删除bootstrap.css的最后一行即可：
/*# sourceMappingURL=bootstrap.css.map */
English:
from bootstrap-theme.css remove last line /*# sourceMappingURL=bootstrap-theme.css.map */
bootstrap-theme.css
/*# sourceMappingURL=bootstrap-theme.css.map */
bootstrap.css.map 404
原文：https://www.cnblogs.com/chancy/p/9738037.html
