HTMLify

@import url("https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800;900&display=swap");

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: "Poppins", "Franklin Gothic Medium", "Arial Narrow", Arial, sans-serif;
  background-color: #141414;
  color: #fff;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

#nav {
  display: flex;
  align-items: center;
  background-color: #fff;
  padding: 1rem;
  border-radius: 0.5rem;
  width: 55px;
  transition: all 0.6s linear;
}
#nav.active {
  width: 400px;
}
#nav ul {
  display: flex;
  align-items: center;
  width: 0;
  padding: 0;
  margin: 0;
}
#nav.active ul {
  width: 100%;
}
#nav ul li {
  list-style-type: none;
  white-space: nowrap;
  transform: rotateY(0deg);
  opacity: 0;
  transition: transform 0.6s linear, opacity 0.6s linear;
}
nav.active ul li {
  transform: rotateY(360deg) !important;
  opacity: 1 !important;
}
#nav ul li a {
  text-decoration: none;
  color: #141414;
  font-weight: 500;
  margin-right: 1.5rem;
}
.icon {
  background-color: #fff;
  border: none;
  cursor: pointer;
  padding: 0;
  position: relative;
  height: 30px;
  width: 30px;
}
.icon .line {
  position: absolute;
  height: 1px;
  width: 20px;
  background-color: #141414;
  position: absolute;
  top: 10px;
  left: 0;
  transition: transform 0.6s ease;
}
.line2 {
  top: auto !important;
  bottom: 10px !important;
}
nav.active .line1 {
  transform: rotate(-765deg) translateY(6.5px) !important;
}
nav.active .line2 {
  transform: rotate(765deg) translateY(-6.5px) !important;
}