Css : nth child selector

i was solving one of the exercises " Handlebars ", could’t help notice the css coded.
i see below code


background-color: #4b54ef;

margin-left: 25px;


can someone explain in detail about this code snipet

Take a look at the MDN web docs on the topic: They explain (clearly and in-depth) nth-child syntax and use.

For a more “learner-targeted” experience, try CSS-Tricks.