*{margin:0;padding:0;box-sizing:border-box}:root{font-family:system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark;color:#ffffffde;background-color:#000;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{margin:0;padding:0;overflow:hidden}.app{min-height:100vh;background:linear-gradient(135deg,#667eea,#764ba2);display:flex;justify-content:center;align-items:center;padding:20px}.todo-container{background:#fff;border-radius:10px;padding:30px;box-shadow:0 10px 40px #0000001a;width:100%;max-width:500px}h1{margin:0 0 25px;color:#333;text-align:center;font-size:32px}.input-container{display:flex;gap:10px;margin-bottom:25px}.todo-input{flex:1;padding:12px;border:2px solid #e0e0e0;border-radius:5px;font-size:16px;outline:none;transition:border-color .3s}.todo-input:focus{border-color:#667eea}.add-button{padding:12px 24px;background:#667eea;color:#fff;border:none;border-radius:5px;font-size:16px;cursor:pointer;transition:background .3s}.add-button:hover{background:#5568d3}.todo-list{list-style:none;padding:0;margin:0}.todo-item{display:flex;align-items:center;gap:12px;padding:15px;background:#f8f9fa;border-radius:5px;margin-bottom:10px;transition:background .3s}.todo-item:hover{background:#f0f1f3}.todo-checkbox{width:20px;height:20px;cursor:pointer}.todo-item span{flex:1;font-size:16px;color:#333}.todo-item span.completed{text-decoration:line-through;color:#999}.delete-button{padding:8px 16px;background:#ef4444;color:#fff;border:none;border-radius:5px;font-size:14px;cursor:pointer;transition:background .3s}.delete-button:hover{background:#dc2626}.empty-message{text-align:center;color:#999;font-style:italic;margin-top:20px}