Function curCSS

src/modules/jquery.js:6557–6641

(elem, name, computed)

  })();

  function curCSS(elem, name, computed) {
    var width,
      minWidth,
      maxWidth,
      ret,
      isCustomProp = rcustomProp.test(name),
      // Support: Firefox 51+
      // Retrieving style before computed somehow
      // fixes an issue with getting wrong values
      // on detached elements
      style = elem.style;

    computed = computed || getStyles(elem);

    // getPropertyValue is needed for:
    //   .css('filter') (IE 9 only, trac-12537)
    //   .css('--customProperty) (gh-3144)
    if (computed) {
      // Support: IE <=9 - 11+
      // IE only supports `"float"` in `getPropertyValue`; in computed styles
      // it's only available as `"cssFloat"`. We no longer modify properties
      // sent to `.css()` apart from camelCasing, so we need to check both.
      // Normally, this would create difference in behavior: if
      // `getPropertyValue` returns an empty string, the value returned
      // by `.css()` would be `undefined`. This is usually the case for
      // disconnected elements. However, in IE even disconnected elements
      // with no styles return `"none"` for `getPropertyValue( "float" )`
      ret = computed.getPropertyValue(name) || computed[name];

      if (isCustomProp && ret) {
        // Support: Firefox 105+, Chrome <=105+
        // Spec requires trimming whitespace for custom properties (gh-4926).
        // Firefox only trims leading whitespace. Chrome just collapses
        // both leading & trailing whitespace to a single space.
        //
        // Fall back to `undefined` if empty string returned.
        // This collapses a missing definition with property defined
        // and set to an empty string but there's no standard API
        // allowing us to differentiate them without a performance penalty
        // and returning `undefined` aligns with older jQuery.
        //
        // rtrimCSS treats U+000D CARRIAGE RETURN and U+000C FORM FEED
        // as whitespace while CSS does not, but this is not a problem
        // because CSS preprocessing replaces them with U+000A LINE FEED
        // (which *is* CSS whitespace)
        // https://www.w3.org/TR/css-syntax-3/#input-preprocessing
        ret = ret.replace(rtrimCSS, '$1') || undefined;
      }

      if (ret === '' && !isAttached(elem)) {
        ret = jQuery.style(elem, name);
      }

      // A tribute to the "awesome hack by Dean Edwards"
      // Android Browser returns percentage for some values,
      // but width seems to be reliably pixels.
      // This is against the CSSOM draft spec:
      // https://drafts.csswg.org/cssom/#resolved-values