label {

display: block;

margin: 5px 0;

}

table {

border-collapse: collapse;

border-spacing: 0;

}

td, th {

padding: 5px;

border-bottom: 1px solid #aaa;

}

.serif {
  font-family: "Times New Roman", Times, serif;
}

ul.a {
  list-style-type: circle;
}

ul.b {
  list-style-type: square;
}

table, th, td {
  border: 1px solid black;
}

input[type=text] {
  border: none;
  border-bottom: 2px solid red;
}

 {
  box-sizing: border-box;
}

body {
  margin: 0;
}

.header {
  background-color: #f1f1f1;
  padding: 20px;
  text-align: center;
}

.topnav {
  overflow: hidden;
  background-color: #333;
}

.topnav a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

.topnav a:hover {
  background-color: #ddd;
  color: black;
}


.column {
  float: left;
  width: 33.33%;
  padding: 15px;
}

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

@media screen and (max-width:600px) {
  .column {
    width: 100%;
  }
}

.serif {
  font-family: "Times New Roman", Times, serif;
}

ul.a {
  list-style-type: circle;
}

ul.b {
  list-style-type: square;
}

table, th, td {
  border: 1px solid black;
}

input[type=text] {
  border: none;
  border-bottom: 2px solid red;
}

 {
  box-sizing: border-box;
}

body {
  margin: 0;
}

.header {
  background-color: #f1f1f1;
  padding: 20px;
  text-align: center;
}

.topnav {
  overflow: hidden;
  background-color: #333;
}

.topnav a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

.topnav a:hover {
  background-color: #ddd;
  color: black;
}


.column {
  float: left;
  width: 33.33%;
  padding: 15px;
}

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

.button {
  background-color: #e7e7e7 
  border: none;
  color: black;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
}