body {
  width: 90%;
  margin: 0 auto;
}

@media (min-width: 800px) {
  body {
    width: 800px;
    margin: 0 auto;
  }
}

@media (min-width: 640px) {
  body {
    background-color: #eaf6ff;
  }
}

h1 {
  font-size: 2rem;
}

@media (max-width: 499px) {
  h1 {
    font-size: 1.5rem;
  }
}

@media (min-width: 640px) {
  h1 {
    font-size: 2.5rem;
  }
}

.box-grid {
  display: flex;
  flex-wrap: wrap;         
  list-style-type: none;
  padding-left: 0;       
  margin: 0;             
}

.box-grid aside {
  width: 170px;
  margin: 10px;
  font-size: 0.8rem;
}

.responsive-grid {
  display: flex;
  flex-wrap: wrap;
  list-style-type: none;
  padding-left: 0;
  margin: 1rem -10px;
}

.responsive-grid li {
  width: 100%;
}

.responsive-grid aside {
  margin: 10px;
  font-size: 0.8rem;
  padding: 10px;
  border-radius: 6px;
}

@media (min-width: 480px) {
  .responsive-grid li {
    width: 50%;
  }
}

@media (min-width: 640px) {
  .responsive-grid li {
    width: 25%;
  }
}