html, body {
  height: 100%;
  font-family: Sans-Serif;
}

a {
  color: hotpink;
}

.full-height {
  height: 100%;
}
h2  {
  margin-bottom: -20px;
}

.bw{
  background-color: black;
  color: white;
  padding: 20px;
  display: inline-flex;
}

.center {
  background-color: black;
  color: white;
  margin: 100;
  position: absolute;
  top: 50%;
  left: 50%;
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
  padding: 20px;
}

h1.center{
  top: 10%;
}

.footer {
  background-color: black;
  color: white;
  margin: 100;
  position: absolute;
  top: 90%;
  left: 50%;
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
  padding: 20px;
}

.tooltip {
  position: relative;
  display: inline-block;
  border-bottom: 1px dotted black; /* If you want dots under the hoverable text */
}

/* Tooltip text */
.tooltip .tooltiptext {
  visibility: hidden;
  width: 240px;
  background-color: black;
  color: #fff;
  text-align: center;
  padding: 6px 6px;
  border-radius: 7px;

  /* Position the tooltip text - see examples below! */
  position: absolute;
  z-index: 1;
}

/* Show the tooltip text when you mouse over the tooltip container */
.tooltip:hover .tooltiptext {
  visibility: visible;
}