/* Posie site. Tokens mirror ios/Posie/Components/AcademicStyle.swift
   (Academic.Palette): monochrome paper, surface, tile, rule and ink. */
:root {
  --paper: #F5F5F4;
  --surface: #FFFFFF;
  --tile: #EDEDEB;
  --rule: #E3E3E0;
  --ink: #1F2124;
  --ink-soft: #E6E6E4;
  --on-ink: #FFFFFF;
  --text: #16181D;
  --text-2: #5B616E;
  --text-3: #9097A3;
  --radius: 6px;
  --card: 12px;
  --serif: ui-serif, "New York", "Newsreader", Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --wrap: 1120px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #111214;
    --surface: #1A1C1F;
    --tile: #222427;
    --rule: #2C2F33;
    --ink: #E6E6E8;
    --ink-soft: #2A2C30;
    --on-ink: #111214;
    --text: #ECECEE;
    --text-2: #9EA3AD;
    --text-3: #6B717B;
  }
  /* Line art is black on white; invert it so it reads as light ink on dark. */
  .plate img { filter: invert(1) brightness(0.92); }
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font: 17px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
h1, h2, h3 { font-family: var(--serif); font-weight: 600; letter-spacing: -0.01em; margin: 0; color: var(--text); }
h1 { font-size: clamp(2.4rem, 5.2vw, 3.9rem); line-height: 1.06; letter-spacing: -0.02em; }
h1 em { font-style: italic; font-weight: 400; }
h2 { font-size: clamp(1.8rem, 3.4vw, 2.6rem); line-height: 1.12; }
h3 { font-size: 1.3rem; line-height: 1.25; }
p { margin: 0; }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.wrap.narrow { max-width: 760px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--on-ink); padding: 8px 12px; border-radius: var(--radius); z-index: 100; }
.skip:focus { left: 8px; }

.eyebrow {
  font: 600 0.72rem/1.2 var(--sans);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-3);
  margin-bottom: 14px;
}
.lede { font-size: 1.15rem; color: var(--text-2); max-width: 36em; }
.fine { font-size: 0.85rem; color: var(--text-3); }
.center-text { text-align: center; }

/* Buttons mirror AcademicButtonStyle: filled ink, 12pt radius. */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 0 22px;
  border-radius: var(--card);
  font: 600 0.95rem/1 var(--sans);
  text-decoration: none;
  transition: transform .15s ease, opacity .15s ease, background .15s ease;
}
.btn:active { transform: scale(0.98); }
.btn-ink { background: var(--ink); color: var(--on-ink); }
.btn-ink:hover { opacity: 0.88; }
.btn-ghost { background: var(--surface); color: var(--text); border: 1px solid var(--rule); }
.btn-ghost:hover { background: var(--tile); }
.btn-small { min-height: 38px; padding: 0 16px; font-size: 0.88rem; }
.link-arrow { display: inline-block; margin-top: 20px; font-weight: 600; text-decoration: none; border-bottom: 1px solid var(--text); padding-bottom: 2px; }
.link-arrow::after { content: " \2192"; }

.store-badge {
  display: inline-flex; align-items: center; gap: 10px;
  min-height: 48px; padding: 0 18px 0 14px;
  border: 1px solid var(--rule); border-radius: var(--card);
  background: var(--surface); color: var(--text-2);
  font: 600 1rem/1.05 var(--sans);
}
.store-badge svg { width: 22px; height: 22px; }
.store-badge small { display: block; font-size: 0.66rem; font-weight: 500; color: var(--text-3); }

/* Navigation */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(14px);
  -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease;
}
.nav.scrolled { border-bottom-color: var(--rule); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 8px; border: 1px solid var(--rule); }
.brand span { font: 600 1.3rem/1 var(--serif); letter-spacing: -0.01em; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a:not(.btn) { text-decoration: none; font-size: 0.93rem; color: var(--text-2); }
.nav-links a:not(.btn):hover { color: var(--text); }
.nav-toggle { display: none; background: none; border: 0; width: 40px; height: 40px; padding: 0; cursor: pointer; }
.nav-toggle span { display: block; width: 20px; height: 1.5px; background: var(--text); margin: 6px auto; transition: transform .2s ease; }
.nav-toggle[aria-expanded="true"] span:first-child { transform: translateY(3.75px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:last-child { transform: translateY(-3.75px) rotate(-45deg); }

/* Hero */
.hero { padding: 72px 0 40px; }
.hero-grid { display: grid; gap: 56px; }
.hero-text { max-width: 760px; }
.hero-text h1 { margin-bottom: 24px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin: 32px 0 16px; }
.hero-cta.center { justify-content: center; }

/* Plates: artwork framed like the app's white cards. */
.plate {
  margin: 0;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--card);
  overflow: hidden;
}
.plate img { width: 100%; }
.plate-hero img { aspect-ratio: 2 / 1; object-fit: cover; }

/* Sections */
.section { padding: 96px 0; }
.section-tile { background: var(--tile); }
.section-head { max-width: 640px; margin-bottom: 48px; }
.section-head h2 + p { margin-top: 16px; color: var(--text-2); font-size: 1.08rem; }

.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--rule); border: 1px solid var(--rule); border-radius: var(--card); overflow: hidden; }
.step { background: var(--surface); padding: 32px 28px 36px; }
.step-num { display: block; font: 400 1.75rem/1 var(--serif); font-variant-numeric: tabular-nums; color: var(--text-3); margin-bottom: 28px; }
.step h3 { margin-bottom: 10px; }
.step p { color: var(--text-2); font-size: 0.98rem; }

.section-showcase { padding-top: 24px; }
.showcase { display: grid; grid-template-columns: 1fr 1fr; gap: 72px; align-items: center; padding: 56px 0; }
.showcase + .showcase { border-top: 1px solid var(--rule); }
.showcase.flip .showcase-text { order: 2; }
.showcase-text h3 { font-size: clamp(1.6rem, 2.8vw, 2.15rem); line-height: 1.15; margin-bottom: 18px; }
.showcase-text > p { color: var(--text-2); }
.plate img[width="900"] { aspect-ratio: 1; object-fit: cover; }

.ticks { list-style: none; margin: 24px 0 0; padding: 0; border-top: 1px solid var(--rule); }
.ticks li { padding: 12px 0 12px 28px; border-bottom: 1px solid var(--rule); position: relative; font-size: 0.97rem; }
.ticks li::before { content: ""; position: absolute; left: 2px; top: 19px; width: 12px; height: 6px; border-left: 1.5px solid var(--ink); border-bottom: 1.5px solid var(--ink); transform: rotate(-45deg); }

.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.feature { background: var(--surface); border-radius: var(--card); padding: 28px; }
.feature svg { width: 26px; height: 26px; fill: none; stroke: var(--ink); stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; margin-bottom: 22px; }
.feature h3 { font-size: 1.15rem; margin-bottom: 8px; }
.feature p { color: var(--text-2); font-size: 0.95rem; }

/* Teaching */
.section-teach { border-top: 1px solid var(--rule); }
.roles { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--rule); border: 1px solid var(--rule); border-radius: var(--card); overflow: hidden; margin-bottom: 56px; }
.role { background: var(--surface); padding: 26px 28px; }
.role .eyebrow { color: var(--text); margin-bottom: 8px; }
.role p:last-child { color: var(--text-2); font-size: 0.97rem; }
.teach-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 72px; align-items: start; }
.teach-item { display: grid; grid-template-columns: 26px 1fr; gap: 18px; padding: 22px 0; border-top: 1px solid var(--rule); }
.teach-item:first-child { border-top: 0; padding-top: 0; }
.teach-item svg { width: 26px; height: 26px; fill: none; stroke: var(--ink); stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; margin-top: 2px; }
.teach-item h3 { font-size: 1.2rem; margin-bottom: 6px; }
.teach-item p { color: var(--text-2); font-size: 0.97rem; }

.mock { margin: 0; background: var(--surface); border: 1px solid var(--rule); border-radius: var(--card); overflow: hidden; position: sticky; top: 100px; }
.mock-head { padding: 26px 26px 20px; }
.mock-head .eyebrow { margin-bottom: 8px; }
.mock-head h3 { font-size: 1.45rem; }
.mock-sub { color: var(--text-3); font-size: 0.88rem; margin-top: 4px; }
.mock-row { display: flex; justify-content: space-between; gap: 16px; padding: 14px 26px; border-top: 1px solid var(--rule); font-size: 0.92rem; }
.mock-row span { color: var(--text-2); }
.mock-row strong { font-weight: 600; text-align: right; }
.mock-code { font-family: ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: 0.08em; background: var(--tile); border-radius: var(--radius); padding: 2px 8px; }
.mock-block { padding: 20px 26px; border-top: 1px solid var(--rule); }
.mock-block .eyebrow { margin-bottom: 14px; }
.bar { display: grid; grid-template-columns: 120px 1fr 40px; align-items: center; gap: 12px; font-size: 0.9rem; margin-top: 10px; }
.bar span { color: var(--text-2); }
.bar i { height: 6px; border-radius: 3px; background: var(--tile); position: relative; overflow: hidden; }
.bar i::after { content: ""; position: absolute; inset: 0 auto 0 0; width: var(--v); background: var(--ink); border-radius: 3px; }
.bar b { font-weight: 600; text-align: right; font-variant-numeric: tabular-nums; }
.mock-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.mock-tags span { border: 1px solid var(--rule); border-radius: 999px; padding: 4px 12px; font-size: 0.85rem; color: var(--text-2); }
.mock figcaption { padding: 16px 26px 20px; border-top: 1px solid var(--rule); background: var(--tile); color: var(--text-3); font-size: 0.82rem; }

.privacy-grid { display: grid; grid-template-columns: 5fr 7fr; gap: 64px; align-items: start; }
.privacy-grid .section-head { margin-bottom: 0; position: sticky; top: 110px; }
.promises { margin: 0; display: grid; gap: 1px; background: var(--rule); border: 1px solid var(--rule); border-radius: var(--card); overflow: hidden; }
.promises div { background: var(--surface); padding: 24px 28px; }
.promises dt { font: 600 1.12rem/1.3 var(--serif); margin-bottom: 6px; }
.promises dd { margin: 0; color: var(--text-2); font-size: 0.97rem; }

.cta { border-top: 1px solid var(--rule); }
.cta-inner { text-align: center; max-width: 640px; }
.cta-icon { width: 96px; height: 96px; border-radius: 22px; margin: 0 auto 28px; border: 1px solid var(--rule); }
.cta-inner p { color: var(--text-2); margin-top: 16px; font-size: 1.08rem; }

/* Legal */
.legal { padding: 64px 0 96px; }
.legal-grid { display: grid; grid-template-columns: 240px 1fr; gap: 64px; align-items: start; }
.legal-toc { position: sticky; top: 100px; }
.legal-toc ol { list-style: none; margin: 0; padding: 0; border-left: 1px solid var(--rule); }
.legal-toc a { display: block; padding: 6px 0 6px 16px; font-size: 0.88rem; color: var(--text-2); text-decoration: none; }
.legal-toc a:hover { color: var(--text); }
.legal-body { max-width: 720px; background: var(--surface); border-radius: var(--card); padding: 48px 56px 56px; }
.legal-body h1 { font-size: clamp(2rem, 4vw, 2.8rem); margin-bottom: 8px; }
.legal-body .lede { margin: 28px 0 8px; font-size: 1.05rem; }
.legal-body section { padding-top: 28px; margin-top: 28px; border-top: 1px solid var(--rule); }
.legal-body h2 { font-size: 1.3rem; margin-bottom: 12px; }
.legal-body p, .legal-body li { color: var(--text-2); font-size: 0.98rem; }
.legal-body p + p, .legal-body ul + p { margin-top: 12px; }
.legal-body ul { padding-left: 1.15rem; margin: 10px 0 0; }
.legal-body li { margin: 6px 0; }
.legal-body strong { color: var(--text); font-weight: 600; }
.legal-body a { text-underline-offset: 3px; }
.legal-body .company { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--rule); }

/* Support */
.support { padding: 72px 0 96px; }
.support h1 { margin-bottom: 18px; }
.support h2 { font-size: 1.6rem; margin: 64px 0 20px; }
.contact-card { display: grid; gap: 4px; margin-top: 36px; padding: 28px; background: var(--surface); border: 1px solid var(--rule); border-radius: var(--card); text-decoration: none; transition: background .15s ease; }
.contact-card:hover { background: var(--tile); }
.contact-card .eyebrow { margin: 0; }
.contact-card strong { font: 600 1.45rem/1.3 var(--serif); }
.faq { border: 1px solid var(--rule); border-radius: var(--card); overflow: hidden; background: var(--rule); display: grid; gap: 1px; }
.faq-item { background: var(--surface); }
.faq-item summary { list-style: none; cursor: pointer; padding: 20px 56px 20px 24px; font: 600 1.08rem/1.35 var(--serif); position: relative; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: ""; position: absolute; right: 26px; top: 26px; width: 8px; height: 8px; border-right: 1.5px solid var(--text-2); border-bottom: 1.5px solid var(--text-2); transform: rotate(45deg); transition: transform .2s ease; }
.faq-item[open] summary::after { transform: rotate(-135deg); top: 30px; }
.faq-item p { padding: 0 24px 22px; color: var(--text-2); font-size: 0.98rem; }
.support .center-text .btn { margin-top: 32px; }

/* Footer */
.site-footer { border-top: 1px solid var(--rule); padding: 64px 0 40px; }
.footer-cols { display: grid; grid-template-columns: 1.2fr 2fr; gap: 48px; }
.footer-brand p { margin-top: 16px; color: var(--text-2); font-size: 0.93rem; max-width: 26em; }
.footer-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.footer-links h4 { font: 600 0.72rem/1.2 var(--sans); text-transform: uppercase; letter-spacing: 0.12em; color: var(--text-3); margin: 0 0 14px; }
.footer-links a { display: block; text-decoration: none; color: var(--text-2); font-size: 0.93rem; padding: 4px 0; }
.footer-links a:hover { color: var(--text); }
.footer-legal { margin-top: 48px; padding-top: 24px; border-top: 1px solid var(--rule); font-size: 0.82rem; color: var(--text-3); display: grid; gap: 4px; }

/* Scroll reveal (enabled by app.js; content stays visible without JS). */
.js .reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
.js .reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .js .reveal { opacity: 1; transform: none; transition: none; } }

/* Responsive */
@media (max-width: 960px) {
  .showcase, .privacy-grid, .teach-grid { grid-template-columns: 1fr; gap: 36px; }
  .mock { position: static; }
  .showcase.flip .showcase-text { order: 0; }
  .privacy-grid .section-head { position: static; }
  .features { grid-template-columns: repeat(2, 1fr); }
  .legal-grid { grid-template-columns: 1fr; }
  .legal-toc { display: none; }
}
@media (max-width: 760px) {
  body { font-size: 16px; }
  .nav-toggle { display: block; }
  .nav-links {
    position: absolute; top: 68px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--paper); border-bottom: 1px solid var(--rule);
    padding: 8px 24px 20px; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a:not(.btn) { padding: 14px 0; border-bottom: 1px solid var(--rule); font-size: 1rem; }
  .nav-links .btn { margin-top: 16px; min-height: 46px; }
  .hero { padding-top: 40px; }
  .section { padding: 72px 0; }
  .steps, .features, .footer-cols, .roles { grid-template-columns: 1fr; }
  .bar { grid-template-columns: 96px 1fr 36px; }
  .footer-links { grid-template-columns: repeat(2, 1fr); }
  .legal-body { padding: 32px 22px 40px; }
}