:root{--primary-color: #f6821f;--bg-color: #f0f0f0;--text-color: #333;--card-bg: #fff;--completed-color: #888}body{font-family:Inter,system-ui,-apple-system,sans-serif;background-color:var(--bg-color);color:var(--text-color);margin:0;padding:0;display:flex;justify-content:center;min-height:100vh}.container{width:100%;max-width:600px;margin-top:50px;padding:20px}h1{text-align:center;color:var(--primary-color);font-weight:700;margin-bottom:30px}.todo-input-container{display:flex;gap:10px;margin-bottom:20px}.todo-input{flex:1;padding:12px;border:1px solid #ddd;border-radius:8px;font-size:16px;box-shadow:0 2px 4px #0000000d}.add-btn{background-color:var(--primary-color);color:#fff;border:none;padding:12px 24px;border-radius:8px;font-size:16px;cursor:pointer;font-weight:600;transition:opacity .2s}.add-btn:hover{opacity:.9}.todo-list{list-style:none;padding:0;background:var(--card-bg);border-radius:12px;box-shadow:0 4px 6px #0000000d;overflow:hidden}.todo-item{display:flex;align-items:center;padding:16px;border-bottom:1px solid #eee;transition:background .2s}.todo-item:last-child{border-bottom:none}.todo-item:hover{background:#f9f9f9}.todo-checkbox{margin-right:15px;width:20px;height:20px;cursor:pointer}.todo-text{flex:1;font-size:16px}.todo-text.completed{text-decoration:line-through;color:var(--completed-color)}.delete-btn{background:transparent;border:none;color:#ff4d4d;cursor:pointer;padding:5px 10px;font-size:14px}.delete-btn:hover{text-decoration:underline}