/* howtall.net — SEO pages. Direction A "Scoreboard", Ledger architecture (owner duyệt 19-09).
   Ink ground #0B0E14 · hot orange #FF5A2B · Archivo display over Public Sans body.

   The page is one reading column: readout → CTA → data → prose → open FAQ → aside rail.
   Deliberately NOT heightpredictor's hero-card + four sections + accordion (brand-test G7,
   enforced by check-seo S15) — the shape is the brand, not just the palette. */

:root {
  --bg: #0B0E14;
  --card: #131926;
  --raise: #1D2534;
  --ink: #FFFFFF;
  --ink2: #A6B0C0;
  --ink3: #8E99AB;
  --line: #232B38;
  --line2: #1B2230;
  --edge: #2B3444;
  --accent: #FF5A2B;
  --accent-ink: #0B0E14;
  --link: #FF8A5C;
  --grow: #3DDC84;
  --font-display: 'Archivo', 'Arial Black', sans-serif;
  --font-body: 'Public Sans', 'Helvetica Neue', Arial, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { overflow-x: clip; }
body { font-family: var(--font-body); background: var(--bg); color: var(--ink); font-size: 16px; line-height: 1.5; -webkit-font-smoothing: antialiased; }
img, svg { max-width: 100%; display: block; }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { font-family: var(--font-display); letter-spacing: -0.03em; }
h1 { font-weight: 800; font-size: 44px; line-height: 0.98; letter-spacing: -0.035em; }
h2 { font-weight: 800; font-size: 25px; line-height: 1.08; letter-spacing: -0.025em; margin-top: 26px; }
h3 { font-weight: 700; font-size: 17px; letter-spacing: -0.01em; margin-top: 18px; }
p { color: var(--ink2); }
strong, b { color: var(--ink); }
.wrap { max-width: 720px; margin: 0 auto; padding: 0 20px; }
.small { font-size: 12px; line-height: 1.5; color: #7C8799; }
.src { display: block; margin-top: 8px; font-size: 12px; line-height: 1.5; color: #7C8799; }

/* ---------- header: one row of links, no hamburger panel ---------- */
.site-header { border-bottom: 1px solid var(--line2); }
.site-header .wrap { padding-top: 12px; padding-bottom: 10px; display: flex; flex-direction: column; gap: 10px; }
.brand { display: inline-flex; align-items: center; gap: 8px; font-family: var(--font-display); font-weight: 800; font-size: 17px; letter-spacing: -0.02em; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand img { width: 22px; height: 22px; border-radius: 6px; }
.site-nav { display: flex; gap: 16px; font-size: 13px; font-weight: 700; overflow-x: auto; scrollbar-width: none; }
.site-nav::-webkit-scrollbar { display: none; }
/* a label that wraps breaks the row and leaves the active underline on line two */
.site-nav a { color: var(--ink3); padding-bottom: 2px; white-space: nowrap; }
.site-nav a:hover { color: var(--ink); text-decoration: none; }
.site-nav a[aria-current="page"] { color: var(--ink); border-bottom: 2px solid var(--accent); }

/* ---------- the sheet: four flat blocks, head / side / data / prose ---------- */
.sheet { padding-top: 20px; }
.head .lead { font-size: 16px; line-height: 1.45; margin-top: 10px; }
.prose > h2:first-child { margin-top: 26px; }
.prose p + p { margin-top: 10px; }
.prose h2 + p, .prose h3 + p { margin-top: 8px; }

/* readout: label left, value right, ruled — a record, not a card */
.readout { margin-top: 20px; border-top: 2px solid var(--accent); border-bottom: 1px solid var(--line); }
.rd-top { display: flex; align-items: baseline; justify-content: space-between; padding: 14px 0 10px; border-bottom: 1px solid var(--line2); }
.rd-k { font-size: 11px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink3); }
/* the readout shows a worked example, not the reader's own result — say so on the label */
.rd-eg { margin-left: 6px; padding: 1px 5px; border: 1px solid var(--line); border-radius: 4px; font-size: 10px; font-weight: 600; letter-spacing: 0.06em; color: var(--ink3); }
.rd-n { display: flex; align-items: baseline; gap: 8px; font-family: var(--font-display); font-weight: 800; font-size: 46px; line-height: 0.85; letter-spacing: -0.05em; }
.rd-n .off { color: #3A4557; }
.rd-row { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; padding: 11px 0; border-bottom: 1px solid var(--line2); }
.rd-row:last-child { border-bottom: 0; padding-bottom: 13px; }
.rd-row > span { font-size: 13px; font-weight: 600; color: var(--ink3); }
.rd-row > b { font-family: var(--font-display); font-size: 17px; text-align: right; }
.rd-row > b.up { color: var(--grow); }
.rd-row > b.dim { color: var(--ink2); }
.rd-sub { font-family: var(--font-body); font-weight: 400; font-size: 13px; color: var(--ink3); }

.cta { margin-top: 18px; display: flex; align-items: center; justify-content: center; height: 60px; border-radius: 14px; background: var(--accent); color: var(--accent-ink); font-family: var(--font-display); font-weight: 800; font-size: 19px; letter-spacing: -0.01em; }
.cta:hover { text-decoration: none; filter: brightness(1.06); }
.cta-sub { margin-top: 10px; text-align: center; font-size: 12px; font-weight: 700; color: var(--ink3); }

/* data block: sits above the prose, never below it */
.data { margin-top: 26px; }
.data-k { margin-bottom: 10px; font-size: 11px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink3); }
.steps { list-style: none; }
.steps li { display: flex; gap: 12px; padding: 11px 0; border-bottom: 1px solid var(--line2); }
.steps li:last-child { border-bottom: 0; }
.steps b.n { flex: none; width: 20px; font-family: var(--font-display); font-size: 14px; color: var(--accent); }
.steps b.n.up { color: var(--grow); }
.steps span { font-size: 15px; line-height: 1.4; color: #C6CEDB; }
.data table { width: 100%; border-collapse: collapse; font-size: 15px; }
.data th, .data td { padding: 8px 4px; border-bottom: 1px solid var(--line2); }
.data thead th { border-bottom: 1px solid var(--edge); font-size: 12px; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink3); text-align: right; }
.data thead th:first-child { text-align: left; }
.data tbody th { text-align: left; font-weight: 600; color: var(--ink); }
.data tbody td { text-align: right; color: var(--ink2); }
.data tbody tr.hi { background: var(--card); }
.data tbody tr.hi th { color: var(--link); }
.data tbody tr.hi td { color: var(--ink); font-weight: 700; }

/* FAQ: an open definition list. Nothing to click to read an answer. */
.faq-h { margin-top: 26px; }
.faq { margin-top: 6px; }
.faq dt { font-size: 15px; font-weight: 700; color: var(--ink); padding-top: 14px; border-top: 1px solid var(--line); }
.faq dd { margin: 5px 0 12px; font-size: 14px; line-height: 1.5; color: var(--ink2); }
.faq dd:last-child { margin-bottom: 0; }

/* aside rail: the other tools, marked by a bar rather than another full-width band */
.rail { margin-top: 24px; }
.rail-k { font-size: 11px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink3); }
.rail-links { margin-top: 8px; font-size: 15px; line-height: 1.7; }
main .rail { border-left: 3px solid var(--accent); background: var(--card); padding-top: 14px; padding-bottom: 14px; max-width: 720px; }

/* ---------- prose (legal / support) ---------- */
.prose-page { max-width: 720px; margin: 0 auto; padding: 28px 20px 8px; }
.prose-page h1 { font-size: 30px; line-height: 1.05; overflow-wrap: anywhere; }
.prose-page .sub { font-size: 16px; margin-top: 8px; color: var(--ink2); }
.prose-page .prose { margin-top: 20px; }
.prose-page .prose h2 { font-size: 20px; margin: 26px 0 8px; }
.prose-page .prose h3 { margin: 16px 0 6px; }
.prose-page .prose p, .prose-page .prose li { font-size: 15px; color: var(--ink2); }
.prose-page .prose ul, .prose-page .prose ol { padding-left: 20px; }
.prose-page .prose li + li { margin-top: 6px; }
.prose-page .prose a { text-decoration: underline; }
.prose-page .faq { border-top: 0; }
.prose-page details { border-bottom: 1px solid var(--line); }
.prose-page summary { cursor: pointer; list-style: none; padding: 14px 0; font-size: 15px; font-weight: 600; color: var(--ink); display: flex; justify-content: space-between; gap: 12px; }
.prose-page summary::-webkit-details-marker { display: none; }
.prose-page summary::after { content: "+"; color: var(--ink3); font-weight: 400; }
.prose-page details[open] summary::after { content: "\2013"; }
.prose-page details p { padding: 0 0 14px; font-size: 14px; }
.callout-vio { padding: 14px 16px; border-left: 3px solid var(--accent); background: var(--card); }
.callout-vio, .callout-vio p { font-size: 15px; color: #C6CEDB; }

/* ---------- footer: links live in the sentence, not in a nav ---------- */
.site-footer { margin-top: 26px; padding: 18px 0 30px; border-top: 1px solid var(--line2); }
.site-footer .small + .small { margin-top: 8px; }
.site-footer a { color: #98A2B3; }

/* ---------- desktop: two reading columns, readout rail on the left ---------- */
@media (min-width: 900px) {
  .wrap { max-width: 1160px; }
  .site-header .wrap { flex-direction: row; align-items: center; justify-content: space-between; height: 68px; padding-top: 0; padding-bottom: 0; }
  .site-nav { font-size: 14px; gap: 26px; }

  /* The readout rail sits beside the headline and the data block; the prose runs the full
     width underneath it. `side` spans both upper rows so the headline never leaves a hole. */
  .sheet {
    display: grid;
    grid-template-columns: 392px minmax(0, 1fr);
    column-gap: 72px;
    align-content: start;
    padding-top: 44px;
    grid-template-areas:
      "side head"
      "side data"
      "prose prose";
  }
  .head { grid-area: head; }
  .side { grid-area: side; align-self: start; }
  .data { grid-area: data; align-self: start; margin-top: 26px; }
  .prose { grid-area: prose; max-width: 760px; }
  .head h1 { font-size: 64px; line-height: 0.94; letter-spacing: -0.04em; }
  .head .lead { font-size: 19px; margin-top: 12px; }
  .side .readout { margin-top: 0; }
  main .rail { display: flex; align-items: baseline; gap: 20px; max-width: none; }
  .rail-links { margin-top: 0; }
}