nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  color: var(--nav-primary-color);
  font-size: 1.8rem;
  z-index: 2;
}
nav .menu {
  position: relative;
  margin-left: auto;
}
nav .menu li:hover {
  background-color: rgba(0, 0, 0, 0.05);
}
nav .menu li.inactive {
  color: #666666;
  font-weight: normal;
}
nav .menu-button {
  position: absolute;
  top: 0;
  right: 0;
  width: 60px;
  height: 60px;
  cursor: pointer;
  z-index: 4;
  overflow: hidden;
}
nav .menu-button .menu-button-line {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 40px;
  height: 1px;
  background-color: var(--nav-secondary-color);
  transform: translate(-50%, -50%);
  transition: all .3s 0s cubic-bezier(0.0, 0.995, 0.99, 1.0);
}
nav .menu.open .menu-button .menu-button-line {
  /* background-color: #ffffff; */
  background-color: var(--nav-primary-color);
  /* border-radius: 1px; */
}
nav .menu-button .line-1 {
  top: 35%;
}
nav .menu.open .menu-button .line-1 {
  top: -50%;
}
nav .menu.open .menu-button .line-2 {
  transform: translate(-50%, -50%) rotate(45deg);
}
nav .menu.open .menu-button .line-3 {
  transform: translate(-50%, -50%) rotate(-45deg);
}

nav .menu-button .line-4 {
  top: 65%;
}
nav .menu.open .menu-button .line-4 {
  top: 150%;
}

nav .menu-title {
  position: absolute;
  width: 60px;
  font-size: 1.15rem;
  top: 46px;
  text-align: center;
  right: 0;
  color: var(--nav-secondary-color);
  font-weight: bold;
}

nav .menu.open .menu-title {
  display: none;
}

nav .menu .menu-back {
  position: absolute;
  width: 100vw;
  height: 240px;
  top: 0;
  right: 0;
  overflow: hidden;
  display: none;
}
nav .menu.show .menu-back {
  display: block;
}

nav .menu.open .menu-back {
  box-shadow: 0px 4px 9px 0px #0000001f;
  display: block;
}
@media (min-width: 480px) {
  nav .menu .menu-back {
    width: 360px;
    top: 4px;
    right: 4px;
  }
}
nav .menu .menu-back .menu-circle {
  position: absolute;
  top: 22px;
  right: 22px;
  width: 0;
  height: 0;
  border-radius: 0;
  background-color: rgba(255, 255, 255, 0.9);
  transform-origin: top right;
  transition: all .3s 0s cubic-bezier(0.0, 0.995, 0.99, 1.0);
}
nav .menu.open .menu-back .menu-circle {
  width: 1200px;
  height: 1200px;
  border-radius: 600px;
  transform: translate(578px, -578px);
}

@media (min-width: 480px) {
  nav .menu .menu-back .menu-circle {
    top: 18px;
    right: 18px;
  }
}

nav .menu ul {
  position: absolute;
  top: 0;
  right: 0;
  width: 100vw;
  margin: 0;
  padding: 52px 0 24px 0;
  list-style: none;
  text-align: center;
  font-weight: bold;
  display: block;
  opacity: 0;
  z-index: 2;
  display: none;
}
nav .menu.show ul {
  display: block;
  transition: all .1s 0s ease;
}

@media (min-width: 480px) {
  nav .menu ul {
    top: 4px;
    right: 4px;
    width: 360px;
  }
}

nav .menu.open ul {
  display: block;
}
nav .menu ul.show-list {
  opacity: 1;
}

nav .menu ul li {
  height: 48px;
  line-height: 48px;
}
nav .menu ul a {
  display: block;
  width: 100%;
}
nav .menu ul a:visted {
  color: inherit;
}