body {
    background-image: url('images/blackhole.png');
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center center;
    color: #ffffff;
    padding-bottom: 50px;
    min-height: 100vh;
}

header {
    background-color: #333;
    color: #fff;
    padding: 1rem 0;
    text-align: center;
}

header h1 {
    margin: 0;
    font-size: 2.5rem;
}

nav {
    margin-top: 1rem;
}

nav a {
    color: #ffffff;
    margin: 0 1rem;
    text-decoration: none;
    font-size: 1.2rem;
}

section {
    padding: 2rem;
    text-align: center;
}

/* Semester layout */
.semester {
    display: flex;
    justify-content: space-between;
    margin-bottom: 2rem;
}

.semester div {
    flex: 1;
    padding: 0 1rem;
}

/* Underline for semester titles */
.semester div h3 {
    border-bottom: 1px solid #ffffff;
    padding-bottom: 0.5rem;
    margin-bottom: 1rem;
}

section h2 {
    margin-top: 0;
}

footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 1rem 0;
    position: fixed;
    bottom: 0;
    width: 100%;
}

footer p {
    margin: 0;
}

#notes {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    padding: 2rem;
    flex-wrap: wrap;
}

#notes img {
    width: 200px;
    height: auto;
    border-radius: 50%;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

#notes div {
    max-width: 500px;
    text-align: left;
    padding: 1rem;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Base responsive adjustments */
@media (max-width: 768px) {
    body {
        font-size: 1rem;
    }

    header h1 {
        font-size: 1.8rem;
    }

    nav a {
        font-size: 1rem;
        margin: 0 0.5rem;
    }

    section {
        padding: 1rem;
    }

    #about {
        flex-direction: column;
        text-align: center;
    }

    #about div {
        padding: 1rem 0;
    }

    /* Semester responsive layout */
    .semester {
        flex-direction: column;
        align-items: center;
    }

    .semester div {
        padding: 1rem 0;
    }

    .semester iframe {
        width: 100%;
        height: auto;
        aspect-ratio: 16/9;
    }

    .semester img {
        max-width: 90%;
        height: auto;
    }

    footer {
        position: static;
        margin-top: 2rem;
    }
}

a:link {
    color: rgb(0, 195, 255);
}

a:visited {
    color: rgb(233, 38, 200);
}

header .header-link:link {
    color: white;
}

header .header-link:visited {
    color: lightgray;
}

header .header-link:hover {
    color: lightblue;
}

header .header-link:active {
    color: darkgray;
}
header .header-link.current {
color: lightblue;
}