.rbbutton {
  align-items: center;
  background-color: cornflowerblue;
  border: 0;
  border-radius: .75rem;
  box-sizing: border-box;
  color: white;
  cursor: pointer;
  display: flex;
  font-family: sans-serif;
  font-size: 1.1rem;
  height: 2.4rem;
  justify-content: center;
  overflow: hidden;
  padding: 0 1.5rem;
  position: relative;
  transition: all 0.3s cubic-bezier(.25, .8, .25, 1);
}

.rbbutton:hover,
.rbbutton:focus {
  filter: brightness(1.15);
  outline: none;
}

.rbbutton:active {
  filter: brightness(.85);
  outline: none;
}

.rbbutton__text {
  opacity: 1;
  position: block;
  transition: all 0.3s cubic-bezier(.25, .8, .25, 1);
  user-select: none;
}

@keyframes spinner {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

.rbbutton--spinner,
.rbbutton--textSpinner,
.rbbutton--text,
.rbbutton--filler {
  cursor: progress;
}

.rbbutton--spinner {
  animation: spinner .75s linear 0s infinite;
  background-color: transparent;
  border-bottom: .4rem solid transparent;
  border-left: .4rem solid cornflowerblue;
  border-radius: 50%;
  border-right: .4rem solid cornflowerblue;
  border-top: .4rem solid transparent;
  padding: 0;
  width: 2.4rem;
}

.rbbutton--spinner > .rbbutton__text {
  opacity: 0;
}

.rbbutton--textSpinner > .rbbutton__text {
  animation: spinner .75s linear 0s infinite;
  border-bottom: .2rem solid transparent;
  border-left: .2rem solid white;
  border-radius: 50%;
  border-right: .2rem solid white;
  border-top: .2rem solid transparent;
  color: transparent;
  height: 1rem;
  width: 1rem;
}

@keyframes filler {
  from {
    width: 0%;
  }
  to {
    width: 100%;
  }
}

.rbbutton--filler > .rbbutton__filler {
  animation: filler .75s linear 0s infinite;
  background-color: rgba(255, 255, 255, .2);
  border-radius: .75rem;
  bottom: 0;
  left: 0;
  position: absolute;
  top: 0;
}