body {
  background: dimgrey;
  color: black;
  font-family: 'Inter', Helvetica, sans-serif;
}
.lead { font-size: 1.5rem; font-weight: 300; }
.container { margin: 150px auto; max-width: 960px; }
ul, li {
  margin: 0;
  padding: 0;
  list-style: none;
}
li {
  float: left;
}
ul {
  width: 250px;
}
button {
  color: #fff;
  background: #000;
  width: 40px;
  height: 40px;
  font-size: 20px;
  margin: 5px;
  border: none;
  border-radius: 50% 50%;
}
button:focus {
  color: #000;
  background: #fff;
}