/* Uses the existing site's white, neutral surfaces, blue accent and system type. */
:root {
  color-scheme:light;
  --ink:#1d1d1f;
  --muted:#6e6e73;
  --surface:#f5f5f7;
  --line:#e5e5ea;
  --accent:#007aff
}

* {
  box-sizing:border-box
}

html {
  scroll-behavior:smooth;
  scroll-padding-top:132px
}

body {
  margin:0;
  color:var(--ink);
  background:#fff;
  font:16px/1.65 -apple-system,BlinkMacSystemFont,"SF Pro Text","Segoe UI",system-ui,sans-serif;
  -webkit-font-smoothing:antialiased
}

a {
  color:inherit
}

button,input,select {
  font:inherit
}

button,a,input,select,summary {
  -webkit-tap-highlight-color:transparent
}

button {
  cursor:pointer
}

a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible {
  outline:3px solid var(--accent);
  outline-offset:5px
}

h1,h2,h3,p {
  margin:0
}

h1,h2 {
  white-space:pre-line;
  text-wrap:balance;
  letter-spacing:-.045em;
  line-height:1.06
}

h1 {
  font-size:clamp(44px,6.4vw,76px);
  font-weight:700;
  max-width:880px
}

h2 {
  font-size:clamp(34px,4.7vw,52px);
  max-width:850px
}

h3 {
  font-size:21px;
  line-height:1.3;
  letter-spacing:-.02em;
  font-weight:600
}

p+p {
  margin-top:16px
}

.page-width {
  max-width:1056px;
  margin-inline:auto;
  padding-inline:32px
}

.eyebrow {
  font-size:13px;
  font-weight:600;
  letter-spacing:.025em;
  color:var(--muted);
  margin-bottom:18px
}

.small {
  font-size:13px;
  line-height:1.65
}

.muted {
  color:var(--muted)
}

.site-header {
  position:sticky;
  top:0;
  z-index:30;
  background:rgba(255,255,255,.94);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(16px)
}

.header-inner {
  max-width:1120px;
  margin:auto;
  min-height:58px;
  padding:10px 32px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px
}

.brand {
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-size:18px;
  font-weight:600;
  text-decoration:none;
  letter-spacing:-.02em
}

.brand img {
  border-radius:7px
}

.back-link {
  font-size:13px;
  color:var(--muted);
  text-decoration:none
}

.back-link:hover,.footer-links a:hover {
  color:var(--ink);
  text-decoration:underline
}

.skip-link {
  position:fixed;
  z-index:100;
  top:8px;
  left:8px;
  padding:10px 16px;
  background:#fff;
  transform:translateY(-150%)
}

.skip-link:focus {
  transform:translateY(0)
}

.hero {
  padding-top:80px;
  padding-bottom:52px
}

.hero-intro {
  max-width:680px;
  font-size:21px;
  line-height:1.5;
  margin-top:28px;
  color:#4b4b4f
}

.hero-note {
  font-size:14px;
  max-width:680px;
  margin-top:18px
}

.hero-facts {
  display:flex;
  gap:16px 40px;
  flex-wrap:wrap;
  padding-top:32px;
  margin-top:36px;
  border-top:1px solid var(--line);
  font-size:13px;
  font-weight:600
}

.section-nav {
  position:sticky;
  top:58px;
  z-index:20;
  background:rgba(255,255,255,.96);
  border-block:1px solid var(--line);
  backdrop-filter:blur(16px)
}

.section-nav>div {
  display:flex;
  gap:32px;
  overflow-x:auto;
  white-space:nowrap
}

.section-nav a {
  padding-block:16px;
  color:#4b4b4f;
  text-decoration:none;
  font-size:13px;
  font-weight:500
}

.section-nav a:hover {
  color:var(--accent)
}

.section {
  padding-top:88px;
  padding-bottom:88px
}

.section-intro {
  font-size:18px;
  line-height:1.65;
  color:#4b4b4f;
  max-width:770px;
  margin-top:24px;
  margin-bottom:40px
}

.table-scroll {
  overflow-x:auto;
  margin-block:28px 16px
}

table {
  width:100%;
  border-collapse:collapse;
  text-align:left;
  font-size:14px
}

th,td {
  padding:16px 14px;
  border-bottom:1px solid var(--line);
  vertical-align:top
}

thead th {
  font-size:12px;
  font-weight:500;
  color:var(--muted);
  white-space:nowrap
}

tbody th {
  font-weight:600
}

th:first-child,td:first-child {
  padding-left:0
}

th:last-child,td:last-child {
  padding-right:0
}

.steps {
  list-style:none;
  margin:52px 0 40px;
  padding:0;
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:40px 48px
}

.steps li {
  display:flex;
  align-items:flex-start;
  gap:18px
}

.step-number {
  font-size:14px;
  color:var(--muted);
  line-height:1.8;
  font-variant-numeric:tabular-nums
}

.steps h3 {
  font-size:18px
}

.steps p {
  margin-top:10px;
  font-size:15px;
  color:#4b4b4f
}

.note-block {
  padding:28px 0;
  border-block:1px solid var(--line)
}

.note-block p {
  margin-top:12px;
  color:#4b4b4f
}

.conditions {
  margin-top:16px
}

.score-section,.references-section {
  background:var(--surface)
}

.weights {
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:36px 32px;
  margin:48px 0 64px
}

.weight-top {
  display:flex;
  align-items:first baseline;
  justify-content:space-between;
  gap:12px
}

.weight h3 {
  font-size:16px;
  letter-spacing:-.01em
}

.weight-top>span {
  font-size:24px;
  font-weight:600;
  letter-spacing:-.03em;
  font-variant-numeric:tabular-nums
}

.weight-track {
  height:4px;
  background:var(--line);
  margin:14px 0 16px;
  border-radius:2px;
  overflow:hidden
}

.weight-track span {
  display:block;
  height:100%;
  background:var(--accent);
  border-radius:2px
}

.weight p {
  font-size:14px;
  color:#4b4b4f
}

.formula-block {
  max-width:850px
}

.formula-block ol {
  padding-left:24px;
  margin:24px 0 32px
}

.formula-block li {
  padding-left:8px;
  margin:16px 0;
  color:#4b4b4f
}

.equation {
  font-size:clamp(22px,3.6vw,36px);
  line-height:1.7;
  letter-spacing:-.03em;
  font-variant-numeric:tabular-nums;
  display:flex;
  flex-wrap:wrap;
  gap:0 10px;
  margin-bottom:12px
}

.equation span {
  white-space:nowrap
}

.equation sup {
  font-size:.52em;
  margin-left:1px
}

.method-details {
  margin-top:48px
}

.method-details>h3 {
  margin-bottom:16px
}

details {
  border-bottom:1px solid var(--line)
}

summary {
  cursor:pointer;
  list-style:none;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:20px;
  min-height:64px;
  padding:16px 0;
  font-size:15px;
  font-weight:600
}

summary::-webkit-details-marker {
  display:none
}

summary:after {
  content:"+";
  color:var(--muted);
  font-size:24px;
  font-weight:300;
  flex:none
}

details[open]>summary:after {
  content:"−"
}

details p {
  padding-bottom:24px;
  max-width:850px;
  font-size:15px;
  color:#4b4b4f
}

.calculator {
  display:grid;
  grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr);
  gap:56px;
  border-top:1px solid var(--line);
  padding-top:32px
}

.calculator[hidden] {
  display:none
}

.preset-buttons {
  display:flex;
  gap:10px;
  flex-wrap:wrap;
  margin-bottom:20px
}

.preset-buttons button {
  font-size:13px;
  border:1px solid var(--line);
  padding:10px 16px;
  border-radius:999px;
  background:white;
  color:var(--ink);
  min-height:44px
}

.preset-buttons button[aria-pressed=true] {
  color:white;
  background:var(--ink);
  border-color:var(--ink)
}

.control {
  margin-top:20px
}

.control-label {
  display:flex;
  justify-content:space-between;
  align-items:baseline;
  gap:12px;
  font-size:14px
}

.control output {
  font-variant-numeric:tabular-nums;
  color:var(--muted);
  white-space:nowrap
}

.control input {
  accent-color:var(--accent);
  width:100%;
  height:32px;
  margin:4px 0 0;
  cursor:pointer
}

.memory-control {
  border-top:1px solid var(--line);
  padding-top:20px;
  margin-top:16px
}

.text-button {
  border:0;
  background:none;
  color:var(--ink);
  font-size:13px;
  text-decoration:underline;
  text-underline-offset:4px;
  min-height:44px;
  padding:8px 0;
  margin-top:12px
}

.score-output {
  background:var(--surface);
  border-radius:20px;
  padding:36px;
  align-self:stretch
}

.score-output-inner {
  position:sticky;
  top:152px
}

.score-output .eyebrow {
  font-size:12px;
  margin-bottom:12px
}

.score-output output {
  display:block;
  font-size:clamp(64px,7vw,88px);
  font-weight:600;
  line-height:1.1;
  letter-spacing:-.065em;
  font-variant-numeric:tabular-nums
}

.score-output #example-name {
  font-size:15px;
  margin-top:18px;
  margin-bottom:36px
}

.score-output .small {
  font-size:13px
}

.references-table {
  font-variant-numeric:tabular-nums
}

.reference-global {
  font-weight:700
}

.download-link {
  display:inline-block;
  margin-top:24px;
  margin-bottom:10px;
  font-size:14px;
  text-underline-offset:4px
}

.guards {
  list-style:none;
  margin:48px 0;
  padding:0;
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:36px 48px
}

.guards li {
  display:flex;
  gap:18px
}

.guard-number {
  border:1px solid var(--line);
  border-radius:50%;
  width:28px;
  height:28px;
  display:flex;
  align-items:center;
  justify-content:center;
  flex:none;
  font-size:12px;
  color:var(--muted)
}

.guards h3 {
  font-size:18px
}

.guards p {
  font-size:15px;
  color:#4b4b4f;
  margin-top:12px
}

.publication-note {
  border-block:1px solid var(--line);
  padding-block:28px;
  margin-bottom:40px
}

.publication-note p {
  margin-top:14px;
  color:#4b4b4f
}

.review-labels {
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:28px;
  margin:24px 0
}

.review-labels dt {
  font-size:14px;
  font-weight:600
}

.review-labels dd {
  margin:10px 0 0;
  font-size:14px;
  color:#4b4b4f
}

.limits {
  margin-top:40px;
  background:var(--surface);
  border-radius:20px;
  padding:32px
}

.limits ul {
  padding-left:20px;
  margin:20px 0 0
}

.limits li {
  padding-left:6px;
  margin-bottom:14px;
  font-size:14px;
  color:#4b4b4f
}

.limits li:last-child {
  margin-bottom:0
}

.site-footer {
  background:#000;
  color:#f5f5f7;
  padding:64px 0 40px
}

.site-footer h2 {
  font-size:28px;
  line-height:1.25;
  letter-spacing:-.02em
}

.site-footer p {
  max-width:800px;
  margin-top:20px;
  font-size:14px;
  color:#a1a1a6
}

.site-footer .small {
  font-size:12px
}

.footer-links {
  display:flex;
  align-items:center;
  gap:16px 24px;
  flex-wrap:wrap;
  border-top:1px solid #2a2a2c;
  padding-top:28px;
  margin-top:36px;
  font-size:13px
}

.footer-links a {
  color:#d1d1d6;
  text-decoration:none
}

.footer-links a:hover {
  color:white
}

.footer-links label {
  margin-left:auto;
  color:#a1a1a6
}

.footer-links select {
  background:#1c1c1e;
  color:#f5f5f7;
  border:1px solid #4b4b4f;
  border-radius:8px;
  padding:8px 12px;
  min-height:44px;
  font-size:13px
}

@media(max-width:760px) {
  .hero {
    padding-top:56px
  }
  .weights {
    grid-template-columns:repeat(2,minmax(0,1fr))
  }
  .steps,.guards {
    gap:32px;
    grid-template-columns:1fr
  }
  .calculator {
    grid-template-columns:1fr;
    gap:32px
  }
  .score-output {
    grid-row:1;
    padding:24px
  }
  .score-output-inner {
    position:static;
    display:grid;
    grid-template-columns:1fr auto;
    column-gap:20px
  }
  .score-output .eyebrow {
    grid-column:1
  }
  .score-output output {
    grid-column:2;
    grid-row:1/3;
    font-size:60px;
    align-self:center
  }
  .score-output #example-name {
    grid-column:1;
    margin:0;
    align-self:center
  }
  .score-output .small {
    grid-column:1/-1;
    margin-top:20px
  }
  .review-labels {
    grid-template-columns:1fr;
    gap:20px
  }
  .section {
    padding-block:64px
  }
  .table-scroll table {
    min-width:480px
  }
  .hero-facts {
    gap:12px 24px
  }
  .section-nav>div {
    gap:24px
  }
  .footer-links label {
    margin-left:0
  }
}

@media(max-width:480px) {
  .page-width {
    padding-inline:22px
  }
  .header-inner {
    padding-inline:22px
  }
  .hero-intro {
    font-size:19px
  }
  .section-intro {
    font-size:17px
  }
  .weights {
    gap:28px 22px
  }
  .weight-top {
    flex-direction:column;
    gap:4px;
    align-items:flex-start
  }
  .weight h3 {
    min-height:42px
  }
  .formula-block li {
    padding-left:0
  }
  .equation {
    font-size:22px
  }
  .score-output-inner {
    display:block
  }
  .score-output output {
    font-size:72px
  }
  .score-output #example-name {
    margin-top:12px
  }
  .limits {
    padding:24px
  }
  .section-nav a {
    font-size:12px
  }
  .hero-facts {
    display:grid;
    gap:8px
  }
  .table-scroll th,.table-scroll td {
    padding-right:16px
  }
}

@media(prefers-reduced-motion:reduce) {
  html {
    scroll-behavior:auto
  }
  *,*:before,*:after {
    animation:none!important;
    transition:none!important
  }
}