To create styles that apply to three different sections of a web page in CSS, you'll typically start by defining a CSS rule set for each section. However, if you're looking for a way to apply different styles to these sections, you would usually use class selectors or ID selectors. Here's how you might structure the first line of your CSS for three different sections:
If you're using class selectors:
.section1 { /* Styles for the first section */ }
.section2 { /* Styles for the second section */ }
.section3 { /* Styles for the third section */ }
If you're using ID selectors:
#section1 { /* Styles for the first section */ }
#section2 { /* Styles for the second section */ }
#section3 { /* Styles for the third section */ }
In both cases, replace the comments with the actual styles you want to apply.
If you meant a specific line of CSS or a shorthand method for styling, please provide more context, and I'd be happy to assist further!