In CSS, you can control the width of an element's border using the `border-width` property. This property allows you to set the thickness of the border around an HTML element. Here's how you can use it:
```css
.element {
border-width: 2px; /* You can adjust the value (e.g., 1px, 3px) */
}
```
In this example, the `.element` will have a border with a thickness of 2 pixels. You can use different units such as pixels (`px`), ems (`em`), or percentages (`%`) to define the border width.
If you want to set different border widths for different sides of an element (top, right, bottom, left), you can use the `border-width` property with individual values:
```css
.element {
border-width: 2px 1px 3px 1px; /* top right bottom left */
}
```
This sets the top border to 2 pixels, right and left borders to 1 pixel, and the bottom border to 3 pixels.
Remember, the `border-width` property is part of the broader CSS border styling options that allow you to control the appearance of borders around HTML elements.
