body {
  background-color: transparent;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  display: flex;
}

.btn__und-0010 {
  color: #2a3239;
  text-align: center;
  letter-spacing: 1px;
  text-transform: uppercase;
  border-bottom: 4px solid #0000;
  flex: none;
  align-self: center;
  font-family: Droid Serif, serif;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  text-decoration: none;
  display: inline-block;
}

.btn__und-0010:hover {
  border-bottom-color: #2a3239;
}

.und-0010__label {
  padding-bottom: 6px;
}