A basic understanding of CSS is essential if you plan on customizing a theme. Each theme has one or more stylesheets—and the name is often style.css
.
The stylesheet contains many entries that determine how a theme looks. Each entry is called a selector, and each selector has at least one property with a value. All of these rules together create the theme, by specifying all of the structural elements, such as the width of the page and columns, the colors used, fonts, alignment, background images, etc.
CSS syntax is very important. It is always the same, and looks like this:
selector {property:value;}
Let us emphasize:
1. The properties and values must be wrapped in curly braces.
2. A colon (:) must separate a property and a value.
3. A semicolon (;) terminates the value, allowing the computer to continue reading.
If you disrupt this syntax, your site will probably not display correctly, or at all.