@import url("tokens.css");
@import url("nav.css");
@import url("shared.css");

/* ==========================================================================
   CASE STUDY SYSTEM — canonical stylesheet (v1.1)
   Do not edit per case study. Brand and page-specific values go in the
   <style id="page"> block of the page (see RULEBOOK.md §4 and §16).
   ========================================================================== */

@font-face { font-family: "Nimbus Sans"; src: url("fonts/NimbusSans-Regular.otf") format("opentype"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "Nimbus Sans"; src: url("fonts/NimbusSans-Bold.otf") format("opentype"); font-weight: 700; font-style: normal; font-display: swap; }

/* ── 2. Base ───────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  font-size: var(--t-body);
  line-height: var(--lh-body);
  letter-spacing: var(--ls-body);
  color: var(--body);
  background: var(--page);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; border-radius: 4px; }

.skip {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 100;
  background: var(--ink);
  color: #fff;
  padding: 8px 12px;
  font-size: 14px;
  letter-spacing: 0;
  text-decoration: none;
  border-radius: 6px;
}
.skip:focus { top: 16px; z-index: 100; }

/* ── 3. Type ───────────────────────────────────────────────────────────── */
h1 {
  font-size: var(--t-h1);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: var(--lh-h1);
  color: var(--ink);
  max-width: var(--read-hero);
  text-wrap: balance;
}
h2 {
  font-size: var(--t-h2);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: var(--lh-h2);
  color: var(--ink);
}
h3 {
  font-size: var(--t-card-title);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--ink);
}
.lede { max-width: var(--read-hero); margin-top: var(--gap-h1-lede); }
.prose { max-width: var(--read); }
.prose strong, .cell strong, .card strong, .caption strong { color: var(--ink); font-weight: 700; }
.caption { max-width: var(--read); margin-inline: auto; text-align: center; }
.caption .aside { display: block; margin-top: 14px; color: var(--soft); }

/* ── 4. Page frame ─────────────────────────────────────────────────────── */
.wrap {
  width: min(var(--page-max), 100%);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.hero { padding-top: calc(var(--nav-h) + var(--hero-top)); }

.layout {
  width: min(var(--page-max), 100%);
  margin: var(--gap-hero) auto 0;
  padding: 0 calc(var(--gutter) + var(--inset)) 120px;
}
.rail { display: none; }

@media (min-width: 1280px) {
  .layout {
    display: grid;
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    column-gap: 84px;
    align-items: start;
    margin-top: calc(var(--gap-hero) - 40px);
    padding-inline: var(--gutter) calc(var(--gutter) + 54px);
  }
  .rail {
    position: sticky;
    top: var(--nav-h);
    height: calc(100vh - var(--nav-h));
    padding: 40px 0 32px;
    border-right: 1px solid var(--hair);
    display: flex;
    flex-direction: column;
    letter-spacing: 0;
  }
  main { padding-top: 40px; }
}
.toc-title { font-size: 22px; line-height: 1.2; color: var(--ink); margin-bottom: 30px; }
nav.toc { display: grid; gap: 13px; }
nav.toc a, .back-top {
  font-size: 14px;
  line-height: 1.2;
  color: var(--mute);
  text-decoration: none;
  transition: color var(--ease);
}
nav.toc a:hover, .back-top:hover, nav.toc a.active { color: var(--ink); }
.back-top { margin-top: auto; }

/* ── 5. Section rhythm ─────────────────────────────────────────────────── */
.chapter { scroll-margin-top: calc(var(--nav-h) + 40px); }
.chapter + .chapter { margin-top: var(--gap-section); }
.chapter > h2 + .prose { margin-top: var(--gap-head-text); }
.chapter > .prose + .prose { margin-top: var(--gap-text-text); }
.chapter > .panel,
.chapter > .panel + .prose { margin-top: var(--gap-panel); }
.chapter > .caption { margin-top: var(--gap-caption); }
.chapter > .panel.tight, .hero > .panel.tight { margin-top: var(--gap-tight); }

/* ── 6. Panel + card: the two surfaces ─────────────────────────────────── */
.panel {
  background: var(--panel);
  border-radius: var(--r-panel);
}
.card {
  background: var(--card);
  border-radius: var(--r-card);
  padding: 24px;
  letter-spacing: -0.01em;
}
.card h3 + p { margin-top: 10px; }
.card p, .cell p { font-size: var(--t-card-text); line-height: 1.35; }
.card.float { box-shadow: var(--shadow-card); }
.k { font-size: 14px; line-height: 1.3; color: var(--mute); letter-spacing: 0; }

/* ── 7. Devices ────────────────────────────────────────────────────────── */
.ph { container-type: inline-size; }
.device {
  overflow: hidden;
  border-radius: var(--phone-r);
  background: #fff;
  box-shadow: var(--shadow-device);
}
.device.crop { aspect-ratio: var(--ar); border-radius: var(--phone-r) var(--phone-r) 0 0; }
.device img { width: 100%; }

.browser {
  overflow: hidden;
  border-radius: var(--r-browser);
  background: #fff;
  box-shadow: var(--shadow-device);
}
.browser-bar {
  position: relative;
  height: 44px;
  background: #fdfdfd;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 0 16px;
}
.browser-bar i { width: 11px; height: 11px; border-radius: 50%; background: #e3e3e3; }
.browser-url {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  font-size: 13px;
  letter-spacing: 0;
  color: var(--soft);
  background: #f1f1f1;
  border-radius: 6px;
  padding: 4px 36px;
  white-space: nowrap;
}
.browser img { width: 100%; }

/* ── 8. Hero panel ─────────────────────────────────────────────────────── */
.hero-panel {
  margin-top: var(--gap-lede-hero);
  border-radius: var(--r-panel);
  overflow: hidden;
  position: relative;
  aspect-ratio: 21 / 10;
  container-type: inline-size;
  background:
    radial-gradient(60cqw 38cqw at 78% 8%, rgba(255, 255, 255, 0.85), rgba(255, 255, 255, 0) 70%),
    radial-gradient(50cqw 36cqw at 12% 96%, var(--hero-glow), rgba(255, 255, 255, 0) 70%),
    linear-gradient(135deg, var(--hero-1) 0%, var(--hero-2) 55%, var(--hero-3) 100%);
}
/* phone product: three screens stepping up left to right */
.hero-phone {
  position: absolute;
  width: 24cqw;
  border-radius: 2.3cqw;
  overflow: hidden;
  background: #fff;
  box-shadow: var(--shadow-device);
}
.hero-phone img { width: 100%; }
.hero-phone:nth-child(1) { left: 17cqw; top: 13cqw; }
.hero-phone:nth-child(2) { left: 38cqw; top: 8cqw; }
.hero-phone:nth-child(3) { left: 59cqw; top: 3cqw; }
/* web product: two windows, the main one in front on the left */
.hero-window { position: absolute; }
.hero-window:nth-child(1) { left: 5cqw; top: 9cqw; width: 54cqw; z-index: 2; }
.hero-window:nth-child(2) { left: 52cqw; top: 4cqw; width: 44cqw; }

@media (max-width: 1199px) {
  .hero-panel { aspect-ratio: 7 / 4; }
  .hero-phone { width: 27cqw; border-radius: 2.6cqw; }
  .hero-phone:nth-child(1) { left: 12cqw; top: 15cqw; }
  .hero-phone:nth-child(2) { left: 36.5cqw; top: 9.5cqw; }
  .hero-phone:nth-child(3) { left: 61cqw; top: 4cqw; }
}
@media (max-width: 809px) {
  .hero-panel { aspect-ratio: 100 / 86; }
  .hero-phone { width: 36cqw; border-radius: 3.4cqw; }
  .hero-phone:nth-child(1) { left: 5cqw; top: 24cqw; }
  .hero-phone:nth-child(2) { left: 32cqw; top: 15cqw; }
  .hero-phone:nth-child(3) { left: 59cqw; top: 6cqw; }
  .hero-window:nth-child(1) { left: 4cqw; top: 16cqw; width: 78cqw; }
  .hero-window:nth-child(2) { left: 40cqw; top: 6cqw; width: 70cqw; }
}

/* ── 9. Hairline grid ──────────────────────────────────────────────────── */
.grid { padding: 16px 40px; letter-spacing: -0.01em; }
.cells {
  display: grid;
  grid-template-columns: var(--grid, repeat(var(--cols, 4), minmax(0, 1fr)));
  margin: 0 -28px;
  clip-path: inset(1px 28px 0);
}
.cell {
  min-width: 0;
  padding: 28px;
  margin: -1px 0 0 -1px;
  border-left: 1px solid var(--hair);
  border-top: 1px solid var(--hair);
}
.cell h3 + p { margin-top: 12px; }
.cell .k { margin-bottom: 8px; }
.cell-label p { font-size: var(--t-card-title); font-style: italic; color: var(--ink); }
.ico { width: 34px; height: 34px; display: block; margin-bottom: 18px; }

.stat { display: flex; align-items: baseline; gap: 8px; margin-bottom: 18px; color: var(--ink); }
.stat-n { font-size: var(--t-stat); letter-spacing: -0.03em; line-height: 1; }
.stat-c { font-size: 13px; letter-spacing: 0; color: var(--soft); }

@media (max-width: 999px) {
  .cells { grid-template-columns: 1fr 1fr; }
  .cell { padding: 22px 28px; }
  .cell-label { grid-column: 1 / -1; padding-bottom: 16px; }
  .cell-empty { display: none; }
}
@media (max-width: 599px) {
  .grid { padding: 8px 20px; }
  .cells { grid-template-columns: 1fr; margin: 0; clip-path: inset(0); }
  .cell { padding: 20px 0; border-left: 0; }
}

/* ── 10. Card rows ─────────────────────────────────────────────────────── */
.cards {
  display: grid;
  grid-template-columns: repeat(var(--cols, 4), minmax(0, 1fr));
  gap: 12px;
  padding: 96px 20px;
  align-items: stretch;
}
.cards.media { padding: 28px 20px; gap: 20px; }
.cards.media figure { display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.cards.media img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; border-radius: var(--r-card); }
.cards.media .card { flex: 1; }
@media (max-width: 999px) {
  .cards { grid-template-columns: 1fr 1fr; padding: 56px 20px; }
  .cards.media { grid-template-columns: 1fr; }
}
@media (max-width: 599px) {
  .cards { grid-template-columns: 1fr; padding: 20px; }
}

/* ── 11. Showcase: one device, optional callout cards ──────────────────── */
.showcase {
  position: relative;
  padding: 48px;
  display: flex;
  justify-content: center;
  align-items: center;
}
.showcase.flush { padding-bottom: 0; align-items: flex-end; }
.showcase .ph { width: 280px; flex: 0 0 auto; }
.showcase .browser { width: min(720px, 100%); flex: 0 1 auto; }
.showcase .card.float { position: relative; z-index: 2; width: 280px; }
.showcase .card.after { margin-left: -20px; }
.showcase .card.before { margin-right: -20px; }
.showcase.flush .card.float { margin-bottom: 64px; }
.showcase .card.low { align-self: flex-end; margin-bottom: 72px; }
.showcase .card.high { align-self: flex-start; margin-top: 96px; }

/* stage: the screen is the only loud thing; labels sit on the panel itself */
.showcase.stage { padding: 56px 48px 64px; }
.showcase.stage .ph { width: 340px; }
.stage-label { position: absolute; left: 44px; top: 44px; width: 190px; letter-spacing: 0; }
.stage-label h3 {
  font-size: 14px;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--soft);
  margin-bottom: 14px;
}

/* live prototype loop inside a stage */
.live-phone { display: flex; flex-direction: column; align-items: center; }
.live-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  letter-spacing: 0;
  color: var(--soft);
  margin-bottom: 14px;
}
.live-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--brand);
  animation: live-pulse 1.8s ease-out infinite;
}
@keyframes live-pulse {
  0% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--brand) 45%, transparent); }
  100% { box-shadow: 0 0 0 8px color-mix(in srgb, var(--brand) 0%, transparent); }
}
.live-device { position: relative; aspect-ratio: 390 / 844; }
.live-device iframe {
  position: absolute;
  left: 0;
  top: 0;
  width: 390px;
  height: 844px;
  border: 0;
  transform-origin: 0 0;
  transform: scale(var(--k, 0.87));
  pointer-events: none;
  background: #fff;
}

/* step list: click a step to jump the loop there */
.steps { list-style: none; display: grid; gap: 2px; margin: 0 -8px; }
.steps button {
  appearance: none;
  border: 0;
  background: transparent;
  font: inherit;
  font-size: 15px;
  letter-spacing: 0;
  text-align: left;
  color: var(--mute);
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 6px 8px;
  border-radius: 8px;
  cursor: pointer;
  transition: color var(--ease), background-color var(--ease);
}
.steps button:hover { color: var(--ink); }
.steps .n {
  flex: 0 0 22px;
  height: 22px;
  border-radius: 50%;
  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.18);
  display: grid;
  place-items: center;
  font-size: 11px;
  color: var(--mute);
  transition: background-color var(--ease), color var(--ease);
}
.steps button[aria-current="step"] { color: var(--ink); background: rgba(0, 0, 0, 0.06); }
.steps button[aria-current="step"] .n { background: var(--brand); color: #fff; box-shadow: none; }

@media (max-width: 1279px) {
  .showcase { flex-wrap: wrap; gap: 24px; }
  .showcase .card.float { margin: 0; align-self: center; width: min(320px, 100%); }
  .showcase.flush { flex-direction: column-reverse; align-items: center; }
  .showcase.flush .card.float { margin: 0; }
  .showcase.stage { flex-direction: column; padding: 40px 28px; }
  .stage-label { position: static; width: min(340px, 100%); }
}
@media (max-width: 809px) {
  .showcase, .showcase.stage { padding: 32px 20px; }
  .showcase.flush { padding-bottom: 0; }
  .showcase .ph { width: min(260px, 78%); }
  .showcase.stage .ph { width: min(300px, 82%); }
}

/* ── 12. Versus: believed / found ──────────────────────────────────────── */
.versus {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  padding: 56px 32px 60px;
  text-align: center;
}
.versus-item { display: flex; flex-direction: column; align-items: center; }
.bubble {
  position: relative;
  width: 168px;
  height: 168px;
  border-radius: 50%;
  background: var(--bubble);
  display: grid;
  place-items: center;
}
.bubble svg.art, .bubble img.art { width: 92px; height: 92px; }
.mark {
  position: absolute;
  top: -4px;
  right: -8px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--page);
  display: grid;
  place-items: center;
}
.mark svg { width: 22px; height: 22px; }
.versus-k { margin-top: 24px; font-size: var(--t-versus); font-weight: 400; letter-spacing: -0.03em; line-height: 1.2; }
.versus-k.no { color: var(--no); }
.versus-k.yes { color: var(--yes); }
.versus-item p:last-child { margin-top: 10px; max-width: 320px; font-size: var(--t-card-text); letter-spacing: -0.01em; line-height: 1.35; }
@media (max-width: 809px) {
  .versus { grid-template-columns: 1fr; gap: 44px; padding: 40px 20px; }
}

/* ── 13. Ask: one centred statement card ───────────────────────────────── */
.ask { padding: 96px 32px; display: grid; place-items: center; }
.ask.action { padding-block: 64px; }
.ask .card {
  position: relative;
  width: min(680px, 100%);
  padding: 40px 52px;
  text-align: center;
}
.ask .k { margin-bottom: 10px; }
.ask .ask-line {
  font-size: var(--t-ask);
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-wrap: balance;
}
.ask-line span { color: var(--brand-ink); font-weight: 700; }
.ask .deco { position: absolute; left: -6px; bottom: -4px; width: 64px; height: 64px; }

.action .card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 32px;
  text-align: left;
}
.action p { font-size: var(--t-card-title); color: var(--ink); letter-spacing: -0.02em; }
.btn {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  background: var(--ink);
  color: #fff;
  font-size: 15px;
  letter-spacing: 0;
  text-decoration: none;
  padding: 12px 22px;
  border-radius: 999px;
  transition: background-color var(--ease);
}
.btn:hover { background: #333; }
@media (max-width: 1199px) {
  .ask { padding-block: 64px; }
}
@media (max-width: 809px) {
  .ask, .ask.action { padding: 32px 16px; }
  .ask .card { padding: 28px 24px 36px; }
  .action .card { flex-direction: column; align-items: flex-start; }
}

/* ── 14. Flow chart ────────────────────────────────────────────────────── */
.flow {
  padding: 56px 32px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 14px 8px;
  letter-spacing: 0;
}
.node {
  background: var(--node);
  color: var(--body);
  font-size: 15px;
  line-height: 1.3;
  padding: 9px 16px;
  border-radius: 4px;
  white-space: nowrap;
}
.node.start { background: var(--node-start); }
.node.on { background: var(--node-on); color: var(--node-on-ink); }
.flow .arrow { width: 34px; height: 12px; flex: 0 0 auto; }
.hop { display: inline-flex; align-items: center; gap: 8px; }
@media (max-width: 809px) { .flow { padding: 36px 16px; } }

/* ── 15. Diagram, figure, embed ────────────────────────────────────────── */
.diagram { padding: 28px 24px; overflow-x: auto; }
.diagram svg { display: block; width: 100%; min-width: 700px; height: auto; }
.diagram text { font-family: var(--font); fill: #1c1c1c; letter-spacing: 0; }

.figure { padding: 40px; }
.figure img { width: 100%; border-radius: 4px; }
.embed { overflow: hidden; aspect-ratio: 16 / 9; }
.embed iframe { width: 100%; height: 100%; border: 0; display: block; }
@media (max-width: 809px) { .figure { padding: 20px; } }

/* ── 16. Annotated screens: screen + hand notes + verdict card ─────────── */
.cuts {
  display: grid;
  grid-template-columns: repeat(var(--cols, 2), minmax(0, 1fr));
  gap: 24px;
  padding: 48px 32px 32px;
}
.cut { display: flex; flex-direction: column; min-width: 0; }
.cut-stage { position: relative; display: flex; justify-content: center; }
.cut-stage .ph { width: min(230px, 52%); }
.note {
  position: absolute;
  width: calc(50% - min(115px, 26%) - 14px);
  font-family: var(--hand);
  font-size: 20px;
  font-weight: 500;
  line-height: 1.05;
  letter-spacing: 0;
  color: var(--sketch);
}
.note svg { display: block; width: 46px; height: 22px; margin-top: 6px; }
.note.l { left: 0; text-align: right; }
.note.l svg { margin-left: auto; }
.note.r { right: 0; }
.note.r svg { transform: scaleX(-1); }
.cut .card { margin-top: 32px; flex: 1; }
@media (max-width: 999px) {
  .cuts { grid-template-columns: 1fr; gap: 48px; }
}
@media (max-width: 809px) {
  .cuts { padding: 32px 20px 20px; }
  .cut-stage { flex-direction: column; align-items: center; }
  .cut-stage .ph { width: min(220px, 70%); }
  .note { position: static; width: auto; text-align: center; margin-top: 14px; }
  .note svg { display: none; }
  .note.first { margin-top: 20px; }
}

/* ── 17. Footer ────────────────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--hair);
  padding: 28px 0 40px;
  font-size: 14px;
  letter-spacing: 0;
  color: var(--mute);
}

/* ── 18. Motion ────────────────────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .live-dot { animation: none; }
}