JavaScript sets and modifies CSS styles

Syntax:
nodeObject.style.cssProperty=newStyle
Among them, nodeObject is the node object, cssProperty is the CSS property, and newStyle is the value of the CSS property.

Note: For CSS properties separated by "-", remove the "-" and capitalize the first letter after the "-".

For example:

document.getElementById("demo").style.height = "50px" ;
document.getElementById("demo").style.border = " 1px solid #ddd ";
document.getElementById("demo").style.backgroundColor = " #ccc ";
document.getElementById("demo").style.textAlign = " center ";

For example, set the style of the node with id="demo":

<style>
#demo{
    height:50px;
    width:250px;
    margin-top:10px;
    text-align:center;
    line-height:50px;
    background-color:#ccc;
    }
</style>
<div id="demo">
    点击这里改变CSS样式
</div>
<script type="text/javascript">
    document.getElementById("demo").onclick=function(){
        this.style.height = " 70px ";
        this.style.lineHeight = " 70px ";
        this.style.backgroundColor = " #000 ";
        this.style.color=" #fff ";
    }
</script>