:root {
  --ink: #0b2d26;
  --ink-2: #17483e;
  --paper: #fbf7ea;
  --paper-2: #f1ebd9;
  --white: #fffdf7;
  --lime: #c9f23d;
  --lime-dark: #8fb600;
  --coral: #ff6948;
  --coral-dark: #c63c23;
  --blue: #4168e8;
  --muted: #586c67;
  --line: rgba(11, 45, 38, 0.17);
  --line-strong: rgba(11, 45, 38, 0.38);
  --shadow: 0 22px 55px rgba(11, 45, 38, 0.13);
  --radius-small: 9px;
  --radius: 17px;
  --shell: 1180px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Aptos, "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

body::before {
  position: fixed;
  z-index: -2;
  inset: 0;
  content: "";
  pointer-events: none;
  background-image:
    linear-gradient(rgba(11, 45, 38, 0.033) 1px, transparent 1px),
    linear-gradient(90deg, rgba(11, 45, 38, 0.033) 1px, transparent 1px);
  background-size: 44px 44px;
}

body::after {
  position: fixed;
  z-index: -1;
  inset: 0;
  content: "";
  pointer-events: none;
  background: radial-gradient(circle at 82% 10%, rgba(201, 242, 61, 0.17), transparent 28rem);
}

a {
  color: inherit;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 0.2em;
}

img {
  display: block;
  max-width: 100%;
}

button,
input,
select {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid var(--coral);
  outline-offset: 4px;
}

.shell {
  width: min(calc(100% - 40px), var(--shell));
  margin-inline: auto;
}

.narrow-shell {
  width: min(calc(100% - 40px), 840px);
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 12px;
  left: 12px;
  padding: 10px 16px;
  transform: translateY(-180%);
  border-radius: var(--radius-small);
  background: var(--ink);
  color: white;
}

.skip-link:focus {
  transform: none;
}

.site-header {
  position: sticky;
  z-index: 50;
  top: 0;
  border-bottom: 1px solid rgba(11, 45, 38, 0.1);
  background: rgba(251, 247, 234, 0.93);
  backdrop-filter: blur(16px);
}

.header-inner {
  display: flex;
  min-height: 78px;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--ink);
  font-size: 1.26rem;
  font-weight: 760;
  letter-spacing: -0.045em;
  text-decoration: none;
}

.brand img {
  box-shadow: 0 7px 18px rgba(11, 45, 38, 0.14);
  border-radius: 11px;
}

.brand strong {
  color: var(--coral-dark);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 5px;
}

.site-nav a {
  position: relative;
  padding: 10px 13px;
  color: #24483f;
  font-size: 0.91rem;
  font-weight: 740;
  text-decoration: none;
}

.site-nav a::after {
  position: absolute;
  right: 13px;
  bottom: 4px;
  left: 13px;
  height: 3px;
  content: "";
  transform: scaleX(0);
  transform-origin: left;
  background: var(--lime-dark);
  transition: transform 180ms ease;
}

.site-nav a:hover::after,
.site-nav a[aria-current="page"]::after {
  transform: scaleX(1);
}

.menu-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-small);
  background: transparent;
  color: var(--ink);
  font-size: 0.85rem;
  font-weight: 750;
}

.menu-icon,
.menu-icon::before,
.menu-icon::after {
  display: block;
  width: 18px;
  height: 2px;
  content: "";
  background: currentColor;
}

.menu-icon {
  position: relative;
}

.menu-icon::before {
  position: absolute;
  top: -6px;
}

.menu-icon::after {
  position: absolute;
  top: 6px;
}

.home-hero {
  overflow: hidden;
  padding: clamp(58px, 7vw, 98px) 0 clamp(72px, 8vw, 116px);
}

.hero-grid {
  display: grid;
  align-items: center;
  grid-template-columns: minmax(0, 0.95fr) minmax(430px, 0.75fr);
  gap: clamp(48px, 7vw, 96px);
}

.eyebrow,
.section-kicker,
.mini-kicker {
  margin: 0;
  color: var(--coral-dark);
  font-size: 0.76rem;
  font-weight: 850;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
}

.eyebrow > span {
  width: 31px;
  height: 3px;
  background: var(--coral);
}

.hero-copy h1,
.page-hero h1,
.calculator-title-grid h1,
.article-hero h1,
.simple-page h1,
.not-found h1 {
  margin: 0;
  font-size: clamp(3.25rem, 6.4vw, 6.45rem);
  line-height: 0.93;
  letter-spacing: -0.072em;
}

.hero-copy h1 {
  max-width: 10.2ch;
}

.hero-copy h1 em {
  display: block;
  color: var(--coral-dark);
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 400;
  letter-spacing: -0.06em;
}

.hero-lede {
  max-width: 610px;
  margin: 30px 0 0;
  color: var(--muted);
  font-size: 1.16rem;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 11px 19px;
  border: 2px solid var(--ink);
  border-radius: 10px;
  font-size: 0.91rem;
  font-weight: 810;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  background: var(--ink);
  color: white;
  box-shadow: 5px 5px 0 var(--lime);
}

.button-secondary {
  background: transparent;
  color: var(--ink);
}

.button-secondary:hover {
  background: var(--white);
}

.trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 28px 0 0;
  padding: 0;
  color: #47645d;
  font-size: 0.78rem;
  font-weight: 730;
  list-style: none;
}

.trust-list li::before {
  margin-right: 7px;
  color: var(--lime-dark);
  content: "✓";
  font-weight: 900;
}

.hero-tool-wrap {
  position: relative;
}

.hero-tool-wrap::before {
  position: absolute;
  z-index: -1;
  right: -38px;
  bottom: -38px;
  width: 78%;
  height: 74%;
  content: "";
  background: var(--blue);
  clip-path: polygon(7% 0, 100% 11%, 92% 100%, 0 88%);
}

.tool-sticker {
  position: absolute;
  z-index: 2;
  top: -35px;
  right: -24px;
  display: grid;
  width: 82px;
  height: 82px;
  place-items: center;
  transform: rotate(8deg);
  border: 3px solid var(--ink);
  border-radius: 50%;
  background: var(--coral);
  color: var(--ink);
  font-size: 2rem;
  font-weight: 900;
  box-shadow: 5px 5px 0 var(--ink);
}

.tool-card {
  border: 2px solid var(--ink);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 10px 10px 0 var(--ink);
}

.tool-card-hero,
.tool-card-main {
  padding: clamp(24px, 4vw, 38px);
}

.tool-card-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 25px;
}

.tool-card-heading h2 {
  margin: 5px 0 0;
  font-size: clamp(1.42rem, 3vw, 2rem);
  line-height: 1.08;
  letter-spacing: -0.045em;
}

.tool-number {
  color: var(--coral-dark);
  font-family: Georgia, serif;
  font-size: 1.3rem;
  font-weight: 700;
}

.calculator-form {
  display: grid;
  gap: 18px;
}

.field {
  display: grid;
  min-width: 0;
  gap: 7px;
}

.field > span:first-child {
  color: #33574e;
  font-size: 0.79rem;
  font-weight: 780;
}

.field input,
.field select {
  width: 100%;
  min-height: 52px;
  padding: 10px 13px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--radius-small);
  background: #fffef9;
  color: var(--ink);
  font-weight: 730;
}

.field input:focus,
.field select:focus {
  border-color: var(--blue);
  outline: 3px solid rgba(65, 104, 232, 0.17);
}

.input-affix {
  position: relative;
  display: block;
}

.input-affix input {
  padding-right: 45px;
}

.input-affix b {
  position: absolute;
  top: 50%;
  right: 14px;
  transform: translateY(-50%);
  color: var(--coral-dark);
  font-size: 0.9rem;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 13px;
}

.field-help,
.form-error {
  margin: -6px 0 0;
  font-size: 0.78rem;
  line-height: 1.45;
}

.field-help {
  color: var(--muted);
}

.form-error {
  padding: 11px 13px;
  border-left: 4px solid var(--coral-dark);
  background: #fff0eb;
  color: #7d291b;
  font-weight: 720;
}

.button-calculate {
  width: 100%;
  border-color: var(--ink);
  background: var(--lime);
  color: var(--ink);
  box-shadow: 4px 4px 0 var(--ink);
}

.button-calculate:hover {
  background: #daf86f;
}

.result-panel {
  padding: 19px;
  border: 2px solid var(--ink);
  border-radius: 12px;
  background: var(--ink);
  color: white;
}

.result-panel[hidden],
.form-error[hidden] {
  display: none;
}

.result-label {
  display: block;
  margin-bottom: 4px;
  color: var(--lime);
  font-size: 0.72rem;
  font-weight: 850;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.result-panel > strong {
  display: block;
  overflow-wrap: anywhere;
  font-size: clamp(1.9rem, 5vw, 3.2rem);
  line-height: 1.05;
  letter-spacing: -0.055em;
}

.result-panel p {
  margin: 9px 0 0;
  color: #d9e6df;
  font-size: 0.8rem;
}

.result-breakdown {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.result-breakdown span {
  padding: 7px 10px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  color: #d9e6df;
  font-size: 0.78rem;
}

.result-breakdown b {
  color: white;
}

.converter-units {
  display: grid;
  align-items: end;
  grid-template-columns: minmax(0, 1fr) 48px minmax(0, 1fr);
  gap: 10px;
}

.swap-button {
  display: grid;
  width: 44px;
  height: 52px;
  place-items: center;
  padding: 0;
  border: 1.5px solid var(--ink);
  border-radius: var(--radius-small);
  background: var(--paper-2);
  color: var(--ink);
  font-size: 1.25rem;
  font-weight: 900;
  cursor: pointer;
  transition: background 150ms ease, transform 150ms ease;
}

.swap-button:hover {
  transform: translateY(-2px);
  background: var(--lime);
}

.converter-result > strong {
  font-variant-numeric: tabular-nums;
}

.section {
  padding: clamp(72px, 8vw, 116px) 0;
}

.section-tools {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 253, 247, 0.7);
}

.section-heading {
  margin-bottom: 42px;
}

.split-heading {
  display: grid;
  align-items: end;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: 50px;
}

.section-heading h2,
.editorial-callout h2,
.prose-grid h2,
.method-card h2,
.article-body h2,
.about-grid h2,
.guide-roadmap h2 {
  margin: 8px 0 0;
  font-size: clamp(2rem, 4.2vw, 4rem);
  line-height: 1;
  letter-spacing: -0.058em;
}

.split-heading > p {
  margin: 0;
  color: var(--muted);
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.calculator-card {
  position: relative;
  display: grid;
  min-height: 300px;
  align-content: space-between;
  padding: 25px;
  overflow: hidden;
  border: 1.5px solid var(--ink);
  border-radius: 14px;
  background: var(--white);
  box-shadow: 6px 6px 0 rgba(11, 45, 38, 0.1);
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.calculator-card::before {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 8px;
  content: "";
  background: var(--card-accent);
}

.calculator-card:hover {
  transform: translateY(-5px);
  box-shadow: 9px 11px 0 rgba(11, 45, 38, 0.13);
}

.calculator-symbol {
  display: grid;
  width: 98px;
  height: 98px;
  place-items: center;
  transform: rotate(-4deg);
  border: 2px solid var(--ink);
  background: var(--card-accent);
  color: var(--ink);
  font-size: 2.15rem;
  font-weight: 900;
  letter-spacing: -0.06em;
  box-shadow: 5px 5px 0 var(--ink);
}

.calculator-card h3 {
  margin: 27px 0 6px;
  font-size: 1.55rem;
  letter-spacing: -0.04em;
}

.calculator-card h3 a {
  text-decoration: none;
}

.calculator-card h3 a::after {
  position: absolute;
  inset: 0;
  content: "";
}

.calculator-card p {
  max-width: 30ch;
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.card-arrow {
  position: absolute;
  top: 25px;
  right: 23px;
  font-size: 1.35rem;
  font-weight: 900;
}

.section-method {
  background: var(--ink);
}

.method-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.method-card {
  min-height: 325px;
  padding: 29px;
  border: 1px solid rgba(255, 255, 255, 0.21);
  background: var(--paper);
  color: var(--ink);
}

.method-card-dark {
  background: #133f36;
  color: white;
}

.method-card-accent {
  background: var(--lime);
}

.method-index {
  display: block;
  margin-bottom: 90px;
  font-family: Georgia, serif;
  font-size: 1.2rem;
  font-style: italic;
}

.method-card h2 {
  font-size: clamp(1.9rem, 3.1vw, 3rem);
}

.method-card p {
  margin: 15px 0 0;
  color: inherit;
  opacity: 0.78;
}

.editorial-callout {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: clamp(45px, 8vw, 100px);
  padding: clamp(35px, 5vw, 58px);
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 9px 9px 0 var(--coral);
}

.editorial-callout h2 {
  font-size: clamp(2rem, 4vw, 3.65rem);
}

.editorial-callout p {
  margin-top: 0;
  color: var(--muted);
}

.text-link {
  display: inline-flex;
  gap: 9px;
  align-items: center;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 820;
}

.page-hero,
.calculator-intro,
.article-hero {
  border-bottom: 1px solid var(--line);
}

.compact-hero {
  padding: clamp(48px, 7vw, 84px) 0 clamp(65px, 8vw, 105px);
}

.compact-hero h1 {
  max-width: 12ch;
  font-size: clamp(3rem, 6.3vw, 6rem);
}

.compact-hero > .shell > p:last-child {
  max-width: 660px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: 1.12rem;
}

.breadcrumbs {
  margin-bottom: 37px;
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 9px;
  margin: 0;
  padding: 0;
  color: #5d706b;
  font-size: 0.74rem;
  font-weight: 700;
  list-style: none;
}

.breadcrumbs li:not(:last-child)::after {
  margin-left: 9px;
  content: "/";
  opacity: 0.5;
}

.breadcrumbs a {
  text-decoration: none;
}

.catalog-section {
  border-top: 0;
}

.roadmap-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-top: 31px;
  padding: 20px 22px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-size: 0.8rem;
}

.roadmap-strip strong {
  margin-right: auto;
}

.roadmap-strip span {
  padding: 6px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--white);
  font-weight: 720;
}

.section-soft {
  background: var(--paper-2);
}

.prose-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(360px, 1.2fr);
  gap: clamp(50px, 9vw, 120px);
}

.prose-grid h2 {
  font-size: clamp(2rem, 4vw, 3.6rem);
}

.prose-copy p {
  margin: 0 0 20px;
  color: #405c55;
  font-size: 1.02rem;
}

.calculator-intro {
  padding: 45px 0 54px;
}

.calculator-title-grid {
  display: grid;
  align-items: end;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 45px;
}

.calculator-title-grid h1 {
  max-width: 12ch;
  font-size: clamp(3rem, 5.8vw, 5.5rem);
}

.calculator-title-grid > div > p:last-child {
  max-width: 700px;
  margin: 25px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.back-catalog {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  padding-bottom: 8px;
  font-size: 0.82rem;
  font-weight: 800;
  white-space: nowrap;
}

.calculator-workspace {
  padding: clamp(50px, 7vw, 82px) 0;
  background: #e8e2cf;
}

.calculator-layout {
  display: grid;
  align-items: start;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: 30px;
}

.tool-card-main {
  box-shadow: 9px 9px 0 var(--ink);
}

.side-note {
  padding: 27px;
  border-top: 7px solid var(--lime);
  background: var(--ink);
  color: white;
}

.side-note h2 {
  margin: 0;
  font-size: 1.35rem;
  letter-spacing: -0.035em;
}

.side-note > p {
  margin: 12px 0 24px;
  color: #cfddd8;
  font-size: 0.88rem;
}

.formula-chip {
  display: grid;
  gap: 3px;
  padding: 12px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.17);
}

.formula-chip span {
  color: var(--lime);
  font-size: 0.68rem;
  font-weight: 850;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.formula-chip code {
  overflow-wrap: anywhere;
  color: white;
  font-size: 0.79rem;
}

.privacy-note {
  display: grid;
  gap: 4px;
  padding: 15px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: #1c5146;
}

.privacy-note strong {
  color: var(--lime);
}

.privacy-note span {
  color: #d7e3de;
  font-size: 0.77rem;
}

.check-field {
  display: flex;
  align-items: flex-start;
  gap: 11px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-small);
  background: var(--paper);
  cursor: pointer;
}

.check-field input {
  width: 20px;
  height: 20px;
  margin: 2px 0 0;
  accent-color: var(--ink);
}

.check-field span {
  display: grid;
  gap: 2px;
}

.check-field small {
  color: var(--muted);
  font-size: 0.75rem;
}

.mini-calendar {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 5px;
  margin-top: 23px;
}

.mini-calendar span {
  display: grid;
  aspect-ratio: 1;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: #cad7d2;
  font-size: 0.7rem;
}

.mini-calendar .is-active {
  background: var(--lime);
  color: var(--ink);
  font-weight: 900;
}

.article-layout {
  display: grid;
  align-items: start;
  grid-template-columns: minmax(0, 1fr) 285px;
  gap: clamp(45px, 8vw, 100px);
}

.article-body {
  min-width: 0;
}

.article-body > p,
.article-body > ul {
  color: #38554e;
}

.article-body h2 {
  margin-top: 54px;
  font-size: clamp(2rem, 4vw, 3.35rem);
}

.article-body .section-kicker + h2 {
  margin-top: 8px;
}

.article-body h3 {
  margin: 35px 0 8px;
  font-size: 1.32rem;
  letter-spacing: -0.025em;
}

.article-body li + li {
  margin-top: 8px;
}

.article-callout {
  margin: 37px 0;
  padding: 21px 23px;
  border-left: 7px solid var(--coral);
  background: #fff0e9;
  color: #4d3a33;
}

.article-body details {
  border-top: 1px solid var(--line);
}

.article-body details:last-of-type {
  border-bottom: 1px solid var(--line);
}

.article-body summary {
  padding: 17px 3px;
  font-weight: 790;
  cursor: pointer;
}

.article-body details p {
  margin: -3px 0 18px;
  color: var(--muted);
}

.article-aside {
  position: sticky;
  top: 105px;
  padding: 24px;
  border: 1.5px solid var(--ink);
  background: var(--white);
  box-shadow: 6px 6px 0 var(--lime);
}

.article-aside h3 {
  margin: 8px 0 10px;
  font-size: 1.45rem;
  line-height: 1.08;
  letter-spacing: -0.04em;
}

.article-aside p {
  color: var(--muted);
  font-size: 0.86rem;
}

.related-section {
  padding: 52px 0;
  background: var(--coral);
}

.related-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 35px;
}

.related-inner h2 {
  margin: 5px 0 2px;
  font-size: 2rem;
  letter-spacing: -0.045em;
}

.related-inner p:last-child {
  margin: 0;
}

.guide-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(320px, 0.75fr);
  gap: 24px;
}

.guide-collection {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.guide-collection .guide-featured {
  grid-template-columns: 150px minmax(0, 1fr);
}

.guide-collection .guide-featured h2 {
  font-size: clamp(1.65rem, 2.7vw, 2.35rem);
}

.guide-visual-units {
  background: #f6bf3c;
}

.guide-roadmap-wide {
  margin-top: 24px;
}

.guide-roadmap-wide ul {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 15px;
}

.guide-roadmap-wide li {
  padding: 14px;
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.guide-featured {
  display: grid;
  align-items: center;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 32px;
  padding: 28px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 8px 8px 0 var(--coral);
}

.guide-featured h2 {
  margin: 7px 0 12px;
  font-size: clamp(1.8rem, 3.2vw, 2.8rem);
  line-height: 1;
  letter-spacing: -0.05em;
}

.guide-featured h2 a {
  text-decoration: none;
}

.guide-featured p {
  color: var(--muted);
}

.guide-visual {
  position: relative;
  display: grid;
  aspect-ratio: 1;
  place-items: center;
  background: var(--lime);
  color: var(--ink);
  box-shadow: 6px 6px 0 var(--ink);
}

.guide-visual span {
  font-size: 4rem;
  font-weight: 900;
  letter-spacing: -0.08em;
}

.guide-visual b {
  position: absolute;
  top: 15px;
  right: 18px;
  color: var(--coral-dark);
  font-size: 2rem;
}

.guide-visual i {
  position: absolute;
  bottom: 15px;
  left: 18px;
  font-family: Georgia, serif;
}

.guide-roadmap {
  padding: 30px;
  background: var(--ink);
  color: white;
}

.guide-roadmap .section-kicker {
  color: var(--lime);
}

.guide-roadmap h2 {
  font-size: 2.3rem;
}

.guide-roadmap ul {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.guide-roadmap li {
  padding: 12px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.17);
  color: #d7e1de;
  font-size: 0.87rem;
}

.article-hero {
  padding: 46px 0 65px;
}

.article-hero h1 {
  max-width: 13ch;
  font-size: clamp(3rem, 6vw, 5.75rem);
}

.article-lede {
  max-width: 700px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: 1.17rem;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin-top: 27px;
  color: #59706a;
  font-size: 0.78rem;
  font-weight: 720;
}

.article-section {
  padding-top: 66px;
}

.article-body-wide > p:first-child {
  font-size: 1.13rem;
}

.article-index {
  display: grid;
  gap: 8px;
  margin: 38px 0 55px;
  padding: 22px;
  border: 1px solid var(--line);
  background: var(--paper-2);
}

.article-index a {
  font-size: 0.88rem;
  font-weight: 710;
}

.formula-display {
  margin: 25px 0;
  padding: 22px;
  overflow-x: auto;
  border-left: 8px solid var(--lime);
  background: var(--ink);
  color: white;
}

.formula-display code {
  font-size: clamp(0.87rem, 2vw, 1.12rem);
  white-space: nowrap;
}

.table-wrap {
  max-width: 100%;
  margin: 28px 0;
  overflow-x: auto;
  border: 1px solid var(--line);
  background: var(--white);
}

.reference-table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.reference-table th,
.reference-table td {
  padding: 13px 15px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.reference-table th {
  background: var(--ink);
  color: white;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.reference-table tbody tr:last-child td {
  border-bottom: 0;
}

.reference-table tbody tr:nth-child(even) {
  background: var(--paper-2);
}

.table-note {
  margin-top: -18px;
  font-size: 0.75rem;
}

.compact-buttons {
  margin-top: 0;
}

.guide-action {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 25px;
  margin-top: 58px;
  padding: 27px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 7px 7px 0 var(--lime);
}

.guide-action h2 {
  margin: 5px 0 0;
  font-size: 1.8rem;
}

.about-grid {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: clamp(50px, 9vw, 120px);
}

.about-grid h2 {
  font-size: clamp(2rem, 3.6vw, 3.3rem);
}

.about-grid p {
  color: var(--muted);
}

.number-list {
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.number-list li {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 15px;
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.number-list li > span {
  color: var(--coral-dark);
  font-family: Georgia, serif;
  font-style: italic;
}

.number-list p {
  margin: 3px 0 0;
  font-size: 0.88rem;
}

.simple-page {
  min-height: 65vh;
  padding: 48px 0 90px;
}

.simple-page h1 {
  max-width: 12ch;
  font-size: clamp(3rem, 6vw, 5.6rem);
}

.simple-lede {
  max-width: 670px;
  margin: 25px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.contact-card {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 40px;
  margin-top: 48px;
  padding: 30px;
  border: 2px solid var(--ink);
  background: var(--white);
  box-shadow: 8px 8px 0 var(--lime);
}

.contact-card > div {
  display: grid;
  align-content: start;
  gap: 5px;
}

.contact-card span {
  color: var(--coral-dark);
  font-size: 0.73rem;
  font-weight: 850;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.contact-card a {
  font-size: 1.15rem;
  font-weight: 800;
  overflow-wrap: anywhere;
}

.contact-card p {
  margin: 0;
  color: var(--muted);
}

.legal-copy {
  display: grid;
  gap: 0;
  margin-top: 50px;
}

.legal-copy section {
  padding: 26px 0;
  border-top: 1px solid var(--line);
}

.legal-copy h2 {
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: -0.035em;
}

.legal-copy p {
  margin: 10px 0 0;
  color: var(--muted);
}

.not-found {
  min-height: 67vh;
  padding: 90px 0;
  text-align: center;
}

.error-code {
  display: block;
  color: var(--coral-dark);
  font-family: Georgia, serif;
  font-size: 4rem;
  font-style: italic;
}

.not-found h1 {
  margin-inline: auto;
  font-size: clamp(3rem, 7vw, 6rem);
}

.not-found p {
  color: var(--muted);
}

.not-found .button-row {
  justify-content: center;
}

.site-footer {
  padding: 48px 0 20px;
  background: #08241e;
  color: white;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(260px, 1fr) minmax(360px, 1fr);
  gap: 60px;
  align-items: start;
}

.brand-footer {
  color: white;
}

.footer-brand p {
  max-width: 440px;
  margin: 15px 0 0;
  color: #b8cbc4;
  font-size: 0.85rem;
}

.footer-grid nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 9px 21px;
}

.footer-grid nav a {
  color: #d8e3df;
  font-size: 0.78rem;
  font-weight: 710;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-top: 35px;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.13);
  color: #93aaa2;
  font-size: 0.71rem;
}

@media (max-width: 960px) {
  .hero-grid,
  .calculator-layout,
  .guide-grid,
  .about-grid {
    grid-template-columns: 1fr;
  }

  .hero-copy h1 {
    max-width: 11ch;
  }

  .hero-tool-wrap {
    width: min(100%, 620px);
  }

  .tool-grid,
  .method-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .method-card:last-child {
    grid-column: 1 / -1;
  }

  .method-card:last-child {
    min-height: 260px;
  }

  .calculator-title-grid {
    grid-template-columns: 1fr;
  }

  .back-catalog {
    justify-self: start;
  }

  .side-note {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 28px;
  }

  .side-note h2,
  .side-note > p {
    grid-column: 1 / -1;
  }

  .article-layout {
    grid-template-columns: minmax(0, 1fr) 245px;
    gap: 45px;
  }

  .guide-featured {
    grid-template-columns: 190px 1fr;
  }

  .guide-collection {
    grid-template-columns: 1fr;
  }

  .guide-roadmap-wide ul {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  .shell,
  .narrow-shell {
    width: min(calc(100% - 28px), var(--shell));
  }

  .header-inner {
    min-height: 68px;
  }

  .brand {
    font-size: 1.15rem;
  }

  .brand img {
    width: 38px;
    height: 38px;
  }

  .menu-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 1px);
    right: 0;
    left: 0;
    display: none;
    padding: 12px 14px 18px;
    border-bottom: 2px solid var(--ink);
    background: var(--paper);
    box-shadow: 0 18px 35px rgba(11, 45, 38, 0.14);
  }

  .site-nav.is-open {
    display: grid;
  }

  .site-nav a {
    padding: 13px 11px;
    border-bottom: 1px solid var(--line);
  }

  .site-nav a::after {
    display: none;
  }

  .home-hero {
    padding-top: 43px;
  }

  .hero-grid {
    gap: 58px;
  }

  .hero-copy h1,
  .page-hero h1,
  .calculator-title-grid h1,
  .article-hero h1,
  .simple-page h1 {
    font-size: clamp(2.9rem, 14vw, 4.55rem);
  }

  .hero-lede {
    font-size: 1.02rem;
  }

  .trust-list {
    display: grid;
  }

  .hero-tool-wrap::before {
    right: -10px;
    bottom: -23px;
  }

  .tool-sticker {
    top: -26px;
    right: 12px;
    width: 65px;
    height: 65px;
    font-size: 1.55rem;
  }

  .tool-card {
    box-shadow: 6px 6px 0 var(--ink);
  }

  .tool-card-hero,
  .tool-card-main {
    padding: 22px 18px;
  }

  .form-row,
  .split-heading,
  .tool-grid,
  .method-grid,
  .editorial-callout,
  .prose-grid,
  .article-layout,
  .guide-featured,
  .contact-card,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .converter-units {
    grid-template-columns: 1fr;
  }

  .swap-button {
    justify-self: center;
    width: 52px;
    height: 42px;
    transform: rotate(90deg);
  }

  .swap-button:hover {
    transform: rotate(90deg) translateX(-2px);
  }

  .calculator-card:last-child,
  .method-card:last-child {
    grid-column: auto;
  }

  .calculator-card {
    min-height: 260px;
  }

  .calculator-symbol {
    width: 82px;
    height: 82px;
    font-size: 1.8rem;
  }

  .method-card,
  .method-card:last-child {
    min-height: 245px;
  }

  .method-index {
    margin-bottom: 55px;
  }

  .editorial-callout {
    gap: 30px;
    padding: 27px 22px;
    box-shadow: 6px 6px 0 var(--coral);
  }

  .roadmap-strip strong {
    width: 100%;
    margin-right: 0;
  }

  .calculator-intro {
    padding-top: 30px;
  }

  .calculator-title-grid {
    gap: 24px;
  }

  .calculator-workspace {
    padding: 33px 0 40px;
  }

  .side-note {
    display: block;
  }

  .article-aside {
    position: static;
  }

  .related-inner,
  .guide-action {
    align-items: flex-start;
    flex-direction: column;
  }

  .guide-visual {
    width: min(100%, 220px);
  }

  .guide-collection .guide-featured {
    grid-template-columns: 1fr;
  }

  .guide-roadmap-wide ul {
    grid-template-columns: 1fr;
  }

  .article-hero {
    padding-top: 30px;
  }

  .article-body h2 {
    scroll-margin-top: 90px;
  }

  .formula-display code {
    white-space: normal;
  }

  .footer-grid {
    gap: 28px;
  }

  .footer-grid nav {
    justify-content: flex-start;
  }

  .footer-bottom {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 420px) {
  .button-row .button {
    width: 100%;
  }

  .tool-card-heading {
    gap: 8px;
  }

  .tool-number {
    font-size: 1rem;
  }

  .result-panel > strong {
    font-size: 1.8rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}