.body_400 {
  margin: auto;
  width: 600px;
  font-size: 1em;
  font-family: Century Gothic, Muli, CenturyGothic, AppleGothic, sans-serif; 
  font-weight: bold;
  text-align: center;
}

 /* The side navigation menu */
.sidebar {
  font-size: 1.2em;
  /* font-size: 1.375em; */
  /* font-size: 1.5em; */
  margin: 0;
  width: 160px;
  background-color: #fff;
  /* position: fixed; */
  float: left;
  height: 100%;
  overflow: auto;
  text-align: left;
}

/* Sidebar links */
.sidebar a {
  display: block;
  color: black;
  /* padding: 16px; */
  padding: 5px;
  text-decoration: none;
}

/* Active/current link */
.sidebar a.active {
  /* text-decoration: underline; */
  /* color: #ff9900; */
}

/* Links on mouse-over */
.sidebar a:hover:not(.active) {
  background-color: #eee;
}

.logo {
  margin-bottom: 10px;
  margin-top: 10px;
  /* width: 120px; */
  width: 100px;
} 


@media screen and (max-width: 600px) {
  
  .body_400 {
    width: 100vw;
    font-size: 4.5vw; 
    margin-left: 0px;
    width: 100%;
  }
 
  .sidebar {
    font-size: 1em;
    width: 100vw;
    padding: 0px;
    height: auto;
    position: relative;
    background-color: #f8f8f8;
    float: none;                        /****************************/
    padding-bottom: 1.0em;              /*****************************/
  }
  
  .sidebar a {
    text-align: center;
    float: left;
    width: 28vw;
    padding: 5vw 0px; /* top&bottom left&right */ 
  }
  
 .logo {
    max-width:14vw; 
    height:auto; 
  /* position: fixed; */
    float: left;
    margin-left: 2vw;
    /* margin-top: 1vw; */
    margin-top: 0.5em;
  } 
  
}