Lined paper

<div class="container">
...
</div>
.container {
/* Lined background */
background-image: linear-gradient(rgba(0, 0, 0, 0.3) 1px, transparent 0px);
background-size: 100% 2em;
/*
Display the content on top of the lines.
The line height must be the same as the background size defined above
*/
background-position-y: 24px;
line-height: 2em;
}
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language like HTML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript.
— Wikipedia