CSS only tooltip

dabblet.css

/**
 * CSS only tooltip 
 */

.tooltip:hover {
  position: relative;
}

.tooltip:before,
.tooltip:after {
  opacity: 0;
  position: absolute;
  pointer-events: none;  
}

.tooltip:after {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  content: attr(title);
  padding: 6px 8px;  
  bottom: calc(100% + 8px);
  left: 0;
  min-width: 100%;
  background-color: rgba(0,0,0,.7);
  color: white;
  font-size: 14px;
  border-radius: 4px;
  text-align: center;
  -webkit-font-smoothing: antialiased;  
}
.tooltip:before {
  content: "";
  left: 50%;
  bottom: calc(100% - 4px);
  margin-left: -6px;
  width: 0;
  height: 0;
  border-color: transparent;
  border-width: 6px;
  border-style: solid;
  border-top-color: rgba(0,0,0,.7); 
}

.tooltip:hover:after,
.tooltip:hover:before {
  opacity: 1;
  -webkit-transition: opacity .5s ease; 
  transition: opacity .5s ease;  
}

html {
  font-family: sans-serif;
}

dabblet.html

<br><br><br>
<a href="#" title="tasad" class="tooltip">132215</a>

dabblet.js

// alert('Hello world!');

settings.json

{"view":"separate","fontsize":"100","seethrough":"","prefixfree":"1","page":"all"}