css
body {
  background-color: #f7f7f7;
  font-family: Arial, sans-serif;
  font-size: 14px;
  line-height: 1.5;
  margin: 0;
  padding: 0;
}

a {
  color: #00ff00;
  text-decoration: none;
  font-weight: bold;
}

a:hover {
  text-decoration: underline;
}

h1 {
  color: #333;
  margin: 0 0 0 0;
  padding: 16px 0 8px 0;
  border-top: 4px solid #000;
  text-shadow: 0 1px 0 #000;
  font-size: 36px;
  font-weight: bold;
  text-align: center;
  background-color: #fff;
}

h2 {
  color: #333;
  margin: 0 0 0 0;
  padding: 16px 0 8px 0;
  border-top: 4px solid #000;
  text-shadow: 0 1px 0 #000;
  font-size: 24px;
  font-weight: bold;
  text-align: center;
  background-color: #fff;
  border-bottom: 4px solid #000;
}

h3 {
  color: #333;
  margin: 0 0 8px 0;
  padding: 0 0 8px 0;
  border-top: 4px solid #000;
  text-shadow: 0 1px 0 #000;
  font-size: 18px;
  font-weight: bold;
  text-align: center;
  background-color: #fff;
  border-bottom: 4px solid #000;
}

p {
  color: #333;
  margin: 8px 0 8px 0;
  padding: 0 0 8px 0;
  border-bottom: 4px solid #000;
  text-align: justify;
  text-justify: auto;
  font-size: 14px;
  line-height: 1.5;
  font-weight: normal;
  background-color: #fff;
}

#time-dilation {
  background-color: #fff;
  border: 4px solid #000;
  padding: 16px 0 16px 0;
  text-align: center;
  font-size: 24px;
  font-weight: bold;
  color: #000;
}

#time-dilation p {
  background-color: #fff;
  border: 4px solid #000;
  padding: 16px 0 16px 0;
  text-align: center;
  font-size: 18px;
  font-weight: bold;
}

#time-dilation h2 {
  background-color: #fff;
  border: 4px solid #000;
  padding: 16px 0 8px 0;
  text-align: center;
  font-size: 24px;
  font-weight: bold;
  color: #000;
  text-shadow: 0 1px 0 #000;
}

#time-dilation a {
  color: #000;
  text-decoration: none;
  font-weight: bold;
  text-align: center;
  border: 4px solid #000;
  padding: 16px 0 16px 0;
  background-color: #fff;
}