flex布局

flex布局不仅使用方便而且能大大缩短页面开发的时间，主要需要掌握2点，排列方向和对齐方式，下面进行详细介绍

.flex-wrp{
    display: flex;
    flex-direction: row;//默认水平：row  垂直：column
}
.flex-item{
    width:300px;
}

<div class="flex-wrp">
    <div class="flex-item">1</div>
    <div class="flex-item">2</div>
    <div class="flex-item">3</div>
</div>

.flex-wrp{
    display: flex;
    flex-direction: row;
    justify-content: center;
}