LoveIt/assets/css/_partial/_header.scss

header {
  width: 100%;
  z-index: 100;
  background-color: $header-background-color;

  .dark-theme & {
    background-color: $header-background-color-dark;
  }

  .header-title {
    font-size: 1.5rem;
    font-weight: bold;
  }

  .menu .menu-item {
    position: relative;
  }

  .language-select {
    position: absolute;
    opacity: 0;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;

    &:hover {
      cursor: pointer;
    }
  }

  .theme-switch i {
    transform: rotate(225deg);
  }
}

#header-desktop {
  display: block;
  position: $header-position-desktop;
  height: $header-height-desktop;
  line-height: $header-height-desktop;

  .header-wrapper {
    width: auto;
    text-align: center;
    padding: 0 3rem;
    display: flex;
    justify-content: space-between;

    .menu {
      .menu-item {
        margin: 0 .5rem;

        &.theme-switch {
          margin: 0 .3rem;
        }
      }

      a.active {
        font-weight: 900;
        color: $header-hover-color;

        .dark-theme & {
          color: $header-hover-color-dark;
        }
      }
    }
  }
}

#header-mobile {
  display: none;
  position: $header-position-mobile;
  height: $header-height-mobile;
  line-height: $header-height-mobile;

  .header-wrapper {
    padding: 0;
    margin: 0;
    transition: all 0.3s ease 0s;

    .header-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      font-size: 1.125rem;
      padding-right: 1rem;
      padding-left: 1rem;
      box-sizing: border-box;

      .menu-toggle {
        cursor: pointer;
        line-height: 4rem;

        span {
          display: block;
          background: $global-font-color;
          width: 1.5rem;
          height: 2px;
          -webkit-border-radius: 3px;
          -moz-border-radius: 3px;
          border-radius: 3px;
          -webkit-transition: .1s margin .1s, .1s transform;
          -moz-transition: .1s margin .1s, .1s transform;
          transition: .1s margin .1s, .1s transform;

          .dark-theme & {
            background: $global-font-color-dark;
          }
        }

        span:nth-child(1) {
          margin-bottom: .5rem;
        }

        span:nth-child(3) {
          margin-top: .5rem;
        }

        &.active {
          span {
            -webkit-transition: .1s margin, .1s transform .1s;
            -moz-transition: .1s margin, .1s transform .1s;
            transition: .1s margin, .1s transform .1s;
          }

          span:nth-child(1) {
            -moz-transform: rotate(45deg) translate(.4rem, .5rem);
            -ms-transform: rotate(45deg) translate(.4rem, .5rem);
            -webkit-transform: rotate(45deg) translate(.4rem, .5rem);
            transform: rotate(45deg) translate(.4rem, .5rem);
          }

          span:nth-child(2) {
            opacity: 0
          }

          span:nth-child(3) {
            -moz-transform: rotate(-45deg) translate(.4rem, -.5rem);
            -ms-transform: rotate(-45deg) translate(.4rem, -.5rem);
            -webkit-transform: rotate(-45deg) translate(.4rem, -.5rem);
            transform: rotate(-45deg) translate(.4rem, -.5rem);
          }
        }
      }
    }

    .menu {
      text-align: center;
      background: $global-background-color;
      border-top: 2px solid $global-font-color;
      display: none;
      box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.1), 0px 4px 8px rgba(0, 0, 0, 0.1);

      a {
        display: block;
        line-height: 2.5rem;
      }

      &.active {
        display: block;
      }

      .dark-theme & {
        background: $global-background-color-dark;
        border-top: 2px solid $global-font-color-dark;
      }
    }
  }
}