main.css

body {
  font-family: sans-serif;
  width: 940px;
  margin-top: 20px;
  margin-left: auto;
  margin-right: auto;
  background-color: rgba(246, 249, 244, .85);
  color: rgba(34, 12, 16, .70);
  border: 20px solid #82BE61;
  border-radius: 34px;
  text-align: center;
}

p {
  font-size: 22px;
  line-height: 130%;
}

header {
  background-color: #82BE61;
  width: auto;
  padding: 10px;
  margin: -2px;
  margin-bottom: 0;
}

h1 {
  text-align: center;
  text-transform: uppercase;
  font-size: 3em;
  margin-bottom: 10px;
  padding: 10px 80px 30px;
}

h2 {
  text-align: center;
  color: rgba(79, 51, 40, .90);
  margin-bottom: 10px;
  padding: 25px 80px;
}

article {
  width: 80%;
  padding: 20px 80px;
  display: inline-block;
  margin-bottom: 20px;
}

h3 {
  text-align: center;
  width: auto;
  margin-top: 10px;
  padding: 20px 110px;
  line-height: 150%;
}

h4 {
  text-align: center;
  width: auto;
  margin-top: 10px;
  padding: 10px 80px 5px;
  line-height: 130%;
}

section {
  background-color: rgba(243, 232, 187, .3);
  border: 1px solid rgba(243, 232, 187, .7);
  border-radius: 10px;
  width: auto;
  margin-bottom: 10px;
  padding: 10px 40px;
}

.form {
  width: auto;
  padding: 10px 100px 30px;
}

.form input {
  font-size: 22px;
  line-height: 130%;
}

input[type="text"] {
  width: 70%;
  border: 1px solid rgba(199, 190, 154, .5);
}

input[type="text"]:hover {
  border: 1px solid rgba(199, 190, 154, .9);
}

input[type="submit"] {
  background-color: rgba(130, 190, 97, .3);
  color: rgba(34, 12, 16, .75);
  width: auto;
  border-radius: 5px;
  border: 3px solid rgba(130, 190, 97, .5);
  padding: 5px 12px;
}

input[type="submit"]:hover {
  background-color: rgba(130, 190, 97, .4);
  color: rgba(34, 12, 16, .95);
  border: 4px solid rgba(130, 190, 97, .7);
  padding: 4px 11px;
}

.hide {
  display: none !important;
}

footer {
  background-color: #82BE61;
  margin: -2px;
  min-height: 20px;
  margin-top: 20px;
  padding: 2px;
  width: auto;
}

footer p {
  text-align: center;
  color: rgba(34, 12, 16, .5)
  font-size: 14px;
}