body {
  overflow: hidden;
  height: 100vh;
}
main {
  overflow-y: auto;
}
ul {
  list-style: none;
}
li {
  color: #fff;
}
aside {
  border-right:  1px solid #ededed;
  background: #36c;
  flex: 1 0 10%;
  padding: 1rem;
}
.wrapper {
  display: flex;
  height: 100%;
}
@media (max-width: 500px) {
  .wrapper {
    flex-direction: column-reverse;
  }
  ul {
    display: flex;
    align-items: center;
    justify-content: space-between;
  }
  
}
.wrapper_inner {
  width: 90%;
  margin: 0px auto;
}