:root {
    color-scheme: light dark;
    --bg: #0f1419;
    --surface: #1a2332;
    --text: #e8eef5;
    --muted: #9aa8b8;
    --accent: #2dd4bf;
    --border: #2a3647;
    --max: 720px;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
}

@media (prefers-color-scheme: light) {
    :root {
        --bg: #f4f7fa;
        --surface: #ffffff;
        --text: #1a2332;
        --muted: #5a6b7d;
        --accent: #0d9488;
        --border: #d8e0ea;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
}

header {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.25rem;
    position: sticky;
    top: 0;
    z-index: 10;
}

.header-inner {
    max-width: var(--max);
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem 1rem;
    justify-content: space-between;
}

.brand {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--accent);
    text-decoration: none;
}

.lang-select label {
    font-size: 0.85rem;
    color: var(--muted);
    margin-right: 0.5rem;
}

.lang-select select {
    font: inherit;
    padding: 0.35rem 0.6rem;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: var(--bg);
    color: var(--text);
}

main {
    max-width: var(--max);
    margin: 0 auto;
    padding: 2rem 1.25rem 3rem;
}

.notice {
    background: color-mix(in srgb, var(--accent) 12%, var(--surface));
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.85rem 1rem;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
    color: var(--muted);
}

h1 {
    font-size: 1.75rem;
    line-height: 1.25;
    margin: 0 0 0.5rem;
}

.updated {
    color: var(--muted);
    font-size: 0.9rem;
    margin-bottom: 2rem;
}

section {
    margin-bottom: 1.75rem;
}

h2 {
    font-size: 1.15rem;
    margin: 0 0 0.65rem;
    color: var(--accent);
}

p, li {
    margin: 0 0 0.65rem;
}

ul {
    margin: 0 0 0.65rem;
    padding-left: 1.25rem;
}

a {
    color: var(--accent);
}

footer {
    max-width: var(--max);
    margin: 0 auto;
    padding: 0 1.25rem 2rem;
    color: var(--muted);
    font-size: 0.85rem;
}

.loading {
    color: var(--muted);
    padding: 2rem 0;
}