<header>
  <h1>Logo</h1>
  <input type="checkbox" id="menuToggle">
  <label for="menuToggle">☰ Menu</label>
  <nav>
    <label for="menuToggle">Close</label>
    <ul>
      <li><a href="#">Home</a></li>
      <li><a href="#">Portfolio</a></li>
      <li><a href="#">About</a></li>
      <li><a href="#">Contact</a></li>
    </ul>
  </nav>
</header>

@import url(https://fonts.googleapis.com/css2?family=Rubik);

:root {
  --primary-text-color: #222;
  --secondary-text-color: #fff;
  --primary-bg-color: #222;
  --secondary-bg-color: brown;
}

body {
  color: var(--primary-text-color);
  font-family: "Rubik", serif;
  font-size: 1.2rem;
  line-height: 1.6;
}

header {
  align-items: center;
  display: flex;
  justify-content: space-between;
  padding: 1rem;
}

h1 {
  font-size: inherit;
  line-height: inherit;
  margin: 0;
}

#menuToggle {
  display: none;
}

label {
  cursor: pointer; 
}

nav {
  background-color: var(--primary-bg-color);
  color: var(--secondary-text-color);
  height: 100vh;
  left: 50%;
  position: absolute;
  text-align: right;
  transform: translate(-50%, -50%) scale(0);
  top: 50%;
  width: 100vw;
}

nav label {
  line-height: 3;
  margin-right: 1rem
}

ul {
  list-style: none;
  margin: 0;
  padding: 0;
  text-align: center;
}

ul a:link,
ul a:visited,
ul a:hover,
ul a:active {
  color: var(--secondary-text-color);
}

#menuToggle:checked + label + nav {
  transform: translate(-50%, -50%) scale(1);
  transition: 0.3s;
}

@media (min-width: 600px) {
  header > label,
  nav label {
    display: none;
  }
  
  nav {
    background-color: transparent;
    color: var(--primary-text-color);
    display: flex;
    height: auto;
    left: auto;
    position: relative;
    transform: none;
    transition: none;
    top: auto;
    width: auto;  
  }
  
  ul {
    display: flex;
  }
  
  ul li {
    margin-left: 1rem;
  }
  
  ul a:link,
  ul a:visited,
  ul a:hover,
  ul a:active {
    color: var(--primary-text-color);
  }
}