SOURCE

<div class="container">
  <h1>H1标签的效果</h1>
  <h2>H2标签的效果</h2>
  <h3>H3标签的效果</h3>
  <h4>H4标签的效果</h4>
  <h5>H5标签的效果</h5>
  <h6>H6标签的效果</h6>
  <h7>H7标签的效果</h7>
</div>

h1,h2,h3,h4,h5,h6{
  margin: 20px 0;
  font-family: inherit;
  font-weight: bold;
  line-height: 20px;
  color:inherit;
  text-rendering:optimizeLegibility;
  border: 3px solid red;
  
}