Style sheet for government site


body {background-color: #FFFAFA; background: linear-gradient(#B22222, #FFFAFA, #4682B4);}
h1 {background-color: #002171; color: #F0F8FF;
text-align: center; font-size: 75px; border-width: 5px; 
border-style: solid; border-color: #8B0000;}
nav {color: #F0F8FF; text-align: center; font-size: 25px;}
nav ul {list-style-type: none; 
text-align: center;
font-size: 25px;}
nav li {display: inline;}
h2 {color: #191970; text-align: center; font-size: 35px;}
h3 {color: #191970; text-align: center;}
p {text-align: center; font-size: 20px;}
ul{font-size: 18px;}
table{ width: 75%; margin:auto;}
#wrapper {width:950px;
margin-left: auto; margin-right: auto; background-color: #FFFAFA;}
.thirdoption{display: block; margin-left: auto; margin-right: auto; width: 50%;}
figure {margin-left: auto; margin-right: auto;} 
#gallery {display: flex; flex-direction: row;
flex-wrap: wrap; justify-content: space-around;}
figcaption {text-align: center; display: wrap;}
#anthem {display: flex; justify-content: center; align-items: center;}
<!DOCTYPE html>
<html lang="en">
<head>
<title> Style sheet for government site </title>
<meta charset="utf-8">
</head>