body {
  background: white;
  font-family: 'sourcesanspro', 'Helvetica Neue', Arial, sans-serif;
  margin: 0;
  font-size: 1em;
  line-height: 1.6;
  --primary-text-color: rgba(0, 0, 0, .87);
  --secondary-text-color: rgba(0, 0, 0, .54);
  --accent-color: #42a5f5;
  --card-background: #e3f2fd;
  color: var(--primary-text-color);
}

body {
  display: grid;
  grid-gap: 10px;
  grid-template-columns: 240px auto;
  grid-template-rows: 60px auto;
  grid-template-areas:
    "....... header"
    "sidebar content";
}

main {
  grid-area: content;
}

#top-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 60px;
  grid-area: header;
}

#top-nav > ul {
  margin: 0;
}

#top-nav > ul > li {
  display: inline-block;
  padding: 10px;
  text-transform: uppercase;
  box-sizing: border-box;
  height: 48px;
}

#top-nav > ul > li.selected, #top-nav > ul > li:hover {
  border-bottom: solid 2px var(--accent-color);
}

#top-nav > ul > li > a {
  color: rgba(0, 0, 0, .87);
  text-decoration: none;
}

#top-nav > .icon-large {
  font-size: 1.8em;
}

#side-nav {
  grid-area: sidebar;
  padding: 0 0 0 20px;
}

#side-nav > ul {
  list-style-type: none;
  padding: 0;
}

#side-nav li > ul {
  list-style-type: none;
  padding: 0 0 0 20px;
}

#side-nav ul a {
  display: inline-block;
  padding: 5px 0;
}

#side-nav li.selected > a {
  font-weight: 600;
}

#side-nav li.page {
  font-size: .85em;
  color: var(--secondary-text-color);
}

/* #side-nav li[level="1"] {
  padding-left: 0px;
}

#side-nav li[level="2"] {
  padding-left: 8px;
}

#side-nav li[level="3"] {
  padding-left: 16px;
} */

a {
  color: var(--accent-color);
}

nav a {
  color: inherit;
  text-decoration: none;
}

nav a:hover {
  color: var(--accent-color);
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Roboto Slab', Roboto, Noto, sans-serif;
  font-weight: 400;
}

h1 {
  font-size: 1.8em;
}

h2 {
  font-size: 1.4em;
  /* font-weight: 600; */
  border-bottom: solid 1px currentcolor;
  margin: 30px 0 15px 0;
}

a.cta {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 40px;
  padding: 0 20px;
  border: solid 1px var(--accent-color);
  border-radius: 20px;
  text-transform: capitalize;
  text-decoration: none;
  margin: 0 10px;
}

a.cta:hover {
  background: var(--accent-color);
  color: white;
}

section.feature {
  display: flex;
  justify-content: center;
}

section.cards {
  display: grid;
  grid-template-columns: auto auto auto;
  justify-content: center;
  grid-column-gap: 10px;
}

div.card {
  box-sizing: border-box;
  background: var(--card-background);
  padding: 8px;
  color: var(--secondary-text-color);
  font-size: .9em;
}

div.card > h3 {
  color: var(--primary-text-color);
  margin: 0 0 5px 0 ;
}

@media screen and (min-width: 740px) {
  main, #top-nav {
    width: 740px;
  }
}

footer {
  color: var(--secondary-text-color);
  border-top: solid 1px currentcolor;
  margin: 20px 0;
  padding: 20px 0;
  text-align: center;
  font-size: .9em;
}