<!-- styles.css of cs198.1x -->
background: linear-gradient(60deg, #3d3393 0%, #2b76b9 37%, #2cacd1 65%, #35eb93 100%);
body {
  font-family: Bahnschrift, "Avenir Next", Calibri, Verdana, sans-serif;
  font-size: 15px;  /* 13.5 */
  margin-left: 15px;
}

#myBtn {
  display: none;
  position: fixed;
  bottom: 20px;
  right: 30px;
  z-index: 99;
  font-size: 12px;
  border: none;
  outline: none;
  background-color: #bc0000;  /* strong red, ff0000=pure red */
  color: white;
  cursor: pointer;
  padding: 10px;
  border-radius: 2px;
}
#myBtn:hover {
  background-color: #ffff00;  /* yellow */
  color: black;
}

img.displayed {
    display: block;
    margin: 0 auto; 
}
  .border {
    border-width: 1px;
    border-color: #778899;  /* dark grayish blue */
    border-style: solid; 
  }
p {
  font-size: 15px;
  font-family: Bahnschrift, Inter, Helvetic, sans-serif, Consolas;
  text-align: left;
  margin-left: 15px;
}
p.em2 {
  background-color: #fff;  /* f2f2f2 very light gray */
}

a {
  text-decoration: none;
}
a.hover {
  color: #ffff00;  /* pure (or mostly pure) yellow */
  text-decoration: underline;
}
a.hover:hover {
  color: #ffff00;  /* pure (or mostly pure) yellow */
  text-decoration: underline;
}

h1 {
  padding: 20px 0 0 0;
  font-size: 24px;
  font-family: normal 1.4em Bahnschrift, verdana, tahoma, arial, sans-serif, helvetica;
  text-transform: uppercase;
  letter-spacing: 3px;
  margin-left: 15px;
  color: #acaf2c;			/* dark yellow (olive tone) */
  background: inherit;
  text-align: center;
}
h2 {
  padding: 20px 0 0 0;
  font-size: 22px;
  font: normal 1.4em Bahnschrift, verdana, calibri, arial, sans-serif, tahoma;
  letter-spacing: 3px;
  color: #3800aa;			/* dark violet */
  background: inherit;
  text-align: left;
  margin-left: 15px;
}
h3 {
  padding: 20px 0 0 0;
  font-size: 18px;
  font: normal 1.4em Bahnschrift, frente, verdana, helvetica, arial, sans-serif;
  letter-spacing: 3px;
  color: #326908;			/* very dark green */
  background: inherit;
  text-align: left;
  margin-left: 15px;
}
h4 {
  padding: 20px 0 0 0;
  font-size: 16px;
  font: normal 1.4em Bahnschrift, verdana, helvetica, arial, sans-serif;
  <!---- frente, helvetica, garamond, futura, didot; --->
  <!--- verdana, helvetica, arial, sans-serif --->
  letter-spacing: 3px;
  color: #900001 ;			/* dark red */
  background: inherit;
  text-align: left;
  margin-left: 15px;
}
h5 {
  padding: 20px 0 0 0;
  font-size: 12px;
  font: normal 1.4em Bahnschrift, frente, verdana, helvetica, arial, sans-serif;
  letter-spacing: 3px;
  color: #326908;			/* very dark green */
  background: inherit;
  text-align: left;
  margin-left: 15px;
}
h6 {
  padding: 20px 0 0 0;
  font-size: 10px;
  font: normal 1.4em Bahnschrift, frente, verdana, helvetica, arial, sans-serif;
  letter-spacing: 3px;
  color: #326908;			/* very dark green */
  background: inherit;
  text-align: left;
  margin-left: 15px;
}

<!-- list item styles -->
li {
  line-height: 140%;
}

ul.a {list-style-type: circle;}
ul.b {list-style-type: square;}

ol.c {list-style-type: decimal;}
ol.d {list-style-type: decimal-leading-zero;}
ol.e {list-style-type: lower-roman;}
ol.f {list-style-type: lower-alpha;}
ol.g {list-style-type: lower-latin;
}
<!-- drop down menu -->
.dropbtn {
  background-color: #04006d;  /* very dark blue */
  color: #ffffff;  /* white */
  padding: 14px;
  font-size: 12px;
  border: none;
}
.dropdown {
  position: relative;
  display: inline-block;
}
.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f1f1f1;  /* very light gray */
  min-width: 200px;
  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
  z-index: 1;
}
.dropdown-content a {
  color: #000000;  /* black */
  padding: 12px 16px;
  text-decoration: none;
  display: block;
}
.dropdown-content a:hover {background-color: #cccccc;}  /* light gray */
.dropdown:hover .dropdown-content {display: block;}
.dropdown:hover .dropbtn {background-color: #398e41;}  /* dark moderate lime green */