html {
  box-sizing: border-box;
}
*, *:before, *:after {
  box-sizing: inherit;
}
body {
font-family: arial, sans-serif;

}

.column {
  float: left;
  width: 25%;
  margin-bottom: 16px;
  padding: 0 8px;
}

@media screen and (max-width: 650px) {
  .column {
    width: 100%;
    display: block;
  }
}

.card {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
}

.container {
  padding: 0 16px;
}

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

.title {
  color: grey;
}

.button {
  border: none;
  outline: 0;
  display: inline-block;
  padding: 8px;
  color: white;
  background-color: #000;
  text-align: center;
  cursor: pointer;
  width: 100%;
}

.button:hover {
  background-color: #555;
}

/*nav css*/
/*for nav bar */
ul {
   list-style-type: none;
   margin: 0;
   padding: 0;
   overflow: hidden;
   background-color: #333;
}

li {
   float: left;
   border-right:1px solid #bbb;
}

li:last-child {
    border-right: none;
}

li a {
   display: block;
   color: white;
   text-align: center;
   padding: 14px 16px;
   text-decoration: none;
}

li a:hover:not(.active) {
   background-color: #111;
}

.active {
   background-color: #4CAF50;
}

nav {
width: 100%;
height: 50px;
}
.selected {
	background-color: red;
	}