site.css

:root {
  background-color: #F1F1F1;
  font-family: 'Montserrat', sans-serif;
}

body {
  margin:0; 
}

a {
  color:black;
}

.navbar {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #9DA9EB;
  position: relative;
  top: 0;
  width: 100%;
}

.navbar li {
  float: left;
}

.navbar li a {
  display: block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-family: 'Montserrat', sans-serif;
  -webkit-transition: background-color 500ms linear;
  -moz-transition: background-color 500ms linear;
  -o-transition: background-color 500ms linear;
  -ms-transition: background-color 500ms linear;
  transition: background-color 500ms linear;

}

.navbar li a:hover:not(.active) {
  background-color: #7B8CF0;
}

.active {
  background-color: #04AA6D;
}

.center {
  text-align:center;
  justify-content:center; 
}

.card-center {
  margin:auto; 
}

.subhead {
  width:80%;
  text-align: center;
  margin: auto;
  justify-content: center;
}

.title {
  margin-left:15px; 
}

.notice {
  background:red;
  color:white;
  font-size:16px;
  padding:10px;
  text-align:center;
}

.card {
  padding:10px;
  background:#fff;
  border-radius:6px;
  width:80%;
  margin-top:10px;
}

.images {
  display:inline-block;
}

@media only screen and (max-width: 600px) {
  .subhead {
    width:90%;
  }

  .card {
    width:90%;
  }
}