<body>
    <div id="wrap">
        <div id="header"></div>
        <div id="nav"></div>
        <div id="main" class="clearfix">
            <div id="aside"></div>
            <div id="article1"></div>
            <div id="article2"></div>
            <div id="article3"></div>
        </div>
        <div id="footer"></div>
    </div>
    <!-- 
        layout03_01 : float 방식 레이아웃
        layout03_02 : float 방식 반응형 레이아웃
        layout03_03 : flex 방식 레이아웃
        layout03_04 : flex 방식 반응형 레이아웃
        layout03_05 : grid 방식 레이아웃->복잡한 레이아웃을 편하게 가능함
        layout03_06 : grid 방식 반응형 레이아웃 
    -->
</body>
 <style>
        * {
            margin: 0;
            padding: 0;
        }
        body {
            background-color: #E1F5FE;
        }
        #wrap {
            width: 1200px;
            margin: 0 auto;
        }
        #header {
            height: 100px;
            background-color: #B3E5FC;
        }
        #nav {
            height: 100px;
            background-color: #81D4FA;
        }
        #main {
        }
        #aside {
            width: 30%;
            height: 780px;
            background-color: #4FC3F7;
            float: left;
        }
        #article1 {
            width: 70%;
            height: 260px;
            background-color: #29B6F6;
            float: left;
        }
    
        #article2 {
            width: 70%;
            height: 260px;
            background-color: #03A9F4;
            float: left;
        }
        #article3 {
            width: 70%;
            height: 260px;
            background-color: #039BE5;
            float: left;
        }
    
        #footer {
            height: 100px;
            background-color: #0288D1;
        }
        /* clearfix = 가상으로 요소를 주는 것->제일 안정적인 방법*/
        .clearfix::before,
        .clearfix::after {
            content: '';
            display: block;
            line-height: 0;
        }
        .clearfix::after {
            clear: both;
        }
    
        /* 미디어쿼리 */
        @media (max-width: 1300px){
            #wrap {
                width: 96%;
            }
            #article2 {
                width: 35%;
                height: 520px;
            }
            #article3 { 
                width: 35%;
                height: 520px;
            }
        }
        @media (max-width: 768px){
            #wrap {
                width: 100%;
            }
            #article1 {
                width: 70%;
                height: 390px;
            }
            #article2 {
                width: 70%;
                height: 390px;
            }
            #article3 { 
                display: none;
            }
        }
        @media (max-width: 480px){
            #aside {
                width: 100%;
                height: 200px;
            }
            #article1 {
                width: 100%;
                height: 430px;
            }
            #article2 { 
                width: 100%;
                height: 150px;
            }
        }
        
    </style>

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.