html, body, #page-one, #page-two, #page-three, #page-four {
    height: auto;
    min-height: 100vh;
    background-color: #90d5ff2b;
}

#page-one, #page-two, #page-three, #page-four {
    padding-top: 2em;
}

#mainNav {
    background-color: #668AE4;
    color: #ddd;
    line-height: 4em;
    padding: 0 1em;
    position: absolute;
    top: 7em;
    width: 100%;
    text-align: center;
}

    #mainNav a,
    #mainNav a:link,
    #mainNav a:visited,
    #mainNav a:hover,
    #mainNav a:active {
        color: #eee;
        text-decoration: none;
        display: inline-block;
        padding: 0 1em;
    }

        #mainNav a:hover {
            color: #4861A2;
        }

h2 {
    font-size: 3em;
    padding-top: 1em;
    text-align: center;
}

.eduMainCont {
    margin-top: 60px;
}

li {
    font-family: 'Cambria Math';
    font-size: large;
}

h4 {
    color: #084298;
}

.box {
    width: 850px;
    padding: 20px;
    margin: 50px auto;
    background-color: #9eb8df;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    border-radius: 10px;
    text-align: center;
    font-family: Arial, sans-serif;
    margin-top: 110px;
}

.row {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
}
.responsive-img {
    max-width: 100%;
    height: 800px;
    display: block;
    margin: 0 auto; /* centers image */
}

/* ============================= */
/* 📱 MEDIA QUERIES START HERE  */
/* ============================= */

/* Tablet view (width ≤ 1024px) */
@media screen and (max-width: 1024px) {
    .box {
        width: 90%;
        margin-top: 80px;
        padding: 15px;
    }

    #mainNav {
        top: 5em;
    }

    h2 {
        font-size: 2.2em;
    }
}

/* Mobile view (width ≤ 768px) */
@media screen and (max-width: 768px) {
    #mainNav {
        position: relative;
        top: 0;
        line-height: 3em;
        padding: 0.5em;
    }

        #mainNav a {
            display: block;
            padding: 0.8em;
            border-bottom: 1px solid rgba(255, 255, 255, 0.2);
        }

    .box {
        width: 95%;
        margin-top: 60px;
        padding: 10px;
    }

    h2 {
        font-size: 1.8em;
    }

    li {
        font-size: medium;
    }

    .row {
        flex-direction: column;
    }
    .responsive-img {
        height: 400px; /* smaller height for mobile */
    }
}

/* Small mobile screens (width ≤ 480px) */
@media screen and (max-width: 480px) {
    #mainNav a {
        font-size: 14px;
        padding: 0.6em;
    }

    h2 {
        font-size: 1.5em;
    }

    .box {
        width: 100%;
        margin: 20px auto;
        padding: 8px;
    }
}