直接上代码

background-blend-mode参考如下：

mix-blend-mode: normal;          /*正常*/
mix-blend-mode: multiply;        /*正片叠底*/
mix-blend-mode: screen;          /*滤色*/
mix-blend-mode: overlay;         /*叠加*/
mix-blend-mode: darken;          /*变暗*/
mix-blend-mode: lighten;         /*变亮*/
mix-blend-mode: color-dodge;     /*颜色减淡*/
mix-blend-mode: color-burn;      /*颜色加深*/
mix-blend-mode: hard-light;      /*强光*/
mix-blend-mode: soft-light;      /*柔光*/
mix-blend-mode: difference;      /*差值*/
mix-blend-mode: exclusion;       /*排除*/
mix-blend-mode: hue;             /*色相*/
mix-blend-mode: saturation;      /*饱和度*/
mix-blend-mode: color;           /*颜色*/
mix-blend-mode: luminosity;      /*亮度*/
mix-blend-mode: initial;         /*初始*/
mix-blend-mode: inherit;         /*继承*/
mix-blend-mode: unset;           /*复原*/