三个div之间的行css、html

<style>
    .div-container {
        width: 100%;
    }

    .div {
        float: left;
        width: 33.33%;
        height: 100px;
        background-color: #ccc;
    }

    .clear {
        clear: both;
    }
</style>

<div class="div-container">
    <div class="div"></div>
    <div class="div"></div>
    <div class="div"></div>
    <div class="clear"></div>
</div>

<style>
    .div-container {
        display: flex;
        flex-wrap: wrap;
    }

    .div {
        flex: 1 0 33.33%;
        height: 100px;
        background-color: #ccc;
    }
</style>

<div class="div-container">
    <div class="div"></div>
    <div class="div"></div>
    <div class="div"></div>
</div>

<style>
    .div-container {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        grid-auto-rows: 100px;
        grid-gap: 10px;
    }

    .div {
        background-color: #ccc;
    }
</style>

<div class="div-container">
    <div class="div"></div>
    <div class="div"></div>
    <div class="div"></div>
</div>