/* ============ Reset ============ */
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: system-ui, -apple-system, sans-serif; line-height: 1.5; }

/* ============ Tokens ============ */
:root {
  --bg:        oklch(0.99 0.004 280);
  --surface:   oklch(1 0 0);
  --surface-2: oklch(0.975 0.006 280);
  --code-bg:   oklch(0.97 0.008 280);
  --text:      oklch(0.24 0.02 280);
  --muted:     oklch(0.48 0.02 280);
  --border:    oklch(0.9 0.01 280);
  --accent:    oklch(0.48 0.11 222);     /* airhacks cyan, darkened for AA text on white */
  --accent-strong: oklch(0.44 0.11 222);
  --accent-soft:   oklch(0.95 0.035 222);
  --good:      oklch(0.60 0.17 47);       /* airhacks orange — the single spark */
  --good-soft: oklch(0.96 0.04 47);
  --bad:       oklch(0.50 0.008 240);     /* slate gray (no decorative red) */
  --bad-soft:  oklch(0.965 0.004 240);
  --cta-bg:    oklch(0.74 0.094 222);     /* brand cyan #3EB0D8 for filled buttons */
  --cta-fg:    oklch(0.20 0.03 240);      /* dark ink on cyan */
  --star:       oklch(0.45 0.02 280 / 0.55);  /* dark stars on light bg */
  --star-spark: oklch(0.60 0.17 47 / 0.9);    /* orange spark, matches --good */
  --star-cyan:  oklch(0.74 0.094 222 / 0.9);  /* brand cyan spark, matches --cta-bg */

  --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", Menlo, Consolas, monospace;

  --measure: 62ch;
  --radius: 12px;
  --space: clamp(1rem, 0.6rem + 1.6vw, 1.6rem);
  --section-pad: clamp(3.5rem, 2rem + 7vw, 7rem);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:        oklch(0.17 0.02 280);
    --surface:   oklch(0.21 0.02 280);
    --surface-2: oklch(0.2 0.022 280);
    --code-bg:   oklch(0.235 0.025 280);
    --text:      oklch(0.93 0.01 280);
    --muted:     oklch(0.72 0.02 280);
    --border:    oklch(0.32 0.02 280);
    --accent:    oklch(0.80 0.095 222);   /* bright brand cyan on dark */
    --accent-strong: oklch(0.84 0.09 222);
    --accent-soft:   oklch(0.30 0.05 222);
    --good:      oklch(0.77 0.16 47);       /* bright orange on dark */
    --good-soft: oklch(0.30 0.05 47);
    --bad:       oklch(0.72 0.008 240);     /* gray */
    --bad-soft:  oklch(0.27 0.004 240);
    --star:       oklch(0.97 0.01 280 / 0.95);  /* white stars on dark bg */
    --star-spark: oklch(0.80 0.17 47 / 1);      /* bright orange spark on dark */
    --star-cyan:  oklch(0.80 0.095 222 / 1);    /* bright cyan spark on dark */
  }
}

/* ============ Base ============ */
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

html { background: var(--bg); }
body {
  background: transparent;
  color: var(--text);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

/* ============ Starfield ============ */
/* A fixed, motionless star field behind all content. The stars never move;
   a second layer of brand-colored stars (cyan + orange) occasionally sparks
   in place. Sparking is frozen by the prefers-reduced-motion rule above. */
.starfield {
  position: fixed;
  inset: -20%;
  z-index: -1;
  pointer-events: none;
  opacity: 0.9;
}
.starfield::before,
.starfield::after {
  content: "";
  position: absolute;
  inset: 0;
  background-repeat: repeat;
}
/* the field — fixed white/dark stars, two densities merged, never moving */
.starfield::before {
  background-image:
    radial-gradient(2px 2px at 12% 22%, var(--star), transparent 65%),
    radial-gradient(2.2px 2.2px at 78% 16%, var(--star), transparent 65%),
    radial-gradient(1.8px 1.8px at 44% 64%, var(--star), transparent 65%),
    radial-gradient(1.8px 1.8px at 28% 88%, var(--star), transparent 65%),
    radial-gradient(2px 2px at 62% 38%, var(--star), transparent 65%),
    radial-gradient(1.6px 1.6px at 6% 54%, var(--star), transparent 65%),
    radial-gradient(2px 2px at 36% 8%, var(--star), transparent 65%),
    radial-gradient(1.7px 1.7px at 94% 46%, var(--star), transparent 65%),
    radial-gradient(1.9px 1.9px at 54% 92%, var(--star), transparent 65%),
    radial-gradient(1.4px 1.4px at 33% 18%, var(--star), transparent 65%),
    radial-gradient(1.4px 1.4px at 66% 52%, var(--star), transparent 65%),
    radial-gradient(1.2px 1.2px at 9% 71%, var(--star), transparent 65%),
    radial-gradient(1.3px 1.3px at 52% 86%, var(--star), transparent 65%),
    radial-gradient(1.2px 1.2px at 20% 40%, var(--star), transparent 65%),
    radial-gradient(1.4px 1.4px at 73% 9%, var(--star), transparent 65%);
  background-size: 240px 240px;
}
/* brand sparks — a few cyan & orange stars that flicker in place, never moving */
.starfield::after {
  background-image:
    radial-gradient(2.4px 2.4px at 24% 30%, var(--star-cyan), transparent 60%),
    radial-gradient(2.2px 2.2px at 80% 22%, var(--star-spark), transparent 60%),
    radial-gradient(2.4px 2.4px at 60% 72%, var(--star-cyan), transparent 60%),
    radial-gradient(2px 2px at 40% 86%, var(--star-spark), transparent 60%),
    radial-gradient(2.2px 2.2px at 90% 60%, var(--star-cyan), transparent 60%),
    radial-gradient(2px 2px at 14% 64%, var(--star-spark), transparent 60%);
  background-size: 240px 240px;
  opacity: 0;
  will-change: opacity;
  animation: spark 8s ease-in-out infinite;
}
/* mostly dark, brief brightenings — reads as occasional sparkles */
@keyframes spark {
  0%, 100% { opacity: 0; }
  10%      { opacity: 0.95; }
  22%      { opacity: 0.1; }
  46%      { opacity: 0.8; }
  60%      { opacity: 0.05; }
}

h1, h2, h3 { line-height: 1.12; letter-spacing: -0.02em; font-weight: 680; }
p { max-inline-size: var(--measure); }

a { color: var(--accent-strong); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
a:hover { color: var(--accent); }

code {
  font-family: var(--mono);
  font-size: 0.92em;
  background: var(--code-bg);
  padding: 0.12em 0.4em;
  border-radius: 5px;
  border: 1px solid var(--border);
}

pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(1rem, 0.6rem + 1.5vw, 1.6rem);
  overflow-x: auto;
  font-size: clamp(0.8rem, 0.74rem + 0.3vw, 0.92rem);
  line-height: 1.6;
}
pre code { background: none; border: none; padding: 0; font-size: inherit; }

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}

.skip-link {
  position: absolute;
  inset-block-start: -3rem;
  inset-inline-start: 1rem;
  background: var(--cta-bg);
  color: var(--cta-fg);
  padding: 0.6rem 1rem;
  border-radius: 8px;
  z-index: 10;
  transition: inset-block-start 0.2s;
}
.skip-link:focus { inset-block-start: 1rem; color: var(--cta-fg); }

/* ============ Layout helpers ============ */
.section, .hero, .site-nav, .site-footer > p {
  margin-inline: auto;
  max-inline-size: 72rem;
  padding-inline: var(--space);
}

/* ============ Header ============ */
.site-header {
  position: sticky;
  inset-block-start: 0;
  z-index: 5;
  background: color-mix(in oklch, var(--bg) 86%, transparent);
  backdrop-filter: blur(10px);
  border-block-end: 1px solid var(--border);
}
.site-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  padding-block: 0.9rem;
}
.wordmark {
  font-weight: 750;
  letter-spacing: 0.02em;
  font-size: 1.15rem;
  color: var(--accent);
  text-decoration: none;
}
.wordmark .ipa {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0;
}
.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.1rem;
  list-style: none;
  font-size: 0.92rem;
}
.nav-links a { color: var(--muted); text-decoration: none; }
.nav-links a:hover { color: var(--accent); }

/* related-site family links, separated by centered dots */
.nav-family {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.7rem;
  list-style: none;
  font-family: var(--mono);
  font-size: 0.82rem;
}
.nav-family li + li::before {
  content: "·";
  color: var(--border);
  margin-inline-end: 0.7rem;
}
.nav-family a { color: var(--muted); text-decoration: none; }
.nav-family a:hover { color: var(--accent); }

/* ============ Hero ============ */
.hero {
  padding-block: clamp(3.5rem, 2rem + 9vw, 8rem) var(--section-pad);
  text-align: start;
}
.eyebrow {
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-block-end: 1rem;
}
.eyebrow a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}
.eyebrow a:hover { color: var(--accent-strong); }
.hero h1 {
  font-size: clamp(2.3rem, 1.3rem + 4.8vw, 4.4rem);
  font-weight: 720;
  margin-block-end: 1.4rem;
}
.hero .muted { color: var(--muted); }
.lead {
  font-size: clamp(1.05rem, 0.95rem + 0.6vw, 1.3rem);
  color: var(--text);
  max-inline-size: 56ch;
  margin-block-end: 1.5rem;
}
.tagline {
  font-size: clamp(1.3rem, 1rem + 1.4vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--good);
  margin-block-end: 2rem;
}
.cta-row { display: flex; flex-wrap: wrap; gap: 0.9rem; margin-block-end: 2rem; }
.btn {
  display: inline-block;
  padding: 0.7rem 1.4rem;
  border-radius: 10px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform 0.15s ease, background 0.15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--cta-bg); color: var(--cta-fg); }
.btn-primary:hover { background: color-mix(in oklch, var(--cta-bg) 88%, black); color: var(--cta-fg); }
.btn-ghost { border-color: var(--border); color: var(--text); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.hero-cmd {
  font-family: var(--mono);
  font-size: 0.92rem;
  color: var(--muted);
  line-height: 2;
}
.hero-cmd code { background: var(--surface-2); }
.hero-cmd-alt {
  display: block;
  margin-block-start: 0.6rem;
  font-size: 0.85rem;
  opacity: 0.85;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

/* ============ Zero strip ============ */
.zero-strip {
  background: var(--surface-2);
  border-block: 1px solid var(--border);
}
.zero-list {
  margin-inline: auto;
  max-inline-size: 72rem;
  padding: clamp(2rem, 1.2rem + 3vw, 3.2rem) var(--space);
  display: grid;
  gap: var(--space);
  grid-template-columns: 1fr;
}
@media (min-width: 46rem) { .zero-list { grid-template-columns: repeat(3, 1fr); } }
.zero-item {
  padding-inline-start: 1.1rem;
  border-inline-start: 2px solid color-mix(in oklch, var(--accent) 45%, var(--border));
}
.zero-item dt {
  font-size: clamp(1.2rem, 1rem + 1vw, 1.55rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-block-end: 0.5rem;
}
.zero-no {
  color: var(--accent);
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.zero-item dd { color: var(--muted); max-inline-size: 34ch; }

/* ============ Sections ============ */
.section { padding-block: var(--section-pad); }
.section-alt {
  background: var(--surface-2);
  max-inline-size: none;
  border-block: 1px solid var(--border);
}
.section-alt > * {
  margin-inline: auto;
  max-inline-size: 72rem;
}
.section-head { margin-block-end: clamp(2rem, 1rem + 3vw, 3.5rem); }
.section-head h2 {
  font-size: clamp(1.7rem, 1.2rem + 2.4vw, 2.8rem);
  margin-block-end: 1rem;
}
.section-sub { font-size: clamp(1rem, 0.95rem + 0.3vw, 1.15rem); color: var(--muted); max-inline-size: 60ch; }

/* ============ Contrast cards ============ */
.contrast {
  display: grid;
  gap: var(--space);
  grid-template-columns: 1fr;
}
@media (min-width: 48rem) { .contrast { grid-template-columns: 1fr 1fr; } }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(1.2rem, 0.8rem + 1.5vw, 1.8rem);
}
.card figcaption, .card > h3 { font-weight: 650; margin-block-end: 1rem; }
.card pre { background: var(--code-bg); }
.card-bad {
  border-inline-start: 3px solid var(--border);
}
.card-bad figcaption { color: var(--muted); }
.card-good {
  border-inline-start: 3px solid var(--good);
}
.card-good figcaption { color: var(--good); }

/* ============ Code figure ============ */
.code-figure { margin-block-end: clamp(2rem, 1rem + 3vw, 3.5rem); }
.code-figure figcaption {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--muted);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-block-end: none;
  border-radius: var(--radius) var(--radius) 0 0;
  padding: 0.6rem 1rem;
}
.code-figure pre {
  border-radius: 0 0 var(--radius) var(--radius);
  margin: 0;
}

/* ============ Grids ============ */
.feature-grid, .loop-grid, .tenet-grid {
  display: grid;
  gap: var(--space);
  grid-template-columns: 1fr;
  list-style: none;
}
@media (min-width: 40rem) { .loop-grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 52rem) {
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .tenet-grid { grid-template-columns: 1fr 1fr; }
}
.feature-grid li, .tenet-grid li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(1.2rem, 0.8rem + 1.5vw, 1.7rem);
}
.feature-grid h3, .tenet-grid h3, .loop-grid h3 {
  font-size: 1.15rem;
  margin-block-end: 0.6rem;
}
.feature-grid p, .tenet-grid p, .loop-grid p { color: var(--muted); }

.loop-grid h3 { display: flex; align-items: baseline; gap: 0.6rem; }
.mode {
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid color-mix(in oklch, var(--accent) 30%, var(--border));
  padding: 0.15rem 0.55rem;
  border-radius: 6px;
  letter-spacing: 0.02em;
}

.sync-dirs {
  margin-block: 1rem;
  display: grid;
  gap: 0.7rem;
}
.sync-dirs dt {
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent);
  margin-block-end: 0.2rem;
}
.sync-dirs dd { color: var(--muted); }

.composition-note {
  margin-block-start: 2rem;
  color: var(--muted);
  max-inline-size: 60ch;
}

/* ============ Footer ============ */
.site-footer {
  border-block-start: 1px solid var(--border);
  padding-block: 2.5rem;
  color: var(--muted);
  font-size: 0.92rem;
}
.site-footer strong { color: var(--text); }