html {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

body {
    background-color: #f4f4f4;
    color: #333;
    font-size: 16px;
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

header {
    background-color: #333;
    color: #fff;
    padding: 10px 0;
    text-align: center;
}

header h1 {
    margin: 0;
}

nav {
    background-color: #444;
    color: #fff;
    padding: 10px 0;
    text-align: center;
}

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

nav ul li {
    display: inline;
    margin: 0 10px;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
}

nav ul li a:hover {
    text-decoration: underline;
}

main {
    padding: 20px;
}

section {
    margin-bottom: 20px;
}

article {
    margin-bottom: 20px;
}

footer { 
    background-color: #333;
    color: #fff; 
    padding: 10px 0; 
    text-align: center;  }

footer p { 
    margin: 0; 
} 
/* ============================== */

/*Mobile Styles */
@media (max-width: 768px) {
    header, nav {
        padding: 5px 0;
    }
    nav ul {
        flex-direction: column;
    }
    nav ul li {
        margin: 5px 0;
    }
}

@media (max-width: 600px) {
    nav ul {
        flex-direction: column;
    }

    nav ul li {
        margin: 10px 0;
    }
}

@media (max-width: 540px) {
    nav ul {
        flex-direction: column;
    }

    nav ul li {
        margin: 10px 0;
    }
}


@media (max-width: 480px) {
    nav ul {
        flex-direction: column;
    }

    nav ul li {
        margin: 10px 0;
    }
}

body {
        font-family: Arial, sans-serif;
        margin: 0;
        padding: 0;
        background-color: #f4f4f9;
    }
    header {
        background-color: #333;
        color: #fff;
        padding: 10px 0;
        text-align: center;
    }

    nav ul {
        list-style-type: none;
        padding: 0;
        display: flex;
        justify-content: center;
    }

    nav ul li {
        margin: 0 10px;
    }

    nav ul li a {
        color: #fff;    
        text-decoration: none;
    }

    nav ul li a:hover {
        text-decoration: underline;
    }

    main {
        padding: 20px;
    }

    section {
        margin-bottom: 20px;
    }

    h1 {
        color: #fff9f9;
    }

    h2 {
        color: #333;
    }

    h2 {
        margin-top: 0;
    }

    p {
        color: #666;
    }

    a {
        color: #333;
        text-decoration: none;
        transition: background-color 0.3s, color 0.3s;
    }

    a:hover {
        color: #019eff;
        transition: background-color 0.3s, color 0.3s;
    }

    .mode_switcher {
        text-align: center; 
        margin-top: 20px;
    }

    .mode_switcher label {
        margin-right: 10px;
    }

    .mode_switcher input[type="checkbox"] {
        margin-right: 10px;
    }

    button {
        background-color: #333;
        color: #fff;
        border: none;
        cursor: pointer;
    }

    button:hover {
        background-color: #555;
    }

    .dark-mode {
        background-color: #333;
        color: #fff;
    }

    .dark-mode h1 {
        color: #fff9f9;
    }

    .dark-mode h2 {
        color: #fff9f9;
    }

    .dark-mode p {
        color: #fff1f1;
    }

    .dark-mode button {
        background-color: #555;
        color: #fff;
        transition: background-color 0.3s, color 0.3s;
    }

    .dark-mode button:hover {
        background-color: #1188ff;
        border-radius: 8px;
        border: solid 1px #019eff;
        border-radius: 5px;
        padding: 5px 10px;
        margin-right: 10px;
        transition: background-color 0.3s, color 0.3s;
    }

    .dark-mode .mode_switcher {
        text-align: center; 
        margin-top: 20px;
    }

    .dark-mode .mode_switcher label {
        margin-right: 10px;
    }

    .dark-mode .mode_switcher input[type="checkbox"] {
        margin-right: 10px;
    }

    .dark-mode a {
        color: #019eff;
        border: solid 1px #019eff;
        border-radius: 5px;
        padding: 5px 10px;
        margin-right: 10px;
        transition: background-color 0.3s, color 0.3s;
    }

    .dark-mode a:hover {
        background-color: #019eff;
        border: solid 3px #019eff;
        color: #fff;
        border-radius: 8px;
        margin-right: 10px;
        transition: background-color 0.3s, color 0.3s;
    }

    @media (max-width: 992px) {
        nav ul {
            flex-direction: row;
        }
    }

    @media (max-width: 768px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 576px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 480px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 600px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 480px) {
        .mode_switcher {
            margin-top: 10px;
        }
    }body {
        font-family: Arial, sans-serif;
        margin: 0;
        padding: 0;
        background-color: #f4f4f9;
    }
    header {
        background-color: #333;
        color: #fff;
        padding: 10px 0;
        text-align: center;
    }

    nav ul {
        list-style-type: none;
        padding: 0;
        display: flex;
        justify-content: center;
    }

    nav ul li {
        margin: 0 10px;
    }

    nav ul li a {
        color: #fff;    
        text-decoration: none;
    }

    nav ul li a:hover {
        text-decoration: underline;
    }

    main {
        padding: 20px;
    }

    section {
        margin-bottom: 20px;
    }

    h1 {
        color: #fff9f9;
    }

    h2 {
        color: #333;
    }

    h2 {
        margin-top: 0;
    }

    p {
        color: #666;
    }

    a {
        color: #333;
        text-decoration: none;
        transition: background-color 0.3s, color 0.3s;
    }

    a:hover {
        color: #019eff;
        transition: background-color 0.3s, color 0.3s;
    }

    .mode_switcher {
        text-align: center; 
        margin-top: 20px;
    }

    .mode_switcher label {
        margin-right: 10px;
    }

    .mode_switcher input[type="checkbox"] {
        margin-right: 10px;
    }

    button {
        background-color: #333;
        color: #fff;
        border: none;
        cursor: pointer;
    }

    button:hover {
        background-color: #555;
    }

    .dark-mode {
        background-color: #333;
        color: #fff;
    }

    .dark-mode h1 {
        color: #fff9f9;
    }

    .dark-mode h2 {
        color: #fff9f9;
    }

    .dark-mode p {
        color: #fff1f1;
    }

    .dark-mode button {
        background-color: #555;
        color: #fff;
        transition: background-color 0.3s, color 0.3s;
    }

    .dark-mode button:hover {
        background-color: #1188ff;
        border-radius: 8px;
        border: solid 1px #019eff;
        border-radius: 5px;
        padding: 5px 10px;
        margin-right: 10px;
        transition: background-color 0.3s, color 0.3s;
    }

    .dark-mode .mode_switcher {
        text-align: center; 
        margin-top: 20px;
    }

    .dark-mode .mode_switcher label {
        margin-right: 10px;
    }

    .dark-mode .mode_switcher input[type="checkbox"] {
        margin-right: 10px;
    }

    .dark-mode a {
        color: #019eff;
        border: solid 1px #019eff;
        border-radius: 5px;
        padding: 5px 10px;
        margin-right: 10px;
        transition: background-color 0.3s, color 0.3s;
    }

    .dark-mode a:hover {
        background-color: #019eff;
        border: solid 3px #019eff;
        color: #fff;
        border-radius: 8px;
        margin-right: 10px;
        transition: background-color 0.3s, color 0.3s;
    }

    @media (max-width: 992px) {
        nav ul {
            flex-direction: row;
        }
    }

    @media (max-width: 768px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 576px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 480px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 600px) {
        nav ul {
            flex-direction: column;
        }
    }

    @media (max-width: 480px) {
        .mode_switcher {
            margin-top: 10px;
        }
    }