* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Tahoma, Arial, sans-serif;
    background-color: #f4f8fc;
    color: #222222;
    line-height: 1.6;
}

header, nav, main, footer {
    width: 85%;
    max-width: 900px;
    margin: auto;
}

header {
    background-color: white;
    border: 1px solid #cccccc;
    padding: 20px;
    margin-top: 20px;
    text-align: center;
}

header h1 {
    color: #1f4e79;
    margin-bottom: 10px;
}

nav {
    background-color: white;
    border: 1px solid #cccccc;
    padding: 12px;
    margin-top: 15px;
    text-align: center;
}

nav a {
    color: #1f4e79;
    text-decoration: none;
    font-weight: bold;
    margin: 6px 10px;
    display: inline-block;
}

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

main {
    margin-top: 20px;
}

section, article {
    background-color: white;
    border: 1px solid #cccccc;
    padding: 20px;
    margin-bottom: 20px;
}

h2 {
    color: #1f4e79;
    margin-top: 0;
}

a {
    color: #1f4e79;
}

a:hover {
    color: #a64b00;
}

.video-wrapper {
    width: 100%;
    max-width: 700px;
    aspect-ratio: 16 / 9;
    margin: 15px 0;
}

.video-wrapper iframe {
    width: 100%;
    height: 100%;
    border: 0;
}

footer {
    background-color: white;
    border: 1px solid #cccccc;
    color: #222222;
    text-align: center;
    padding: 12px;
    margin-bottom: 20px;
}

@media (max-width: 700px) {
    header, nav, main, footer {
        width: 94%;
    }

    nav a {
        display: block;
        margin: 8px 0;
    }

    section, article {
        padding: 15px;
    }
}