:root {
  --paper: #f6f1e8;
  --paper-strong: #fffaf0;
  --ink: #171715;
  --muted: #6f6a61;
  --night: #242321;
  --gold: #d9b36f;
  --cyan: #25c8c5;
  --line: rgba(23, 23, 21, .14);
  --shadow: 0 22px 60px rgba(23, 23, 21, .13);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 82% 2%, rgba(37, 200, 197, .11), transparent 28rem),
    var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.65;
}

a { color: inherit; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid rgba(217, 179, 111, .45);
  background: rgba(36, 35, 33, .95);
  color: var(--paper);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
}

.nav-shell {
  width: min(1180px, calc(100% - 32px));
  min-height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: #fff;
  font-weight: 850;
  letter-spacing: -.02em;
  text-decoration: none;
}

.brand img {
  width: 38px;
  height: 38px;
  padding: 7px;
  border-radius: 10px;
  background: var(--gold);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: .9rem;
  font-weight: 720;
}

.site-nav a {
  color: rgba(255, 255, 255, .78);
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a:focus-visible { color: var(--gold); }

.hero {
  padding: clamp(72px, 10vw, 132px) 0 clamp(58px, 8vw, 96px);
  color: #fff;
  background:
    linear-gradient(115deg, rgba(36, 35, 33, .98), rgba(36, 35, 33, .87)),
    url("home-calculator-background.webp") center / cover;
}

.hero-inner,
.page-shell {
  width: min(1100px, calc(100% - 32px));
  margin: 0 auto;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--gold);
  font-size: .78rem;
  font-weight: 850;
  letter-spacing: .15em;
  text-transform: uppercase;
}

h1 {
  max-width: 860px;
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.7rem, 7vw, 5.8rem);
  font-weight: 500;
  letter-spacing: -.055em;
  line-height: .98;
}

.hero-copy {
  max-width: 720px;
  margin: 26px 0 0;
  color: rgba(255, 255, 255, .78);
  font-size: clamp(1rem, 1.6vw, 1.22rem);
}

.hero-actions,
.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  min-height: 46px;
  padding: 0 19px;
  border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  background: rgba(255, 255, 255, .08);
  font-weight: 800;
  text-decoration: none;
}

.button.primary {
  border-color: var(--gold);
  color: var(--night);
  background: var(--gold);
}

.button.dark {
  border-color: var(--night);
  color: #fff;
  background: var(--night);
}

.page-shell {
  padding: clamp(52px, 7vw, 88px) 0 96px;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(300px, .8fr);
  gap: clamp(34px, 6vw, 76px);
  align-items: start;
}

.calculator-card {
  position: sticky;
  top: 96px;
  padding: 26px;
  border: 1px solid rgba(217, 179, 111, .54);
  border-radius: 22px;
  background: var(--paper-strong);
  box-shadow: var(--shadow);
}

.calculator-card h2 {
  margin-top: 0;
  font-size: 1.55rem;
}

.field {
  margin-top: 16px;
}

.field label {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: .8rem;
  font-weight: 800;
}

.field input {
  width: 100%;
  min-height: 46px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--ink);
  background: #fff;
  font: inherit;
}

.field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.result-box {
  margin-top: 22px;
  padding: 18px;
  border-radius: 14px;
  color: #fff;
  background: var(--night);
}

.result-row {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 8px 0;
  border-bottom: 1px solid rgba(255, 255, 255, .12);
}

.result-row:last-child { border-bottom: 0; }
.result-row strong { color: var(--gold); text-align: right; }

.fine-print {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: .78rem;
  line-height: 1.55;
}

.article h2 {
  margin: 2.1em 0 .55em;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 500;
  letter-spacing: -.035em;
  line-height: 1.1;
}

.article h2:first-child { margin-top: 0; }

.article h3 {
  margin: 1.8em 0 .45em;
  font-size: 1.15rem;
}

.article p,
.article li { color: #393732; }

.article a {
  color: #0b6f6d;
  text-underline-offset: 3px;
}

.callout {
  margin: 28px 0;
  padding: 20px 22px;
  border-left: 4px solid var(--cyan);
  background: rgba(37, 200, 197, .08);
}

.formula {
  margin: 24px 0;
  padding: 18px 20px;
  border: 1px solid rgba(217, 179, 111, .58);
  border-radius: 14px;
  background: rgba(255, 250, 240, .8);
  font-weight: 780;
}

.guide-grid {
  margin: 28px 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.guide-link {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255, 250, 240, .64);
  text-decoration: none;
}

.guide-link strong {
  display: block;
  margin-bottom: 6px;
}

.guide-link span {
  color: var(--muted);
  font-size: .86rem;
}

.faq {
  margin-top: 54px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.faq details {
  padding: 17px 0;
  border-bottom: 1px solid var(--line);
}

.faq summary {
  cursor: pointer;
  font-weight: 820;
}

.faq details p { margin-bottom: 0; }

.source-list {
  padding-left: 20px;
  font-size: .9rem;
}

.reviewed {
  color: var(--muted);
  font-size: .8rem;
}

.site-footer {
  padding: 38px 0;
  color: rgba(255, 255, 255, .7);
  background: var(--night);
  font-size: .86rem;
}

.footer-inner {
  width: min(1100px, calc(100% - 32px));
  margin: 0 auto;
}

.footer-links {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
}

.footer-links a { color: var(--gold); }

@media (max-width: 840px) {
  .site-nav { display: none; }
  .layout { grid-template-columns: 1fr; }
  .calculator-card { position: static; }
}

@media (max-width: 560px) {
  .field-grid,
  .guide-grid { grid-template-columns: 1fr; }
  .hero { padding-top: 60px; }
  h1 { font-size: clamp(2.6rem, 13vw, 4.2rem); }
}