:root, .arc-dark {
  --canvas: var(--arc-bg, #0b0d0f); --surface: var(--arc-surface, #11161a);
  --ink: var(--arc-text, #f7f7f3); --muted: var(--arc-muted, #9ca3af);
  --accent: var(--arc-accent, #22c55e); --soft: var(--arc-elevated, #171d22);
  --border: var(--arc-border, rgba(255,255,255,.12)); --bad: var(--arc-danger, #f09696);
}
* { box-sizing: border-box; }
html { font-family: var(--arc-font, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif); color: var(--ink); background: var(--canvas); line-height: 1.6; color-scheme: light; }
body { margin: 0; }
a { color: var(--accent); text-underline-offset: 4px; }
a, button, input, select, summary { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
.wrap, .nav { width: min(1120px, calc(100% - 48px)); margin-inline: auto; }
header { background: var(--canvas); border-bottom: 1px solid var(--border); }
.nav { min-height: 80px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 8px; flex: 0 0 auto; color: var(--ink); text-decoration: none; font-size: 1.4rem; font-weight: 750; letter-spacing: -.045em; min-height: 44px; }
.brand img { display: block; }
.brand-accent { color: var(--accent); }
.navlinks { display: flex; gap: 20px; flex-wrap: wrap; justify-content: flex-end; align-items: center; }
.navlinks a { display: inline-flex; align-items: center; min-height: 44px; text-decoration: none; color: var(--muted); font-size: .9rem; }
.navlinks a:hover { color: var(--ink); }
.navlinks a.nav-cta { color: var(--ink); border-left: 1px solid var(--border); padding-left: 20px; gap: 12px; }
main { padding-bottom: 80px; }
.breadcrumbs { display: flex; flex-wrap: wrap; gap: 8px; font-size: .82rem; color: var(--muted); padding-top: 22px; }
.breadcrumbs a { display: inline-flex; align-items: center; min-height: 32px; color: var(--muted); text-transform: capitalize; }
.hero { padding: 48px 0 22px; }
.eyebrow { color: var(--accent); font-weight: 650; text-transform: uppercase; letter-spacing: .16em; font-size: .75rem; }
h1 { font-size: clamp(2.25rem, 5vw, 3.7rem); line-height: 1.08; letter-spacing: -.045em; max-width: 880px; margin: .35em 0; font-weight: 650; }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); line-height: 1.2; margin-top: 0; letter-spacing: -.025em; font-weight: 600; }
h3 { font-size: 1.1rem; }
p, li { max-width: 76ch; }
.lede { font-size: 1.15rem; color: var(--muted); max-width: 760px; }
.actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 28px; }
.button, button { display: inline-flex; gap: 16px; min-height: 48px; align-items: center; justify-content: center; padding: 11px 20px; border-radius: 6px; background: #047857; color: #ffffff; text-decoration: none; font: inherit; font-size: .93rem; font-weight: 700; border: 1px solid transparent; cursor: pointer; transition: background .15s ease, border-color .15s ease; }
.button:hover, button:hover { background: #065f46; }
.button.secondary { background: transparent; color: var(--ink); border-color: var(--border); }
.button.secondary:hover { border-color: var(--muted); }
.trust, .muted, .note { color: var(--muted); font-size: .88rem; }
.trust { margin-top: 22px; }
main > section:not(.hero) { margin-top: 48px; }
.grid, .card-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card, .calculator, .notice, .cta, .formula { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 28px; }
.card-link { color: var(--ink); text-decoration: none; transition: border-color .15s ease; }
.card-link:hover { border-color: var(--accent); }
.card-link p { color: var(--muted); }
.notice { border-left: 3px solid var(--accent); }
.cta { padding: 40px; }
.calculator { max-width: 780px; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; margin-bottom: 20px; }
.form-grid label { display: grid; align-content: start; gap: 8px; font-weight: 600; }
.form-grid input, .form-grid select { width: 100%; min-width: 0; min-height: 48px; border: 1px solid #94a3b8; border-radius: 5px; padding: 10px 12px; font: inherit; color: var(--ink); background: var(--canvas); }
.form-grid input::placeholder { color: var(--muted); }
.form-grid input:focus, .form-grid select:focus { outline: 2px solid var(--accent); outline-offset: 2px; }
.result { margin-top: 22px; padding: 20px; border-radius: 6px; background: var(--soft); min-height: 86px; font-variant-numeric: tabular-nums; }
.result.error { color: var(--bad); border-left: 3px solid var(--bad); }
.metric { font-size: 1.7rem; font-weight: 650; color: var(--accent); }
.faq details { border-bottom: 1px solid var(--border); padding: 16px 0; }
.faq summary { cursor: pointer; font-weight: 600; min-height: 44px; align-content: center; }
#analytics-consent .arc-consent-settings { margin-top: 32px; }
#analytics-consent button { min-height: 44px; padding: 8px 16px; }
#analytics-consent button[data-consent=denied] { background: var(--soft); color: var(--ink); border-color: var(--border); }
footer { border-top: 1px solid var(--border); padding: 38px 0; color: var(--muted); font-size: .88rem; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.footer-inner nav { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-inner nav a { color: var(--muted); min-height: 44px; display: inline-flex; align-items: center; }
.footer-brand { color: var(--ink); font-size: 1.2rem; }
.footer-brand small { display: block; font-size: .65rem; color: var(--muted); letter-spacing: .23em; margin-top: 8px; }
.ad-slot[hidden] { display: none !important; }
.skip-link { position: absolute; left: 16px; top: -80px; padding: 12px 18px; background: var(--surface); z-index: 100; }
.skip-link:focus { top: 12px; }
.related { border-top: 1px solid var(--border); padding-top: 32px; }
.related nav { display: flex; flex-wrap: wrap; gap: 12px 24px; }
.related a { min-height: 44px; display: inline-flex; align-items: center; }
.table-scroll { overflow-x: auto; }
table { width: 100%; max-width: 780px; border-collapse: collapse; font-variant-numeric: tabular-nums; }
th,td { padding: 14px; text-align: left; border-bottom: 1px solid var(--border); }
caption { text-align: left; color: var(--muted); font-size: .9rem; margin-bottom: 12px; }
/* The landing page is editorial: one hand example and three clear pathways. */
main.home > section { margin-top: 0; }
.home-hero { display: grid; grid-template-columns: 1.15fr 1fr; align-items: center; gap: 72px; padding: 85px 0 90px; }
.home-hero h1 { font-size: clamp(3.6rem, 6.8vw, 5.8rem); line-height: 1; letter-spacing: -.055em; margin: 24px 0 28px; }
.home-hero .lede { font-size: 1.35rem; line-height: 1.5; color: var(--ink); }
.hero-detail { color: var(--muted); max-width: 44ch; font-size: .95rem; }
.hand-preview { padding: 28px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; }
.preview-top, .preview-bottom { display: flex; align-items: center; justify-content: space-between; gap: 10px; color: var(--muted); font-size: .65rem; letter-spacing: .12em; }
.example-label { border: 1px solid var(--border); border-radius: 4px; padding: 4px 8px; letter-spacing: 0; }
.preview-heading { padding: 30px 0 22px; }
.preview-heading .eyebrow { display: block; font-size: .65rem; }
.preview-heading strong { font-size: 2.9rem; font-weight: 500; letter-spacing: -.025em; }
.suit { font-size: .7em; margin-right: 16px; }
.preview-line { display: flex; justify-content: space-between; gap: 12px; border-top: 1px solid var(--border); padding: 13px 0; font-size: .85rem; }
.preview-line span { color: var(--muted); }
.preview-line strong { font-weight: 500; }
.board { display: flex; gap: 10px; margin-top: 20px; }
.board > span { display: inline-flex; align-items: center; justify-content: center; gap: 4px; border: 1px solid var(--border); background: var(--soft); border-radius: 6px; width: 58px; height: 74px; font-size: 1.3rem; }
.red-suit { color: #b44747; }
.preview-question { margin: 24px 0; color: var(--muted); font-size: .9rem; }
.preview-bottom { border-top: 1px solid var(--border); padding-top: 20px; }
.principles { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.principles > div { padding: 34px 30px; }
.principles > div:first-child { padding-left: 0; }
.principles > div + div { border-left: 1px solid var(--border); }
.principles .index { color: var(--muted); font-size: .75rem; }
.principles h2 { margin: 25px 0 12px; }
.principles p { color: var(--muted); font-size: .95rem; }
.principles a { display: inline-flex; align-items: center; min-height: 44px; font-size: .9rem; }
.editorial { padding: 84px 0; max-width: 730px; }
.editorial h2 { font-size: clamp(2rem, 4vw, 3rem); margin: 24px 0; }
.editorial p { color: var(--muted); }
.tool-list { border-top: 1px solid var(--border); padding: 55px 0 80px; display: grid; grid-template-columns: 1fr 1.4fr; gap: 40px; }
.tool-list a { display: flex; justify-content: space-between; align-items: center; color: var(--ink); text-decoration: none; font-size: 1.35rem; border-bottom: 1px solid var(--border); padding: 24px 0; gap: 24px; }
.tool-list a:first-child { padding-top: 0; }
.tool-list a:hover { color: var(--accent); }
.tool-list small { display: block; margin-top: 8px; font-size: .85rem; color: var(--muted); }
@media (max-width: 850px) {
 .home-hero { gap: 32px; padding: 55px 0; }
 .hand-preview { padding: 20px; }
 .home-hero h1 { font-size: 3.8rem; }
}
@media (max-width: 680px) {
  .nav { padding-block: 14px; gap: 12px; flex-wrap: wrap; }
  .navlinks { gap: 8px 16px; justify-content: flex-start; }
  .navlinks a.nav-cta { padding-left: 12px; }
  .hero { padding-top: 28px; }
  .grid, .grid.two, .card-grid, .form-grid, .home-hero, .principles, .tool-list { grid-template-columns: 1fr; }
  .card, .calculator, .notice, .cta, .formula { padding: 20px; }
  .footer-inner { align-items: flex-start; flex-direction: column; }
  .home-hero { padding-top: 42px; }
  .home-hero h1 { font-size: clamp(3.3rem, 13vw, 4.4rem); }
  .home-hero .lede { font-size: 1.15rem; }
  .hand-preview { max-width: 460px; width: 100%; margin-top: 8px; }
  .principles > div, .principles > div:first-child { padding: 26px 0; }
  .principles > div + div { border-left: 0; border-top: 1px solid var(--border); }
  .principles h2 { margin-top: 14px; }
  .editorial { padding-block: 55px; }
  .tool-list { gap: 20px; padding-block: 40px 55px; }
}
@media (max-width: 400px) {
  .wrap, .nav { width: calc(100% - 32px); }
  .actions .button { width: 100%; }
  .preview-top, .preview-bottom { font-size: .6rem; letter-spacing: .06em; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { transition: none !important; scroll-behavior: auto !important; } }

/* Hybrid D: dark brand frame; light, readable content and calculators. */
.arc-dark { color: var(--ink); background: var(--canvas); color-scheme: dark; }
header.arc-dark { border-color: var(--border); }
.home-hero.arc-dark { position: relative; isolation: isolate; }
.home-hero.arc-dark::before { content: ""; position: absolute; inset: 0 calc((min(1120px, 100vw - 48px) - 100vw) / 2); z-index: -1; background: var(--canvas); }
.home-hero .hand-preview { --ink: #0f172a; --muted: #64748b; --surface: #ffffff; --soft: #f1f3f5; --border: #e5e7eb; --accent: #047857; color: var(--ink); box-shadow: 0 16px 40px rgb(0 0 0 / .12); }
.home-hero .hand-preview .brand-accent { color: #047857; }
.home-hero .button.secondary { border-color: #64748b; }
.home-hero .button:not(.secondary) { background: #10b981; color: #06271d; }
.home-hero .button:not(.secondary):hover { background: #34d399; }
.home .principles { margin-top: 48px; }
.home .cta { background: #ffffff; }
.card, .calculator { box-shadow: 0 2px 8px rgb(15 23 42 / .025); }
.calculator { margin-top: 20px; }
.result { border: 1px solid var(--border); }
input, select, .preview-heading strong { font-variant-numeric: tabular-nums; }
footer { background: var(--surface); }
@media (max-width: 400px) { .home-hero.arc-dark::before { inset-inline: -16px; } }

.metric.is-negative { color: #b44747; }
.metric.is-neutral { color: var(--ink); }