標題：CSS實現點擊變色的效果

```css

background-color: #ff0000;

color: #000000;

font-weight: bold;

cursor: pointer;

```css

color: #007bff;

text-decoration: none;

font-size: 16px;

font-weight: bold;

background-color: #ff0000;

color: #000000;

font-weight: bold;

cursor: pointer;

3. 測試效果