style.css

body {
  background-color: rgb(245, 245, 245);
  color: rgb(20, 20, 20);
  font-family: 'Open Sans', sans-serif;
  font-size: 18px;
  line-height: 30px;
  margin: 0;
}

h1, h2, h3 {
  font-family: 'Open Sans', sans-serif;
  font-weight: lighter;
}

h1 {
  font-weight: bold;
}

h3 {
  font-size: 1.2em;
  color: rgb(140, 140, 140);
}

.banner {
  background-image: url("https://source.unsplash.com/random");
  background-size: cover;
  color: rgb(245, 245, 245);
  padding: 120px 0;
}

a {
  text-decoration: none;
  color: rgb(20, 20, 20);
  font-size: 1.2em;
  background-color: rgb(121,247,178, 0.2);
}

a:hover {
  background-color: rgb(121,247,178, 1);
}

.container {
  margin: 50px auto;
  width: 700px;
}

@media(max-width: 992px) {
  .container {
    width: 600px;
  }
}

@media (max-width: 720px) {
  .container {
    width: 500px;
  }
}
@media (max-width: 540px) {
  .container {
    width: 300px;
  }
}

.list-inline > li {
  display: inline-block;
  padding: 0px 20px;
}

.list-inline {
  list-style: none;
  padding-left: 0px;
}

.card {
  width: 33%;
  display: inline-block;
}

.card img {
  display: inline-block;
  width: 90%;
  height: 100px;
  padding: 10px;
}

.card .img-round {
  display: inline-block;
  height: 30px;
  width: 30px;
  border-radius: 15px;
}

.card-img-container {
  background-color: rgb(255, 255, 255);
}