添加阴影渐变背景颜色，添加斜角

background: linear-gradient(to right, #2499eb, #1d6bb6);

background: linear-gradient(to bottom, #49e6ff, #2495ff);


 box-shadow:0px 0px 5px 2px #cccc;


background: linear-gradient(-45deg, transparent .5rem, rgba(16, 121, 175, 0.35) 0);