custom.css

html, body {
  margin: 0;
  padding: 0;
  background: #1f1f1f;
  color: white;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.header {
  padding: 0 1rem;
  text-align: center;
  min-height: 5rem;
  line-height: 5rem;
  background: hsla(208, 56%, 46%, 1);
  align-self: stretch;
}

.header h1 {
  margin: 0;
}

.container {
  max-width: 90%;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
}

.container .card {
  width: 100%;
  margin: 1rem 0;
  border: 1px solid hsla(208, 56%, 46%, 1);
  border-radius: .25rem;
  box-sizing: border-box;

  display: flex;
  flex-direction: column;
}

@media screen and (min-width: 700px) {
  .container {
    max-width: 80%;
  }
  .container .card {
    width: 48%;
  }
}

@media screen and (min-width: 1000px) {
  .container .card {
    width: 32%;
  }
}

@media screen and (min-width: 1500px) {
  .container {
    max-width: 70%;
  }
  .container .card {
    width: 23%;
  }
}

.card-header, .card-body, .card-footer {
  padding: 1rem;
  border-radius: .25rem;
}

.container .card-header, .container .card-footer {
  background: #292929;
}

.card-header h4 {
  font-size: 1.5rem;
  margin: 0;
  word-wrap: break-word;
}

.card-header .text-muted {
  color: #e6e6e6;
}

.card-body {
  line-height: 1.5;
}

.card-body h5 {
  margin: 0;
  margin-bottom: 0.5rem;
  font-size: 1.25rem;
  line-height: 1.2;
}

.card-footer .btn {
  background: hsla(208, 56%, 46%, 1);
  padding: 0.5rem;
  border-radius: 0.25rem;
  color: white;
  text-decoration: none;
  display: inline-block;
  margin-bottom: 0.5rem;
}

.card-footer .btn:hover {
  background: hsla(208, 56%, 36%, 1);
}

.card-footer a {
  color: hsla(208, 56%, 56%, 1);
}

.card-footer a:hover {
  color: hsla(208, 56%, 46%, 1);
}

.container .card-body {
  flex: 1 1 auto;
}

.flag {
  margin-top: 0.5rem;
  height: 1em;
  width: 1.5em;
  object-fit: cover;
  border: 1px solid white;
}

.footer {
  margin-top: 1rem;
  text-align: center;
  height: 3rem;
}

.footer a {
  color: hsla(208, 56%, 56%, 1);
}