```html

```css

#link {

color: blue;

text-decoration: none;

font-weight: bold;

```css

#link.red {

color: red;

使用class屬性時(shí)，需要將“red”作為class名稱，并將值設(shè)置為相應(yīng)的樣式。

```css

#link {

color: blue;

text-decoration: none;

font-weight: bold;

#link:hover {

text-decoration: underline;

#link:hover:after {

content: "";

background-color: blue;

border-radius: 50%;

padding: 2px;

margin-top: -2px;

```css

#link {

color: blue;

```css

#link {

color: blue;

background-color: #007bff;

```css

#link {

font-size: 16px;

font-weight: bold;

#link:hover {

font-size: 14px;

font-weight: bold;

#link:hover {

background-color: #0069d9;