:6px;margin:1rem 0;text-align:center}.message.error{background:#fee;color:#c33;border:1px solid #fcc}.message.success{background:#efe;color:#363;border:1px solid #cfc}.decoded-message{background:#f8f9fa;padding:1.5rem;border-radius:8px;margin-top:1.5rem}.decoded-message h3{margin-bottom:1rem;margin-top:0;color:#363}.decoded-message pre{background:#fff;padding:1rem;border-radius:6px;border:1px solid #e0e0e0;white-space:pre-wrap;word-wrap:break-word;font-family:Courier New,Courier,monospace;font-size:.95rem;line-height:1.5;color:#333;max-height:300px;overflow-y:auto}footer{color:#fff}.info-section{background:#ffffff1a;padding:1.5rem;border-radius:8px;margin-bottom:1rem}.info-section h3{color:#fff;margin-bottom:.8rem;font-size:1.1rem}.info-section ul{margin-left:1.5rem;line-height:1.8}.info-section li{margin-bottom:.5rem}.info-section a{color:#fff;text-decoration:underline;font-weight:600}.info-section a:hover{opacity:.8}footer>p{text-align:center;opacity:.9}footer a{color:#fff;text-decoration:none;font-weight:600}footer a:hover{text-decoration:underline}@media(max-width:1024px){main.side-by-side{grid-template-columns:1fr}}@media(max-width:600px){.app{padding:1rem}header h1{font-size:2rem}.column{padding:1.5rem}}