Listing 10-5: CSS rule-sets vs. JavaScript style objects

/* CSS rule-set */
.headingStyle{
  background-color: #999999;
  color: #eee;
  border: 1px solid black;
  border-radius: 4px;
  width: 50%;
}

//JavaScript style object
const headingStyle = {
  backgroundColor: '#999999',
  color: '#eee',
  border: '1px solid black',
  borderRadius: '4px',
  width: '50%'
};