*{margin:0;padding:0;box-sizing:border-box}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:linear-gradient(135deg,#fafafa,#f0f0f0);min-height:100vh;color:#1a1a1a;-webkit-font-smoothing:antialiased}.app{min-height:100vh;display:flex;justify-content:center;padding:60px 24px}.container{width:100%;max-width:520px}.header{text-align:center;margin-bottom:48px}.header h1{font-size:42px;font-weight:600;letter-spacing:-1.5px;color:#111;margin-bottom:8px}.subtitle{font-size:15px;color:#888;font-weight:400;letter-spacing:.3px}.input-section{display:flex;gap:12px;margin-bottom:32px}.todo-input{flex:1;padding:18px 24px;font-size:16px;border:none;border-radius:16px;background:#fff;box-shadow:0 2px 8px #0000000a,0 1px 2px #0000000f;transition:all .2s ease;font-family:inherit}.todo-input:focus{outline:none;box-shadow:0 4px 20px #00000014,0 2px 4px #0000000a}.todo-input::placeholder{color:#aaa}.add-button{width:56px;height:56px;border:none;border-radius:16px;background:linear-gradient(135deg,#111,#333);color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .2s ease;flex-shrink:0}.add-button:hover{transform:translateY(-2px);box-shadow:0 8px 24px #0003}.add-button:active{transform:translateY(0)}.todo-list{list-style:none;display:flex;flex-direction:column;gap:8px}.todo-item{display:flex;align-items:center;gap:16px;padding:18px 20px;background:#fff;border-radius:14px;box-shadow:0 1px 3px #0000000a;transition:all .2s ease;animation:slideIn .3s ease}@keyframes slideIn{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}.todo-item:hover{box-shadow:0 4px 12px #0000000f}.todo-item.completed .todo-text{color:#bbb;text-decoration:line-through}.checkbox-container{position:relative;cursor:pointer;display:flex;align-items:center;justify-content:center}.checkbox-container input{position:absolute;opacity:0;cursor:pointer;height:0;width:0}.checkmark{width:24px;height:24px;border:2px solid #ddd;border-radius:8px;display:flex;align-items:center;justify-content:center;transition:all .2s ease}.checkbox-container:hover .checkmark{border-color:#bbb}.checkbox-container input:checked~.checkmark{background:linear-gradient(135deg,#10b981,#059669);border-color:transparent}.checkmark svg{color:#fff}.todo-text{flex:1;font-size:15px;line-height:1.5;transition:all .2s ease}.delete-button{width:32px;height:32px;border:none;background:transparent;color:#ccc;cursor:pointer;display:flex;align-items:center;justify-content:center;border-radius:8px;opacity:0;transition:all .2s ease}.todo-item:hover .delete-button{opacity:1}.delete-button:hover{background:#fee2e2;color:#ef4444}.footer{display:flex;justify-content:space-between;align-items:center;margin-top:24px;padding:0 4px}.count{font-size:13px;color:#999}.clear-button{font-size:13px;color:#999;background:none;border:none;cursor:pointer;padding:8px 12px;border-radius:8px;transition:all .2s ease;font-family:inherit}.clear-button:hover{background:#f5f5f5;color:#666}.empty-state{text-align:center;padding:64px 24px;color:#999}.empty-icon{margin-bottom:20px;color:#ddd}.empty-state p{font-size:18px;font-weight:500;color:#666;margin-bottom:6px}.empty-state span{font-size:14px;color:#aaa}@media (max-width: 480px){.app{padding:40px 16px}.header h1{font-size:36px}.todo-input{padding:16px 20px}.add-button{width:52px;height:52px}.todo-item{padding:16px}.delete-button{opacity:1}}