网格画法： backgroundImage: "linear-gradient(90deg, rgba(50, 0, 0, 0.06) 3%, rgba(0, 0, 0, 0) 3%), linear-gradient(360deg, rgba(50, 0, 0, 0.06) 3%, rgba(0, 0, 0, 0) 3%)", backgroundSize: "20px 20px", backgroundPosition: "center center",
网点画法： background-image: linear-gradient(#2c2c2c 14px, transparent 0), linear-gradient(90deg, transparent 14px, #86909c 0) background-size: 15px 15px, 15px 15px;
兔: 径向渐变在画布边缘好像有点问题，之前用的
兔: 锥形渐变应该更好