body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #fff
}

.topnav {
  overflow: hidden;
  background: #fff;
}

.topnav a {
  float: left;
  color: #000;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 12px;
}

.topnav a:hover {
  background: rgb(7, 52, 253);
  color: #000;
}

.topnav a.active {
  background: #fff;
  color: #000;
}

.header {
    background: dodgerblue;
}
.header input {
    position: relative;
    top: -16px;
    width: 800px;
}
.header img {
    position: relative;
    left: 4px;
    top: 2.5px;
}
.logo {
    width: 250px;
}



.footer {
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  background-color: red;
  color: white;
  text-align: center;
}
</style>

<div class="footer">
  <p>Footer</p>
</div>