Why doesn't this CSS class work?

? It's not obvious in your screenshot that the style of header container a covers it, and the child element selector has higher priority than the class selector

#header-container a{
    color: rgb(51, 51, 51)
}

The weight of ID is greater than that of class

The weight of the ID selector is higher than that of the class selector.

Attached:

• CSS selector weight calculation chart

Priority relation: important > inline style > ID selector > class selector = attribute selector = pseudo class selector > label selector = pseudo element selector

Weight problem ha, ID weight is greater than class weight important > inline style > ID selector > class selector, try not to use ID to write style ha, nothing wrong also don't declare ID