:root {
    --ink: #0f1117;
    --paper: #f7f4ee;
    --paper-warm: #ede9df;
    --accent: #c8622a;
    --accent-light: #f0936a;
    --accent-faint: rgba(200,98,42,0.08);
    --muted: #7a7468;
    --border: #d4cfc5;
    --border-soft: #e8e4dc;
    --card-shadow: 0 1px 3px rgba(15,17,23,0.07), 0 6px 20px rgba(15,17,23,0.05);
    --green: #2d6a1f; --green-bg: #edf7e6; --green-border: #b8dfa8;
    --blue: #1e4d8c;  --blue-bg: #e8f0fe;  --blue-border: #b3ccf5;
    --amber: #92580a; --amber-bg: #fef3dc; --amber-border: #f5d48a;
    --purple: #4a2d8e; --purple-bg: #f3f0ff; --purple-border: #c4b5fd;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'DM Sans', sans-serif; background: var(--paper); color: var(--ink); min-height: 100vh; }

/* Breadcrumb */
.breadcrumb {
    padding: 0.85rem 3rem; display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap;
    font-size: 0.78rem; color: var(--muted);
    border-bottom: 1px solid var(--border-soft); background: #fff;
}
.breadcrumb a { color: var(--muted); text-decoration: none; transition: color 0.2s; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb-sep { opacity: 0.35; font-size: 0.7rem; }
.breadcrumb-current { color: var(--ink); font-weight: 600; }

/* Layout */
.page-wrap {
    max-width: 1060px; margin: 0 auto;
    padding: 2rem 2rem 5rem;
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 2rem; align-items: start;
    width: 100%;
}
.main-col { min-width: 0; }

/* Category header */
.cat-header {
    background: #fff; border: 1px solid var(--border); border-radius: 16px;
    padding: 2rem 2.2rem 1.8rem;
    margin-bottom: 1.5rem; box-shadow: var(--card-shadow);
    position: relative; overflow: hidden;
}
.cat-header::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: linear-gradient(90deg, var(--accent), var(--accent-light));
}
.cat-top-meta { display: flex; align-items: center; gap: 0.5rem; margin-bottom: 1.1rem; flex-wrap: wrap; }
.meta-badge {
    font-family: 'IBM Plex Mono', monospace; font-size: 0.62rem; font-weight: 500;
    padding: 0.2rem 0.55rem; border-radius: 4px; letter-spacing: 0.06em; text-transform: uppercase;
}
.badge-std    { background: var(--blue-bg);   color: var(--blue);   border: 1px solid var(--blue-border); }
.badge-cn     { background: var(--green-bg);  color: var(--green);  border: 1px solid var(--green-border); }
.badge-level  { background: var(--purple-bg); color: var(--purple); border: 1px solid var(--purple-border); }
.cat-code-row { display: flex; align-items: center; gap: 1rem; margin-bottom: 0.75rem; flex-wrap: wrap; }
.cat-code {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 2.4rem; font-weight: 500; color: var(--accent);
    line-height: 1; letter-spacing: 0.02em;
}
.cat-title {
    font-family: 'Noto Serif SC', serif;
    font-size: 1.55rem; font-weight: 600; color: var(--ink); line-height: 1.3;
}
.cat-desc { font-size: 0.88rem; color: var(--muted); line-height: 1.7; max-width: 560px; }

/* Stats row */
.cat-stats-row {
    display: flex; gap: 2rem; margin-top: 1.4rem;
    padding-top: 1.2rem; border-top: 1px solid var(--border-soft);
    flex-wrap: wrap;
}
.cat-stat { text-align: left; }
.cat-stat-num {
    font-family: 'IBM Plex Mono', monospace; font-size: 1.3rem;
    font-weight: 500; color: var(--ink); line-height: 1;
}
.cat-stat-label { font-size: 0.7rem; color: var(--muted); margin-top: 0.2rem; letter-spacing: 0.03em; }

/* Section label */
.section-label {
    display: flex; align-items: center; gap: 0.75rem;
    font-family: 'IBM Plex Mono', monospace; font-size: 0.65rem;
    letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted);
    margin-bottom: 1rem;
}
.section-label::after { content: ''; flex: 1; height: 1px; background: var(--border-soft); }

/* Children grid */
.children-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}
.child-card {
    background: #fff; border: 1px solid var(--border); border-radius: 12px;
    padding: 1.2rem 1.4rem; text-decoration: none; color: inherit;
    box-shadow: var(--card-shadow); display: flex; flex-direction: column;
    transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
    position: relative; overflow: hidden;
    animation: fadeUp 0.35s ease both;
}
.child-card::before {
    content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
    background: var(--border-soft); transition: background 0.2s;
}
.child-card:hover { border-color: rgba(200,98,42,0.28); box-shadow: 0 4px 20px rgba(15,17,23,0.09); transform: translateY(-2px); }
.child-card:hover::before { background: var(--accent); }
.child-code {
    font-family: 'IBM Plex Mono', monospace; font-size: 1.05rem; font-weight: 500;
    color: var(--ink); margin-bottom: 0.35rem; letter-spacing: 0.02em;
}
.child-name {
    font-size: 0.88rem; font-weight: 600; color: var(--ink);
    line-height: 1.4; margin-bottom: 0.55rem; flex: 1;
}
.child-meta {
    display: flex; align-items: center; justify-content: space-between;
    margin-top: auto; padding-top: 0.5rem; border-top: 1px solid var(--border-soft);
}
.child-count {
    font-size: 0.68rem; color: var(--muted);
    font-family: 'IBM Plex Mono', monospace; letter-spacing: 0.04em;
}
.child-arrow {
    color: var(--border); font-size: 0.85rem;
    transition: color 0.2s, transform 0.2s;
}
.child-card:hover .child-arrow { color: var(--accent); transform: translateX(3px); }
.child-card.leaf .child-code { color: var(--accent); }

/* Pagination */
.pagination {
    display: flex; align-items: center; justify-content: center; gap: 0.4rem;
    padding-top: 1rem;
}
.page-btn {
    width: 34px; height: 34px; border-radius: 8px; border: 1px solid var(--border);
    background: #fff; font-size: 0.82rem; font-family: 'IBM Plex Mono', monospace;
    color: var(--muted); cursor: pointer; display: flex; align-items: center; justify-content: center;
    transition: all 0.15s;
}
.page-btn:hover { border-color: var(--accent); color: var(--accent); }
.page-btn.active { background: var(--ink); color: #fff; border-color: var(--ink); }
.page-btn.arrow { font-size: 0.95rem; }

/* Sidebar */
.detail-sidebar { position: sticky; top: 80px; }
.sidebar-card {
    background: #fff; border: 1px solid var(--border); border-radius: 14px;
    padding: 1.5rem 1.6rem; box-shadow: var(--card-shadow);
    margin-bottom: 1.2rem;
}
.sidebar-title {
    font-family: 'IBM Plex Mono', monospace; font-size: 0.64rem;
    letter-spacing: 0.16em; text-transform: uppercase; color: var(--muted);
    margin-bottom: 1rem; padding-bottom: 0.75rem; border-bottom: 1px solid var(--border-soft);
}
.sibling-list { display: flex; flex-direction: column; gap: 0.3rem; }
.sibling-item {
    display: flex; align-items: center; gap: 0.6rem;
    padding: 0.45rem 0.6rem; border-radius: 7px;
    text-decoration: none; color: inherit; transition: background 0.15s;
    font-size: 0.8rem;
}
.sibling-item:hover { background: var(--paper); }
.sibling-item.current { background: var(--accent-faint); }
.sibling-code-chip {
    font-family: 'IBM Plex Mono', monospace; font-size: 0.7rem; font-weight: 500;
    padding: 0.1rem 0.45rem; border-radius: 4px; background: var(--paper-warm);
    border: 1px solid var(--border-soft); color: var(--ink); flex-shrink: 0;
}
.sibling-item.current .sibling-code-chip { background: var(--accent-faint); border-color: rgba(200,98,42,0.3); color: var(--accent); }
.sibling-name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--muted); }
.sibling-item.current .sibling-name { color: var(--ink); font-weight: 600; }

/* Convert CTA */
.sidebar-cta {
    background: var(--ink); border-radius: 14px;
    padding: 1.4rem 1.6rem; margin-bottom: 1.2rem;
}
.sidebar-cta-title { font-size: 0.88rem; font-weight: 600; color: #fff; margin-bottom: 0.4rem; }
.sidebar-cta-sub { font-size: 0.76rem; color: rgba(255,255,255,0.5); line-height: 1.6; margin-bottom: 1rem; }
.sidebar-cta-btn {
    display: flex; align-items: center; justify-content: center; gap: 0.4rem;
    width: 100%; padding: 0.7rem; border-radius: 9px;
    background: var(--accent); color: #fff; border: none;
    font-family: 'DM Sans', sans-serif; font-size: 0.84rem; font-weight: 600;
    cursor: pointer; transition: background 0.2s; text-decoration: none;
    letter-spacing: 0.03em;
}
.sidebar-cta-btn:hover { background: #b5531f; }

/* Animations */
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(14px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 860px) {
    .page-wrap { display: block; padding: 1.5rem 1rem 3.5rem; }
    .detail-sidebar { position: static; }
}
@media (max-width: 500px) {
    .children-grid { grid-template-columns: 1fr; }
    .cat-code { font-size: 1.8rem; }
    .cat-title { font-size: 1.2rem; }
}