.btn {
  /**
    * Button base
    */
  display: flex;
  vertical-align: middle;
  touch-action: manipulation;
  user-select: none;
  cursor: pointer;
  white-space: nowrap;
  text-decoration: none;
  text-align: center;
  border: 0;
  background: transparent;
  transition: all 0.15s ease-in-out;

  &:focus {
    outline: 0;
  }

  &--primary {
    background: $primary-color;
    color: white;
    border: 1px solid $primary-color;
    padding: 10px 30px;
    letter-spacing: 3px;
    font-size: 1rem;
    font-family: $ff-serif;
    transform: perspective(1px) translateZ(0);
    transition-property: color;
    transition-duration: 0.25s;

    &:before {
      content: '';
      position: absolute;
      z-index: -1;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background: #fff;
      transform: scaleY(0);
      transform-origin: 50% 100%;
      transition-property: transform;
      transition-duration: 0.25s;
      transition-timing-function: ease-out;
    }

    &:hover {
      color: $primary-color;
    }

    &:hover:before {
      transform: scaleY(1);
    }
  }

  &--secondary {
    background: #fff;
    color: #000;
    border: 1px solid;
    padding: 10px 30px;
    letter-spacing: 3px;
    font-size: 1rem;
    font-family: $ff-serif;
    transform: perspective(1px) translateZ(0);
    transition-property: color;
    transition-duration: 0.25s;
    display: flex;
    justify-content: center;

    &:before {
      content: '';
      position: absolute;
      z-index: -1;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background: #000;
      transform: scaleY(0);
      transform-origin: 50% 100%;
      transition-property: transform;
      transition-duration: 0.25s;
      transition-timing-function: ease-out;
    }

    &:hover {
      color: #fff;
    }

    &:hover:before {
      transform: scaleY(1);
    }
  }

  &--tertiary {
    text-decoration: underline;
    text-transform: uppercase;
    letter-spacing: 3px;
    font-family: $ff-serif;
    font-size: 0.8rem;
    transform: perspective(1px) translateZ(0);
    transition-property: color;
    transition-duration: 0.25s;

    &:before {
      content: '';
      position: absolute;
      z-index: -1;
      top: -8px;
      left: -15px;
      right: -15px;
      bottom: -8px;
      background: $secondary-color;
      transform: scaleY(0);
      transform-origin: 50% 100%;
      transition-property: transform;
      transition-duration: 0.25s;
      transition-timing-function: ease-out;
    }

    &:hover {
      color: #fff;
      text-decoration: none;
    }

    &:hover:before {
      transform: scaleY(1);
    }
  }

  &--quaternary {
    text-decoration: underline;
    text-transform: uppercase;
    letter-spacing: 3px;
    font-family: $ff-serif;
    font-size: 0.8rem;
    transition: all 0.25s ease-in-out;

    &:hover {
      color: $primary-color;
      text-decoration: none;
    }
  }

  &--link {
    text-decoration: underline;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-family: $ff-serif;
    font-size: 0.8rem;
    transition: all 0.25s ease-in-out;

    &:hover {
      color: $primary-color;
      text-decoration: none;
    }
  }

  &--close {
    background-color: $secondary-color;
    padding: 8px;
  }
}