styles.css

:root {
  --main-margin: 0.3rem;
  --main-padding: 0.98rem;
  --main-radius: 0.8rem;
}

.container {
  display: grid;
  height: 100vh;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  grid-template-rows: 0.53fr 0.53fr 2.7fr 0.53fr;
  grid-template-areas:
    "header header header header"
    "sidebar nav nav nav"
    "sidebar article article article"
    "footer footer footer footer";
  grid-gap: 0.2rem;
  font-weight: bold;
  font-family: sans-serif;
  font-size: 1.3rem;
  color: #ffffff;
  text-align: center;
}

#header {
  background: #286057;
  grid-area: header;
  margin: var(--main-margin);
  padding-top: var(--main-padding);
  border-radius: var(--main-radius);
}

nav {
  background: #5e2fd5;
  grid-area: nav;
  margin: var(--main-margin);
  padding-top: var(--main-padding);
  border-radius: var(--main-radius);
}

#sidebar {
  background: #265990;
  grid-area: sidebar;
  margin: var(--main-margin);
  padding-top: var(--main-padding);
  border-radius: var(--main-radius);
}

#article {
  background: #7425bc;
  grid-area: article;
  margin: var(--main-margin);
  padding-top: var(--main-padding);
  border-radius: var(--main-radius);
}

footer {
  background: #393f4b;
  grid-area: footer;
  margin: var(--main-margin);
  padding-top: var(--main-padding);
  border-radius: var(--main-radius);
}

p {
  font-weight: 100;
  font-family: sans-serif;
  font-size: 1.1rem;
  color: #ffffff;
  text-align: left;
  padding-left: var(--main-padding);
}
@media only screen and (max-width: 414px) {
  .container {
    grid-template-columns: 1fr;
    grid-template-rows: 0.53fr 0.53fr 0.53fr 2.7fr 0.53fr;
    grid-template-areas:
      "header"
      "nav"
      "sidebar"
      "article"
      "footer";
  }
}