/* keel.css - self-contained, offline stylesheet for the Keel landing page.
   No runtime third-party dependencies (no Tailwind CDN, no Google Fonts,
   no Lucide unpkg). Utility classes below are hand-authored equivalents of
   the Tailwind v3 classes the page uses, plus the page's component classes. */

/* ---- Base / fonts (system stacks; Inter + JetBrains Mono removed) ---- */
html, body {
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: #0a0a0a; color: #f4f4f5; -webkit-font-smoothing: antialiased;
  overflow-x: hidden; max-width: 100%;
}
* { box-sizing: border-box; }
body { margin: 0; }

/* ============================================================
   Component classes (moved verbatim from the inline <style>,
   with font-families swapped to system stacks).
   ============================================================ */
.grid > * { min-width: 0; }
code, pre { font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace; }
.grid-bg {
  background-image:
    linear-gradient(to right, rgba(255,255,255,0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at top, black 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at top, black 30%, transparent 75%);
}
.hairline { border-color: rgba(255,255,255,0.08); }
.hairline-b { border-bottom: 1px solid rgba(255,255,255,0.08); }
.hairline-t { border-top: 1px solid rgba(255,255,255,0.08); }
.chip {
  display: inline-flex; align-items: center; gap: .375rem;
  padding: .125rem .5rem; border-radius: 9999px;
  font-size: .6875rem; letter-spacing: .04em; text-transform: uppercase;
  color: #d4d4d8; border: 1px solid rgba(255,255,255,0.10);
  background: rgba(255,255,255,0.025);
}
.accent-dot { width: .375rem; height: .375rem; border-radius: 9999px; background: #fafafa; }
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .625rem 1rem; border-radius: .375rem;
  font-size: .875rem; font-weight: 500;
  transition: background-color .15s ease, border-color .15s ease, color .15s ease;
}
.btn-primary { background: #f4f4f5; color: #0a0a0a; }
.btn-primary:hover { background: #ffffff; }
.btn-ghost { background: transparent; color: #f4f4f5; border: 1px solid rgba(255,255,255,0.12); }
.btn-ghost:hover { background: rgba(255,255,255,0.04); border-color: rgba(255,255,255,0.22); }
.link { color: #d4d4d8; transition: color .15s ease; }
.link:hover { color: #ffffff; }
.kbd { font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace; font-size: .75rem; padding: .0625rem .375rem; border-radius: .25rem; background: rgba(255,255,255,0.06); color: #e4e4e7; border: 1px solid rgba(255,255,255,0.08); }
.code-block { background: #0f0f10; border: 1px solid rgba(255,255,255,0.08); border-radius: .5rem; overflow: hidden; }
.code-block header { padding: .5rem .875rem; border-bottom: 1px solid rgba(255,255,255,0.06); font-size: .6875rem; color: #a1a1aa; letter-spacing: .04em; text-transform: uppercase; display: flex; align-items: center; gap: .5rem; }
.code-block pre { padding: 1rem 1.125rem; overflow-x: auto; font-size: .8125rem; line-height: 1.6; color: #e4e4e7; }
.tk-attr { color: #c4b5fd; }
.tk-type { color: #f0abfc; }
.tk-key { color: #c4b5fd; }
.tk-str { color: #86efac; }
.tk-num { color: #fcd34d; }
.tk-com { color: #808089; font-style: italic; }
.tk-fn  { color: #93c5fd; }
.tk-kw  { color: #f0abfc; }
.tk-id  { color: #e4e4e7; }
.tk-acc { color: #22d3a8; }
.rule { height: 1px; background: linear-gradient(to right, transparent, rgba(255,255,255,0.08), transparent); }
.cmp-table { width: 100%; border-collapse: collapse; font-size: .8125rem; }
.cmp-table th, .cmp-table td { padding: .75rem 1rem; text-align: left; border-bottom: 1px solid rgba(255,255,255,0.06); }
.cmp-table thead th { font-size: .6875rem; text-transform: uppercase; letter-spacing: .04em; color: #a1a1aa; font-weight: 500; background: rgba(255,255,255,0.015); }
.cmp-table tbody td:not(:first-child) { text-align: center; font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace; font-size: .875rem; }
.cmp-table tbody tr:hover { background: rgba(255,255,255,0.015); }
.cmp-table tbody tr:last-child td { border-bottom: 0; }
.maturity-table tbody td:not(:first-child) { text-align: left; font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; font-size: .8125rem; }
.maturity-table tbody td:nth-child(2) { width: 8.5rem; font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace; font-size: .75rem; text-transform: uppercase; letter-spacing: .04em; white-space: nowrap; }
.cmp-yes { color: #22d3a8; }
.cmp-no  { color: #52525b; }
.cmp-part { color: #a78bfa; font-size: .75rem !important; letter-spacing: .04em; }
.cmp-keel-col { background: rgba(34,211,168,0.04); border-left: 1px solid rgba(34,211,168,0.15); border-right: 1px solid rgba(34,211,168,0.15); }
.stat-num { font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace; font-weight: 500; color: #fafafa; font-size: 1.5rem; line-height: 1; }
.stat-num small { font-size: .875rem; color: #a1a1aa; margin-left: .125rem; }
.stat-label { font-size: .75rem; text-transform: uppercase; letter-spacing: .06em; color: #a1a1aa; margin-top: .5rem; }
.stat-foot  { font-size: .75rem; color: #a1a1aa; margin-top: .375rem; line-height: 1.4; }
.layer-card { border: 1px solid rgba(255,255,255,0.08); border-radius: .625rem; background: rgba(255,255,255,0.015); overflow: hidden; }
.layer-card header { padding: .625rem .875rem; border-bottom: 1px solid rgba(255,255,255,0.06); display: flex; align-items: center; gap: .5rem; }
.layer-tag { font-size: .625rem; text-transform: uppercase; letter-spacing: .08em; color: #808089; margin-left: auto; }

/* Architecture uses normal text boxes so labels remain readable on small screens. */
.hero-spacing { padding-top: 3rem; padding-bottom: 3rem; }
.nav-desktop { display: none; }
.architecture-map { margin: 0; padding: 1.25rem; border: 1px solid rgba(255,255,255,0.12); border-radius: .625rem; background: #0f0f10; }
.arch-stage { padding: 1rem; border: 1px solid rgba(255,255,255,0.10); border-radius: .375rem; min-width: 0; }
.arch-semantics { border-color: rgba(34,211,168,0.45); }
.arch-label { color: #22d3a8; font-size: .6875rem; text-transform: uppercase; letter-spacing: .07em; line-height: 1.5; }
.architecture-map p { margin: .625rem 0 0; font-size: .875rem; line-height: 1.6; overflow-wrap: anywhere; }
.architecture-map code { font-size: .8125rem; }
.architecture-map .arch-note { font-size: .8125rem; color: #a1a1aa; }
.arch-connector { text-align: center; color: #808089; padding: .25rem; }
.arch-axes { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: .75rem; }
.arch-stage .rule { margin-top: .875rem; }
.arch-platform { margin-top: .75rem; padding: 1rem; border-left: 2px solid #808089; }
.architecture-map figcaption { margin-top: 1rem; font-size: .875rem; color: #e4e4e7; }
.architecture-detail > summary { cursor: pointer; padding: .5rem 0; font-size: .875rem; }
.evidence-list { padding-left: 1.125rem; }
.evidence-list li + li { margin-top: .75rem; }
section[id] { scroll-margin-top: 4.5rem; }
@media (max-width: 600px) {
  .arch-axes { grid-template-columns: minmax(0,1fr); }
  .architecture-map { padding: .875rem; }
}
@media (min-width: 1024px) {
  .hero-spacing { padding-top: 4rem; padding-bottom: 4rem; }
  .nav-desktop { display: flex; }
  .nav-mobile { display: none; }
}

/* ============================================================
   Tailwind v3 utility classes used by the page.
   ============================================================ */

/* ---- Layout / display ---- */
.relative { position: relative; }
.absolute { position: absolute; }
.sticky { position: sticky; }
.inset-0 { top: 0; right: 0; bottom: 0; left: 0; }
.top-0 { top: 0; }
.z-30 { z-index: 30; }
.block { display: block; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }
.hidden { display: none; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.shrink-0 { flex-shrink: 0; }
.overflow-hidden { overflow: hidden; }
.overflow-x-auto { overflow-x: auto; }
.pointer-events-none { pointer-events: none; }

/* ---- Sizing ---- */
.h-3 { height: .75rem; }
.h-3\.5 { height: .875rem; }
.h-4 { height: 1rem; }
.h-5 { height: 1.25rem; }
.h-6 { height: 1.5rem; }
.h-14 { height: 3.5rem; }
.w-3 { width: .75rem; }
.w-3\.5 { width: .875rem; }
.w-4 { width: 1rem; }
.w-5 { width: 1.25rem; }
.w-6 { width: 1.5rem; }

/* ---- Max width ---- */
.max-w-xl { max-width: 36rem; }
.max-w-2xl { max-width: 42rem; }
.max-w-6xl { max-width: 72rem; }

/* ---- Grid ---- */
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

/* ---- Spacing: margin ---- */
.mx-auto { margin-left: auto; margin-right: auto; }
.ml-auto { margin-left: auto; }
.ml-1\.5 { margin-left: .375rem; }
.mb-2 { margin-bottom: .5rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mt-0\.5 { margin-top: .125rem; }
.mt-1 { margin-top: .25rem; }
.mt-3 { margin-top: .75rem; }
.mt-4 { margin-top: 1rem; }
.mt-5 { margin-top: 1.25rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }
.mt-10 { margin-top: 2.5rem; }

/* ---- Spacing: padding ---- */
.p-5 { padding: 1.25rem; }
.px-3 { padding-left: .75rem; padding-right: .75rem; }
.px-6 { padding-left: 1.5rem; padding-right: 1.5rem; }
.py-1 { padding-top: .25rem; padding-bottom: .25rem; }
.py-8 { padding-top: 2rem; padding-bottom: 2rem; }
.py-10 { padding-top: 2.5rem; padding-bottom: 2.5rem; }
.py-14 { padding-top: 3.5rem; padding-bottom: 3.5rem; }
.py-16 { padding-top: 4rem; padding-bottom: 4rem; }
.pt-12 { padding-top: 3rem; }
.pb-16 { padding-bottom: 4rem; }

/* ---- Gap ---- */
.gap-1\.5 { gap: .375rem; }
.gap-2 { gap: .5rem; }
.gap-2\.5 { gap: .625rem; }
.gap-3 { gap: .75rem; }
.gap-4 { gap: 1rem; }
.gap-5 { gap: 1.25rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }
.gap-10 { gap: 2.5rem; }
.gap-x-6 { column-gap: 1.5rem; }
.gap-y-2 { row-gap: .5rem; }
.gap-y-3 { row-gap: .75rem; }

/* ---- Space between (vertical stacks) ---- */
.space-y-4 > :not([hidden]) ~ :not([hidden]) { margin-top: 1rem; }
.space-y-5 > :not([hidden]) ~ :not([hidden]) { margin-top: 1.25rem; }
.space-y-6 > :not([hidden]) ~ :not([hidden]) { margin-top: 1.5rem; }

/* ---- Borders / radius ---- */
.border { border-width: 1px; border-style: solid; border-color: rgba(255,255,255,0.08); }
.border-white\/10 { border-color: rgba(255,255,255,0.10); }
.rounded-full { border-radius: 9999px; }
.rounded-lg { border-radius: .5rem; }

/* ---- Backgrounds ---- */
.bg-ink-900 { background-color: #111111; }
.bg-ink-900\/50 { background-color: rgba(17,17,17,0.5); }
.bg-ink-950\/80 { background-color: rgba(10,10,10,0.8); }
.bg-white\/\[0\.015\] { background-color: rgba(255,255,255,0.015); }
.bg-white\/\[0\.025\] { background-color: rgba(255,255,255,0.025); }

/* ---- Effects ---- */
.backdrop-blur-md { -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px); }
.shadow-xl { box-shadow: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1); }
.shadow-black\/40 { --tw-shadow-color: rgba(0,0,0,0.4); box-shadow: 0 20px 25px -5px rgba(0,0,0,0.4), 0 8px 10px -6px rgba(0,0,0,0.4); }
.transition { transition-property: color, background-color, border-color, text-decoration-color, fill, stroke, opacity, box-shadow, transform, filter, -webkit-backdrop-filter, backdrop-filter; transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1); transition-duration: 150ms; }
.scroll-smooth { scroll-behavior: smooth; }

/* ---- Typography ---- */
.font-sans { font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
.font-mono { font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.uppercase { text-transform: uppercase; }
.no-underline { text-decoration-line: none; }
.leading-relaxed { line-height: 1.625; }
.leading-\[1\.05\] { line-height: 1.05; }
.tracking-tight { letter-spacing: -0.025em; }
.tracking-tightish { letter-spacing: -0.015em; }
.tracking-widest { letter-spacing: 0.1em; }

/* ---- Font sizes ---- */
.text-\[10px\] { font-size: 10px; }
.text-\[11px\] { font-size: 11px; }
.text-\[2rem\] { font-size: 2rem; }
.text-xs { font-size: .75rem; line-height: 1rem; }
.text-sm { font-size: .875rem; line-height: 1.25rem; }
.text-base { font-size: 1rem; line-height: 1.5rem; }
.text-xl { font-size: 1.25rem; line-height: 1.75rem; }
.text-2xl { font-size: 1.5rem; line-height: 2rem; }

/* ---- Text colors ---- */
.text-accent { color: #22d3a8; }
.text-paper-50 { color: #fafafa; }
.text-paper-100 { color: #f4f4f5; }
.text-paper-200 { color: #e4e4e7; }
.text-mute-400 { color: #a1a1aa; }
.text-mute-500 { color: #808089; }

/* ---- Opacity ---- */
.opacity-80 { opacity: 0.8; }
.opacity-90 { opacity: 0.9; }

/* ---- Hover / group states ---- */
.hover\:bg-white\/\[0\.05\]:hover { background-color: rgba(255,255,255,0.05); }
.hover\:bg-white\/10:hover { background-color: rgba(255,255,255,0.10); }
.hover\:border-white\/20:hover { border-color: rgba(255,255,255,0.20); }
.hover\:text-paper-50:hover { color: #fafafa; }
.hover\:text-paper-100:hover { color: #f4f4f5; }
.group:hover .group-hover\:opacity-100 { opacity: 1; }

/* ============================================================
   Responsive variants.
   ============================================================ */

/* sm: >= 640px */
@media (min-width: 640px) {
  .sm\:inline-flex { display: inline-flex; }
  .sm\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sm\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .sm\:text-4xl { font-size: 2.25rem; line-height: 2.5rem; }
}

/* md: >= 768px */
@media (min-width: 768px) {
  .md\:flex { display: flex; }
  .md\:flex-row { flex-direction: row; }
  .md\:items-center { align-items: center; }
  .md\:col-span-4 { grid-column: span 4 / span 4; }
  .md\:col-span-8 { grid-column: span 8 / span 8; }
  .md\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .md\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .md\:grid-cols-12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
  .md\:pt-28 { padding-top: 7rem; }
  .md\:pb-32 { padding-bottom: 8rem; }
  .md\:py-16 { padding-top: 4rem; padding-bottom: 4rem; }
  .md\:py-20 { padding-top: 5rem; padding-bottom: 5rem; }
  .md\:text-lg { font-size: 1.125rem; line-height: 1.75rem; }
  .md\:text-2xl { font-size: 1.5rem; line-height: 2rem; }
  .md\:text-3xl { font-size: 1.875rem; line-height: 2.25rem; }
  .md\:text-5xl { font-size: 3rem; line-height: 1; }
}

/* lg: >= 1024px */
@media (min-width: 1024px) {
  .lg\:col-span-4 { grid-column: span 4 / span 4; }
  .lg\:col-span-5 { grid-column: span 5 / span 5; }
  .lg\:col-span-7 { grid-column: span 7 / span 7; }
  .lg\:col-span-8 { grid-column: span 8 / span 8; }
  .lg\:gap-12 { gap: 3rem; }
  .lg\:gap-16 { gap: 4rem; }
  .lg\:grid-cols-12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
  .lg\:text-6xl { font-size: 3.75rem; line-height: 1; }
}

/* xl: >= 1280px (declared for completeness; theme parity) */
@media (min-width: 1280px) {
  .xl\:block { display: block; }
}

/* ============================================================
   Component media queries (moved verbatim from inline <style>).
   ============================================================ */
@media (max-width: 640px) {
  .code-block pre { padding: .75rem .875rem; font-size: .75rem; }
  .cmp-table th, .cmp-table td { padding: .5rem .625rem; font-size: .75rem; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
    animation: none !important;
    scroll-behavior: auto !important;
  }
  /* !important + universal selector so this beats the .scroll-smooth class on <html>. */
  html { scroll-behavior: auto !important; }
}

/* ============================================================
   Accessibility (C5-3): skip link, landmarks focus, visible
   focus ring, screen-reader-only text, and a no-JS mobile nav.
   ============================================================ */

/* Screen-reader-only (used for table captions and off-screen labels). */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

/* Keyboard-visible skip link: off-screen until focused, then pinned top-left. */
.skip-link {
  position: fixed; left: .75rem; top: .75rem; z-index: 50;
  transform: translateY(-160%);
  background: #f4f4f5; color: #0a0a0a;
  padding: .5rem .875rem; border-radius: .375rem;
  font-size: .875rem; font-weight: 500; text-decoration: none;
  transition: transform .15s ease;
}
.skip-link:focus { transform: translateY(0); }

/* Visible focus indicator across interactive controls. */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid #22d3a8;
  outline-offset: 2px;
  border-radius: 3px;
}
/* main is focus target of the skip link but should not draw a ring on programmatic focus. */
main:focus { outline: none; }

/* No-JS navigation disclosure below the 1024px desktop breakpoint. */
.nav-mobile { position: static; }
.nav-mobile > summary {
  display: inline-flex; align-items: center; gap: .375rem;
  list-style: none; cursor: pointer;
  padding: .375rem .625rem; border-radius: .375rem;
  font-size: .8125rem; color: #d4d4d8;
  border: 1px solid rgba(255,255,255,0.12); background: transparent;
}
.nav-mobile > summary::-webkit-details-marker { display: none; }
.nav-mobile > summary:hover { background: rgba(255,255,255,0.04); color: #f4f4f5; }
.nav-menu {
  position: absolute; left: 0; right: 0; top: 100%;
  display: flex; flex-direction: column;
  padding: .25rem 1.5rem 1rem;
  background: rgba(10,10,10,0.98);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px);
}
.nav-menu a { padding: .625rem 0; font-size: .9375rem; border-top: 1px solid rgba(255,255,255,0.06); }
.nav-menu a:first-child { border-top: 0; }

/* Retained md display utility; navigation uses its own desktop breakpoint. */
@media (min-width: 768px) {
  .md\:hidden { display: none; }
}