assets/css/partials/header.scss
#header {
  min-height: 400px;
  height: $banner-height;
  position: relative;

  img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 150%;
    z-index: -2;
    user-select: none;
    display: block;
    object-fit: cover;
    transition: 0.3s;
    -webkit-mask: linear-gradient(to top, transparent, #fff 50%);
    mask: linear-gradient(to top, transparent, #fff 50%);

    @media #{$mg-large} {
      height: 120%;
    }

    @media #{$mg-normal} {
      height: 100%;
    }
  }
}

#header-outer {
  height: 100%;
  position: relative;
  max-width: 100%;
}

[data-theme="dark"] {
  #header-nav:hover {
    background: var(--color-header-background);
  }
}

#header-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: center;
  background: var(--color-header-background);
  box-shadow: var(--shadow-card);
  transition: background 1s, top 0.3s;
  z-index: 200;

  &:hover {
    background: rgba(255, 255, 255, 0.95);
  }

  &.header-nav-hidden {
    top: -80px;
  }
}

#header-title {
  font-weight: 700;
  text-align: center;
  position: absolute;
  top: 50%;
  margin: $logo-size * -0.5 2.5% 0;
  width: 95%;
  opacity: 0;
  filter: blur(8px);
  will-change: transform, opacity, filter;
  animation: fade-in-blur 800ms ease-out 200ms forwards;
}

@mixin logo-text {
  text-decoration: none;
  color: #fff;
}

#logo {
  @include logo-text;
  font-size: $logo-size;
  font-weight: 700;
  letter-spacing: 2px;
  display: inline-block;
  transform: translateY(-20%);
  text-shadow: 0 0 0.5rem rgba(0, 0, 0, .7);

  @media #{$mg-large} {
    font-size: 36px;
  }

  @media #{$mq-tablet} {
    font-size: 30px;
  }

  @media #{$mq-mobile} {
    font-size: 30px;
  }
}

#subtitle {
  @include logo-text;
  font-size: $subtitle-size;
  font-weight: 400;
  letter-spacing: 1px;
  text-shadow: 0 0 5px rgba(0, 0, 0, 0.7);
  width: 70%;
  margin: 0 auto;
  display: block;
  line-height: 1.5;

  @media #{$mg-large} {
    font-size: 16px;
  }

  @media #{$mq-tablet} {
    font-size: 14px;
  }

  @media #{$mq-mobile} {
    font-size: 13px;
  }
}

#subtitle-wrap {
  margin-top: $subtitle-size;
}

#main-nav {
  display: flex;
  align-items: center;
}

@mixin nav-link {
  color: var(--red-0);
  opacity: 0.8;
  text-decoration: none;
  transition: 0.2s;
  padding: 20px 15px;
}

.nav-icon {
  @include nav-link;
  text-align: center;
  font-size: $font-size;
  width: $font-size;
  height: $font-size;
  will-change: transform;

  &:hover {
    opacity: 1;
    transform: scale(1.1);
  }
}

[data-theme="dark"] {
  .main-nav-link,
  .nav-icon,
  .main-nav-link-wrap {
    color: var(--red-2);
  }
}

.main-nav-link-wrap {
  @include nav-link;
  padding: 0 15px;
  display: flex;
  transition: 0.3s;

  &:hover {
    opacity: 1;
  }

  @media #{$mg-large} {
    padding: 0 10px;
  }

  @media #{$mg-normal} {
    display: none;
  }

  &:hover .main-nav-icon:before {
    transform: rotate(90deg) scale(1.1);
  }

  &:hover .main-nav-icon {
    transform: scale(1.1);
  }

  &:hover .main-nav-icon.rotate {
    transform: rotate(90deg) scale(1.1);
  }
}

.main-nav-link {
  @include nav-link;
  letter-spacing: 1px;
  font-weight: 700;
  opacity: 0.7;
}

.main-nav-icon {
  @include nav-link;
  padding: 15px 5px;
  display: flex;
  align-items: center;
  font-size: 24px;
  font-weight: 400;
  transition: transform 0.3s, color 0.3s;
  will-change: transform;

  &.rotate {
    transform: rotate(90deg);
  }

  &:before {
    font-size: 24px;
    font-weight: 400;
    transform: rotate(90deg);
    transition: transform 0.3s;
    will-change: transform;
  }
}

#main-nav-toggle {
  display: none;

  @media #{$mg-normal} {
    display: block;
  }
}

#sub-nav, #i18n-nav {
  display: flex;
  align-items: center;
}

#nav-sun-btn:before,
#nav-moon-btn:before,
#nav-circle-half-stroke-btn:before {
  font-weight: 700;
}

#i18n-nav {
  margin-left: 8px;
}

.custom-dropdown {
  position: relative;
}

.select-selected {
  padding: 14px;
  color: var(--red-2);
  cursor: var(--cursor-pointer);
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.select-items {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  border-radius: $tag-radius;
  background-color: var(--color-wrap);
  margin-top: 4px;
  display: none;
  z-index: 1;
  font-size: 14px;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.select-items li {
  list-style: none;
  padding: 10px;
  cursor: var(--cursor-pointer);
  color: var(--red-2);
  transition: 1s;
}

.select-items li:hover {
  color: #fff;
  background: var(--red-1);
}

.select-items.show {
  display: block;
}

.select-items li.selected {
  background: var(--red-1);
  color: #fff;
}
