/* World Knowledge — Editorial academic style */

:root {
    /* Warm paper palette */
    --bg: #faf8f5;
    --fg: #2c2825;
    --muted: #7a7067;
    --accent: #b44a2d;
    --accent-soft: #d4764e;
    --link: #1a5276;
    --link-hover: #0e3a53;
    --border: #d6cfc7;
    --border-light: #e8e2da;
    --code-bg: #f0ece6;
    --callout-bg: #f5f0ea;
    --card-bg: #fff;
    --serif: 'Crimson Pro', Georgia, 'Times New Roman', serif;
    --mono: 'JetBrains Mono', 'SF Mono', monospace;
    --max-width: 680px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1c1a17;
        --fg: #e4ded6;
        --muted: #8a8078;
        --accent: #d4764e;
        --accent-soft: #b44a2d;
        --link: #7fb3d3;
        --link-hover: #a8cde6;
        --border: #3a3530;
        --border-light: #2e2924;
        --code-bg: #252220;
        --callout-bg: #221f1c;
        --card-bg: #1f1c19;
    }
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: var(--serif);
    font-size: 18px;
    line-height: 1.75;
    color: var(--fg);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
}

.page-grid {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 3rem 1.5rem 4rem;
}

/* ── Navigation ────────────────────────────────────── */

header nav {
    font-family: var(--mono);
    font-size: 0.75rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 3rem;
}

.nav-home {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
}
.nav-home:hover { color: var(--fg); }

.nav-sep {
    margin: 0 0.6rem;
    opacity: 0.4;
}

/* ── Hero ──────────────────────────────────────────── */

.hero {
    margin-bottom: 3rem;
}

.hero h1 {
    font-size: 2.8rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    line-height: 1.15;
    margin-bottom: 1rem;
}

.hero-rule {
    width: 48px;
    height: 2px;
    background: var(--accent);
    margin: 1.25rem 0;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--muted);
    font-style: italic;
}

/* ── Metadata Card ─────────────────────────────────── */

.metadata-card {
    background: var(--card-bg);
    border: 1px solid var(--border-light);
    border-radius: 2px;
    padding: 1.75rem 2rem;
    margin-bottom: 3rem;
}

.metadata-card h2 {
    font-family: var(--mono);
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 1.25rem;
}

.metadata-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    margin-bottom: 1.25rem;
}

.metadata-item {
    display: flex;
    flex-direction: column;
}

.metadata-value {
    font-size: 1.8rem;
    font-weight: 300;
    color: var(--fg);
    line-height: 1.2;
}

.metadata-label {
    font-family: var(--mono);
    font-size: 0.65rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted);
    margin-top: 0.25rem;
}

.metadata-footer {
    font-family: var(--mono);
    font-size: 0.7rem;
    color: var(--muted);
    padding-top: 1rem;
    border-top: 1px solid var(--border-light);
}

.metadata-sep {
    margin: 0 0.5rem;
    opacity: 0.4;
}

/* ── Article ───────────────────────────────────────── */

article {
    margin-bottom: 3rem;
}

.article-header {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-light);
}

.article-section {
    font-family: var(--mono);
    font-size: 0.65rem;
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent);
    display: block;
    margin-bottom: 0.75rem;
}

h1 {
    font-size: 2rem;
    font-weight: 400;
    line-height: 1.3;
    letter-spacing: -0.01em;
}

h2 {
    font-size: 1.35rem;
    font-weight: 400;
    margin: 2.5rem 0 1rem;
    color: var(--fg);
}

h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin: 2rem 0 0.75rem;
}

h4 {
    font-size: 1rem;
    font-weight: 600;
    margin: 1.5rem 0 0.5rem;
}

.article-body p {
    margin-bottom: 1.15rem;
}

/* ── Links ─────────────────────────────────────────── */

a {
    color: var(--link);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.15s ease;
}
a:hover {
    color: var(--link-hover);
    border-bottom-color: var(--link-hover);
}

/* ── Lists ─────────────────────────────────────────── */

ul, ol {
    margin: 0.75rem 0 1.25rem 1.25rem;
}
li {
    margin-bottom: 0.35rem;
}
li::marker {
    color: var(--accent-soft);
}

/* ── Code ──────────────────────────────────────────── */

code {
    font-family: var(--mono);
    font-size: 0.82em;
    background: var(--code-bg);
    padding: 0.15em 0.45em;
    border-radius: 2px;
}

pre {
    background: var(--code-bg);
    border: 1px solid var(--border-light);
    border-radius: 2px;
    padding: 1.15rem 1.25rem;
    overflow-x: auto;
    margin: 1.25rem 0;
    line-height: 1.55;
}

pre code {
    background: none;
    padding: 0;
    font-size: 0.8rem;
}

/* ── Tables ────────────────────────────────────────── */

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.25rem 0;
    font-size: 0.92rem;
}

th, td {
    border: 1px solid var(--border-light);
    padding: 0.6rem 0.85rem;
    text-align: left;
}

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

/* ── Blockquotes / Callouts ────────────────────────── */

blockquote {
    border-left: 2px solid var(--accent);
    padding: 0.75rem 1.15rem;
    margin: 1.25rem 0;
    background: var(--callout-bg);
    font-size: 0.95rem;
    color: var(--muted);
}

blockquote p:last-child { margin-bottom: 0; }

/* ── Horizontal Rules ──────────────────────────────── */

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

/* ── Images ────────────────────────────────────────── */

img { max-width: 100%; height: auto; border-radius: 2px; }

/* ── SMILES ────────────────────────────────────────── */

.smiles-canvas {
    display: block;
    max-width: 100%;
    margin: 1rem 0;
    border: 1px solid var(--border-light);
    border-radius: 2px;
}

/* ── Mermaid ───────────────────────────────────────── */

.mermaid {
    text-align: center;
    margin: 1.5rem 0;
}

/* ── KaTeX ─────────────────────────────────────────── */

.katex-display {
    margin: 1.25rem 0;
    overflow-x: auto;
    padding: 0.25rem 0;
}

/* ── Broken Links ──────────────────────────────────── */

.broken-link {
    color: var(--muted);
    text-decoration: line-through;
    border-bottom-color: var(--border);
    cursor: help;
}

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

.footer-rule {
    width: 32px;
    height: 1px;
    background: var(--border);
    margin: 0 0 1rem;
}

footer p {
    font-family: var(--mono);
    font-size: 0.7rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted);
}

/* ── Content ───────────────────────────────────────── */

.content {
    margin-top: 2rem;
}

/* ── Wiki Directory ────────────────────────────────── */

.wiki-directory {
    margin-bottom: 3rem;
}

.wiki-directory h2 {
    font-family: var(--mono);
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 1.25rem;
}

.wiki-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.wiki-entry {
    padding: 1.25rem 0;
    border-bottom: 1px solid var(--border-light);
}

.wiki-entry:first-child {
    border-top: 1px solid var(--border-light);
}

.wiki-link {
    font-size: 1.15rem;
    font-weight: 600;
    display: block;
    margin-bottom: 0.35rem;
}

.wiki-desc {
    font-size: 0.92rem;
    color: var(--muted);
    margin-bottom: 0.25rem;
    line-height: 1.5;
}

.wiki-author {
    font-family: var(--mono);
    font-size: 0.7rem;
    color: var(--muted);
    letter-spacing: 0.04em;
}

/* ── Responsive ────────────────────────────────────── */

@media (max-width: 600px) {
    .page-grid { padding: 2rem 1rem 3rem; }
    .hero h1 { font-size: 2rem; }
    h1 { font-size: 1.6rem; }
    .metadata-grid { grid-template-columns: repeat(2, 1fr); }
}