/* =========================================================
   PathShift — base system
   Dark, technical, restrained. Geist + Geist Mono.
   ========================================================= */

:root {
  /* base surface scale (cool near-black) */
  --bg:        oklch(0.155 0.006 250);
  --bg-2:      oklch(0.185 0.008 250);
  --surface:   oklch(0.215 0.009 250);
  --surface-2: oklch(0.245 0.010 250);
  --border:    oklch(0.305 0.012 250);
  --border-2:  oklch(0.380 0.013 250);

  /* text */
  --fg:        oklch(0.975 0.005 250);
  --fg-2:      oklch(0.900 0.007 250);
  --fg-3:      oklch(0.790 0.010 250);
  --fg-4:      oklch(0.680 0.012 250);

  /* accent — electric blue default */
  --accent:    oklch(0.72 0.165 240);
  --accent-2:  oklch(0.82 0.110 240);
  --accent-ink: oklch(0.18 0.04 240);
  --accent-soft: oklch(0.72 0.165 240 / 0.12);
  --accent-line: oklch(0.72 0.165 240 / 0.35);

  /* type */
  --font-sans: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "Geist Mono", ui-monospace, "SF Mono", Menlo, monospace;

  /* metrics */
  --radius-sm: 6px;
  --radius:    10px;
  --radius-lg: 14px;
  --radius-xl: 22px;

  --maxw: 1240px;
  --gutter: 28px;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
::selection { background: var(--accent-soft); color: var(--fg); }

/* ---------- layout ---------- */
.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.app {
  position: relative;
  min-height: 100vh;
}

/* ---------- topographic bg layer ---------- */
.topo-host {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
.topo-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.55;
}
.topo-vignette {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(120% 80% at 50% 0%, transparent 30%, var(--bg) 90%),
    radial-gradient(120% 80% at 50% 100%, transparent 30%, var(--bg) 95%);
}

.app > .nav,
.app > main,
.app > footer { position: relative; z-index: 1; }

/* ---------- nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  border-bottom: 1px solid color-mix(in oklab, var(--border) 60%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  letter-spacing: -0.01em;
  font-weight: 500;
  font-size: 16px;
  color: var(--fg);
}
.logo .mark { width: 22px; height: 22px; }
.logo .word { font-weight: 540; letter-spacing: -0.015em; }
.logo .word b { font-weight: 600; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 13.5px;
  color: var(--fg-3);
}
.nav-links button {
  background: transparent;
  border: 0;
  color: var(--fg-3);
  padding: 8px 12px;
  border-radius: 8px;
  letter-spacing: -0.005em;
  font-size: 13.5px;
  transition: color .2s var(--ease), background .2s var(--ease);
}
.nav-links button:hover { color: var(--fg); background: color-mix(in oklab, var(--fg) 6%, transparent); }
.nav-links button.active { color: var(--fg); }
.nav-cta {
  margin-left: 8px;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: -0.005em;
  border: 1px solid transparent;
  transition: transform .2s var(--ease), background .2s var(--ease), border-color .2s var(--ease), color .2s var(--ease);
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn-primary {
  background: var(--accent);
  color: var(--accent-ink);
  border-color: color-mix(in oklab, var(--accent) 60%, white 40%);
  box-shadow:
    inset 0 1px 0 color-mix(in oklab, white 35%, transparent),
    0 0 0 0 var(--accent-soft);
}
.btn-primary:hover {
  background: color-mix(in oklab, var(--accent) 90%, white 10%);
  box-shadow:
    inset 0 1px 0 color-mix(in oklab, white 40%, transparent),
    0 8px 28px -10px var(--accent);
}
.btn-ghost {
  background: color-mix(in oklab, var(--fg) 4%, transparent);
  color: var(--fg);
  border-color: var(--border);
}
.btn-ghost:hover {
  background: color-mix(in oklab, var(--fg) 8%, transparent);
  border-color: var(--border-2);
}
.btn-quiet {
  background: transparent;
  color: var(--fg-2);
  padding: 8px 0;
  border-radius: 0;
}
.btn-quiet:hover { color: var(--accent-2); transform: none; }
.btn-quiet .arr { transition: transform .25s var(--ease); display:inline-block; }
.btn-quiet:hover .arr { transform: translateX(3px); }
.btn-lg { padding: 14px 22px; font-size: 14.5px; }

/* ---------- type ---------- */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.10em;
  color: var(--fg-3);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
  opacity: 0.5;
}
.eyebrow.solo::before { display: none; }

h1, h2, h3, h4 { margin: 0; letter-spacing: -0.025em; color: var(--fg); }
h1 { font-weight: 500; font-size: clamp(40px, 5.5vw, 72px); line-height: 1.02; }
h2 { font-weight: 500; font-size: clamp(28px, 3.2vw, 44px); line-height: 1.08; }
h3 { font-weight: 500; font-size: 22px; line-height: 1.2; }

p { color: var(--fg-2); line-height: 1.55; margin: 0; font-size: 15.5px; }
.lede { font-size: clamp(17px, 1.5vw, 19px); color: var(--fg-2); max-width: 60ch; line-height: 1.55; }

.mono { font-family: var(--font-mono); }

/* ---------- card ---------- */
.card {
  background: linear-gradient(180deg,
    color-mix(in oklab, var(--surface) 92%, transparent),
    color-mix(in oklab, var(--bg-2) 80%, transparent));
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: border-color .25s var(--ease), transform .25s var(--ease), background .25s var(--ease);
}
.card:hover {
  border-color: var(--border-2);
}
.card-hl { position: relative; overflow: hidden; }
.card-hl::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  border-top: 1px solid color-mix(in oklab, var(--accent) 30%, transparent);
  opacity: 0;
  transition: opacity .3s var(--ease);
}
.card-hl:hover::after { opacity: 1; }

/* ---------- tag/chip ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.02em;
  color: var(--fg-3);
  background: color-mix(in oklab, var(--surface) 50%, transparent);
}
.tag.dot::before {
  content: "";
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--accent);
}
.tag.solid {
  background: color-mix(in oklab, var(--accent) 14%, var(--bg));
  border-color: color-mix(in oklab, var(--accent) 35%, var(--border));
  color: var(--accent-2);
}

/* ---------- divider ---------- */
.hr {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  border: 0;
}

/* ---------- section ---------- */
.section { padding: 96px 0; position: relative; }
.section.tight { padding: 64px 0; }
.section.first { padding-top: 56px; }

/* ---------- footer ---------- */
.footer {
  border-top: 1px solid var(--border);
  padding: 56px 0 40px;
  margin-top: 80px;
  color: var(--fg-3);
  font-size: 13.5px;
}
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  align-items: start;
}
.footer h5 {
  color: var(--fg);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-family: var(--font-mono);
  font-weight: 500;
  margin: 0 0 14px;
}
.footer ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.footer a:hover { color: var(--fg); }

/* ---------- scroll-reveal ---------- */
.reveal { opacity: 1; transform: none; }
.reveal-anim .reveal { opacity: 0; transform: translateY(14px); transition: opacity 0.6s cubic-bezier(0.22, 0.61, 0.36, 1), transform 0.6s cubic-bezier(0.22, 0.61, 0.36, 1); }
.reveal-anim .reveal.in { opacity: 1; transform: translateY(0); }
.no-anim .reveal { opacity: 1 !important; transform: none !important; transition: none !important; }
.no-anim .topo-svg .topo-anim { animation: none !important; }

/* ---------- focus ---------- */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

/* ---------- small screens ---------- */
@media (max-width: 820px) {
  :root { --gutter: 18px; }
  .nav-links button:not(.always) { display: none; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .section { padding: 64px 0; }
}