How do you add CSS with Javascript?

Question

How do you add CSS rules (eg strong { color: red }) by use of Javascript?

Answer 1

The simple-and-direct approach is to create and add a new style node to the document.

// Your CSS as text
var styles = `
    .qwebirc-qui .ircwindow div { 
        font-family: Georgia,Cambria,"Times New Roman",Times,serif;
        margin: 26px auto 0 auto;
        max-width: 650px;
    }
    .qwebirc-qui .lines {
        font-size: 18px;
        line-height: 1.58;
        letter-spacing: -.004em;
    }

    .qwebirc-qui .nicklist a {
        margin: 6px;
    }
`

var styleSheet = document.createElement("style")
styleSheet.type = "text/css"
styleSheet.innerText = styles
document.head.appendChild(styleSheet)