html, body {
  margin: 0;
  padding: 0;
}

html {
  font-size: 10px;
  background-color: #eee;
}

body {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  color: #2a2a2a;
  text-align: justify;
  font-family: Calibri, Arial, sans-serif;
}

h1 {
  font-size: 3rem;
  text-align: center;
}

h2 {
  font-size: 2.5rem;
  text-align: center;
}

h3 {
  font-size: 2rem;
  text-align: center;
}

p, li, dt, dd, #reqs {
  font-size: 1.6rem;
  line-height: 1.5;
}

dt {
  font-weight: bold;
}

#logo {
  width: 40%;
}

details {
  font-size: 1.2rem;
  padding: 1rem;
  border: 1px solid #78909C;
  border-radius: 6px;
  text-align: left;
}

summary {
  padding: 1rem;
  font-size: 1.2em;
  font-weight: bold;
}

summary:focus {
  outline: none;
}

.files {
  text-align: center;
}

small {
  float: right;
  font-size: 1rem;
}

a:link, a:visited {
  color: #04b;
  text-decoration: none;
}

a:hover {
  color: #04b;
  text-decoration: underline;
}

a:active {
  color: red;
  text-decoration: underline;
}

#reqs {
  text-align: center;
}

article, aside, footer {
  background-color: white;
  padding: 1%;
}

main {
  display: flex;
}

article {
  flex: 4;
}

aside {
  flex: 1;
  margin-left: 10px;
  background-color: #d3d4d3;
}

aside li {
  padding-bottom: 10px;
}

footer {
  margin-top: 10px;
}

@media screen and (max-width: 768px) {
  header {
    display: none;
  }

  main {
    display: block;
  }

  article, aside, footer {
    padding: 4%;
  }
  
  aside {
    margin: 0;
  }

  footer {
    margin-top: 0 ;
  }  

}

@media screen and (max-width: 480px) {
  html {
    font-size: 11px;
  }
}