:root {
  --bg: #f6f1e7;
  --surface: #fffdf8;
  --ink: #1f1b16;
  --muted: #655d52;
  --line: #e3d9c7;
  --accent: #a63d24;
  --accent-soft: #f3e2d6;
  --green: #2f5d50;
  --star: #c98a12;
  --star-empty: #ddd2bf;
  --warn-bg: #fbeec8;
  --warn-ink: #5c4300;
  --radius: 14px;
  --serif: 'Lora', Georgia, 'Times New Roman', serif;
  --sans: 'Be Vietnam Pro', system-ui, -apple-system, 'Segoe UI', sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #16130f;
    --surface: #1f1b16;
    --ink: #efe7da;
    --muted: #aca292;
    --line: #342e26;
    --accent: #e8866a;
    --accent-soft: #3a241c;
    --green: #8fc2b0;
    --star: #e2ac3c;
    --star-empty: #4a4238;
    --warn-bg: #3a2f12;
    --warn-ink: #f1d995;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #16130f; --surface: #1f1b16; --ink: #efe7da; --muted: #aca292; --line: #342e26;
  --accent: #e8866a; --accent-soft: #3a241c; --green: #8fc2b0; --star: #e2ac3c; --star-empty: #4a4238;
  --warn-bg: #3a2f12; --warn-ink: #f1d995; color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 400 16px/1.65 var(--sans);
}
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
h1, h2, h3 { font-family: var(--serif); line-height: 1.2; letter-spacing: -0.01em; margin: 0; text-wrap: balance; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.muted { color: var(--muted); }
[hidden] { display: none !important; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 720px) { .wrap { padding: 0 32px; } }

/* Header / footer */
.site-header { border-bottom: 1px solid var(--line); background: var(--bg); position: sticky; top: 0; z-index: 10; }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font: 600 17px/1 var(--serif); color: var(--ink); text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 7px; background: var(--accent); color: var(--bg); font-size: 14px; font-weight: 700; }
.header-nav { display: flex; gap: 18px; font-size: 14px; }
.header-nav a { color: var(--muted); text-decoration: none; white-space: nowrap; }
.header-nav a:hover, .header-nav a[aria-current="page"] { color: var(--ink); }
.header-nav a[aria-current="page"] { font-weight: 600; }
.header-nav .nav-method { padding-left: 18px; border-left: 1px solid var(--line); }
@media (max-width: 520px) { .header-nav { gap: 12px; } .header-nav .nav-method { display: none; } }

/* Phường */
.wards { margin-top: 48px; }
.wards h2 { font-size: 26px; margin-bottom: 20px; }
.ward-grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); }
.ward-card { display: flex; flex-direction: column; gap: 6px; padding: 20px; border-radius: var(--radius); border: 1px solid var(--line); background: var(--surface); color: var(--ink); text-decoration: none; transition: border-color .15s, transform .15s; }
.ward-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.ward-kicker { font-size: 11px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--green); }
.ward-name { font: 600 26px/1.1 var(--serif); }
.ward-old { font-size: 13px; color: var(--muted); }
.ward-blurb { font-size: 14px; margin-top: 4px; flex: 1; }
.ward-meta { font-size: 13px; font-weight: 500; color: var(--accent); margin-top: auto; padding-top: 8px; }
.ward-old { display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.ward-card.is-empty { background: transparent; border-style: dashed; }
.ward-card.is-empty:hover { border-color: var(--line); transform: none; }
.ward-card.is-empty .ward-name { color: var(--muted); }
.ward-card.is-empty .ward-meta { color: var(--muted); font-weight: 400; }
.section-note { max-width: 680px; color: var(--muted); margin: -8px 0 24px; }

/* Danh bạ phường theo quận cũ */
.district-list { display: grid; gap: 0; border-top: 1px solid var(--line); }
.district-row { display: grid; grid-template-columns: 200px 1fr; gap: 12px 24px; padding: 16px 0; border-bottom: 1px solid var(--line); }
.district-row h3 { font-size: 18px; font-weight: 600; }
.district-row h3 a { color: var(--ink); }
.district-row h3 .muted { font: 400 13px var(--sans); }
.ward-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.ward-chip { font-size: 14px; padding: 5px 12px; border-radius: 999px; border: 1px solid var(--ink); color: var(--ink); font-weight: 600; text-decoration: none; }
.ward-chip:hover { background: var(--ink); color: var(--bg); }
.ward-chip.is-empty { border-color: var(--line); color: var(--muted); font-weight: 400; }
.ward-chip.is-empty:hover { background: transparent; color: var(--muted); }
@media (max-width: 640px) { .district-row { grid-template-columns: 1fr; gap: 8px; } }

.siblings { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-top: 20px; font-size: 14px; }
.siblings a { padding: 5px 12px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); text-decoration: none; }
.siblings a:hover { border-color: var(--muted); }
.tag-ward { color: var(--green); border-color: var(--green); text-decoration: none; }
.tag-ward:hover { background: var(--surface); }

.site-footer { border-top: 1px solid var(--line); margin-top: 80px; padding: 32px 0 48px; font-size: 14px; }
.footer-inner p { margin: 0 0 8px; max-width: 640px; }

.demo-banner { margin-top: 16px; padding: 12px 16px; border-radius: 10px; background: var(--warn-bg); color: var(--warn-ink); font-size: 14px; }
.demo-banner code { font-size: 13px; background: rgba(0,0,0,.07); padding: 1px 6px; border-radius: 4px; }

/* Shared */
.eyebrow { margin: 0 0 12px; font-size: 13px; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--green); }
.lede { font-size: 18px; color: var(--muted); max-width: 640px; margin: 20px 0 0; }
.stat-strip { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; margin: 32px 0 0; max-width: 640px; }
.stat-strip div { background: var(--surface); padding: 14px 16px; }
.stat-strip dt { font-size: 12px; color: var(--muted); }
.stat-strip dd { margin: 4px 0 0; font: 600 24px/1.1 var(--serif); font-variant-numeric: tabular-nums; }
.stat-strip small { font-size: 14px; color: var(--muted); font-weight: 500; }
@media (max-width: 480px) { .stat-strip dd { font-size: 19px; } .stat-strip div { padding: 12px; } }

/* Hero */
.hero { padding-top: 56px; padding-bottom: 24px; }
.hero h1 { font-size: clamp(32px, 6vw, 54px); font-weight: 600; max-width: 820px; }
.hero h1 em { color: var(--accent); font-style: italic; font-weight: 500; }

/* Listing */
.listing { margin-top: 56px; }
.listing-head { display: flex; flex-wrap: wrap; align-items: end; justify-content: space-between; gap: 16px; margin-bottom: 24px; }
.listing-head h2 { font-size: 26px; }
.controls { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { font: 500 14px/1 var(--sans); padding: 9px 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); cursor: pointer; }
.chip:hover { border-color: var(--muted); }
.chip[aria-pressed="true"] { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.search input { font: 400 15px var(--sans); padding: 9px 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); width: 260px; max-width: 100%; }
@media (max-width: 600px) { .search, .search input { width: 100%; } }
.empty { color: var(--muted); padding: 32px 0; }

.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); }
.card { position: relative; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 20px 16px; display: flex; flex-direction: column; transition: border-color .15s, transform .15s; }
.card:hover { border-color: var(--muted); transform: translateY(-2px); }
.card .eyebrow { font-size: 11px; margin-bottom: 8px; }
.card h3 { font-size: 20px; font-weight: 600; }
.card h3 a { color: var(--ink); text-decoration: none; }
.card h3 a::after { content: ''; position: absolute; inset: 0; }
.card-top { list-style: none; counter-reset: r; margin: 14px 0 0; padding: 0; font-size: 14px; flex: 1; }
.card-top li { counter-increment: r; display: flex; gap: 10px; align-items: baseline; padding: 6px 0; border-top: 1px dashed var(--line); }
.card-top li::before { content: counter(r); font: 600 13px var(--serif); color: var(--accent); width: 12px; }
.card-name { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.card-metric { color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
.card-foot { margin: 12px 0 0; font-size: 13px; color: var(--muted); }

/* Article */
.article { padding-top: 32px; max-width: 820px; }
.crumbs { font-size: 14px; color: var(--muted); margin-bottom: 24px; }
.crumbs a { color: var(--muted); }
.article-head h1 { font-size: clamp(30px, 5.2vw, 46px); font-weight: 600; }

.rank-list { list-style: none; padding: 0; margin: 48px 0 0; }
.rank-item { display: grid; grid-template-columns: 64px 1fr; gap: 20px; padding: 28px 0; border-top: 1px solid var(--line); }
.rank-num { font: 600 52px/0.9 var(--serif); color: var(--accent); font-variant-numeric: lining-nums; }
.rank-name { font-size: 24px; font-weight: 600; }
.rank-addr { margin: 6px 0 0; color: var(--muted); font-size: 14px; }
.rank-figures { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 18px; margin-top: 14px; font-size: 14px; font-variant-numeric: tabular-nums; }
.rank-figures strong { font-weight: 600; }
.rating { display: inline-flex; align-items: center; gap: 8px; }
.stars { position: relative; display: inline-block; width: 86px; height: 16px; background: var(--star-empty); -webkit-mask: var(--star-mask) repeat-x left / 17.2px 16px; mask: var(--star-mask) repeat-x left / 17.2px 16px; }
.stars-fill { position: absolute; inset: 0 auto 0 0; background: var(--star); }
:root { --star-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M12 2.5l2.9 6.1 6.6.8-4.9 4.6 1.3 6.6L12 17.3l-5.9 3.3 1.3-6.6-4.9-4.6 6.6-.8z'/%3E%3C/svg%3E"); }
.score { background: var(--accent-soft); color: var(--ink); padding: 3px 10px; border-radius: 999px; }
.tag { font-size: 12px; padding: 3px 10px; border-radius: 999px; border: 1px solid var(--line); color: var(--muted); }
.price { color: var(--green); font-weight: 600; letter-spacing: .05em; }
.bar { height: 6px; border-radius: 3px; background: var(--line); margin-top: 14px; max-width: 420px; overflow: hidden; }
.bar span { display: block; height: 100%; background: var(--accent); border-radius: 3px; }
.rank-blurb { margin: 14px 0 0; max-width: 620px; }
.maps-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.maps-actions.is-disabled { display: block; color: var(--muted); font-size: 14px; font-style: italic; }
.maps-actions code { font-style: normal; font-size: 13px; background: var(--line); padding: 1px 6px; border-radius: 4px; }
.btn { display: inline-flex; align-items: center; gap: 6px; min-height: 40px; padding: 8px 16px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); font: 500 14px/1 var(--sans); text-decoration: none; }
.btn:hover { border-color: var(--muted); text-decoration: none; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.btn-primary:hover { border-color: var(--accent); filter: brightness(1.08); }
@media (max-width: 560px) {
  .rank-item { grid-template-columns: 40px 1fr; gap: 12px; }
  .rank-num { font-size: 36px; }
  .rank-name { font-size: 21px; }
}

.method, .caveat { margin-top: 40px; padding: 24px; border-radius: var(--radius); }
.method { background: var(--surface); border: 1px solid var(--line); }
.caveat { background: var(--accent-soft); }
.method h2, .caveat h2 { font-size: 20px; margin-bottom: 8px; }
.method p, .caveat p { margin: 8px 0 0; }
.caveat .muted { font-size: 14px; }

.related { margin-top: 64px; }
.related h2 { font-size: 24px; margin-bottom: 20px; }
.article .related .grid { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }

/* Prose (phương pháp) */
.prose h2 { font-size: 24px; margin: 40px 0 12px; }
.prose p, .prose li { max-width: 660px; }
.prose ul { padding-left: 20px; }
.prose li { margin: 6px 0; }
.formula { font: 500 14px/1.6 ui-monospace, 'Cascadia Code', Consolas, monospace; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 16px; overflow-x: auto; }