thelyoncompany.com/assets/scss/templates/_header.scss

/*------------------------------------------------------------------
 # header style
-------------------------------------------------------------------*/
.header-nav {
  z-index: 9;
  .navbar {
    padding-top: 25px;
    padding-bottom: 25px;
  }

  .nav-item {
    .nav-link {
      font-weight: 600;
      font-size: 15px;
      color: $black-200 !important;
      padding-left: 17px !important;
      padding-right: 17px !important;
    }

    &:hover,
    &.active {
      .nav-link {
        color: $color-primary !important;
      }
    }
  }
}

@media (min-width:1200px) {
  .navbar .dropdown-menu {
    display: block;
    height: 0;
    overflow: hidden;
    width: 220px;
    transition: 0.2s;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 5px;
    background-color: transparent;
    z-index: 1;

    &::after {
      position: absolute;
      content: "";
      height: 0;
      width: 100%;
      background-color: $white;
      top: 0;
      left: 0;
      z-index: -1;
      border-radius: inherit;
      transition: .3s ease-out;
      box-shadow: 0 10px 30px rgba(22, 28, 45, .10);
    }

    li {
      opacity: 0;
      visibility: hidden;
      transform: translateY(-5px);
    }

    li:first-child {
      margin-top: 15px
    }

    li:last-child {
      margin-bottom: 15px
    }
  }

  .navbar .dropdown:hover .dropdown-menu {
    height: auto;
    overflow: visible;

    &::after {
      height: 100%;
    }

    li {
      opacity: 1;
      visibility: visible;
      transform: translateY(0px);
      transition: 0.25s;
      transition-delay: .2s;
    }
  }

  .navbar .sub-dropdown {
    position: relative;

    .dropdown-submenu {
      position: absolute;
      display: block;
      z-index: 2;
      width: 90%;
      left: 100%;
      top: -10px;
      height: 0;
      overflow: hidden;
      transition: .3s;
      background-color: transparent;

      &::after {
        position: absolute;
        content: "";
        height: 0;
        width: 100%;
        background-color: $white;
        top: 0;
        left: 0;
        z-index: -1;
        transition: .3s ease-out;
        box-shadow: 0 10px 30px rgba(22, 28, 45, .10);
        transition-delay: padding .25s;
      }

      li {
        opacity: 0 !important;
        visibility: hidden !important;
        transform: translateY(-5px) !important;
        transition: 0s !important;
        transition-delay: 0s !important;
      }

      li:first-child {
        margin-top: 10px
      }

      li:last-child {
        margin-bottom: 10px
      }
    }

    &:hover .dropdown-submenu {
      height: auto;
      overflow: visible;

      &::after {
        height: 100%;
      }

      li {
        opacity: 1 !important;
        visibility: visible !important;
        transform: translateY(0px) !important;
        transition: 0.25s !important;
        transition-delay: .2s !important;
      }
    }
  }
}

.dropdown-menu {
  border: 0;
  margin-top: 0;
  padding: 0 8px;
}

.dropdown-submenu {
  list-style: none;
  display: none;
  padding: 0 8px;
  background-color: $white;
}

.dropdown-item {
  padding: 6px 12px;
  font-weight: 600;
  font-size: 15px;
}

.sub-dropdown.active,
.sub-dropdown.active>.dropdown-item,
.sub-dropdown:hover>.dropdown-item,
.dropdown-item.active,
.dropdown-item:active,
.dropdown-item:focus,
.dropdown-item:hover {
  color: $color-primary;
  background-color: rgba($color-primary, 0.08);
  border-radius: 5px;
}

.sub-dropdown.active>.dropdown-item {
  background-color: rgba($color-primary, 0.02);
}

.dropdown-toggle {
  &::after {
    display: none;
  }
}

@include breakAt(xl-device) {
  .dropdown-menu {
    border: 0;
    padding: 0;
    text-align: left !important;
    background: rgba($color-primary, 0.05);
    border-radius: 6px;
  }

  .navbar {
    .navbar-nav {
      margin-top: 15px;
      width: 280px;
      max-width: 100%;
      margin-right: auto;
      align-items: initial !important;
    }

    .nav-item {
      display: block;
      text-align: left;
    }

    .nav-link {
      padding: 8px 4px !important;
    }

    .dropdown-menu {
      li:first-child {
        padding-top: 10px;
      }

      li:last-child {
        padding-bottom: 10px;
      }
    }
  }

  .navbar-collapse {
    position: fixed;
    background-color: $white;
    width: calc(100% - 30px);
    height: auto;
    max-height: calc(100% - 100px);
    z-index: 9999;
    border-radius: 3px;
    box-shadow: 0 1.5rem 4rem rgba($black, .1);
    padding: 5px 20px 28px;
    text-align: center;
    top: 90px;
    left: 15px;
  }

  .navbar-collapse.collapsing,
  .navbar-collapse.show {
    -webkit-transition: all .2s ease-in-out;
    transition: all .2s ease-in-out;
    transition-property: opacity, transform, -webkit-transform;
    -webkit-transform-origin: top;
    transform-origin: top;
  }

  .navbar-collapse.show {
    overflow-x: hidden;
    overflow-y: auto;
    opacity: 1;
    -webkit-transform: scale(1);
    transform: scale(1);
  }

  .navbar-collapse.collapsing {
    opacity: 0;
    -webkit-transform: scale(.95);
    transform: scale(.95);
  }

  .navbar-button {
    width: 280px;
    max-width: 100%;
    margin: 15px auto 0;
  }

  .dropdown-item {
    padding: 6px 18px;
  }
}

.navbar-toggler {
  .nav-toggle-icon {
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
    transition: transform .4s;
    user-select: none;

    .top {
      stroke-dasharray: 40 121;
    }

    .bottom {
      stroke-dasharray: 40 121;
    }

    &.active {
      transform: rotate(45deg);

      .top {
        stroke-dashoffset: -68px;
      }

      .bottom {
        stroke-dashoffset: -68px;
      }
    }

    .line {
      fill: none;
      transition: stroke-dasharray .4s, stroke-dashoffset .4s;
      stroke: $black-300;
      stroke-width: 5.5;
      stroke-linecap: round;
    }
  }
}