<div class="header">  
  <div class="header__logo">
    <strong>LOGO</strong>
  </div>
  <nav class="navbar">
    <ul class="navbar__menu">
      <li class="navbar__item">
        <a href="#" class="navbar__link"><i data-feather="home"></i><span>Home</span> </a>
      </li>
      <li class="navbar__item">
        <a href="#" class="navbar__link"><i data-feather="message-square"></i><span>Messages</span></a>        
      </li>
      <li class="navbar__item">
        <a href="#" class="navbar__link"><i data-feather="users"></i><span>Customers</span></a>        
      </li>
      <li class="navbar__item">
        <a href="#" class="navbar__link"><i data-feather="folder"></i><span>Projects</span></a>        
      </li>
      <li class="navbar__item">
        <a href="#" class="navbar__link"><i data-feather="archive"></i><span>Resources</span></a>        
      </li>
      <li class="navbar__item">
        <a href="#" class="navbar__link"><i data-feather="help-circle"></i><span>Help</span></a>        
      </li>
      <li class="navbar__item">
        <a href="#" class="navbar__link"><i data-feather="settings"></i><span>Settings</span></a>        
      </li>
    </ul>
  </nav>
</div>

$borderRadius: 10px;
$spacer: 1rem;
$primary: #C4151C;
$text: #fff;
$linkHeight: $spacer * 3.5;
$timing: 250ms;
$transition: $timing ease all;
$linkWidth: 10rem;

@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@600&display=swap');
body{
  background:#000 url(https://unsplash.it/1600/1000/?random);
  background-size:cover;
  background-position:center;
  font-family: 'Open Sans', sans-serif;
}

.header{
    $ref: &;
    position: sticky;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(0,0,0,0.9);  
    color: $text;
    padding: 0 $spacer*2;
    box-shadow: 0 0 40px rgba(0,0,0,0.03);
    height: 6rem;
    display: flex;
    align-items:center;
    gap: 3rem;
  }

  .navbar{
    display: flex;
    align-items: center;
    height: 100%;
    margin: 0 auto;
    overflow: hidden;
  &__menu{
    position: relative;
    display:flex;
  }
  &__link{
    position:relative;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    align-items: center;
    justify-content: center;
    height: $linkHeight;
    width: $linkWidth;
    color: $text;
    transition: $transition;
    text-decoration: none;
    width: $linkWidth;
    text-transform: uppercase;
    transition: 500ms ease all;
    svg{
      transition: 500ms ease all;
    }
    &:hover{
      svg{
        stroke: $primary;
      }
    }
    .navbar:not(:hover) &:focus,
    &:hover{
      span{
        opacity: 1;
        transform: translate(0);
      }
    }
  }
  &__item{
    &:last-child{
      &:before {
        content: '';
        position: absolute;
        left: -8rem;
        margin-left: $linkWidth/2;
        bottom: -1.25rem;
        height: 0.5rem;
        width: 2px;
        background: $primary;
        $speedlineColor: rgba(#fff,0.2);
        $speedGap: 3rem;
        $shadow : 0 -0.5rem $primary,0 -0.5rem $primary, 0 0 $speedGap 0.5rem $primary,2rem 0 0 $speedlineColor, -$speedGap 0 0 $speedlineColor;
        @for $i from 2 to 120{
          $shadow: $shadow + #{","}+ $i*$speedGap 0 0 $speedlineColor;
          $shadow: $shadow + #{","}+ $i*-$speedGap 0 0 $speedlineColor;
        }
        box-shadow: $shadow;
        transition: 500ms ease all;
      }
    }
    
    @for $i from 1 to 12 {
      &:first-child:nth-last-child(#{$i}),
      &:first-child:nth-last-child(#{$i}) ~ li {
        @for $j from 1 to $i {
          &:nth-child(#{$j}):hover, {
            ~ li:last-child:before {
              left: (100% / $i) * ($j - 1);
            }
          }
        }
        &:last-child:hover:before, {
          left: (100% / $i) * ($i - 1);
        }
      }
    }
    
  }
}

feather.replace()
//https://twitter.com/One_div