<div style="text-align: center;">
  <p>
    <a href="#" data-tooltip="left tooltip" data-placement="left">left tooltip</a>
  </p>
  <p>
    <a href="#" data-tooltip="right tooltip" data-placement="right">right tooltip</a>
  </p>
  <p>
    <a href="#" data-tooltip="top tooltip" data-placement="top">top tooltip</a>
  </p>
  <p>
    <a href="#" data-tooltip="bottom tooltip" data-placement="bottom">bottom tooltip</a>
  </p>
</div>

body {
  margin: 20px;
}

a[data-tooltip] {
  position: relative;
}
a[data-tooltip]::before,
a[data-tooltip]::after {
  position: absolute;
  display: none;
  opacity: 0.85;
}
a[data-tooltip]::before {
  /*
   * using data-tooltip instead of title so we 
   * don't have the real tooltip overlapping
   */
  content: attr(data-tooltip);
  background: #000;
  color: #fff;
  font-size: 13px;
  padding: 5px;
  border-radius: 5px;
  /* we don't want the text to wrap */
  white-space: nowrap;
  text-decoration: none;
}
a[data-tooltip]::after {
  width: 0;
  height: 0;
  border: 6px solid transparent;
  content: '';
}

a[data-tooltip]:hover::before,
a[data-tooltip]:hover::after {
  display: block;
}

/** positioning **/

/* left tooltip */
a[data-tooltip][data-placement="left"]::before {
  top: -25%;
  right: 100%;
  margin-right: 10px;
}
a[data-tooltip][data-placement="left"]::after {
  border-left-color: #000;
  border-right: none;
  top: 50%;
  right: 100%;
  margin-top: -6px;
  margin-right: 4px;
}

/* right tooltip */
a[data-tooltip][data-placement="right"]::before {
  top: -25%;
  left: 100%;
  margin-left: 10px;
}
a[data-tooltip][data-placement="right"]::after {
  border-right-color: #000;
  border-left: none;
  top: 50%;
  left: 100%;
  margin-top: -6px;
  margin-left: 4px;
}

/* top tooltip */
a[data-tooltip][data-placement="top"]::before {
  bottom: 100%;
  left: 0;
  margin-bottom: 10px;
}
a[data-tooltip][data-placement="top"]::after {
  border-top-color: #000;
  border-bottom: none;
  bottom: 100%;
  left: 10px;
  margin-bottom: 4px;
}

/* bottom tooltip */
a[data-tooltip][data-placement="bottom"]::before {
  top: 100%;
  left: 0;
  margin-top: 10px;
}
a[data-tooltip][data-placement="bottom"]::after {
  border-bottom-color: #000;
  border-top: none;
  top: 100%;
  left: 10px;
  margin-top: 4px;
}