:root {
  --ink: #101014;
  --muted: #60616a;
  --paper: #f4f2ec;
  --panel: #ffffff;
  --line: rgba(16, 16, 20, 0.14);
  --blue: #2457ff;
  --blue-dark: #173dcc;
  --lime: #c9f53b;
  --orange: #ff5a36;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.72;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; }
a { color: inherit; }
.skip-link {
  position: fixed;
  left: 16px;
  top: 12px;
  z-index: 100;
  transform: translateY(-180%);
  background: var(--lime);
  padding: 10px 14px;
  font-weight: 800;
}
.skip-link:focus { transform: none; }
.seo-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  border-bottom: 1px solid rgba(255,255,255,.13);
  background: rgba(16,16,20,.94);
  color: #fff;
  backdrop-filter: blur(16px);
}
.seo-nav-inner {
  width: min(var(--max), calc(100% - 40px));
  min-height: 76px;
  margin: auto;
  display: flex;
  align-items: center;
  gap: 32px;
}
.seo-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  margin-right: auto;
  color: #fff;
  text-decoration: none;
  font-size: 14px;
  font-weight: 900;
  letter-spacing: .08em;
}
.seo-brand img { width: 46px; height: 46px; object-fit: contain; }
.seo-nav-links { display: flex; align-items: center; gap: 26px; }
.seo-nav-links a {
  color: rgba(255,255,255,.78);
  text-decoration: none;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .07em;
  text-transform: uppercase;
}
.seo-nav-links a:hover, .seo-nav-links a:focus-visible { color: var(--lime); }
.nav-login {
  border: 1px solid rgba(255,255,255,.34);
  border-radius: 999px;
  padding: 9px 16px;
}
.seo-hero {
  position: relative;
  overflow: hidden;
  color: #fff;
  background: var(--blue);
  border-bottom: 1px solid var(--ink);
}
.seo-hero::before {
  content: "";
  position: absolute;
  width: 620px;
  height: 620px;
  right: -170px;
  top: -310px;
  border: 1px solid rgba(255,255,255,.28);
  border-radius: 50%;
  box-shadow: 0 0 0 90px rgba(255,255,255,.035), 0 0 0 180px rgba(255,255,255,.025);
}
.seo-hero::after {
  content: attr(data-word);
  position: absolute;
  right: -1vw;
  bottom: -10vw;
  color: rgba(255,255,255,.08);
  font-size: clamp(150px, 26vw, 430px);
  font-weight: 950;
  line-height: .8;
  letter-spacing: -.09em;
  white-space: nowrap;
}
.seo-hero-inner {
  position: relative;
  z-index: 1;
  width: min(var(--max), calc(100% - 40px));
  min-height: 600px;
  margin: auto;
  padding: 76px 0 88px;
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(280px, .55fr);
  gap: 72px;
  align-items: end;
}
.eyebrow, .section-kicker, .source-label {
  display: block;
  margin-bottom: 22px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.seo-hero h1 {
  max-width: 920px;
  margin: 0;
  font-size: clamp(51px, 7.2vw, 112px);
  font-weight: 900;
  line-height: .91;
  letter-spacing: -.066em;
  text-wrap: balance;
}
.seo-hero-summary {
  border-left: 1px solid rgba(255,255,255,.38);
  padding-left: 28px;
  color: rgba(255,255,255,.86);
  font-size: 18px;
  line-height: 1.6;
}
.seo-hero-summary p { margin: 0 0 22px; }
.updated {
  display: inline-flex;
  gap: 9px;
  align-items: center;
  color: #fff;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}
.updated::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--lime); }
.topic-strip {
  overflow: hidden;
  border-bottom: 1px solid var(--ink);
  background: var(--lime);
}
.topic-strip div {
  width: min(var(--max), calc(100% - 40px));
  min-height: 62px;
  margin: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .05em;
  text-transform: uppercase;
}
.topic-strip a { text-underline-offset: 5px; }
.seo-layout {
  width: min(var(--max), calc(100% - 40px));
  margin: 0 auto;
  padding: 80px 0 112px;
  display: grid;
  grid-template-columns: minmax(0, 780px) 280px;
  gap: 80px;
  align-items: start;
}
.seo-article { min-width: 0; }
.seo-article > p:first-of-type {
  margin-top: 0;
  color: #25262c;
  font-size: clamp(21px, 2.5vw, 30px);
  line-height: 1.48;
  letter-spacing: -.025em;
}
.seo-article h2 {
  margin: 80px 0 22px;
  font-size: clamp(34px, 4vw, 58px);
  line-height: 1.04;
  letter-spacing: -.05em;
}
.seo-article h3 {
  margin: 42px 0 12px;
  font-size: 24px;
  line-height: 1.25;
  letter-spacing: -.025em;
}
.seo-article p, .seo-article li { color: #42434a; }
.seo-article strong { color: var(--ink); }
.seo-article a:not(.button) { color: var(--blue-dark); text-decoration-thickness: 1px; text-underline-offset: 3px; }
.seo-article ul, .seo-article ol { padding-left: 23px; }
.seo-article li + li { margin-top: 10px; }
.seo-article blockquote {
  margin: 38px 0;
  border-left: 8px solid var(--blue);
  background: #e7ebf8;
  padding: 25px 28px;
  color: #242735;
  font-size: 19px;
  font-weight: 650;
}
.notice {
  margin: 32px 0;
  border: 1px solid var(--ink);
  background: var(--lime);
  padding: 24px 26px;
  box-shadow: 9px 9px 0 var(--ink);
}
.notice.orange { background: #ffd5ca; }
.notice strong { display: block; margin-bottom: 6px; }
.fact-grid {
  margin: 34px 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--ink);
  background: var(--ink);
  gap: 1px;
}
.fact-grid > div { min-height: 150px; padding: 24px; background: #fff; }
.fact-grid b { display: block; font-size: 34px; line-height: 1; letter-spacing: -.05em; }
.fact-grid span { display: block; margin-top: 14px; color: var(--muted); font-size: 14px; line-height: 1.45; }
.table-wrap { margin: 30px 0; overflow-x: auto; border: 1px solid var(--ink); background: #fff; }
table { width: 100%; border-collapse: collapse; min-width: 620px; }
th, td { padding: 17px 18px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: var(--ink); color: #fff; font-size: 13px; letter-spacing: .06em; text-transform: uppercase; }
tr:last-child td { border-bottom: 0; }
.source-box {
  margin-top: 68px;
  border-top: 1px solid var(--ink);
  padding-top: 28px;
}
.source-box ol { margin: 0; }
.source-box li { font-size: 14px; }
.source-box a { overflow-wrap: anywhere; }
.toc {
  position: sticky;
  top: 106px;
  border-top: 6px solid var(--blue);
  background: #fff;
  padding: 24px;
  box-shadow: 0 18px 50px rgba(16,16,20,.08);
}
.toc > span {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .1em;
}
.toc ol { margin: 20px 0 0; padding: 0; list-style: none; counter-reset: item; }
.toc li { display: flex; gap: 12px; counter-increment: item; }
.toc li + li { margin-top: 14px; }
.toc li::before { content: "0" counter(item); color: var(--blue); font: 700 11px/1.8 ui-monospace, monospace; }
.toc a { color: #4a4b53; text-decoration: none; font-size: 14px; line-height: 1.45; }
.toc a:hover { color: var(--blue); }
.calculator {
  margin: 36px 0;
  border: 1px solid var(--ink);
  background: #fff;
  box-shadow: 12px 12px 0 var(--blue);
}
.calculator-head { background: var(--ink); color: #fff; padding: 24px 28px; }
.calculator-head h3 { margin: 0; font-size: 27px; }
.calculator-head p { margin: 6px 0 0; color: rgba(255,255,255,.68); font-size: 14px; }
.calculator-body { padding: 28px; }
.score-fields { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.score-fields label { font-size: 12px; font-weight: 850; letter-spacing: .06em; text-transform: uppercase; }
.score-fields input {
  width: 100%;
  margin-top: 7px;
  border: 1px solid #a8a9ad;
  border-radius: 0;
  padding: 13px;
  font: 750 20px/1 ui-monospace, monospace;
}
.score-fields input:focus { outline: 3px solid rgba(36,87,255,.25); border-color: var(--blue); }
.calculator button, .button {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 9px;
  min-height: 48px;
  border: 1px solid var(--ink);
  background: var(--lime);
  color: var(--ink);
  padding: 12px 20px;
  text-decoration: none;
  font: 850 13px/1.1 ui-monospace, monospace;
  letter-spacing: .06em;
  text-transform: uppercase;
  cursor: pointer;
}
.calculator button { margin-top: 18px; }
.button:hover, .calculator button:hover { transform: translate(-2px,-2px); box-shadow: 4px 4px 0 var(--ink); }
.score-result { margin-top: 22px; border-top: 1px solid var(--line); padding-top: 20px; }
.score-result[hidden] { display: none; }
.score-result strong { display: block; font-size: 25px; }
.score-result p { margin: 8px 0 0; }
.practice-card {
  margin: 34px 0;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: #fff;
  padding: clamp(24px, 4vw, 40px);
}
.practice-card .tag { color: var(--lime); font: 800 12px/1 ui-monospace, monospace; letter-spacing: .1em; }
.practice-card h3 { margin: 20px 0 22px; font-size: clamp(25px, 3.5vw, 38px); }
.practice-card ol { padding: 0; list-style: none; }
.practice-card li { border: 1px solid rgba(255,255,255,.22); padding: 13px 15px; color: rgba(255,255,255,.78); }
.practice-card li + li { margin-top: 8px; }
.practice-card .answer-note { margin-top: 20px; color: var(--lime); font-weight: 750; }
.related {
  padding: 88px 0;
  background: #e7e5df;
  border-top: 1px solid var(--ink);
}
.related-inner { width: min(var(--max), calc(100% - 40px)); margin: auto; }
.related h2 { margin: 0 0 30px; font-size: clamp(38px, 5vw, 66px); letter-spacing: -.055em; line-height: 1; }
.related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.related-card {
  min-height: 235px;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--ink);
  background: #fff;
  padding: 24px;
  text-decoration: none;
  transition: transform .2s ease, box-shadow .2s ease;
}
.related-card:nth-child(2) { background: var(--lime); }
.related-card:hover { transform: translateY(-5px); box-shadow: 7px 7px 0 var(--ink); }
.related-card span { font: 800 11px/1 ui-monospace, monospace; letter-spacing: .1em; }
.related-card h3 { margin: auto 0 20px; font-size: 24px; line-height: 1.14; letter-spacing: -.03em; }
.related-card b { font-size: 22px; }
.seo-cta { background: var(--blue); color: #fff; border-top: 1px solid var(--ink); }
.seo-cta-inner {
  width: min(var(--max), calc(100% - 40px));
  margin: auto;
  padding: 82px 0;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 40px;
  align-items: end;
}
.seo-cta h2 { margin: 0; max-width: 780px; font-size: clamp(45px, 7vw, 92px); line-height: .92; letter-spacing: -.065em; }
.seo-cta .button { min-height: 62px; padding: 18px 26px; }
.seo-footer { background: var(--ink); color: rgba(255,255,255,.7); }
.seo-footer-inner {
  width: min(var(--max), calc(100% - 40px));
  margin: auto;
  padding: 36px 0;
  display: flex;
  gap: 24px;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}
.seo-footer a { color: #fff; }

@media (max-width: 900px) {
  .seo-nav-links a:not(.nav-login) { display: none; }
  .seo-hero-inner { min-height: 0; padding: 64px 0 70px; grid-template-columns: 1fr; gap: 40px; }
  .seo-hero-summary { max-width: 620px; }
  .seo-layout { grid-template-columns: 1fr; gap: 0; padding-top: 60px; }
  .toc { display: none; }
  .related-grid { grid-template-columns: 1fr; }
  .related-card { min-height: 190px; }
  .seo-cta-inner { grid-template-columns: 1fr; align-items: start; }
}

@media (max-width: 620px) {
  body { font-size: 16px; }
  .seo-nav-inner { width: min(100% - 24px, var(--max)); min-height: 66px; }
  .seo-brand span { display: none; }
  .seo-brand img { width: 42px; height: 42px; }
  .nav-login { padding: 8px 13px; }
  .seo-hero-inner, .topic-strip div, .seo-layout, .related-inner, .seo-cta-inner, .seo-footer-inner { width: min(100% - 28px, var(--max)); }
  .seo-hero h1 { font-size: clamp(46px, 15vw, 72px); }
  .seo-hero-summary { padding-left: 20px; }
  .topic-strip div { min-height: 54px; overflow-x: auto; justify-content: flex-start; white-space: nowrap; }
  .seo-article h2 { margin-top: 62px; }
  .fact-grid, .score-fields { grid-template-columns: 1fr; }
  .fact-grid > div { min-height: 112px; }
  .calculator { box-shadow: 7px 7px 0 var(--blue); }
  .calculator-head, .calculator-body { padding: 21px; }
  .seo-footer-inner { flex-direction: column; align-items: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}