/* =====================================================================
   Teishō — landing v3
   Design language: Vercel-adjacent — monochrome, airy, editorial.
   ===================================================================== */

:root {
  /* Surfaces — Vercel's warm off-white */
  --bg:          #fafafa;
  --bg-2:        #ffffff;
  --bg-3:        #f4f4f4;

  /* Foreground */
  --fg:          #000000;
  --fg-1:        #171717;
  --fg-2:        #525252;
  --fg-3:        #737373;
  --fg-4:        #a3a3a3;
  --fg-5:        #d4d4d4;

  /* Borders */
  --border:      #eaeaea;
  --border-2:    #e0e0e0;
  --border-3:    #d4d4d4;

  /* Type */
  --font-sans:   'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono:   'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  --font-serif:  'Newsreader', 'Times New Roman', Georgia, serif;

  /* Radii */
  --r-sm: 4px;
  --r-md: 6px;
  --r-lg: 10px;

  /* Motion */
  --dur: 160ms;
  --ease: cubic-bezier(0.2, 0, 0, 1);
}

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

html, body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-feature-settings: 'ss01', 'cv11';
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

::selection { background: var(--fg); color: var(--bg); }

.serif { font-family: var(--font-serif); }
.mono { font-family: var(--font-mono); }
.italic { font-style: italic; }
.sub { font-size: 0.7em; vertical-align: sub; }

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 18px 40px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 32px;
}

/* Brand — logo mark + wordmark */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--fg);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.brand:hover { opacity: 0.75; }

.brand-logo {
  width: 26px;
  height: 24px;
  color: var(--fg);
  flex-shrink: 0;
}

.brand-word {
  font-family: var(--font-sans);
  letter-spacing: -0.015em;
  line-height: 1;
}

.nav-center {
  display: inline-flex;
  align-items: center;
  gap: 28px;
  justify-self: center;
}
.nav-center a {
  color: var(--fg-2);
  text-decoration: none;
  font-size: 14px;
  font-weight: 400;
  transition: color var(--dur) var(--ease);
}
.nav-center a:hover { color: var(--fg); }

.nav-right { justify-self: end; }
.nav-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--fg-3);
  letter-spacing: 0;
}
.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--fg);
  animation: pulse 2.6s var(--ease) infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

/* ---------- Hero ---------- */
.hero {
  padding: 120px 40px 100px;
}
.hero-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: 64px;
  align-items: start;
}

.display {
  font-family: var(--font-sans);
  font-size: clamp(48px, 7vw, 88px);
  line-height: 1.02;
  letter-spacing: -0.035em;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 32px;
}
.display em {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  letter-spacing: -0.02em;
}

.lede {
  font-size: 17px;
  line-height: 1.55;
  color: var(--fg-2);
  max-width: 480px;
  margin-bottom: 40px;
}

/* Right-side firm reference (like Vercel's ALL CAPS stacked lines) */
.hero-right {
  padding-top: 12px;
  border-top: 1px solid var(--border);
}
.right-label {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-4);
  letter-spacing: 0.08em;
  margin-bottom: 20px;
  text-transform: uppercase;
}
.right-lines {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--fg);
}

/* CTA */
.cta { max-width: 480px; }
.cta-row {
  display: flex;
  align-items: stretch;
  gap: 8px;
}
.cta input[type='email'] {
  flex: 1;
  min-width: 0;
  padding: 12px 14px;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  outline: none;
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 14px;
  letter-spacing: -0.005em;
  transition: border-color var(--dur) var(--ease);
}
.cta input::placeholder { color: var(--fg-4); }
.cta input:focus { border-color: var(--fg); }

.cta button {
  padding: 12px 20px;
  background: var(--fg);
  color: var(--bg-2);
  border: 1px solid var(--fg);
  border-radius: var(--r-md);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.005em;
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
  white-space: nowrap;
}
.cta button:hover { background: var(--bg-2); color: var(--fg); }
.cta button:disabled { opacity: 0.6; cursor: not-allowed; }

.cta-note {
  margin-top: 12px;
  font-size: 13px;
  color: var(--fg-3);
  letter-spacing: -0.005em;
}

.cta-success {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border: 1px solid var(--border-2);
  background: var(--bg-2);
  border-radius: var(--r-md);
  font-size: 14px;
  color: var(--fg);
  max-width: 480px;
}

/* ---------- Showcase sections ---------- */
.showcase {
  padding: 96px 40px;
  border-top: 1px solid var(--border);
}
.showcase-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: 72px;
  align-items: center;
}
.showcase-inner.reverse .showcase-copy { order: 2; }
.showcase-inner.reverse .artifact { order: 1; }

.h2 {
  font-family: var(--font-sans);
  font-size: clamp(36px, 4.5vw, 56px);
  line-height: 1.05;
  letter-spacing: -0.03em;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 24px;
}
.h2 em {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  letter-spacing: -0.02em;
}

.body {
  font-size: 16px;
  line-height: 1.55;
  color: var(--fg-2);
  max-width: 480px;
  margin-bottom: 40px;
}

.feature-block { max-width: 480px; }
.feature-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-4);
  letter-spacing: 0.08em;
  margin-bottom: 16px;
  text-transform: uppercase;
}
.feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.feature-list li {
  font-family: var(--font-sans);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--fg);
}

/* ---------- Artifacts (floating cards) ---------- */
.artifact {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.02),
    0 8px 24px -8px rgba(0, 0, 0, 0.06);
  overflow: hidden;
}
.art-caption {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-3);
  letter-spacing: 0.04em;
}
.art-caption span:first-child { color: var(--fg-4); }

/* Artifact 1: the equation */
.artifact-equation .eq {
  display: grid;
  grid-template-columns: 1fr auto 1.15fr auto 1fr;
  align-items: center;
  gap: 20px;
  padding: 40px 32px;
}
.eq-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-align: center;
}
.eq-lbl {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--fg-4);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.eq-symbol {
  font-size: 22px;
  color: var(--fg);
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 4px;
}
.eq-symbol.serif {
  font-family: var(--font-serif);
  font-size: 34px;
  font-weight: 400;
}
.eq-desc {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-3);
  letter-spacing: 0;
}
.eq-col-op .eq-symbol { color: var(--fg); }

.eq-op {
  font-family: var(--font-serif);
  font-size: 24px;
  color: var(--fg-4);
  font-weight: 400;
  margin-top: 20px; /* align with symbols */
}

/* Distribution bars — the "resolved" output */
.eq-dist {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 3px;
  height: 64px;
  width: 100%;
}
.eq-dist span {
  flex: 1;
  max-width: 8px;
  background: var(--fg);
  border-radius: 1px;
  transition: height var(--dur) var(--ease);
}
/* Center bar (mode) accented slightly with a top marker */
.eq-dist span:nth-child(6) {
  position: relative;
}

.eq-foot {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--border);
  background: var(--bg);
}
.eq-foot-cell {
  padding: 14px 20px;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.eq-foot-cell:last-child { border-right: none; }
.fk {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--fg-4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.fv {
  font-size: 13px;
  color: var(--fg);
  letter-spacing: 0;
}

/* Artifact 2: the terminal / research output */
.artifact-terminal .term {
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.term-row {
  display: grid;
  grid-template-columns: 80px 20px 1fr;
  align-items: baseline;
  gap: 12px;
}
.term-key {
  color: var(--fg-3);
  font-size: 12px;
  letter-spacing: 0;
}
.term-arrow {
  color: var(--fg-4);
  font-family: var(--font-serif);
  font-size: 14px;
}
.term-val {
  color: var(--fg);
  font-size: 14px;
  letter-spacing: -0.005em;
}
.term-divider {
  height: 1px;
  background: var(--border);
  margin: 12px 0 8px;
}
.term-out {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.term-out-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 20px;
  font-size: 16px;
  color: var(--fg);
  letter-spacing: -0.01em;
}
.term-out-row .serif { font-size: 20px; }
.term-out-val {
  font-size: 18px;
  font-weight: 500;
  letter-spacing: 0;
}

/* ---------- Firm strip (closing CTA) ---------- */
.firm {
  padding: 120px 40px 100px;
  border-top: 1px solid var(--border);
}
.firm-inner {
  max-width: 780px;
  margin: 0 auto;
  text-align: left;
}
.firm-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 24px;
}
.firm-h2 { margin-bottom: 24px; }
.firm-body { max-width: 640px; margin-bottom: 36px; }
.cta-second { max-width: 480px; }

/* ---------- Footer ---------- */
.foot {
  border-top: 1px solid var(--border);
  padding: 32px 40px;
}
.foot-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  font-size: 13px;
  color: var(--fg-3);
}
.foot-brand {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--fg);
}

.foot-meta { display: inline-flex; gap: 10px; align-items: center; }
.foot-meta .sep { color: var(--fg-5); }

/* ---------- Utility ---------- */
.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;
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .hero-inner,
  .showcase-inner {
    grid-template-columns: 1fr;
    gap: 56px;
  }
  .showcase-inner.reverse .showcase-copy { order: initial; }
  .showcase-inner.reverse .artifact { order: initial; }
  .hero-right { border-top: none; padding-top: 0; }
  .artifact-equation .eq {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .eq-op { transform: rotate(90deg); margin: 0; }
}

@media (max-width: 720px) {
  .nav-inner {
    grid-template-columns: 1fr auto;
    padding: 16px 20px;
  }
  .nav-center { display: none; }
  .nav-right .nav-status { font-size: 11px; }
  .hero { padding: 72px 20px 64px; }
  .showcase { padding: 72px 20px; }
  .firm { padding: 80px 20px; }
  .foot { padding: 24px 20px; }
  .foot-inner { flex-direction: column; align-items: flex-start; gap: 8px; }
  .cta-row { flex-direction: column; gap: 8px; }
  .cta button { width: 100%; }
  .eq-foot { grid-template-columns: 1fr; }
  .eq-foot-cell {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .eq-foot-cell:last-child { border-bottom: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}