FreeCodeCamp/HelpFrontEnd

$orange: rgb(255, 89, 0);

body {
  background: green;
}

/* navigation styles start here */
header > img {
  height: 2.5rem;
}

header {
  background-color: rgba(0, 0, 0, 0.25);
  z-index: 999;
  text-align: center;
  position: fixed;
  width: 100%;
  display: block;
}

.logo {
  margin: 20px;
}

nav {
  background-color: rgba(0, 0, 0, 0.25);
  position: absolute;
  text-align: left;
  top: 100%;
  left: 0;
  width: 100%;
  transform: scale(1, 0);
  transform-origin: top;
  transition: transform 400ms ease-in-out;
}

nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

nav li {
  margin-bottom: 1em;
  margin-left: 1em;
}

nav a {
  color: white;
  text-decoration: none;
  font-size: 1.2rem;
  opacity: 0;
  transition: opacity 150ms ease-in-out;
}

nav a:hover {
  color: $orange;
}

@media screen and (min-width: 600px) {
  .nav-toggle-label {
    display: none;
  }

  header {
    display: grid;
    grid-template-columns: 1fr auto minmax(600px, 3fr);
    grid-gap: 1em;
    display: block;
  }

  .logo {
    grid-column: 1/ span 1;
  }

  nav {
    all: unset;
    grid-column: 2 / 4;
    display: flex;
    justify-content: space-evenly;
    align-items: center;
    display: block;
  }

  nav a {
    opacity: 1;
  }

  nav ul {
    display: flex;
  }
}

/*
    Nav toggle/hamburger
*/
.nav-toggle:checked ~ nav {
  transform: scale(1, 1);
}

.nav-toggle:checked ~ nav a {
  opacity: 1;
  transition: opacity 150ms ease-in-out 250ms;
}

.nav-toggle {
  display: none;
}

.nav-toggle-label {
  position: absolute;
  top: 0;
  left: 0;
  margin-left: 1em;

  height: 100%;
  display: flex;
  align-items: center;
}

.nav-toggle-label span,
.nav-toggle-label span::before,
.nav-toggle-label span::after {
  width: 2em;
  height: 2px;
  display: block;
  background: white;
  border-radius: 2px;
  position: relative;
}

.nav-toggle-label span::before,
.nav-toggle-label span::after {
  content: "";
  position: absolute;
}

.nav-toggle-label span::before {
  bottom: 7px;
}

.nav-toggle-label span::after {
  top: 7px;
}
/*
    End of Nav toggle/hamburger
*/
video {
  display: block;
  z-index: -200;
  width: 100%;
  overflow: hidden;
}

.cards {
  display: flex;
}

#show-selection {
  width: 100%;
  background-color: red;
  display: block;
}

#splash {
  background-image: url("https://res.cloudinary.com/dmkct6wfu/image/upload/v1533162642/pexels-photo-1277019_xha4yl.jpg");
  background-repeat: no-repeat;
  background-size: contain;
  background-position: center;
}