About html & css

Question

if i wanna make box in some words
how i can make it and idk should put (div)
cus this is wrong:
<style>
.blue_box {
border: 10px;
pandding: 0.5em;
width: 150px;
height: 100px;
}
and
<h1 class="blue_box">test</h1>

Answer 1

Try this:

<div class="box"></div>

CSS:
.box {
height:150px;
width:150px;
border:2px solid blue;
background-color:blue;
}