code: function fixNestedCalc(value) {
      const reCalcVal = /calc\(([^)]+)\)/g;
  
      (value.match(reCalcVal) || []).forEach(match => {
          const newVal = `calc${match.split('calc').join('')}`;
          value = value.replace(match, newVal);
      });
  
      return value;
  }
docs: Functions (Private) ============================================================================= 
  Removes nested calc keywords for legacy browser compatibility.
  Example: calc(1 + calc(2 + calc(3 + 3))) => calc(1 + (2 + (3 + 3)))
  
  @param {value} string