SOURCE

<div class="body">
    <div class="content">
    内容区域
    </div>
</div>

/* .content{
    height: 200px;
    width: 100px;
    background: red;
    transform: rotate(-90deg) translate(50px,50px);
} */
/* .content{
    height: 100px;
    width: 200px;
    background: red;
    transform: rotate(-90deg) translate(-50px,-50px);
} */
.content{
    height: 180px;
    width: 200px;
    background: red;
    transform: rotate(-90deg) translate(-10px,-10px);
}
.body{
    background:blue;
}