*{margin:0;padding:0;box-sizing:border-box}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-color:#f5f5f5;color:#333;line-height:1.6}.app{min-height:100vh;display:flex;flex-direction:column}.main-content{flex:1;padding:0}@media (max-width: 767px){body{font-size:16px}}.btn{display:inline-block;padding:12px 24px;border:none;border-radius:8px;background-color:#2196f3;color:#fff;font-size:16px;font-weight:600;text-decoration:none;text-align:center;cursor:pointer;transition:all .3s ease;-webkit-appearance:none;-moz-appearance:none;appearance:none}.btn:hover{background-color:#1976d2;transform:translateY(-2px)}.btn:active{transform:translateY(0)}.btn:disabled{background-color:#ccc;cursor:not-allowed;transform:none}.card{background:white;border-radius:12px;padding:20px;box-shadow:0 4px 6px #0000001a;margin-bottom:16px}.loading{display:flex;justify-content:center;align-items:center;padding:40px}.spinner{width:40px;height:40px;border:4px solid #f3f3f3;border-top:4px solid #2196F3;border-radius:50%;animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}@media (min-width: 768px){.main-content{max-width:600px;margin:0 auto;padding:20px}}