style.css

* {
  margin: 0;
}

body {
  display: flex;
  flex-direction: column;
}

.header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  background-color: #333;
  height: 80px;
 
 }

h1 > a {
  text-decoration: none;
  color: #fff;
}

.flex_nav {
  display: flex;
  display: inline-block;
  flex-wrap: wrap;
  background-color: #333;
  padding: 0px 16px;
  }

.flex_nav a {
  color: #fff;
  padding: 8px;
  text-decoration: none;
}

.flex_nav a:hover {
  background-color: #5f5f5f;
  cursor: pointer;
}


img {
  width: 100%;
}

footer {
  padding-top: 30px;
  color: white;
  text-align: center;
  height: 100px;
  background-color: #333;
}

form {
  padding: 30px 20px;
}

label { 
  font-weight: lighter;
  padding: 5px 0;
 }

input[type=text], input[type=password] {
  width: 100%;
  padding: 5px;
  margin: 5px 0 22px 0;
  display: inline-block;
  border: 1px solid;
}

input[type=text]:focus, input[type=password]:focus {
  background-color: #ddd;
  outline: none;
}

div /* This div is from register.html */ {
  width: 50%;
  margin:auto;
  }

.button {
  background-color:#333;;
  border: none;
  color: #ffffff;
  width:35% ;
  padding: 7.5px 25px;
  font-family: sans-serif;
  text-align: center;
  opacity: 0.8;
  font-size: 90%;
  }

.button:hover {
  opacity: 1;
  cursor: pointer;
}