: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:#242424;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{font-weight:500;color:#646cff;text-decoration:inherit}a:hover{color:#535bf2}body{margin:0;display:flex;place-items:center;min-width:320px;min-height:100vh}h1{font-size:3.2em;line-height:1.1}button{border-radius:8px;border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;font-family:inherit;background-color:#1a1a1a;cursor:pointer;transition:border-color .25s}button:hover{border-color:#646cff}button:focus,button:focus-visible{outline:4px auto -webkit-focus-ring-color}.card{padding:2em}#app{max-width:1280px;margin:0 auto;padding:2rem;text-align:center}@media (prefers-color-scheme: light){:root{color:#213547;background-color:#fff}a:hover{color:#747bff}button{background-color:#f9f9f9}}#app{font-family:Avenir,Helvetica,Arial,sans-serif;max-width:600px;margin:0 auto;padding:20px;color:#2c3e50}.input-section{display:flex;gap:10px;margin-bottom:20px}.todo-input{flex:1;padding:10px;border:1px solid #ddd;border-radius:4px;font-size:16px}.add-btn{padding:10px 20px;background-color:#42b883;color:#fff;border:none;border-radius:4px;cursor:pointer;font-size:16px}.add-btn:hover{background-color:#359f72}.todo-list{list-style:none;padding:0}.todo-item{padding:12px;border-bottom:1px solid #eee;display:flex;justify-content:space-between;align-items:center}.todo-item:hover{background-color:#f9f9f9}.todo-item.completed span{text-decoration:line-through;color:#7f8c8d}.empty-state{text-align:center;color:#7f8c8d;font-style:italic}.error{color:#e74c3c;text-align:center}