.side-nav {
  position: fixed;
  top: 8rem;
  right: 0;
  z-index: 99;
  writing-mode: vertical-rl;
  padding: 0.75rem 0.5rem;
  background-color: var(--blue);
  color: var(--snow);
  border-radius: 0.125rem 0 0  0.125rem;
  line-height: 1;
  letter-spacing: 0.15em;
  font-size: 0.875rem;
  transition: opacity ease 200ms;
  &:hover {
    text-decoration: none;
    opacity: 90%;
    color: var(--snow);
  }
  @media (min-width: 1200px) {
    top: 20.75rem;
  }
}

.header {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 99;
  padding: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  @media (min-width: 768px) {
    padding: 2.5rem;
  }
  @media (min-width: 1200px) {
    padding: 0 7.5rem 8.75rem;
    align-items: flex-start;
  }
  
  & .header__logo {
    width: 10.5rem;
    & img {
      width: 100%;
    }
    @media (min-width: 768px) {
      width: 20rem;
    }
    @media (min-width: 1200px) {
      width: 26.375rem;
      margin-top: 2rem;
    }
  }
  
  & .header__links {
    display: none;
    writing-mode: vertical-rl;
    flex-direction: column-reverse;
    justify-content: flex-end;
    gap: 2.5rem;
    line-height: 1;
    letter-spacing: 0.25em;
    flex: 1 1 0%;
    
    @media (min-width: 1200px) {
      display: flex;
    }
    & .header__link {
      position: relative;
      display: flex;
      padding-top: 8.125rem;
      transition: transform ease 200ms;
      &::before {
        content: "";
        display: block;
        position: absolute;
        top: 0;
        left: 55%;
        width: 1px;
        height: 5.625rem;
        background-color: var(--blue);
        transition: all ease 200ms;
      }
      &:hover {
        text-decoration: none;
        color: var(--ink);
        transform: scale(1.05);
        &::before {
          width: 2px;
          height: 7rem;
        }
      }
    }
  }
}

.header-nav__trigger {
  width: 3rem;
  height: 3rem;
  display: flex;
  cursor: pointer;
  position: relative;

  & .header-nav__trigger-toggle {
    top: 50%;
    left: 50%;
    transform-origin: center;
    transform: translate(-50%, -50%);
    border-radius: 1px;
    height: 2px;
    width: 1.25rem;
    display: block;
    background-color: var(--ink);
    position: absolute;
    transition: all 150ms ease;

    &::before,
    &::after {
      content: "";
      top: 0;
      left: 0;
      border-radius: 1px;
      height: 2px;
      width: 1.25rem;
      display: block;
      background-color: var(--ink);
      position: absolute;
      transition: all 150ms ease;
    }

    &::before {
      animation: toggler-top 800ms ease forwards;
    }

    &::after {
      animation: toggler-bottom 800ms ease forwards;
    }
  }

  &.active .header-nav__trigger-toggle {
    transition-delay: 200ms;
    transform: translate(-50%, -50%) rotate(135deg);

    &::before {
      animation: toggler-top-open 800ms ease forwards;
    }

    &::after {
      animation: toggler-bottom-open 800ms ease forwards;
    }
  }
}

.header-nav__content {
  position: fixed;
  top: 0;
  left: 0;
  padding-top: 10rem;
  height: 100%;
  width: 100%;
  background-color: var(--white);
  transition: all 400ms ease;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  z-index: -1;
  color: var(--ink);
}

@media screen and (min-width: 1200px) {
  .header-nav__content,
  .header-nav__trigger {
    display: none;
  }
}

/** Keyframes **/
@keyframes toggler-top-open {
  0% {
    transform: translateY(6px);
  }

  30% {
    transform: translateY(0);
  }

  to {
    transform: translateY(0);
  }
}

@keyframes toggler-bottom-open {
  0% {
    transform: translateY(-6px);
  }

  30% {
    transform: translateY(0);
  }

  to {
    transform: translateY(0) rotate(90deg);
  }
}

@keyframes toggler-bottom {
  0% {
    transform: translateY(0);
  }

  30% {
    transform: translateY(0);
  }

  to {
    transform: translateY(6px);
  }
}

@keyframes toggler-top {
  0% {
    transform: translateY(0) rotate(90deg);
  }

  30% {
    transform: translateY(0);
  }

  to {
    transform: translateY(-6px);
  }
}

/**
 * 開発時にLoading Spinnerで隠れないようにするためのスタイル
 */
.loading-spinner {
  display: none;
}