/* PurplePAI — brand tokens (see Brand Guide v1.2) */
:root {
  --white: #FFFFFF;
  --fog: #F5F5F7;
  --purple: #4E2A84;
  --purple-deep: #401F68;
  --wisteria: #836EAA;
  --lavender: #B6ACD1;
  --whisper: #ECE9F3;
  --violet-current: #7C5CE0;

  --graphite: #1D1D1F;
  --slate: #6E6E73;
  --hairline: #D2D2D7;

  --font-display: "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-mono: Menlo, Consolas, "Courier New", monospace;

  --gutter: 64px;
}

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

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

body {
  font-family: var(--font-display);
  color: var(--graphite);
  background: var(--white);
  line-height: 1.5;
}

a { color: inherit; }

img { max-width: 100%; display: block; }

.wrap { max-width: 1280px; margin: 0 auto; }

/* ---------- Header ---------- */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px var(--gutter);
  border-bottom: 1px solid var(--hairline);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.logo-mark {
  width: 30px;
  height: 30px;
  flex-shrink: 0;
  display: block;
}

.logo-word {
  font-size: 20px;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.logo-word .pai { color: var(--purple); }

.main-nav {
  display: flex;
  align-items: center;
  gap: 40px;
}

.main-nav a {
  text-decoration: none;
  font-size: 15px;
}

.btn {
  display: inline-block;
  text-decoration: none;
  border-radius: 3px;
  font-size: 15px;
  white-space: nowrap;
}

.btn-primary {
  background: var(--purple);
  color: var(--white);
  padding: 14px 26px;
}

.btn-primary:hover { background: var(--purple-deep); }

.nav-cta {
  font-size: 14px;
  padding: 11px 20px;
}

.btn-secondary {
  color: var(--purple);
  border-bottom: 1px solid var(--hairline);
  padding-bottom: 2px;
  font-size: 15px;
  text-decoration: none;
}

/* ---------- Hero ---------- */

.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 64px;
  padding: 96px var(--gutter) 88px;
  align-items: center;
}

.eyebrow {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--wisteria);
  font-weight: 500;
  margin-bottom: 20px;
  text-transform: uppercase;
}

.hero h1 {
  font-size: 60px;
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.01em;
  margin: 0 0 28px;
  max-width: 620px;
}

.hero h1 .accent { color: var(--purple); }

.hero-sub {
  font-size: 19px;
  line-height: 1.6;
  color: var(--slate);
  max-width: 520px;
  margin: 0 0 40px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.hero-demo {
  background: var(--whisper);
  border: 1px solid var(--hairline);
  border-radius: 4px;
  padding: 28px 30px;
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.8;
}

.hero-demo-dots {
  display: flex;
  gap: 8px;
  margin-bottom: 18px;
}

.hero-demo-dots span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--hairline);
  display: block;
}

.hero-demo-prompt { color: var(--graphite); margin-bottom: 14px; }

.hero-demo-output {
  color: var(--violet-current);
  white-space: pre-wrap;
}

.cursor {
  display: inline-block;
  animation: blink 1s step-start infinite;
}

@keyframes blink {
  50% { opacity: 0; }
}

/* ---------- Positioning ---------- */

.section-label {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--slate);
  font-weight: 500;
  text-transform: uppercase;
}

.positioning {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 64px;
  padding: 80px var(--gutter);
  border-top: 1px solid var(--hairline);
}

.positioning .section-label { height: fit-content; }

.positioning p {
  font-size: 30px;
  line-height: 1.45;
  font-weight: 400;
  max-width: 860px;
}

.positioning .accent { color: var(--purple); }

/* ---------- Operating model ---------- */

.operating-model {
  padding: 80px var(--gutter);
  background: var(--fog);
}

.operating-model .section-label { margin-bottom: 44px; }

.model-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.model-item {
  padding: 0 36px 0 32px;
  border-left: 1px solid var(--hairline);
}

.model-item:first-child { padding-left: 32px; }

.model-rule {
  width: 100%;
  height: 1px;
  background: var(--hairline);
  margin-bottom: 24px;
}

.model-rule span {
  display: block;
  height: 1px;
  width: 40%;
  background: var(--purple);
}

.model-index {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--wisteria);
  margin-bottom: 14px;
}

.model-item h3 {
  font-size: 21px;
  font-weight: 500;
  margin-bottom: 12px;
}

.model-item p {
  font-size: 15px;
  line-height: 1.65;
  color: var(--slate);
}

/* ---------- Photography ---------- */

.photo-duo {
  display: grid;
  grid-template-columns: 1fr 1fr;
}

.photo-placeholder {
  height: 420px;
  overflow: hidden;
  border-right: 1px solid var(--hairline);
}

.photo-placeholder:last-child { border-right: none; }

.photo-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- Where the OS runs ---------- */

.os-runs {
  padding: 80px var(--gutter);
  border-top: 1px solid var(--hairline);
}

.os-runs .section-label { margin-bottom: 44px; }

.bars {
  display: flex;
  align-items: flex-end;
  gap: 56px;
  height: 220px;
  border-bottom: 1px solid var(--hairline);
}

.bar-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: 90px;
}

.bar-value {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--graphite);
  font-variant-numeric: tabular-nums;
}

.bar {
  width: 48px;
  background: var(--wisteria);
}

.bar.emphasis { background: var(--purple); }
.bar.light { background: var(--lavender); }

.bar-labels {
  display: flex;
  gap: 56px;
  margin-top: 16px;
}

.bar-label {
  width: 90px;
  text-align: center;
  font-size: 13px;
  color: var(--slate);
}

/* ---------- Quote ---------- */

.quote-band {
  background: var(--whisper);
  padding: 96px var(--gutter);
  text-align: center;
}

.quote-band blockquote {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 28px;
  line-height: 1.5;
  color: var(--graphite);
  max-width: 760px;
  margin: 0 auto;
}

/* ---------- Contact CTA ---------- */

.contact-cta {
  padding: 96px var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  border-top: 1px solid var(--hairline);
  flex-wrap: wrap;
}

.contact-cta h2 {
  font-size: 34px;
  font-weight: 500;
  margin-bottom: 12px;
  max-width: 480px;
}

.contact-cta p {
  font-size: 16px;
  color: var(--slate);
}

/* ---------- Footer ---------- */

.site-footer {
  padding: 40px var(--gutter);
  border-top: 1px solid var(--hairline);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.site-footer .logo-word {
  font-size: 14px;
  font-weight: 500;
}

.footer-contact {
  font-size: 13px;
  color: var(--slate);
}

.footer-confidential {
  font-size: 12px;
  color: var(--slate);
}

/* ---------- Responsive ---------- */

@media (max-width: 1040px) {
  :root { --gutter: 40px; }

  .hero { grid-template-columns: 1fr; }
  .hero-demo { max-width: 520px; }
  .hero h1 { font-size: 48px; }

  .positioning { grid-template-columns: 1fr; gap: 24px; }
  .positioning p { font-size: 26px; }

  .model-grid { grid-template-columns: 1fr; gap: 40px; }
  .model-item { border-left: none; padding-left: 0; border-top: 1px solid var(--hairline); padding-top: 32px; }
  .model-item:first-child { border-top: none; padding-top: 0; }

  .photo-duo { grid-template-columns: 1fr; }
  .photo-placeholder { border-right: none; border-bottom: 1px solid var(--hairline); }
  .photo-placeholder:last-child { border-bottom: none; }
}

@media (max-width: 720px) {
  :root { --gutter: 24px; }

  .main-nav { gap: 20px; }
  .main-nav a:not(.btn) { display: none; }

  .site-header { flex-wrap: wrap; gap: 12px; }

  .hero { padding-top: 56px; padding-bottom: 56px; }
  .hero h1 { font-size: 36px; }
  .hero-sub { font-size: 17px; }

  .positioning p { font-size: 22px; }

  .bars { gap: 24px; }
  .bar-labels { gap: 24px; }
  .bar-col, .bar-label { width: 64px; }

  .quote-band blockquote { font-size: 22px; }

  .contact-cta { flex-direction: column; align-items: flex-start; }
  .contact-cta h2 { font-size: 28px; }

  .site-footer { flex-direction: column; align-items: flex-start; gap: 8px; }
}

@media (max-width: 400px) {
  .nav-cta { font-size: 13px; padding: 9px 14px; }
  .logo-word { font-size: 18px; }
}