/* Structure */
body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: green;
}
#main-header h1, #main-header h2{
    text-align: center;
}
#main-nav a {
    text-align: center;
    padding: 5px;
    color: red;
    text-decoration: none;
}
#main-nav a:hover {
    cursor: pointer;
}
#main-nav li {
    list-style-type: none;
}
footer {
    text-align: center;
}
#arrow {
    width: 0;
    height: 0;
    border: solid 10px;
    border-color: black transparent transparent transparent;
}
.hidden {
    display: none;
}

/* Exercise 1 */
#exercise1 {
    background-color: gray;
    width: 80%;
    height: auto;
    margin-left: auto;
    margin-right: auto;
}
#exercise1 p {
    text-align: center;
    padding: 10px;
}
#exercise1 input {
    margin-left: auto;
    margin-right: auto;
    display: block;
    padding: 5px;
}
#exercise1 img {
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: auto;
    height: 100px;
}

/* Exercise 2 */
#exercise2 {
    background-color: gray;
    width: 80%;
    height: auto;
    display: none;
    margin-left: auto;
    margin-right: auto;
}
#exercise2 h2 {
    text-align: center;
    padding: 10px;
}
#exercise2 p {
    text-align: center;
    padding: 10px;
    font-size: 32px;
}


@media (min-width: 1100px) {
    #main-nav {
        display: flex;
        flex-direction: row;
        justify-content: center;
    }
    #lst:last-child::before {
        content: " | ";
    }
    #arrow {
        display: none;
    }
    
}