body{margin:0;font-family:Inter,Arial,sans-serif;background:#f4f6f8;color:#333;transition:background .3s,color .3s}.app{max-width:600px;margin:40px auto;padding:20px}.task-form{display:flex;gap:10px;margin-bottom:20px}.task-form input[type=text]{flex:1;padding:10px 12px;border:1px solid #ccc;border-radius:8px;font-size:16px;transition:all .3s ease}.task-form input[type=text]:focus{outline:none;border-color:#007bff;box-shadow:0 0 8px #007bff4d}.task-form button{padding:10px 16px;border:none;background:#007bff;color:#fff;border-radius:8px;cursor:pointer;font-weight:600;transition:background .3s ease,transform .2s ease}.task-form button:hover{background:#0056b3;transform:translateY(-1px)}.task-item{display:flex;align-items:center;gap:12px;margin:8px 0;padding:12px 16px;border-radius:10px;background:#fff;box-shadow:0 2px 8px #0000000d;transition:all .3s ease}.task-item.completed span{text-decoration:line-through;color:gray;opacity:.7}.task-item:hover{box-shadow:0 4px 12px #0000001a}.task-item input[type=checkbox]{width:20px;height:20px;cursor:pointer}.task-item button{margin-left:auto;padding:6px 10px;border:none;background:#ff4d4f;color:#fff;border-radius:6px;cursor:pointer;font-weight:600;transition:background .3s ease,transform .2s ease}.task-item button:hover{background:#c41d1d;transform:translateY(-1px)}.filters{display:flex;gap:10px;margin-bottom:20px}.filters button{padding:6px 14px;border:1px solid #007bff;background:transparent;border-radius:6px;cursor:pointer;font-weight:500;transition:all .3s ease}.filters button.active{background-color:#007bff;color:#fff;border:none}.filters button:hover{background-color:#e6f0ff}.light{background:#f4f6f8;color:#333}.dark{background:#1f1f1f;color:#eee}.dark .task-item{background:#2c2c2c;color:#eee}.dark .task-item.completed span{color:#aaa}@media (max-width: 600px){.task-form{flex-direction:column}.task-form button{width:100%}}