使用lin-ui库里的icon和avatar不成功

Question

con/index.wxss:1:10243)
Invalid Selectors: Unsupported Pseudo Classes. Only support :first-child, :last-child. Style Text: “.l-icon-scan:before” (/miniprogram_npm/lin-ui/dist/icon/index.wxss:1:10282)
Invalid Selectors: Unsupported Pseudo Classes. Only support :first-child, :last-child. Style Text: “.l-icon-share:before” (/miniprogram_npm/lin-ui/dist/icon/index.wxss:1:10318)
Invalid Selectors: Unsupported Pseudo Classes. Only support :first-child, :last-child. Style Text: “.l-icon-success:before” (/miniprogram_npm/lin-ui/dist/icon/index.wxss:1:10355)
Invalid Selectors: Unsupported Pseudo Classes. Only support :first-child, :last-child. Style Text: “.l-icon-soud:before” (/miniprogram_npm/lin-ui/dist/icon/index.wxss:1:10394)
Invalid Selectors: Unsupported Pseudo Classes. Only support :first-child, :last-child. Style Text: “.l-icon-time:before” (/miniprogram_npm/lin-ui/dist/icon/index.wxss:1:10430)
Invalid Selectors: Unsupported Pseudo Classes. Only support :first-child, :last-child. Style Text: “.l-icon-warning:before” (/miniprogram_npm/lin-ui/dist/icon/index.wxss:1:10466)