*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:linear-gradient(135deg,#667eea,#764ba2);color:#333}.container,body{min-height:100vh}.container{max-width:600px;margin:0 auto;padding:2rem 1rem;display:flex;flex-direction:column;justify-content:center}header{text-align:center;margin-bottom:2rem;color:white}header h1{font-size:2.5rem;font-weight:700;margin-bottom:.5rem}header p{font-size:1.1rem;opacity:.9}.converter-card{background:white;border-radius:16px;padding:2rem;box-shadow:0 20px 40px rgba(0,0,0,.1);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.conversion-type{display:flex;gap:1rem;margin-bottom:2rem;justify-content:center}.conversion-type label{display:flex;align-items:center;gap:.5rem;padding:.75rem 1.5rem;border:2px solid #e2e8f0;border-radius:8px;cursor:pointer;transition:all .2s ease;font-weight:500}.conversion-type label:hover{border-color:#667eea;background-color:#f8fafc}.conversion-type input[type=radio]:checked+label,.conversion-type label:has(input[type=radio]:checked){border-color:#667eea;background-color:#667eea;color:white}.conversion-type input[type=radio]{margin:0}.file-upload{margin-bottom:2rem;position:relative}#file-input{position:absolute;opacity:0;width:100%;height:100%;cursor:pointer}.file-label{display:block;padding:1.5rem;border:2px dashed #cbd5e0;border-radius:8px;text-align:center;cursor:pointer;transition:all .2s ease;background-color:#f8fafc;color:#64748b;font-weight:500}.file-label:hover{border-color:#667eea;background-color:#f1f5f9;color:#667eea}.convert-btn,.download-btn,.reset-btn{width:100%;padding:1rem 2rem;border:none;border-radius:8px;font-size:1rem;font-weight:600;cursor:pointer;transition:all .2s ease;margin-bottom:1rem}.convert-btn{background:linear-gradient(135deg,#667eea,#764ba2);color:white}.convert-btn:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 10px 20px rgba(102,126,234,.3)}.convert-btn:disabled{opacity:.5;cursor:not-allowed}.download-btn{background:linear-gradient(135deg,#48bb78,#38a169);color:white}.download-btn:hover{transform:translateY(-2px);box-shadow:0 10px 20px rgba(72,187,120,.3)}.reset-btn{background:#f7fafc;color:#4a5568;border:2px solid #e2e8f0}.reset-btn:hover{background:#edf2f7;border-color:#cbd5e0}.loading{text-align:center;padding:2rem 0}.spinner{width:40px;height:40px;border:4px solid #e2e8f0;border-top-color:#667eea;border-radius:50%;animation:spin 1s linear infinite;margin:0 auto 1rem}@keyframes spin{0%{transform:rotate(0deg)}to{transform:rotate(1turn)}}.loading p{color:#64748b;font-weight:500}.download-section{text-align:center}.success{color:#38a169;font-weight:600;font-size:1.1rem}.error,.success{margin-bottom:1rem}.error{background:#fed7d7;color:#c53030;padding:1rem;border-radius:8px;text-align:center;font-weight:500}@media (max-width:640px){.container{padding:1rem}header h1{font-size:2rem}.converter-card{padding:1.5rem}.conversion-type{flex-direction:column}}