SOURCE

<div class="box"><i class="bar"></i>
<!-- 注意第一个i标签没有换行，避免出现空白文字节点 -->
    <i class="bar"></i>
    <i class="bar"></i>
</div>

.box {
    width: 256px; height: 256px;
    text-align: justify;
    border: 1px solid #333;
}
.box::before {
    content: '';
    display: inline-block;
    height: 100%;
}
.box::after {
    content: '';
    display: inline-block;
    width: 100%;
}
.bar {
    display: inline-block;
    width: 20px;
    background: #ff0;
    /* vertical-align: text-bottom; */
}
.bar:nth-last-of-type(1) {
    height: 100px;
}
.bar:nth-last-of-type(2) {
    height: 40px;
}
.bar:nth-last-of-type(3) {
    height: 150px;
}