Header

  <nav class="menu">
    <ol>
      <li class="menu-item active"><a href="#0">Домой</a></li>
      <li class="menu-item"><a href="#0">About</a></li>
      <li class="menu-item">
        <a href="#0">Widgets</a>
        <ol class="sub-menu">
          <li class="menu-item"><a href="#0">Big Widgets</a></li>
          <li class="menu-item"><a href="#0">Bigger Widgets</a></li>
          <li class="menu-item"><a href="#0">Huge Widgets</a></li>
        </ol>
      </li>
      <li class="menu-item">
        <a href="#0">Kabobs</a>
        <ol class="sub-menu">
          <li class="menu-item"><a href="#0">Shishkabobs</a></li>
          <li class="menu-item"><a href="#0">BBQ kabobs</a></li>
          <li class="menu-item"><a href="#0">Summer kabobs</a></li>
        </ol>
      </li>
      <li class="menu-item"><a href="#0">Contact</a></li>
    </ol>
  </nav>

@charset "UTF-8";
*,
*::before,
*::after {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

body {
  background: linear-gradient(90deg, #16a085, #f4d03f);
  font-family: "Montserrat", sans-serif;
  color: #fff;
  height: 100vh;
}

.menu ol {
  list-style: none;
  padding: 0;
  margin: 0;
}
.menu ol:first-child {
  width: 100%;
  max-width: 960px;
  margin: 1rem auto 0 auto;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  align-items: center;
  box-shadow: 0px 3px 8px rgba(0, 0, 0, 0.3);
}
.menu-item {
  display: flex;
  align-items: center;
  justify-content: center;
  border-top: 2px solid #16a085;
  position: relative;
  transition: background 0.3s ease-in-out;
}
.menu-item:nth-child(1) > a::before {
  content: "";
}
.menu-item:nth-child(2) > a::before {
  content: "";
}
.menu-item:nth-child(3) > a::before {
  content: "";
}
.menu-item:nth-child(4) > a::before {
  content: "";
}
.menu-item:nth-child(5) > a::before {
  content: "";
}
.menu-item:nth-child(1) > a::before {
  font-family: "Font Awesome 5 Free";
  font-size: 1.2rem;
  display: block;
  margin-bottom: 1rem;
  font-weight: 900;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  display: inline-block;
  font-style: normal;
  font-variant: normal;
  text-rendering: auto;
  line-height: 1;
  color: #16a085;
}
@media (min-width: 768px) {
  .menu-item:nth-child(1) > a::before {
    font-size: 1.5rem;
  }
}
.menu-item:nth-child(2) > a::before {
  font-family: "Font Awesome 5 Free";
  font-size: 1.2rem;
  display: block;
  margin-bottom: 1rem;
  font-weight: 900;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  display: inline-block;
  font-style: normal;
  font-variant: normal;
  text-rendering: auto;
  line-height: 1;
  color: #16a085;
}
@media (min-width: 768px) {
  .menu-item:nth-child(2) > a::before {
    font-size: 1.5rem;
  }
}
.menu-item:nth-child(3) > a::before {
  font-family: "Font Awesome 5 Free";
  font-size: 1.2rem;
  display: block;
  margin-bottom: 1rem;
  font-weight: 900;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  display: inline-block;
  font-style: normal;
  font-variant: normal;
  text-rendering: auto;
  line-height: 1;
  color: #16a085;
}
@media (min-width: 768px) {
  .menu-item:nth-child(3) > a::before {
    font-size: 1.5rem;
  }
}
.menu-item:nth-child(4) > a::before {
  font-family: "Font Awesome 5 Free";
  font-size: 1.2rem;
  display: block;
  margin-bottom: 1rem;
  font-weight: 900;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  display: inline-block;
  font-style: normal;
  font-variant: normal;
  text-rendering: auto;
  line-height: 1;
  color: #16a085;
}
@media (min-width: 768px) {
  .menu-item:nth-child(4) > a::before {
    font-size: 1.5rem;
  }
}
.menu-item:nth-child(5) > a::before {
  font-family: "Font Awesome 5 Free";
  font-size: 1.2rem;
  display: block;
  margin-bottom: 1rem;
  font-weight: 900;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  display: inline-block;
  font-style: normal;
  font-variant: normal;
  text-rendering: auto;
  line-height: 1;
  color: #16a085;
}
@media (min-width: 768px) {
  .menu-item:nth-child(5) > a::before {
    font-size: 1.5rem;
  }
}
.menu-item .sub-menu > a {
  color: red;
}
.menu-item:not(:last-child) {
  border-right: 1px solid rgba(255, 255, 255, 0.15);
}
.menu-item .sub-menu {
  position: absolute;
  top: 100%;
  width: 100%;
  transform-origin: top;
  transform: rotateX(-90deg);
  transition: transform 0.3s linear;
  background-color: #f4d03f;
}
.menu-item .sub-menu .menu-item {
  border-color: rgba(255, 255, 255, 0.15);
}
.menu-item .sub-menu .menu-item a::before {
  content: "";
}
.menu-item .sub-menu .menu-item:first-child {
  border: 0;
}
.menu-item:hover, .menu-item.active {
  border-top: 2px solid #f4d03f;
  background-color: rgba(255, 255, 255, 0.15);
}
.menu-item:hover a::before, .menu-item.active a::before {
  color: white;
}
.menu-item:hover .sub-menu {
  transform: rotateX(0deg);
}
.menu-item a {
  font-size: 0.8rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  color: #fff;
  text-decoration: none;
  text-transform: uppercase;
  height: 100%;
  width: 100%;
  padding: 1.5em 1em;
}
@media (min-width: 768px) {
  .menu-item a {
    font-size: 1rem;
  }
}