css set var code example
Example 1: css set variable
:root {
--main-bg-color: coral;
}
#div1 {
background-color: var(--main-bg-color);
}
#div2 {
background-color: var(--main-bg-color);
}
Example 2: create variable in css
:root {
--tab-count: 5;
}
#div1 {
width: calc(100% - var(--tab-count));
}
Example 3: javascript use css custom properties
Values in JavaScript
To use the values of custom properties in JavaScript, it is just like standard properties.
// get variable from inline style
element.style.getPropertyValue("--my-var");
// get variable from wherever
getComputedStyle(element).getPropertyValue("--my-var");
// set variable on inline style
element.style.setProperty("--my-var", jsVar + 4);