试试这个

.box{
width: 150px;
height: 50px;
border-radius: 0px 0px 0px 7px;
background: rgba(0,0,0,1);
background: -moz-linear-gradient(-45deg, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 34%, rgba(44,153,221,1) 100%);
background: -webkit-gradient(left top, right bottom, color-stop(0%, rgba(0,0,0,1)), color-stop(34%, rgba(0,0,0,1)), color-stop(100%, rgba(44,153,221,1)));
background: -webkit-linear-gradient(-45deg, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 34%, rgba(44,153,221,1) 100%);
background: -o-linear-gradient(-45deg, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 34%, rgba(44,153,221,1) 100%);
background: -ms-linear-gradient(-45deg, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 34%, rgba(44,153,221,1) 100%);
background: linear-gradient(135deg, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 34%, rgba(44,153,221,1) 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#000000', endColorstr='#2c99dd', GradientType=1 );
}

个字符

这可能是你正在寻找的。

.box {
background: rgba(0,0,0,1);
background: -moz-linear-gradient(-45deg, rgba(0,0,0,1) 18%, rgba(3,152,252,1) 100%);
background: -webkit-gradient(left top, right bottom, color-stop(18%, rgba(0,0,0,1)), color-stop(100%, rgba(3,152,252,1)));
background: -webkit-linear-gradient(-45deg, rgba(0,0,0,1) 18%, rgba(3,152,252,1) 100%);
background: -o-linear-gradient(-45deg, rgba(0,0,0,1) 18%, rgba(3,152,252,1) 100%);
background: -ms-linear-gradient(-45deg, rgba(0,0,0,1) 18%, rgba(3,152,252,1) 100%);
background: linear-gradient(135deg, rgba(0,0,0,1) 18%, rgba(3,152,252,1) 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#000000', endColorstr='#0398fc', GradientType=1 );
  height: 80px;
  width: 200px;
}

个字符

如果你想了解线性梯度是如何工作的，我会去这里：MDN linear-gradient

.link {
  width: 100px;
  height: 1.5em;
  display: inline-block;
  background: linear-gradient(135deg, black 30%, DeepSkyBlue 100%);
}

个字符