ul {
  padding: 0;
  list-style: none;
  margin: 0;
  display: flex;
  flex-direction: column;	
}

li span {
  margin-bottom: 12px;
  display: block;	
  background: #ffffff;
  padding: 16px 20px;
  border-radius: 12px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  transition: transform 0.2s, background-color 0.2s;
  border: 1px solid #999999;
}

li span a {
  color: #0000ff;
  font-weight: 600;
  text-decoration: none;
}

@media (min-width: 600px) {
  li span {
    display: inline-block;
    min-width: 400px;
  }
}