body {
  background-color: lightblue;
}

h1 {
  color: black;
  text-align: center;
}
h2 {
  color: black;
  text-align: center;
}
h3 {
  color: black;
  text-align: center;
}
h4 {
  color: black;
  text-align: center;
}
p {
  font-family: verdana;
  font-size: 20px;
}
header {
  background-color: lightskyblue;
  padding: 10px;
  text-align: center;
  font-size: 28px;
  color: blue;
}
row {
  display: flex;
margin-right: 0px;
  margin-left: 0px;
}
.column {
  flex: 50%;
  padding: 10px;
  height: 300px;
}
.column.side {
  background-color: #aaa;
}
.column.middle {
  background-color: #bbb;
}
.col-center
{
  float: none;
  margin: 0 auto;
}
footer {
  background-color: #555;
  color: #f2f2f2;
  padding: 15px;
  margin-top: 30px;
  padding: 10px;
}
.link {
  color: black;
  text-decoration: underline;
}
.link:hover {
  color: gray;
  text-decoration: none;
}
.button-center {
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 50%;
}
.button {
  background-color: #008CBA;
  border: none;
  color: white;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin: 4px 2px;
  cursor: pointer;
}
.button2 {
  background-color: #008CBA;
}
.button3 {
  background-color: #f44336;
}
.button4 {
  background-color: #e7e7e7;
  color: black;
}
.button5 {
  background-color: #555555;
}
.button6 {
  background-color: #555555;
  color: white;
}
.center_text {
  text-align: center;
}
.col-10 {
  float: left;
  width: 10%;
  margin-top: 6px;
}
.col-15 {
  float: left;
  width: 15%;
  margin-top: 6px;
}
.col-20 {
  float: left;
  width: 20%;
  margin-top: 6px;
}
.col-25 {
  float: left;
  width: 24.9%;
  margin-top: 6px;
}
.col-75 {
  float: left;
  width: 74.9%;
  margin-top: 6px;
}
.col-50 {
  float: left;
  width: 50%;
  margin-top: 6px;
}
.col-33 {
  float: left;
  width: 33.33%;
  margin-top: 6px;
}
.col-66 {
  float: left;
  width: 66.66%;
  margin-top: 6px;
}
table {
  border-collapse: collapse;
  width: 100%;}
table, th, td {
  border: 1px solid black;
  padding: 15px;
  text-align: center;
}
th {
  background-color: #4CAF50;
  color: white;
}
tr:nth-child(even) {
  background-color: #f2f2f2;
}
tr:hover {
  background-color: #ddd;
}
.container {
  border-radius: 5px;
  background-color: #f2f2f2;
  margin: 50px auto;
padding-right: 20px;
  padding-left: 20px;
}
.nav {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333;
}
.nav li {
  float: left;
}
.nav li a {
  display: block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}
.nav li a:hover {
  background-color: #111;
}
.nav li a.active {
  background-color: #4CAF50;
}
.nav li a.active:hover {
  background-color: #4CAF50;
}
.error {
  color: red;
}
.left {
  /* allign content left */
  text-align: left;
}
.right {
  text-align: right;
}
.center {
  text-align: center;
}
.row-center {
  display: flex;
  align-items: center;
  justify-content: center;
}
.space-between {
  display: flex;
  justify-content: space-between;
}