.hamburger {
  display: inline-block;
  cursor: pointer;
  transition-property: opacity, filter;
  transition-duration: 0.15s;
  transition-timing-function: linear;
  font: inherit;
  color: inherit;
  text-transform: none;
  background-color: transparent;
  border: 0;
  margin: 0;
  overflow: visible;
}
.hamburger:hover {
  opacity: 0.8;
}
.hamburger.is-active:hover {
  opacity: 0.8;
}
.hamburger.is-active .hamburger-inner,
.hamburger.is-active .hamburger-inner::before,
.hamburger.is-active .hamburger-inner::after {
  background-color: #fff;
}

.hamburger-box {
  width: 40px;
  height: 24px;
  display: inline-block;
  position: relative;
}

.hamburger-inner {
  display: block;
  top: 50%;
}
.hamburger-inner,
.hamburger-inner::before,
.hamburger-inner::after {
  width: 34px;
  height: 2.5px;
  background-color: #fff;
  border-radius: 4px;
  position: absolute;
  transition-property: transform;
  transition-duration: 0.1s;
  transition-timing-function: ease;
}
.hamburger-inner::before,
.hamburger-inner::after {
  content: "";
  display: block;
}
.hamburger-inner::before {
  top: -10px;
}
.hamburger-inner::after {
  bottom: -10px;
}

/*
   * Spring
   */
.hamburger--spring .hamburger-inner {
  top: 2px;
  transition: background-color 0s 0.13s linear;
}
.hamburger--spring .hamburger-inner::before {
  top: 10px;
  transition: top 0.1s 0.2s cubic-bezier(0.33333, 0.66667, 0.66667, 1),
    transform 0.13s cubic-bezier(0.55, 0.055, 0.675, 0.19);
}
.hamburger--spring .hamburger-inner::after {
  top: 20px;
  transition: top 0.2s 0.2s cubic-bezier(0.33333, 0.66667, 0.66667, 1),
    transform 0.13s cubic-bezier(0.55, 0.055, 0.675, 0.19);
}

.hamburger--spring.is-active .hamburger-inner {
  transition-delay: 0.22s;
  background-color: transparent !important;
}
.hamburger--spring.is-active .hamburger-inner::before {
  top: 0;
  transition: top 0.1s 0.15s cubic-bezier(0.33333, 0, 0.66667, 0.33333),
    transform 0.13s 0.22s cubic-bezier(0.215, 0.61, 0.355, 1);
  transform: translate3d(0, 10px, 0) rotate(45deg);
}
.hamburger--spring.is-active .hamburger-inner::after {
  top: 0;
  transition: top 0.2s cubic-bezier(0.33333, 0, 0.66667, 0.33333),
    transform 0.13s 0.22s cubic-bezier(0.215, 0.61, 0.355, 1);
  transform: translate3d(0, 10px, 0) rotate(-45deg);
}