:root {
  
  --spacing: 0.25rem;
  --space-1: 0.25rem;  --space-2: 0.5rem;  --space-3: 0.75rem; --space-4: 1rem;
  --space-5: 1.5rem;   --space-6: 2rem;    --space-8: 3rem;
  --space-12: 4rem;    --space-16: clamp(3.5rem, 2.2rem + 5.5vw, 5.5rem);

  
  --container-wrap: 1100px;
  --gutter: clamp(1.25rem, 0.9rem + 1.5vw, 2rem);
  --nav-h: 60px;
  --rule-width: 1px;

  
  --text-display: clamp(2.25rem, 1.6273rem + 2.6564vw, 3.75rem);
  --text-h2:      clamp(1.5rem,  1.3757rem + 0.5304vw, 1.8rem);
  --text-h3:      clamp(1.125rem,1.0991rem + 0.1105vw, 1.1875rem);
  --text-lead:    clamp(1.0625rem, 1.0107rem + 0.2210vw, 1.1875rem);
  --text-body:    1rem;
  --text-sm:      0.9375rem;
  --text-xs:      0.8125rem;
  --text-brand:   1.0625rem;

  --leading-tight: 1.08;
  --leading-normal: 1.55;
  --leading-relaxed: 1.65;

  --tracking-display: -0.022em;
  --tracking-heading: -0.014em;
  --tracking-normal:  -0.004em;
  --tracking-label:    0.06em;
  --tracking-brand:   -0.02em;
  --tracking-button:   0;

  --font-weight-display: 600;
  --font-weight-normal: 400;
  --font-weight-semibold: 600;
  --font-weight-brand: 600;

  --display-transform: none;
  --label-transform: uppercase;
  --brand-transform: none;
  --button-transform: none;
  --display-measure: 20ch;

  --font-display: var(--font-ui);
  --font-label:   var(--font-ui);
  --font-ui:   -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  
  --radius-sm: 4px; --radius-md: 6px; --radius-lg: 10px; --radius-xl: 14px; --radius-pill: 999px;

  
  --shadow-raised: none;
  --shadow-pop: none;
  --shadow-button: none;

  
  --btn-pad-x: var(--space-5);
  --btn-pad-y: 0.6875rem;
  --mark-display: grid;
  --logo-h: 14px;      
  

  
  --color-label: var(--color-fg-muted);
}

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

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

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-fg);
  font-family: var(--font-ui);
  font-size: var(--text-body);
  line-height: var(--leading-normal);
  letter-spacing: var(--tracking-normal);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { margin: 0; font-weight: var(--font-weight-display); }

h2, h3, h4 { text-wrap: balance; }
h2 {
  font-size: var(--text-h2);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-heading);
  max-width: var(--measure-heading, none);
}
h3, h4 {
  font-size: var(--text-h3);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-heading);
}
p, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }

main p > a:not([class]),
footer p > a:not([class]) {
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  text-decoration-color: var(--color-line-strong);
}
main p > a:not([class]):hover,
footer p > a:not([class]):hover { text-decoration-color: currentColor; }
img, svg { max-width: 100%; height: auto; display: block; }

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}
::selection { background: var(--color-accent); color: var(--color-accent-fg); }

.wrap {
  width: 100%;
  max-width: var(--container-wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--space-16); }
.section + .section { border-top: var(--rule-width) solid var(--color-line); }
.section--surface { background: var(--color-surface); }

.eyebrow {
  display: block;
  font-family: var(--font-label);
  font-size: var(--text-xs);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--tracking-label);
  text-transform: var(--label-transform);
  color: var(--color-label);
  margin-bottom: var(--space-3);
}

.nav {
  height: var(--nav-h);
  background: var(--color-bg);
  border-bottom: var(--rule-width) solid var(--color-line);
  display: flex; align-items: center;
}
.nav__inner { display: flex; align-items: center; justify-content: space-between; gap: var(--space-6); width: 100%; }
.nav__brand {
  display: inline-flex; align-items: center; gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--text-brand);
  font-weight: var(--font-weight-brand);
  letter-spacing: var(--tracking-brand);
  text-transform: var(--brand-transform);
  color: var(--color-fg);
}

.nav__logo {
  height: var(--logo-h);
  aspect-ratio: 1582.5 / 118.25;
  background-color: var(--logo-color, var(--color-fg));
  -webkit-mask: url("brand/sophon-wordmark-tight.svg") no-repeat center / contain;
          mask: url("brand/sophon-wordmark-tight.svg") no-repeat center / contain;
}
.nav__brand--logo {
  gap: 0;
  
  min-height: 44px;
}

.nav__links { display: flex; align-items: center; gap: var(--space-1); }
.nav__link {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  color: var(--color-fg-muted);
  transition: color 150ms ease, background-color 150ms ease;
  white-space: nowrap;
}
.nav__link:hover { color: var(--color-fg); background: var(--color-surface-raised); }

.btn {
  display: inline-flex; align-items: center; gap: var(--space-2);
  padding: var(--btn-pad-y) var(--btn-pad-x);
  border: var(--rule-width) solid transparent;
  border-radius: var(--radius-md);
  font: inherit;
  font-family: var(--font-ui);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  letter-spacing: var(--tracking-button);
  text-transform: var(--button-transform);
  cursor: pointer; white-space: nowrap;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease;
}
.btn--primary { background: var(--color-accent); color: var(--color-accent-fg); box-shadow: var(--shadow-button); }
.btn--primary:hover { background: var(--color-accent-hover); }

.link-arrow {
  display: inline-flex; align-items: center; gap: var(--space-2);
  color: var(--color-accent);
  font-weight: var(--font-weight-semibold);
  font-size: var(--text-sm);
  
  min-height: 24px;
}
.link-arrow::after { content: "→"; transition: transform 150ms ease; }
.link-arrow:hover::after { transform: translateX(3px); }

.hero { padding-block: var(--space-16) var(--space-12); }
.hero__title {
  font-family: var(--font-display);
  font-size: var(--text-display);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-display);
  font-weight: var(--font-weight-display);
  text-transform: var(--display-transform);
  max-width: var(--display-measure);
  text-wrap: balance;
}

.hero__title em { font-style: normal; color: var(--color-fg-muted); }
.hero__sub {
  margin-top: var(--space-5);
  font-size: var(--text-lead);
  line-height: var(--leading-relaxed);
  color: var(--color-fg-muted);
  max-width: 56ch;
}
.hero__actions { margin-top: var(--space-6); display: flex; flex-wrap: wrap; gap: var(--space-3); }

.hero__grid { display: grid; gap: var(--space-8); }
@keyframes cue-wave { 0%,100% { transform: scaleY(0.45) } 50% { transform: scaleY(1) } }

.grid { display: grid; gap: var(--space-4); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
@media (max-width: 700px) { .grid--2 { grid-template-columns: 1fr; } }

.card {
  position: relative;
  background: var(--color-surface-raised);
  border: var(--rule-width) solid var(--color-line-strong);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-raised);
  padding: var(--space-5);
  display: flex; flex-direction: column; gap: var(--space-3);
  transition: border-color 150ms ease, box-shadow 150ms ease;
}
.card:hover { border-color: var(--color-accent-line); box-shadow: var(--shadow-pop); }
.card h3 {
  font-family: var(--font-display);
  font-size: var(--text-h3);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--font-weight-semibold);
}
.card__body { font-size: var(--text-sm); color: var(--color-fg-muted); line-height: var(--leading-relaxed); }
.card__meta { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-fg-muted); letter-spacing: 0; }
.card__foot { margin-top: auto; padding-top: var(--space-3); }

.card { position: relative; }
.card__link { color: inherit; text-decoration: none; }

.card__link::before { content: ""; position: absolute; inset: 0; border-radius: inherit; }
.card__link:focus-visible { outline: none; }
.card__link:focus-visible::before { outline: 2px solid var(--color-focus); outline-offset: 2px; }
.card:has(.card__link) { transition: border-color 150ms ease, background-color 150ms ease; }
.card:has(.card__link):hover { border-color: var(--color-control); background: var(--color-surface-raised); }

.card > *:not(.card__foot) { position: relative; }

.tags { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.tag {
  display: inline-flex; align-items: center;
  padding: 3px var(--space-2);
  border: var(--rule-width) solid var(--color-line-strong);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-fg-muted);
  letter-spacing: 0;
}
.tag--accent { border-color: var(--color-accent-line); background: var(--color-accent-surface); color: var(--color-accent); }

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

@media (max-width: 880px) {
  .nav__links { display: none; }
  
  :root { --logo-h: 12px; }
}

.facts { margin: var(--space-6) 0 0; max-width: var(--measure-body); }
.facts > div {
  display: grid; grid-template-columns: 11rem minmax(0, 1fr);
  gap: var(--space-4); padding: var(--space-4) 0;
  border-top: 1px solid var(--color-line);
  align-items: baseline;
}
@media (max-width: 640px) { .facts > div { grid-template-columns: 1fr; gap: var(--space-2); } }
.facts dt {
  margin: 0; color: var(--color-fg-muted);
  font-family: var(--font-mono); font-size: var(--text-xs);
  letter-spacing: 0.08em; text-transform: uppercase;
}
.facts dd {
  margin: 0; font-size: var(--text-h3); font-weight: 600;
  letter-spacing: -0.02em; line-height: 1.25; overflow-wrap: anywhere;
}
.facts dd.plain { font-size: var(--text-body); font-weight: 400; letter-spacing: normal; line-height: 1.6; }
.facts dt a { color: var(--color-fg); font-family: var(--font-ui); font-size: var(--text-body);
  font-weight: 600; letter-spacing: normal; text-transform: none;
  display: inline-flex; align-items: center; min-height: 24px;
  text-decoration: underline; text-decoration-thickness: 1px;
  text-underline-offset: 0.18em; text-decoration-color: var(--color-line-strong); }
.facts dt a:hover { text-decoration-color: currentColor; }
.pkg { font-family: var(--font-mono); font-size: var(--text-xs); letter-spacing: 0;
  color: var(--color-fg-muted); display: block; margin-top: 2px; font-weight: 400; }