使用jQuery检测浏览器的CSS选择器支持

#myid > p {
  display: none;
}

if ( $( '#myid > p' ).css('display') != 'none' ) {
 // blah
}

.css()

rgb(255, 0, 0)

function supportsSelector(selector){
  if(selector.indexOf(":") !== 0) {
    selector = ':'+selector;
  }
  try {
    var queryString = "body" + selector + ",body:not(" + selector + ")";
    return !!document.querySelector("body" + selector + ",body:not(" + selector + ")");
  } catch (e) {
    return false;
  }
}

console.log(supportsSelector("hover"));
console.log(supportsSelector(":hover"));
console.log(supportsSelector(":focus-within"));
console.log(supportsSelector("I made this up"));
console.log(supportsSelector(":not(.a, .b)"));