答案 0 :(得分:1)
您可以使用线性渐变
.box{
width:200px;
height:350px;
background:white;
background: -moz-linear-gradient(125deg, red 30%, white 30%);
background: -webkit-linear-gradient(125deg, red 30%, white 30%);
background: -o-linear-gradient(125deg, red 30%, white 30%);
background: -ms-linear-gradient(125deg, red 30%, white 30%);
background: linear-gradient(125deg, red 30%, white 30%);
border: 1px solid #ccc;
}

<div class="box"></div>
&#13;