.hamburger {
  display: none;
}

@media screen and (max-width: 768px) {
  header {
    height: 11vh;
  }
  .hamburger {
    display: block;
    color: #ddd;
    padding: 1em;
    float: right;
    margin-top: 0.5em;
  }
  .hamburger .line {
    width: 35px;
    height: 2.5px;
    background-color: #ecf0f1;
    display: block;
    margin: 8px auto;
    transition: all 0.3s ease-in-out;
  }
  .hamburger:hover {
    cursor: pointer;
  }
  .hamburger.is-active .line:nth-child(2) {
    opacity: 0;
  }
  .hamburger.is-active .line:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }
  .hamburger.is-active .line:nth-child(3) {
    transform: translateY(-13px) rotate(-45deg);
  }
  nav#main-menu {
    z-index: -1;
    opacity: 0;
    height: 0;
    width: 0;
    transform: translateX(-100%);
    margin-top: 11vh;
    padding-top: 4vh;
    transition: all 0.8s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    position: fixed;
    left: 0;
    pointer-events: none;
  }
  nav#main-menu.open {
    transform: none;
    background-color: black;
    opacity: 1;
    height: 100vh;
    width: 100%;
    z-index: 99;
    pointer-events: all;
  }
  nav#main-menu ul {
    margin-top: 2em;
    display: flex;
    flex-direction: column;
    row-gap: 2em;
    width: 100%;
    align-items: center;
    float: none !important;
  }
  nav#main-menu ul a {
    font-size: 1.3em;
  }
  nav#main-menu ul ul.inline {
    display: none;
  }
  #brand h1 {
    font-size: 1.5em;
  }
  nav#main-menu ul#social {
    margin-top: 2em;
    display: flex;
    flex-direction: row;
    column-gap: 2em;
    width: 100%;
    align-items: center;
    float: none !important;
    justify-content: center;
  }
  nav#main-menu li#opensea:hover {
    filter: brightness(0) saturate(100%) invert(41%) sepia(100%) saturate(4659%)
      hue-rotate(347deg) brightness(96%) contrast(96%) opacity(1);
  }
  nav#main-menu li#discord:hover {
    filter: brightness(0) saturate(100%) invert(34%) sepia(94%) saturate(647%)
      hue-rotate(80deg) brightness(96%) contrast(102%) opacity(1);
  }
  nav#main-menu li#twitter:hover {
    filter: brightness(0) saturate(100%) invert(56%) sepia(78%) saturate(1370%)
      hue-rotate(139deg) brightness(98%) contrast(99%) opacity(1);
  }
}