body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen;
    margin: 0;
    padding: 2em;
    background: #fff;
    color: #111;
    line-height: 1.6;
}

main {
    max-width: 1000px;
    margin: 0 auto;
}

h1 {
    font-size: 3em;
    margin-bottom: 0;
    text-align: center;
}

.tagline {
    font-size: 1.25em;
    color: black;
    margin-bottom: 2em;
    text-align: center;
}

:root {
    --icon-size: 48px;
}

.os-buttons {
    display: flex;
    justify-content: center;
    /* center horizontally */
    align-items: center;
    /* center vertically (optional) */
    gap: 1em;
    margin: 1em auto;
    text-align: center;
}

.os-buttons img.selected {
    border: 2px solid #007aff;
    border-radius: 8px;
    padding: 4px;
    background-color: #e6f0ff;
}

.os-buttons img {
    width: var(--icon-size);
    height: var(--icon-size);
    cursor: pointer;
    transition: transform 0.2s;
}

.os-buttons img:hover {
    transform: scale(1.1);
}

pre {
    background: #f4f4f4;
    padding: 1em;
    border-radius: 5px;
    overflow-x: auto;
}

footer {
    margin-top: 3em;
    font-size: 0.9em;
    color: #777;
}

.logo {
    display: block;
    margin: 0 auto 0.5em;
    max-width: 40%;
    height: auto;
}

.github-link {
    text-align: center;
    margin-top: 0.5em;
    font-size: 0.95em;
}

.github-link a {
    color: #0366d6;
    text-decoration: none;
}

.github-link a:hover {
    text-decoration: underline;
}

main {
    max-width: 1000px;
    /* wider layout */
    margin: 0 auto;
    padding: 1em;
}

@media (max-width: 600px) {
     :root {
        --icon-size: 40px;
    }
    .tagline {
        font-size: 1em;
    }
    pre {
        font-size: 0.9em;
    }
}

.os-buttons img.selected {
    border: 2px solid #007aff;
    border-radius: 8px;
    padding: 4px;
    background-color: #e6f0ff;
}

footer {
    margin-top: 3em;
    font-size: 0.9em;
    color: #777;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2em;
    flex-wrap: wrap;
}

.footer-links a {
    color: #0366d6;
    text-decoration: none;
    font-weight: 500;
}

.footer-links a:hover {
    text-decoration: underline;
}

.footer-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2em;
    margin-top: 2em;
}

.footer-logos a img {
    width: 32px;
    height: 32px;
    transition: transform 0.2s ease;
}

.footer-logos a:hover img {
    transform: scale(1.1);
}