hello
"> Document
hello
"> Document
hello
"> 
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        body{
            font-size: 10px;
        }
        .one{
            font-size: 32px;
        }
        .two{
            font-size: 2em;
        }
        .three{
            font-size: 2rem;
        }
        .four{
            width: 50%;
            height: 100px;
            background: red;
        }
        .five{
            width: 50vw; /*vh(높이), vw(넓이)*/
            height: 100px;
            background: aqua;
        }
        .six{
            width: 500px;
        }
    </style>
</head>
<body>
    <!-- font-size : 16px -->
    <div class="two">
        <!-- font-size : 32px -->
        <div class="two">
            <!-- font-size : 64px -->
            <div class="two">
                <!-- font-size : 128px -->
                hello
            </div>
        </div>
    </div>
    <!-- font-size : 16px -->
    <div class="two">
        <!-- font-size : 32px -->
        <div class="two">
            <!-- font-size : 64px -->
            <div class="three">
                <!-- font-size : 32px -->
                hello
            </div>
        </div>
    </div>
    <div class="six">
        <div class="four">hello</div>
    </div>
    <div class="four"></div>
    <div class="five">hello</div>
    <div class="six">
        <div class="five">hello</div>
    </div>
    <h2>고정 크기 단위</h2>
    <p>px</p>
    <h2>가변 크기 단위</h2>
    <p>em, rem, %, vw, vh</p>
</body>
</html>