Title tags in an HTML document define the title of the webpage that appears in the tab bar on the browser. These tags are not directly stylable with CSS because they are not part of the body of the HTML document.
However, if you are referring to changing the appearance of any other titles (which are often set with heading tags such as h1, h2, h3 etc), you can certainly do so with CSS.
Here is an example of how you might change the appearance of an h1 tag:
```
h1 {
color: #333;
font-family: Arial, sans-serif;
font-size: 24px;
font-weight: bold;
margin-bottom: 12px;
text-align: center;
}
```
This CSS snippet would result in h1 headers that are a dark gray color, aligned in the center of wherever they’re placed, using the Arial font, and with some space underneath them. You can adjust these CSS properties to fit your desired appearance.
However, ensure that you are not mixing up the title tag (