body {
  margin: 0; 
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  height: 100%;
  overflow-y: scroll;
  overflow-x: hidden;
}


.headimg {
  position: relative; 
  left: 50%; 
  transform: translate( -50%);
  top: 100px;
  height: 400px;
  border-radius: 40px;
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  z-index: -3;
}

.title {
  position: relative;
  font-size: xx-large;
  left:50%;
  transform: translate( -50%);
  font-weight: bolder;
  width: 600px;
  top: 200px;
}

.line {
  position: relative;
  height: 2px;
  width: 800px;
  left:50%;
  transform: translate( -50%);
  top: 240px;
  background-color: gray;
}

.title_description {
  position: relative;
  font-size: large;
  left:50%;
  transform: translate( -50%);
  width: 600px;
  top: 260px;
}

.author {
  position: relative;
  font-size: large;
  left:50%;
  transform: translate( -50%);
  width: 600px;
  top: 265px;
  color: gray;
  font-family: monospace;

}

.navmenu a {
position: relative;
float: left;
text-decoration: none;
color: gray;

}

.navmenu a:hover {
  color: black;
}

.list1 {
  list-style-type: square;
}

.navmenu {
  position: fixed;
  top: 200px;
  border-radius: 40px;
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  width: 225px;
}

.maintext {
  position: relative;
  text-align: left;
  width: 800px;
  left: 50%; 
  transform: translate( -50%);
  top: 400px;
}