* {
    box-sizing: border-box;
    margin: 0px;
}

body {
    background-image: url("building-839362_1920.jpg");
    background-color: #c0bfbf;
    background-size: cover;
    background-repeat: no-repeat;
    width: 100vw;
    height: 100vh;
    opacity: 0.9;;
}

.row::after {
  content: "";
  clear: both;
  display: table;
}

[class*="col-"] {
  float: left;
  padding: 15px;
}

.col-1 {width: 8.33%;}
.col-2 {width: 16.66%;}
.col-3 {width: 25%;}
.col-4 {width: 33.33%;}
.col-5 {width: 41.66%;}
.col-6 {width: 50%;}
.col-7 {width: 58.33%;}
.col-8 {width: 66.66%;}
.col-9 {width: 75%;}
.col-10 {width: 83.33%;}
.col-11 {width: 91.66%;}
.col-12 {width: 100%;}

html {
  font-family: "Lucida Sans", sans-serif;
}

.header {
  background-color: #003c50;
  color: #ffffff;
  padding: 20px;
  text-align: center;
  font-size: larger;
}

.footer {
  background-color: #003c50;
  color: #ffffff;
  text-align: center;
  font-size: 12px;
  padding: 15px;
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
}

.menu ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

.menu li {
  padding: 8px;
  margin-bottom: 7px;
  background-color: #003c50;
  color: #ffffff;
  box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
}

.menu li:hover {
  background-color: #0099cc;
}

@media only screen and (max-width: 768px) {
  body {
    background-color: lightblue;
  }
  .menu li {
      text-align: center;
  }
}

@media only screen and (max-width: 768px) {
  /* For mobile phones: */
  [class*="col-"] {
    width: 100%;
  }
}