写一个左中右的满屏布局，左右固定220px,中间自适应并且要优先加载

Answer 1

用 grid 布局，通过grid-area属性指定元素放在哪个位置

    <main class="main">
        <div class="center"></div>
        <div class="left"></div>
        <div class="right"></div>
    </main>

    .main {
        display: grid;
        grid-template-columns: 200px auto 200px;
        grid-template-rows: 1fr;
        height: 200px;
    }

    .center {
        grid-area: 1 / 2 / 2 / 3;
        background: deepskyblue;
    }

    .left {
        grid-area: 1 / 1 / 2 / 2;
        background: skyblue;
    }

    .right {
        grid-area: 1 / 3 / 2 / 4;
        background: skyblue;
    }