html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    background-color: #f4f4f9;
    display: flex;
    flex-direction: column;
    transition: background-color 0.3s, color 0.3s;
}

.content {
    flex: 1;
    padding: 20px;
}

h1, h2, h3, p, a, footer {
    transition: color 0.3s;
}

h1 {
    color: #333;
    font-size: 2.5rem;
    margin-bottom: 20px;
}

h2 {
    color: #444;
    font-size: 2rem;
    margin-top: 20px;
}

h3 {
    color: #555;
    font-size: 1.5rem;
    margin-top: 15px;
}

p {
    font-size: 1rem;
    color: #666;
    line-height: 1.6;
}

a {
    color: #1e90ff;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

footer {
    text-align: center;
    padding: 1rem;
    font-size: 0.9rem;
    color: #666;
    background-color: #fff;
    border-top: 1px solid #ddd;
}

/* DARK MODE */
body.dark-mode {
    background-color: #121212;
    color: #e0e0e0;
}

body.dark-mode * {
    color: inherit;
    background-color: transparent;
}

body.dark-mode .content {
    background-color: #121212;
}

body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode p,
body.dark-mode footer {
    color: #e0e0e0;
}

body.dark-mode a {
    color: #90caf9;
}

body.dark-mode footer {
    background-color: #1e1e1e;
    border-top: 1px solid #333;
}

body.dark-mode pre,
body.dark-mode code {
    background-color: #1e1e1e;
    color: #dcdcdc;
}

/* THEME TOGGLE BUTTON */
button.theme-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem 1rem;
    background: #ddd;
    border: none;
    cursor: pointer;
    border-radius: 4px;
    font-size: 1rem;
    transition: background 0.3s ease, color 0.3s ease;
    z-index: 1000;
}

button.theme-toggle:hover {
    background: #bbb;
}

body.dark-mode button.theme-toggle {
    background: #333;
    color: #fff;
}

button.theme-toggle:focus {
    outline: none;
}

/* NAVIGATE BUTTON */
button.navigate-btn {
    position: fixed;
    top: 1rem;
    right: 11rem;
    padding: 0.5rem 1rem;
    background: #ddd;
    border: none;
    cursor: pointer;
    border-radius: 4px;
    font-size: 1rem;
    transition: background 0.3s ease, color 0.3s ease;
    z-index: 1000;
}

button.navigate-btn:hover {
    background: #bbb;
}

body.dark-mode button.navigate-btn {
    background: #333;
    color: #fff;
}