# is the CSS selector for an ID, but since social-icons-dRoPrU-Itp is a class, you would want to use ., so you would have to use .social-icons-dRoPrU-Itp (notice the period before it), which selects all elements in that class.
#
social-icons-dRoPrU-Itp
.
.social-icons-dRoPrU-Itp