Answers for "javascript set styles"

add style javascript

// Bad:
element.setAttribute("style", "background-color: red;");
// Good:
element.style.backgroundColor = "red";

JS change styles

// select element from DOM
const sample = document.getElementById("myid");
// or you can use *vars*
var sample = document.getElementById("myid");

// change css style
sample.style.color = 'red'; // Change color
// or (not recomended)
sample.style = "color: red"; //This changes all styles. NOT RECOMENDED