/* ----------------------------------------------------------------------
   NNF static site — minimal, brand-neutral, mobile-first
   No JS deps, no analytics, no third-party CDN
   ---------------------------------------------------------------------- */

:root {
    --bg:           #ffffff;
    --fg:           #1a1a1a;
    --muted:        #5a5a5a;
    --accent:       #0066cc;
    --accent-hover: #004d99;
    --border:       #e6e6e6;
    --code-bg:      #f5f5f5;
    --card-bg:      #fafafa;
    --warn-bg:      #fff8e6;
    --warn-border:  #f0c800;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg:           #1a1a1a;
        --fg:           #f0f0f0;
        --muted:        #a0a0a0;
        --accent:       #4d9fff;
        --accent-hover: #80b8ff;
        --border:       #333;
        --code-bg:      #2a2a2a;
        --card-bg:      #232323;
        --warn-bg:      #2a2410;
        --warn-border:  #806600;
    }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Sukhumvit Set", "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--fg);
    background: var(--bg);
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 2rem 1.25rem 6rem;
}

/* ── Header / nav ────────────────────────────────────────────────────── */

.site-header {
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    margin-bottom: 2rem;
}

.site-header .container {
    padding-top: 0;
    padding-bottom: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.brand {
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--fg);
    text-decoration: none;
}

.nav {
    display: flex;
    gap: 1rem;
    font-size: 0.95rem;
}

.nav a {
    color: var(--muted);
    text-decoration: none;
}

.nav a:hover {
    color: var(--accent);
}

.lang-switch {
    margin-left: auto;
    font-size: 0.9rem;
    color: var(--muted);
}

.lang-switch a {
    color: var(--muted);
    text-decoration: none;
    padding: 0 0.25rem;
}

.lang-switch a.active {
    color: var(--accent);
    font-weight: 600;
}

/* ── Headings ────────────────────────────────────────────────────────── */

h1 {
    font-size: 2rem;
    line-height: 1.2;
    margin: 0 0 0.5rem;
}

h2 {
    font-size: 1.5rem;
    margin: 2.5rem 0 0.75rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.25rem;
}

h3 {
    font-size: 1.15rem;
    margin: 1.75rem 0 0.5rem;
}

h4 {
    font-size: 1rem;
    margin: 1.25rem 0 0.4rem;
    color: var(--muted);
}

p { margin: 0 0 1rem; }

/* ── Lists & tables ──────────────────────────────────────────────────── */

ul, ol { padding-left: 1.5rem; margin: 0 0 1rem; }
li { margin-bottom: 0.4rem; }
li > ul, li > ol { margin-top: 0.4rem; }

table {
    border-collapse: collapse;
    width: 100%;
    margin: 1rem 0 1.5rem;
    font-size: 0.95rem;
}

th, td {
    border: 1px solid var(--border);
    padding: 0.5rem 0.75rem;
    text-align: left;
    vertical-align: top;
}

th { background: var(--card-bg); font-weight: 600; }

/* ── Inline ──────────────────────────────────────────────────────────── */

a { color: var(--accent); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-hover); }

code {
    font-family: ui-monospace, "SF Mono", Monaco, Menlo, Consolas, monospace;
    background: var(--code-bg);
    padding: 0.1rem 0.35rem;
    border-radius: 3px;
    font-size: 0.95em;
}

strong { font-weight: 600; }

hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 2.5rem 0;
}

/* ── Hero (index) ────────────────────────────────────────────────────── */

.hero {
    text-align: center;
    padding: 3rem 0 1rem;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.hero .tagline {
    color: var(--muted);
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
}

.button-row {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

.button {
    display: inline-block;
    padding: 0.7rem 1.5rem;
    border-radius: 8px;
    background: var(--accent);
    color: #fff;
    text-decoration: none;
    font-weight: 500;
    border: 1px solid transparent;
}

.button:hover {
    background: var(--accent-hover);
    color: #fff;
}

.button.secondary {
    background: transparent;
    color: var(--accent);
    border-color: var(--accent);
}

.button.secondary:hover {
    color: var(--accent-hover);
    border-color: var(--accent-hover);
}

/* ── Section blocks ──────────────────────────────────────────────────── */

.lang-section {
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem 1.25rem 0.5rem;
    margin-bottom: 2rem;
    background: var(--card-bg);
}

.lang-section h2:first-child {
    margin-top: 0;
    border-bottom: none;
    padding-bottom: 0;
}

.warn {
    background: var(--warn-bg);
    border-left: 3px solid var(--warn-border);
    padding: 0.75rem 1rem;
    margin: 1.25rem 0;
    border-radius: 4px;
    font-size: 0.95rem;
}

/* ── Footer ──────────────────────────────────────────────────────────── */

.site-footer {
    margin-top: 4rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: 0.9rem;
    text-align: center;
}

.site-footer a { color: var(--muted); }