body {
    margin: 0;
    font-family: sans-serif;
}

/* black background color to the top navigation */
.topnav {
    font-family: sans-serif;
    background-color: rgb(0, 0, 0);
    overflow: hidden;
}

/* style links inside the navigation bar */
.topnav a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 18px;
}

/* change the color of links on hover */
.topnav a:hover {
    background-color: rgb(167, 241, 241);
    color: black;
}

/* add an active class to highlight the current page */
.topnav a.active {
    background-color: rgb(7, 131, 245);
    color: white;
}

/* hide burger icon that should open and close the topnav on small screens */
.topnav .icon {
    display: none;
}

/* when the screen is less than 800 pixels wide */
@media screen and (max-width: 800px) {
    /* hide all links, except for the selected tab */
    .topnav a:not(.active) {
        display: none;
    }

    /* show burger icon that should open and close the topnav */
    .topnav a.icon {
        float: right;
        display: block;
    }
}

/* when the screen is less than 800 pixels wide, if the user clicks on the icon */
/* the "responsive" class attribute will be added to the topnav by the javaScript code */
/* this media query sets the style for the unfolded topnav */
/* tt makes the topnav look good on small screens (display the links vertically instead of horizontally)  */
@media screen and (max-width: 800px) {
    .topnav.responsive {
        position: relative;
    }

    .topnav.responsive a.icon {
        position: absolute;
        right: 0;
        top: 0;
    }

    .topnav.responsive a {
        float: none;
        display: block;
        text-align: left;
    }
}