<!DOCTYPE html>
<html lang="ko">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>background_color</title>
<style>
/* default setting */
* {margin: 0; padding: 0;}
a {color: black; text-decoration: none;}
li {list-style: none;}
/* test */
div {
width: 300px; height: 300px;
border: 1px solid black;
text-align: center;
line-height: 300px;
float: left;
}
.box01 {background-color: green;}
.box02 {background-color: rgb(0, 255, 0);}
.box03 {background-color: #00ff00;}
.box04 {background-color: rgba(0, 255, 0, 0.5);}
</style>
</head>
<body>
<div class="box01">box01</div>
<div class="box02">box02</div>
<div class="box03">box03</div>
<div class="box04">box04</div>
</body>
</html>