body {
    font-family: 'Courier New', Courier, monospace;
    background-color: #1e1e1e;
    color: #33ff33;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background-color: #333;
    color: #33ff33;
    padding: 20px 0;
    text-align: center;
    font-size: 1em;
}

nav {
    display: flex;
    justify-content: space-around;
    background-color: #252525;
    padding: 10px 0;
}

nav a {
    color: #33ff33;
    text-decoration: none;
    padding: 10px;
    border-radius: 5px;
    transition: background-color 0.3s;
}

nav a:hover {
    background-color: #1e1e1e;
    border: 1px solid #33ff33;
}

main {
    flex-grow: 1; 
    width: 80%; 
    max-width: 1200px; 
    margin: 20px auto;
    padding: 20px;
    background-color: #252525;
    box-shadow: 0 0 10px #33ff33;
    border: 1px solid #33ff33;
    overflow: auto; 
}

main h2 {
    text-align: center;
    margin-bottom: 20px; 
}

main ul {
    list-style-type: none;
    padding: 0;
}

main ul li a {
    color: #33ff33;
    text-decoration: none;
    padding: 10px;
    border-radius: 5px;
    transition: background-color 0.3s;
}

main ul li a:hover, main ul li a:focus {
    text-decoration: underline;
    text-decoration-color: #00FFFF;
}

footer {
    text-align: center;
    padding: 10px 0;
    background-color: #333;
    color: #33ff33;
    width: 100%;
    margin-top: auto;
}

.content-container {
    display: flex;
    justify-content: center;
    margin-bottom: 30px; 
}

.notes-section {
    width: 100%; 
    padding: 20px;
    border: 2px solid #33ff33;
    background-color: #252525;
    border-radius: 5px;
}

.notes-section h3 {
    color: #33ff33;
    margin-bottom: 15px; 
}

.notes-section ul {
    list-style-type: none;
    padding: 0;
}

.notes-section li {
    margin: 10px 20px;
    text-align: center;
    text-decoration: underline;
}

.introduction {
    color: #f8f8f2;
    padding: 20px;
    margin: 0 0 30px 0;
}

.introduction h2, .introduction h3 {
    color: #50fa7b;
}

.introduction p {
    margin-bottom: 15px;
    line-height: 1.6;
}

.introduction strong {
    color: #bd93f9;
}

.introduction ul li {
    margin-bottom: 15px;
    padding: 5px;
}

.back-to-topics {
    text-align: left;
    padding: 10px 20px;
}

.back-to-topics a {
    color: #33ff33;
    text-decoration: none;
    display: inline-block;
    padding: 5px 10px;
    background-color: #252525;
    border-radius: 5px;
    margin-bottom: 20px;
}

.back-to-topics a:hover {
    color: #ffffff;
    background-color: #1e1e1e;
}