body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    color: #333;
    line-height: 1.6;
}

header {
    background: linear-gradient(to right, #0073e6, #00c6ff);
    color: white;
    padding: 20px;
    text-align: center;
    font-size: 1.5em;
}

nav {
    text-align: center;
    padding: 10px;
    background: #005bb5;
}

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

nav ul li {
    display: inline;
    margin: 0 20px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: #ffdd57;
}

main {
    max-width: 900px;
    margin: 30px auto;
    padding: 20px;
    background: white;
    box-shadow: 0px 4px 15px rgba(0, 0, 0, 0.2);
    border-radius: 10px;
}

section {
    margin-bottom: 20px;
    padding: 15px;
    border-left: 5px solid #0073e6;
    background: #f8f8f8;
}

h2 {
    color: #0073e6;
    border-bottom: 2px solid #0073e6;
    padding-bottom: 5px;
}

details {
    background: white;
    border: 1px solid #ddd;
    border-radius: 5px;
    margin: 10px 0;
    padding: 10px;
    transition: 0.3s;
}

details[open] {
    background: #eef;
    border-color: #0073e6;
}

summary {
    font-weight: bold;
    cursor: pointer;
    color: #0073e6;
}

summary:hover {
    color: #005bb5;
}

p {
    font-size: 1.1em;
    margin-bottom: 10px;
}

footer {
    background: #222;
    color: white;
    text-align: center;
    padding: 15px;
    font-size: 0.9em;
    border-top: 4px solid #0073e6;
}

footer p {
    margin: 0;
}

button {
    background: #0073e6;
    color: white;
    padding: 10px 15px;
    border: none;
    cursor: pointer;
    font-size: 1em;
    transition: background 0.3s;
    border-radius: 5px;
}

button:hover {
    background: #005bb5;
}

@media (max-width: 768px) {
    main {
        width: 95%;
        padding: 10px;
    }

    nav ul li {
        display: block;
        margin: 5px 0;
    }
}