html,
body {
  width: 100%;
  min-width: 320px;
  height: 100%;
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.content {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 100vw;
  min-height: 100vh;
  background-color: #222;
  font-family: 'Montserrat', sans-serif;
  font-size: 24px;
  color: #eee;
  text-transform: uppercase;
  margin: 0;
  padding: 0;
  text-align: center;
}

.content span {
  width: 30px;
  display: inline-block;
}

.portfolio {
  margin-top: 30px;
}

.portfolio ul {
  display: flex;
  justify-content: center;
  align-items: start;
  list-style: none;
  padding: 0;
  margin: 0;
}

.portfolio ul li {
  margin-right: 25px;
  transform: translateX(100vw);
}

.portfolio ul li.active:nth-child(1) {
   animation: fly-in 1.5s ease 0ms 1 normal forwards;
}

.portfolio ul li.active:nth-child(2) {
   animation: fly-in 1.5s ease 200ms 1 normal forwards;
}

.portfolio ul li.active:nth-child(3) {
   animation: fly-in 1.5s ease 450ms 1 normal forwards;
}

.portfolio ul li.active:nth-child(4) {
   animation: fly-in 1.5s ease 800ms 1 normal forwards;
}

.portfolio ul li.active:nth-child(5) {
   animation: fly-in 1.5s ease 1200ms 1 normal forwards;
}

.portfolio ul li.active:nth-child(6) {
  animation: fly-in 1.5s ease 1650ms 1 normal forwards;
}

.portfolio ul li:last-child {
  margin-right: 0;
}

.portfolio ul a {
  font-family: 'Montserrat', sans-serif;
  font-size: 14px;
  color: #eee;
  text-decoration: none;
}

@keyframes fly-in {
  0% { transform: translateX(100vw); }
  50% { transform: translateX(-40px); }
  100% { transform: translateX(0); }
}

@media screen and (max-width: 575px) {
  .content {
    font-size: 16px;
  }

  .content span {
    width: 14px;
  }

  .portfolio {
    margin-top: 40px;
  }

  .portfolio ul {
    flex-direction: column;
    align-items: center;
  }
  
  .portfolio ul li {
    margin-top: 15px;
    margin-right: 0;
  }

  .portfolio ul a {
    font-size: 12px;
  }
}