/* SHORT SELECTOR, EMPTY CONTENT */
a{}

/* COMPLEX SELECTOR */
div div>div#id.foo.bar:hover .something>.child~.sibling+.sibling:after{color:red;}
div   div   >   div#id.foo.bar:hover   .something   >   .child   ~   .sibling   +   .sibling:after   {   color   :   red   ;   }
div div>div#id.foo.bar:hover .something>.child~.sibling+.sibling::after{color:red;}
div   div   >   div#id.foo.bar:hover   .something   >   .child   ~   .sibling   +   .sibling::after   {   color   :   red   ;   }
div div>div#id.foo.bar:hover .something>.child~.sibling+:matches(.sibling):after{color:red;}
div   div   >   div#id.foo.bar:hover   .something   >   .child   ~   .sibling   +   :matches(.sibling):after   {   color   :   red   ;   }
div div>div#id.foo.bar:hover .something>.child~.sibling+:matches(.sibling)::after{color:red;}
div   div   >   div#id.foo.bar:hover   .something   >   .child   ~   .sibling   +   :matches(.sibling)::after   {   color   :   red   ;   }