body {
   line-height: 1.6;
   max-width: 960px;
   background: black;
   margin: 0 auto;
   font-family: Verdana, Geneva, sans-serif; 
   color: white;
}

h1 { font-size: 2.5rem; margin: 0.5em 0; font-weight: bold; }
h2 { font-size: 2rem;  margin: 0.5em 0; font-weight: bold; }
h3 { font-size: 1.6rem; margin: 0.5em 0; font-weight: bold; }
h4 { font-size: 1.3rem; margin: 0.5em 0; font-weight: bold; }
h5 { font-size: 1.1rem; margin: 0.5em 0; font-weight: bold; }
h6 { font-size: 1rem;   margin: 0.5em 0; font-weight: bold; }

strong, b {
   font-weight: bold;
}

em, i {
   font-style: italic;
}

ol, ul {
   margin-left: 40px;
   padding: 10px 0;
}

/* page header */
header {
   background: #330570;
   width: 100%;
   color: #FFFFFF;
   text-align: center;
   line-height: 2.5em;
   border-top-right-radius: 20px;
   border-top-left-radius: 20px;
}

header h1 {
   font-size: 48px;
}

header h4 {
   font-size: 24px;
}

/* navigation bar */
nav {
   background-color: lightseagreen;
   text-align: center;
   padding: 10px 0;
}

nav li {
   display: inline-block;
   font-size: 20px;
   padding: 20px;
}

/* main content */
article {
   width: 960px;
   text-align: left;
   background: black;
   color: white;
   border-bottom-right-radius: 20px;
   padding: 20px;
}

article ul li {
   padding: 10px;
   margin-left: 20px;
}