/* ============================================================
   Lucentum — shared design system
   Direction: modern-minimal (Linear / Vercel posture)
   ============================================================ */

:root {
  /* Palette — modern-minimal, strengthened for contrast + presence */
  --bg:      oklch(99% 0.002 240);
  --surface: oklch(100% 0 0);
  --fg:      oklch(14% 0.016 262);
  --muted:   oklch(48% 0.016 258);
  --border:  oklch(88% 0.007 258);
  --border-strong: oklch(80% 0.012 258);
  --accent:  oklch(54% 0.21 256);

  /* Deep ink — anchors dark slabs (hero, CTA) */
  --ink-deep: oklch(17% 0.03 262);
  --ink-2:    oklch(22% 0.035 262);

  /* Derived tints */
  --accent-weak:  oklch(54% 0.21 256 / 0.12);
  --accent-hover: oklch(47% 0.21 256);
  --accent-bright: oklch(72% 0.16 250);
  --fg-weak:      oklch(33% 0.016 258);
  --surface-2:    oklch(97% 0.004 258);

  /* Companion accent — used only in gradients / hero glow */
  --accent-2:      oklch(70% 0.16 205);
  --accent-2-weak: oklch(70% 0.16 205 / 0.12);

  /* Elevation — two levels only, tinted toward ink */
  --shadow-sm: 0 1px 2px oklch(24% 0.03 262 / 0.06), 0 3px 8px oklch(24% 0.03 262 / 0.08);
  --shadow-md: 0 8px 20px oklch(20% 0.03 262 / 0.10), 0 24px 56px oklch(20% 0.03 262 / 0.14);

  --font-display: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', system-ui, sans-serif;
  --font-body:    -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', system-ui, sans-serif;
  --font-mono:    ui-monospace, 'JetBrains Mono', 'SF Mono', Menlo, monospace;

  /* Fluid type scale */
  --step--1: clamp(0.82rem, 0.8rem + 0.1vw, 0.9rem);
  --step-0:  clamp(1rem, 0.96rem + 0.2vw, 1.12rem);
  --step-1:  clamp(1.2rem, 1.1rem + 0.5vw, 1.5rem);
  --step-2:  clamp(1.6rem, 1.35rem + 1.1vw, 2.25rem);
  --step-3:  clamp(2.1rem, 1.6rem + 2.4vw, 3.4rem);
  --step-4:  clamp(2.7rem, 1.9rem + 4vw, 5rem);

  --maxw: 1180px;
  --gutter: clamp(20px, 5vw, 64px);
  --radius: 14px;
  --radius-sm: 10px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

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

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--fg);
  font-size: var(--step-0);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 680;
  line-height: 1.06;
  letter-spacing: -0.025em;
  text-wrap: balance;
}
h1 { letter-spacing: -0.035em; }

p { text-wrap: pretty; }

a { color: inherit; text-decoration: none; }

.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* ---------- Layout ---------- */
.wrap { max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }

section { padding-block: clamp(56px, 9vw, 128px); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.eyebrow::before {
  content: "";
  width: 20px; height: 1px;
  background: var(--accent);
}

.lead { font-size: var(--step-1); color: var(--fg-weak); font-weight: 400; }
.muted { color: var(--muted); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-body);
  font-size: var(--step-0);
  font-weight: 500;
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .16s ease, border-color .16s ease, transform .16s ease, color .16s ease;
  white-space: nowrap;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); }
.btn-ghost { border-color: var(--border); color: var(--fg); background: transparent; }
.btn-ghost:hover { border-color: var(--fg-weak); background: var(--surface-2); }
.btn-arrow { transition: transform .16s ease; }
.btn:hover .btn-arrow { transform: translateX(3px); }

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in oklab, var(--bg) 78%, transparent);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw); margin-inline: auto;
  padding: 14px var(--gutter);
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-family: var(--font-display); font-weight: 600; font-size: 1.12rem; letter-spacing: -0.02em; }
/* Ascend mark — two nested peaks rising to a spark of light.
   Inlined as an SVG data-URI so every nav + footer across the site picks it up. */
.brand-mark {
  width: 28px; height: 28px; flex: none;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 48 48' fill='none'%3E%3Cdefs%3E%3ClinearGradient id='m' x1='14' y1='42' x2='34' y2='24' gradientUnits='userSpaceOnUse'%3E%3Cstop stop-color='%232f6feb'/%3E%3Cstop offset='1' stop-color='%2329a7cc'/%3E%3C/linearGradient%3E%3C/defs%3E%3Cpath d='M6 35 L24 11 L42 35' stroke='%2317181c' stroke-width='4.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3Cpath d='M14 41 L24 27.5 L34 41' stroke='url(%23m)' stroke-width='4.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3Ccircle cx='24' cy='6.5' r='2.8' fill='%2329a7cc'/%3E%3C/svg%3E") center / contain no-repeat;
  transition: transform .2s ease;
}
.brand:hover .brand-mark { transform: translateY(-1px); }
.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a {
  padding: 8px 12px; border-radius: 8px; color: var(--fg-weak); font-size: var(--step--1);
  transition: color .14s, background .14s;
}
.nav-links a:hover { color: var(--fg); background: var(--surface-2); }
.nav-links a.active { color: var(--fg); }
.nav-cta { display: flex; align-items: center; gap: 10px; }
.nav-toggle { display: none; background: none; border: 1px solid var(--border); border-radius: 8px; width: 40px; height: 40px; cursor: pointer; align-items: center; justify-content: center; }
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after {
  content: ""; display: block; width: 16px; height: 1.5px; background: var(--fg); position: relative; transition: .2s;
}
.nav-toggle span::before { position: absolute; top: -5px; }
.nav-toggle span::after { position: absolute; top: 5px; }

@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .nav-links {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 2px;
    background: var(--surface); border-bottom: 1px solid var(--border);
    padding: 12px var(--gutter) 20px;
    transform: translateY(-8px); opacity: 0; pointer-events: none; transition: .18s;
  }
  .nav-links a { padding: 12px; font-size: 1rem; }
  .nav[data-open="true"] .nav-links { transform: none; opacity: 1; pointer-events: auto; }
  .nav-links .mobile-cta { margin-top: 8px; }
}
@media (min-width: 861px) { .nav-links .mobile-cta { display: none; } }

/* ---------- Footer ---------- */
/* Deep-ink slab — anchors every page with a strong dark base + faint rising glow */
.footer {
  padding-block: 64px;
  background: var(--ink-deep);
  color: oklch(80% 0.02 258);
  position: relative;
  overflow: hidden;
  isolation: isolate;
}
.footer::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(70% 90% at 82% -20%, oklch(54% 0.21 256 / 0.22), transparent 62%),
    radial-gradient(50% 70% at 96% 0%, oklch(70% 0.16 205 / 0.14), transparent 70%);
  pointer-events: none;
}
.footer .brand { color: #fff; }
/* White-stroke mark variant so the outer peak stays visible on the dark footer */
.footer .brand-mark {
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 48 48' fill='none'%3E%3Cdefs%3E%3ClinearGradient id='m' x1='14' y1='42' x2='34' y2='24' gradientUnits='userSpaceOnUse'%3E%3Cstop stop-color='%235a9cff'/%3E%3Cstop offset='1' stop-color='%2340c4e8'/%3E%3C/linearGradient%3E%3C/defs%3E%3Cpath d='M6 35 L24 11 L42 35' stroke='%23ffffff' stroke-width='4.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3Cpath d='M14 41 L24 27.5 L34 41' stroke='url(%23m)' stroke-width='4.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3Ccircle cx='24' cy='6.5' r='2.8' fill='%2340c4e8'/%3E%3C/svg%3E") center / contain no-repeat;
}
.footer .footer-brand .muted { color: oklch(70% 0.02 258); }
.footer-grid { display: grid; grid-template-columns: 1.4fr repeat(2, 1fr); gap: 40px; }
.footer h4 { font-size: var(--step--1); font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.06em; color: oklch(66% 0.03 258); margin-bottom: 14px; font-weight: 500; }
.footer a { display: block; color: oklch(78% 0.02 258); padding: 5px 0; font-size: var(--step--1); transition: color .14s; }
.footer a:hover { color: var(--accent-bright); }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; margin-top: 44px; padding-top: 24px; border-top: 1px solid oklch(100% 0 0 / 0.10); color: oklch(62% 0.02 258); font-size: var(--step--1); gap: 16px; flex-wrap: wrap; }
@media (max-width: 680px) { .footer-grid { grid-template-columns: 1fr 1fr; } .footer-brand { grid-column: 1 / -1; } }

/* ---------- Cards / grids ---------- */
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: clamp(22px, 3vw, 32px);
  box-shadow: var(--shadow-sm);
  transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: color-mix(in oklab, var(--accent) 26%, var(--border));
}
.grid { display: grid; gap: 20px; }
.cols-2 { grid-template-columns: repeat(2, 1fr); }
.cols-3 { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 860px) { .cols-3 { grid-template-columns: 1fr; } .cols-2 { grid-template-columns: 1fr; } }

.section-head { max-width: 60ch; margin-bottom: clamp(32px, 5vw, 56px); }
.section-head h2 { font-size: var(--step-2); margin: 16px 0 14px; }

/* ---------- Reveal on scroll ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- Section rhythm ---------- */
/* Tinted band with a faint dot grid — breaks the flat-white scroll */
.section-alt {
  background: var(--surface-2);
  border-block: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}
.section-alt::before {
  content: ""; position: absolute; inset: 0; z-index: 0;
  background-image: radial-gradient(oklch(54% 0.012 250 / 0.16) 1px, transparent 1px);
  background-size: 22px 22px;
  -webkit-mask-image: radial-gradient(120% 100% at 50% 0%, #000, transparent 72%);
          mask-image: radial-gradient(120% 100% at 50% 0%, #000, transparent 72%);
  pointer-events: none;
}
.section-alt > .wrap { position: relative; z-index: 1; }

/* ---------- Interior page hero band ---------- */
/* Tinted surface + faint accent glow + dividing border — gives interior pages
   presence at the top without going full-dark. Pages set their own padding. */
.page-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
  background:
    radial-gradient(58% 92% at 88% -12%, var(--accent-weak), transparent 60%),
    radial-gradient(40% 70% at 100% 0%, var(--accent-2-weak), transparent 72%),
    linear-gradient(var(--surface-2), var(--bg) 78%);
}
.page-hero::before {
  content: ""; position: absolute; inset: 0; z-index: 0; pointer-events: none;
  background-image: radial-gradient(oklch(54% 0.016 258 / 0.14) 1px, transparent 1px);
  background-size: 24px 24px;
  -webkit-mask-image: radial-gradient(120% 120% at 92% 0%, #000, transparent 60%);
          mask-image: radial-gradient(120% 120% at 92% 0%, #000, transparent 60%);
}
.page-hero > .wrap { position: relative; z-index: 1; }

/* ---------- Utility ---------- */
.divider { height: 1px; background: var(--border); border: 0; }
.tag {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.04em;
  text-transform: uppercase; color: var(--muted);
  border: 1px solid var(--border); border-radius: 999px; padding: 4px 10px;
}
.tag.accent { color: var(--accent); border-color: color-mix(in oklab, var(--accent) 40%, var(--border)); background: var(--accent-weak); }

/* ---------- Legal / long-form prose pages ---------- */
.legal { max-width: 780px; margin-inline: auto; }
.legal h1 { font-size: var(--step-3); margin-bottom: 10px; }
.legal .updated { color: var(--muted); font-family: var(--font-mono); font-size: var(--step--1); margin-bottom: 32px; display: block; }
.legal h3 { font-size: var(--step-2); margin: 8px 0 12px; }
.legal h4 { font-size: var(--step-1); margin: 28px 0 10px; }
.legal p { color: var(--fg-weak); margin-bottom: 14px; }
.legal ul, .legal ol { color: var(--fg-weak); margin: 0 0 14px 22px; }
.legal li { margin-bottom: 8px; }
.legal a { color: var(--accent); }
.legal strong { color: var(--fg); font-weight: 600; }