/* Hallmark · macrostructure: API Product · tone: technical · theme: Cobalt
 * paper: cool-light (L98.5, hue250) · display: grotesk-sans (Space Grotesk) · accent: electric cobalt (hue256)
 * pre-emit critique: P5 H4 E5 S5 R4 V5
 */

:root {
  /* ── Colors (OKLCH, Cobalt) ── */
  --color-paper:    oklch(98.5% 0.004 250);
  --color-paper-2:  oklch(96%  0.006 250);
  --color-paper-3:  oklch(93%  0.008 250);
  --color-rule:     oklch(88%  0.010 250);
  --color-rule-2:   oklch(82%  0.012 250);
  --color-neutral:  oklch(56%  0.010 250);
  --color-muted:    oklch(40%  0.014 255);
  --color-ink:      oklch(24%  0.020 258);
  --color-ink-2:    oklch(34%  0.018 257);
  --color-ink-3:    oklch(50%  0.014 256);
  --color-accent:   oklch(58%  0.200 256);   /* electric cobalt */
  --color-accent-hover: oklch(50% 0.200 256);
  --color-accent-muted: oklch(70% 0.080 256 / 0.14);
  --color-focus:    oklch(58%  0.200 256);
  --color-success:  oklch(55%  0.150 150);
  --color-error:    oklch(55%  0.200 25);
  --color-warning:  oklch(65%  0.150 85);
  --color-graphite: oklch(22%  0.016 260);   /* dark band */
  --color-graphite-2: oklch(28% 0.018 260);
  --color-on-graphite: oklch(92% 0.008 250);
  --color-accent-ink: oklch(98% 0.004 250);  /* text on accent fill */
  --color-overlay: oklch(20% 0.02 260 / 0.42);
  --color-success-muted: oklch(90% 0.06 150);
  --color-error-muted: oklch(93% 0.05 25);
  --color-warning-muted: oklch(92% 0.07 85 / 0.35);

  /* ── Typography (2+1: Space Grotesk + Inter + JetBrains Mono) ── */
  --font-display: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

  --text-display: clamp(2.5rem, 5vw, 4rem);
  --text-display-s: clamp(1.8rem, 3.5vw, 2.8rem);
  --text-h1: clamp(1.5rem, 2.5vw, 2rem);
  --text-h2: clamp(1.2rem, 2vw, 1.5rem);
  --text-h3: clamp(1rem, 1.5vw, 1.15rem);
  --text-body: clamp(0.875rem, 1.2vw, 1rem);
  --text-md: 1.125rem;
  --text-sm: 0.8125rem;
  --text-xs: 0.75rem;

  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;

  --leading-tight: 1.15;
  --leading-normal: 1.5;
  --leading-relaxed: 1.65;

  /* ── Spacing (4pt scale) ── */
  --space-xxs: 4px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  /* ── Radii (tight technical) ── */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 10px;
  --radius-xl: 14px;
  --radius-full: 9999px;

  /* ── Shadows (barely-there) ── */
  --shadow-sm: 0 1px 2px oklch(0% 0 0 / 0.04);
  --shadow-md: 0 2px 8px oklch(0% 0 0 / 0.06);
  --shadow-lg: 0 4px 24px oklch(0% 0 0 / 0.08);

  /* ── Duration & Easing ── */
  --dur-fast: 150ms;
  --dur-normal: 250ms;
  --dur-slow: 400ms;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in: cubic-bezier(0.4, 0, 0.68, 0.06);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);

  /* ── Z-index scale (named, six levels) ── */
  --z-base: 1;
  --z-raised: 10;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-modal: 400;
  --z-toast: 500;
  --z-tooltip: 600;
}

/* ── Base ── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; overflow-x: clip; }
body {
  overflow-x: clip;
  margin: 0;
  background: var(--color-paper);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-body);
  line-height: var(--leading-normal);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-style: normal;               /* no italic headers */
  line-height: var(--leading-tight);
  margin: 0 0 var(--space-sm);
  overflow-wrap: anywhere;
  min-width: 0;
}
p { line-height: var(--leading-relaxed); color: var(--color-ink-2); margin: 0 0 var(--space-md); }
a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
code, pre { font-family: var(--font-mono); font-size: 0.9em; }
img, video, audio { max-width: 100%; }
button { font-family: inherit; }
:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }

/* ── Mono labels (machine-readout voice) ── */
.eyebrow, .mono-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-accent);
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-rule-2);
  background: var(--color-paper);
  color: var(--color-ink);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  cursor: pointer;
  text-decoration: none;
  transition: border-color var(--dur-fast), background var(--dur-fast), color var(--dur-fast);
}
.btn:hover { border-color: var(--color-accent); color: var(--color-accent); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--color-accent); border-color: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-hover); border-color: var(--color-accent-hover); color: #fff; }
.btn-secondary { background: var(--color-paper-2); }
.btn-ghost { background: transparent; border-color: transparent; color: var(--color-accent); }
.btn-ghost:hover { background: var(--color-accent-muted); }
.btn-ink { background: var(--color-ink); border-color: var(--color-ink); color: var(--color-paper); }
.btn-ink:hover { background: var(--color-accent); border-color: var(--color-accent); color: #fff; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* ── Cards (hairline, no heavy shadow) ── */
.card {
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}
.card-title { font-size: var(--text-h3); font-weight: var(--weight-semibold); margin: 0 0 var(--space-xs); }
.card-text { color: var(--color-ink-2); font-size: var(--text-sm); line-height: var(--leading-relaxed); }

/* ── Forms ── */
.form-field { margin-bottom: var(--space-md); }
.form-label { display: block; font-size: var(--text-sm); font-weight: var(--weight-medium); margin-bottom: var(--space-xs); color: var(--color-ink); }
.form-input {
  width: 100%;
  box-sizing: border-box;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-rule-2);
  border-radius: var(--radius-md);
  background: var(--color-paper);
  color: var(--color-ink);
  font-size: var(--text-sm);
  font-family: inherit;
}
.form-input:focus { outline: none; border-color: var(--color-accent); box-shadow: 0 0 0 2px var(--color-accent-muted); }
.form-hint { font-size: var(--text-xs); color: var(--color-ink-3); margin-top: var(--space-xxs); }
.form-error { color: var(--color-error); font-size: var(--text-sm); margin-bottom: var(--space-md); }
.form-success { color: var(--color-success); font-size: var(--text-sm); margin-bottom: var(--space-md); }

/* ── Layout primitives ── */
.site-shell { min-height: 100vh; display: flex; flex-direction: column; }
.page-container { width: 100%; max-width: 1100px; margin: 0 auto; padding: var(--space-xl) var(--space-lg); }
.page-section { padding: var(--space-3xl) 0; }
.page-section:first-of-type { padding-top: var(--space-2xl); }
.section-title { font-size: var(--text-h1); font-weight: var(--weight-semibold); }
.lead { font-size: var(--text-h3); color: var(--color-ink-2); line-height: var(--leading-relaxed); max-width: 60ch; }
.text-muted { color: var(--color-ink-3); }

/* ── Nav (bordered, flush) ── */
.site-nav {
  display: flex;
  justify-content: center;
  border-bottom: 1px solid var(--color-rule);
  background: var(--color-paper);
  position: sticky;
  top: 0;
  z-index: 100;
}
.site-nav-inner {
  width: 100%;
  max-width: 1100px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-lg);
}
.nav-brand {
  font-family: var(--font-display);
  font-weight: var(--weight-semibold);
  font-size: var(--text-h3);
  color: var(--color-ink);
  text-decoration: none;
  letter-spacing: -0.01em;
}
.nav-brand:hover { color: var(--color-accent); text-decoration: none; }
.nav-links { display: flex; align-items: center; gap: var(--space-md); }
.nav-link {
  font-size: var(--text-sm);
  color: var(--color-ink-2);
  text-decoration: none;
  padding: var(--space-xxs) 0;
  border-bottom: 2px solid transparent;
  white-space: nowrap;
}
.nav-link:hover { color: var(--color-accent); text-decoration: none; border-bottom-color: var(--color-accent); }

/* ── Footer ── */
.site-footer { border-top: 1px solid var(--color-rule); margin-top: auto; }
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-lg);
  display: flex;
  justify-content: space-between;
  gap: var(--space-md);
  flex-wrap: wrap;
}
.footer-statement { font-size: var(--text-sm); color: var(--color-ink-3); }

/* ── Reveal (fade + rise) ── */
.reveal { opacity: 0; transform: translateY(10px); transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out); }
.reveal.is-in { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ── Responsive (mobile-first) ── */
@media (max-width: 640px) {
  .nav-links { gap: var(--space-sm); }
  .nav-link { font-size: var(--text-xs); }
  .page-container { padding: var(--space-lg) var(--space-md); }
  .page-section { padding: var(--space-2xl) 0; }
}