<p id='special-paragraph'>This is controlled by an ID</p>  

<h1 id="title" class="danger">ID has more weight than classes</h1>
#special-paragraph {
  color: orange;
}

/* The class only changes the font-size */
#title {
  background-color: lightblue;
}

.danger {
  background-color: red;
  font-size: 25px;
}

Rerun