art.css

body {
  /* margin is the space around an element, outside of the border */
  /* padding is inside the border */
  margin: 0px;
}

#main {
  display: grid;            /* div id="main" is the grid container */
  justify-content: center;  /* center it horizontally */
  align-content: center;    /* center it vertically */
  background: #000;         /* bg color */
  width: 100vw;             /* width is 100% of the viewport width */
  height: 90vh;             /* height is 90% of the viewport height */
  overflow: hidden;         /* clip overflow.  no scrollbars */
  border-top: 4px solid black; 
}



/*************************** Navigation Bar ***************************/

.navbar {
  background-color: #283747;
  overflow: hidden;
}

/* links inside the navigation bar */
.navbar a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}

/* Change the color of links on hover */
.navbar a:hover {
  background-color: #f3f3f3;
  color: black;
}

/* Add an active class to highlight the current page */
.navbar a.active {
  background-color: #DE354C;
  color: white;
}

/* Hide the link that should open and close the navbar on small screens */
.navbar .hamburger-icon {
  display: none;
}



/*************************** Media Queries ***************************/

/* When the screen is less than 600 pixels wide, hide all links, except for the first one ("canvas"). Show the link that contains should open and close the navbar (.hamburger-icon) */
@media screen and (max-width: 600px) {
  .navbar a:not(:first-child) {display: none;}
  .navbar a.hamburger-icon {
    float: right;
    display: block;
  }
}

/* The "responsive" class is added to the navbar with JavaScript when the user clicks on the hamburger-icon. This class makes the navbar look good on small screens (display the links vertically instead of horizontally) */
@media screen and (max-width: 600px) {
  .navbar.responsive {position: relative;}
  .navbar.responsive a.hamburger-icon {
    position: absolute;
    right: 0;
    top: 0;
  }
  .navbar.responsive a {
    float: none;
    display: block;
    text-align: left;
  }
}