Learning CSS Selectors

id="X": #X
class="X": .X
descendant not direct: X Y
descendant direct: X > Y
sibling not direct: X ~ Y
sibling direct: X + Y
Elements with Attribute: X[attrName]
Elements with attribute=value: X[attrName ="value"]
attribute value like: X[attrName *="value"]
attribute value begins with: X[attrName ^="value"]
attribute value ends with: X[attrName $="value"]
(attribute, one of values: X[attrName ~="value"]
:checked, :enabled, :disabled, :after
:before

Class is attribute too. We can use for example [class *="value"] for all Elements with the class like "value"