@font-face {
  font-family: "Hanken Grotesk";
  src: url("/fonts/HankenGrotesk-Variable.woff2") format("woff2");
  font-weight: 200 600;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  src: url("/fonts/IBMPlexMono-Regular-Latin1.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

:root {
  --paper: #ffffff;
  --ink: #1a1a1a;
  --gray: #6e6e6e;
  --faint: #858585;
  --line: #e7e7e7;
  --zhu: #b8281e;
  --wood: #1c1511;

  --sans: "Hanken Grotesk", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", system-ui, sans-serif;
  --song: "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", serif;
  --mono: "IBM Plex Mono", "SF Mono", ui-monospace, Menlo, monospace;

  --gutter: clamp(24px, 4.5vw, 64px);
  --page: min(1200px, 100% - 2 * var(--gutter));
}

*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  font-weight: 300;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  font-synthesis-weight: none;
}

img, video { display: block; max-width: 100%; height: auto; }
/* Pictures on this site are part of the design, not content to save: no
   long-press menu, no force-click preview and no dragging a copy off the
   page. Clicks on a picture inside a link still reach the link. */
img {
  pointer-events: none;
  -webkit-touch-callout: none;
  -webkit-user-drag: none;
  user-select: none;
}
a { color: inherit; }
p { text-wrap: pretty; }
code, pre { font-family: var(--mono); }
:focus-visible { outline: 1px solid var(--zhu); outline-offset: 4px; }

.wrap { width: var(--page); margin-inline: auto; }

.link {
  text-decoration: none;
  border-bottom: 1px solid var(--zhu);
  padding-bottom: 3px;
  font-weight: 400;
  color: var(--ink);
}
.link:hover { color: var(--zhu); }

h1, h2 { text-wrap: balance; font-weight: 300; }
:lang(zh) h1, :lang(zh) h2 { font-family: var(--song); letter-spacing: 0.04em; }
:lang(zh) h2 { word-break: keep-all; }

.num {
  display: block;
  margin-bottom: 20px;
  font-family: var(--song);
  font-size: 15px;
  color: var(--zhu);
}
.num span { margin-left: 14px; font-family: var(--sans); font-size: 12.5px; letter-spacing: 0.04em; color: var(--faint); }

/* Hero */

.hero {
  position: relative;
  display: grid;
  /* The text starts on the same left edge as every section below; the
     photograph still bleeds to the right edge of the window. */
  grid-template-columns: calc((100% - var(--page)) / 2) calc(var(--page) * 0.5) minmax(0, 1fr);
  min-height: 100vh;
  min-height: 100svh;
}
.hero-text {
  display: flex;
  flex-direction: column;
  grid-column: 2;
  padding: 36px var(--gutter) 56px 0;
}
.nav {
  display: flex;
  align-items: center;
  gap: 26px;
  font-size: 14.5px;
  color: var(--gray);
}
.nav .brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-right: auto;
  color: var(--ink);
  font-weight: 400;
  text-decoration: none;
}
.nav .brand img { width: 22px; height: 22px; align-self: center; }
.nav .brand small { margin-left: -2px; font-size: 13px; font-weight: 400; color: var(--faint); }
.nav a { text-decoration: none; }
.nav a:hover { color: var(--ink); }

.statement { margin: auto 0 0; padding: 56px 0 0; }
.statement h1 {
  margin: 0;
  font-weight: 200;
  font-size: clamp(40px, 4.4vw, 66px);
  line-height: 1.14;
  letter-spacing: -0.02em;
}
.statement h1 b { font-weight: 400; color: var(--zhu); }
:lang(zh) .statement h1 b { font-weight: inherit; }
:lang(zh) .statement h1 { font-weight: 300; font-size: clamp(36px, 3.8vw, 56px); line-height: 1.35; }
.statement .sub { margin: 26px 0 0; max-width: 26em; font-size: clamp(18px, 1.5vw, 21px); line-height: 1.7; color: #4d4d4d; }
.statement .points { margin: 18px 0 0; padding: 0; list-style: none; font-size: clamp(16px, 1.25vw, 18px); line-height: 1.6; color: #4d4d4d; }
.statement .points li { position: relative; padding-left: 20px; margin-top: 8px; }
.statement .points li b { font-weight: 500; color: var(--ink); }
.statement .points li::before { content: ""; position: absolute; left: 2px; top: 0.72em; width: 8px; height: 2px; background: var(--zhu); }
.statement .sub strong { display: block; margin-bottom: 0; text-wrap: balance; font-size: 1.12em; font-weight: 500; color: var(--ink); }

.intro { margin: 40px 0 auto; }
.cta {
  display: inline-block;
  padding: 13px 28px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-size: 16px;
  font-weight: 400;
  text-decoration: none;
  transition: background 0.2s ease;
}
.cta:hover { background: var(--zhu); }
.ctas { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 28px; }
.cta-alt { font-size: 15px; font-weight: 400; color: var(--gray); text-decoration: none; transition: color 0.2s ease; }
.cta-alt::after { content: " →"; }
.cta-alt:hover { color: var(--zhu); }
.intro .meta { margin: 14px 0 0; font-size: 14px; color: var(--gray); }

.hero-image {
  position: relative;
  margin: 0;
  overflow: hidden;
  grid-column: 3;
  background: var(--wood);
  container-type: inline-size;
}
.hero-image .plate {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  aspect-ratio: 1672 / 941;
  /* Keep the seal (its centre is 73.6% across the photograph) three quarters
     of the way across the column, whatever the window's shape, without ever
     uncovering an edge of the column. */
  transform: translateX(clamp(calc(100cqw - 100%), calc(75cqw - 73.6%), 0px));
}
.hero-image .plate .photo { width: 100%; height: 100%; }
.hero-image .seal {
  position: absolute;
  left: 67.2%;
  top: 37.6%;
  width: 12.9%;
  height: auto;
  mix-blend-mode: multiply;
}

@media (prefers-reduced-motion: no-preference) {
  .hero-image .seal { animation: stamp 0.55s cubic-bezier(0.3, 0.7, 0.2, 1) 0.9s both; }
  .fade { animation: fade 1.1s ease 0.15s both; }
}
@keyframes stamp {
  0% { opacity: 0; transform: scale(1.22); filter: blur(3px); }
  55% { opacity: 1; transform: scale(0.97); filter: blur(0); }
  100% { opacity: 1; transform: none; }
}
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

/* Seals: three permissions, stamped in turn */

.decide { padding: clamp(96px, 12vw, 168px) 0 0; }
.decide-grid { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: clamp(32px, 4vw, 64px); align-items: start; }
.decide h2 { margin: 0 0 20px; font-size: clamp(26px, 2.5vw, 34px); line-height: 1.3; }
.decide p { margin: 0 0 14px; color: var(--gray); font-size: 16px; }

/* The slips start level with the heading, under the section number. */
.desk { position: relative; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(12px, 2vw, 28px); margin-top: 46px; }
.slip {
  position: relative;
  aspect-ratio: 3 / 4;
  padding: 22px 20px;
  background: #f3eee5 url("/assets/paper.jpg") center / cover;
  box-shadow: 0 1px 1px rgba(0, 0, 0, 0.06), 0 18px 30px -18px rgba(40, 25, 10, 0.35);
  transition: opacity 0.8s ease;
}
.slip h3 { margin: 0 0 6px; font-size: 17px; font-weight: 400; }
:lang(zh) .slip h3 { font-family: var(--song); font-size: 19px; }
/* The short lines on the slips break at punctuation, never inside a word. */
:lang(zh) .slip p { word-break: keep-all; }
.slip h3 small { display: inline-block; margin-left: 10px; padding: 0 5px; border: 1px solid var(--zhu); border-radius: 2px; font-family: var(--sans); font-size: 11px; line-height: 1.6; letter-spacing: 0.04em; color: var(--zhu); vertical-align: 3px; }
.slip p { margin: 0; font-size: 14.5px; line-height: 1.65; color: #3f3b35; }
.slip .imp { position: absolute; left: 50%; bottom: 9%; width: 32%; margin-left: -16%; opacity: 0; }
.slip.gone { opacity: 0.55; }
.stone { position: absolute; top: 0; left: 0; width: clamp(48px, 4.4vw, 68px); pointer-events: none; opacity: 0; }
.stone.moving { will-change: transform, opacity; }
.stone img { width: 100%; filter: drop-shadow(0 14px 14px rgba(40, 25, 10, 0.25)); }

.desk:not(.animated) .imp { opacity: 1; }
.desk:not(.animated) .stone { display: none; }
.desk:not(.animated) .hidden-slip { opacity: 0.55; }

/* Clients, limits, download */

.chapter { padding: clamp(96px, 12vw, 168px) 0 0; }
.chapter h2 { margin: 0 0 22px; font-size: clamp(26px, 2.5vw, 34px); line-height: 1.3; }
.chapter p { margin: 0 0 16px; color: var(--gray); font-size: 16px; }

.chapter .lede { max-width: 40em; margin: 0; font-size: clamp(16px, 1.3vw, 18px); }

/* Clients: Ask Key in the middle, a red line to each tool it sets up itself and a
   dotted one to everything else that speaks MCP. motion.js lays the names out;
   without it they read as two plain lists. */
.hub { position: relative; margin-top: clamp(32px, 4vw, 48px); }
.hub-lines { display: none; }
.hub-core { display: none; }
.hub-names { display: flex; flex-wrap: wrap; gap: 4px 28px; margin: 0 0 16px; padding: 0; list-style: none; }
.hub-names.is-auto { font-size: clamp(22px, 2.3vw, 32px); font-weight: 300; letter-spacing: -0.01em; color: var(--ink); }
.hub-names.is-mcp { font-size: clamp(15px, 1.35vw, 18px); font-weight: 300; color: #8d8d8d; }
.hub.is-laid { height: clamp(440px, 42vw, 560px); }
.hub.is-laid .hub-lines { display: block; position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.hub.is-laid .hub-names { display: contents; }
.hub.is-laid .hub-names li { position: absolute; white-space: nowrap; line-height: 1; transform: translateY(-50%); }
.hub.is-laid .hub-names li.is-left { transform: translate(-100%, -50%); }
.hub.is-laid .hub-core { display: block; position: absolute; left: 50%; top: calc(50% - 56px); transform: translateX(-50%); text-align: center; }
.hub-core img { width: 112px; height: 112px; border-radius: 26px; box-shadow: 0 24px 40px -18px rgba(120, 40, 10, 0.45), 0 2px 6px rgba(0, 0, 0, 0.08); }
.hub-core b { display: block; margin-top: 14px; font-family: var(--song); font-size: 19px; font-weight: 400; letter-spacing: 0.08em; }
:lang(en) .hub-core b { font-family: var(--sans); letter-spacing: 0; }
.hub.is-narrow .hub-core { left: 0; top: 0; transform: none; }
.hub.is-narrow .hub-core img { width: 72px; height: 72px; border-radius: 17px; }
.hub.is-narrow .hub-core b { margin-top: 8px; font-size: 15px; }
.hub.is-narrow .hub-names li.is-left { transform: translateY(-50%); }
.hub.is-narrow .hub-names.is-auto { font-size: 24px; }
.hub.is-narrow .hub-names.is-mcp { font-size: 16px; }
.hub-lines path { fill: none; }
.hub-lines .is-auto { stroke: var(--zhu); stroke-width: 1.4; }
.hub-lines .is-mcp { stroke: #cfcfcf; stroke-width: 1; stroke-dasharray: 2 5; stroke-linecap: round; }
.hub.is-pending .hub-lines .is-auto { stroke-dasharray: var(--len); stroke-dashoffset: var(--len); }
.hub.is-pending .hub-lines .is-mcp, .hub.is-pending .hub-names li { opacity: 0; }
.hub-lines .is-auto { transition: stroke-dashoffset 1.2s cubic-bezier(0.6, 0, 0.2, 1) var(--d); }
.hub-lines .is-mcp, .hub-names li { transition: opacity 0.8s ease var(--d); }
.hub-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px 48px; margin: 36px 0 0; padding: 0; list-style: none; font-size: 14.5px; color: var(--gray); }
.hub-legend i { display: inline-block; width: 28px; margin-right: 10px; vertical-align: middle; border-top: 1.4px solid var(--zhu); }
.hub-legend i.is-mcp { border-top: 1.6px dotted #b8b8b8; }
.hub-legend b { margin-right: 6px; font-weight: 500; color: var(--ink); }
.hub.is-narrow + .hub-legend { flex-direction: column; justify-content: flex-start; gap: 8px; }
.hub-copy { margin-left: 14px; padding: 0 0 1px; border: 0; border-bottom: 1px solid var(--zhu); background: none; font: inherit; font-weight: 400; color: var(--ink); cursor: pointer; }
.hub-copy:hover { color: var(--zhu); }
.hub-config { max-width: 560px; margin: 24px auto 0; }
.hub.is-narrow ~ .hub-config { margin-left: 0; }
/* Config is copied as is, so it scrolls rather than wraps inside a path. */
.code { margin: 0; padding: 16px 20px; border-radius: 10px; background: #f5f5f4; font-size: clamp(11px, 1.1vw, 12.5px); line-height: 1.8; white-space: pre; overflow-x: auto; }

/* Limits: a pale blue-grey band that fades in and out of the white page, so the
   honest part of the page reads as a change of air rather than a new page. */
.limits-band { position: relative; isolation: isolate; margin-top: clamp(60px, 7vw, 110px); padding: clamp(150px, 15vw, 220px) 0; }
.limits-band::before { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(to bottom, #fff 0, #eef1f1 160px, #eef1f1 calc(100% - 160px), #fff 100%); }
.limits-grid { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: clamp(40px, 5vw, 80px); align-items: start; }
.limits-band h2 { margin: 0; font-size: clamp(28px, 2.8vw, 38px); line-height: 1.3; }
.limits-lead { margin: 20px 0 30px; max-width: 21em; font-size: 16px; line-height: 1.85; color: var(--gray); }
.limits { margin: 0; padding: 0; list-style: none; }
.limits li { display: grid; grid-template-columns: 64px minmax(0, 1fr); padding: 22px 0 24px; border-top: 1px solid rgba(0, 0, 0, 0.08); }
.limits li:last-child { border-bottom: 1px solid rgba(0, 0, 0, 0.08); }
.limits i { padding-top: 4px; font-size: 13px; font-style: normal; letter-spacing: 0.08em; color: var(--zhu); }
.limits b { display: block; font-size: 17px; font-weight: 500; }
.limits p { margin: 6px 0 0; max-width: 36em; font-size: 15px; line-height: 1.75; color: var(--gray); }

/* Download: the access card on the left, hanging from a vermilion cord; the
   brand, the button and three reassurances on the right. motion.js swings
   and tilts the card; without it the card simply hangs still. */
.download { padding: clamp(110px, 13vw, 180px) 0 clamp(96px, 10vw, 140px); overflow-x: clip; }
.dl-grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: clamp(40px, 6vw, 96px); align-items: center; }
.pass { position: relative; aspect-ratio: 1; background: radial-gradient(closest-side at 50% 52%, #fbecdf 0%, #fff6ee 55%, rgba(255, 255, 255, 0) 100%); touch-action: pan-y; }
.pass-swing { position: absolute; inset: 0; transform-origin: 50% 0; perspective: 900px; perspective-origin: 50% 45%; }
.pass-cord { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.pass-cord circle { fill: var(--zhu); }
.pass-cord path { fill: none; stroke: url(#pass-cord-fade); stroke-width: 1.8; stroke-linecap: round; vector-effect: non-scaling-stroke; }
.pass-tilt { position: absolute; left: 25%; top: 19%; width: 50%; }
.pass-tilt { aspect-ratio: 641 / 720; transform-origin: 49.5% 13.6%; transform-style: preserve-3d; }
/* The cast shadow is a pre-blurred image with 120 px of margin around the
   card, so no browser has to blur anything while the card moves. */
.pass-shadow { position: absolute; left: 15.64%; top: 9.64%; width: 68.72%; transform: translate(14px, 26px); }
.pass-card, .pass-key { position: absolute; inset: 0; width: 100%; height: 100%; }
.pass-key { transform: translateZ(18px); }
.pass-shine { position: absolute; inset: 0; background: linear-gradient(100deg, rgba(255, 255, 255, 0) 40%, rgba(255, 255, 255, 0.46) 50%, rgba(255, 255, 255, 0) 60%) 100% 0 / 300% 100% no-repeat; transform: translateZ(19px); -webkit-mask: url("/assets/pass.webp") center / 100% 100% no-repeat; mask: url("/assets/pass.webp") center / 100% 100% no-repeat; pointer-events: none; }
.lock { margin: 0; font-weight: 400; }
.lock b { display: block; font-family: var(--song); font-size: clamp(44px, 4.6vw, 64px); font-weight: 400; line-height: 1.1; letter-spacing: 0.1em; }
:lang(en) .lock b { font-family: var(--sans); font-weight: 300; letter-spacing: -0.02em; }
.lock span { display: block; margin-top: 10px; font-family: var(--sans); font-size: 13px; letter-spacing: 0.32em; text-transform: uppercase; color: var(--faint); }
.download .tagline { margin: 22px 0 0; font-size: clamp(17px, 1.4vw, 20px); font-weight: 400; color: #3a3a3a; }
.dl-cta { margin-top: 30px; padding: 15px 34px; font-size: 17px; }
.download .req { margin: 14px 0 0; font-size: 13.5px; line-height: 1.8; color: var(--gray); }
.assure { margin: 44px 0 0; padding: 0; list-style: none; }
.assure li { display: grid; grid-template-columns: 9em minmax(0, 1fr); gap: 16px; padding: 14px 0; border-top: 1px solid var(--line); font-size: 14.5px; color: var(--gray); }
:lang(en) .assure li { grid-template-columns: 12em minmax(0, 1fr); }
.assure b { font-weight: 500; color: var(--ink); }
.assure .star { white-space: nowrap; color: var(--ink); text-decoration: none; border-bottom: 1px solid var(--zhu); }
.assure .star:hover { color: var(--zhu); }
.download .fine { display: flex; flex-wrap: wrap; gap: 6px 28px; margin: 24px 0 0; padding: 0; list-style: none; font-size: 13.5px; }
.download .fine a, .download .fine button { padding: 0; border: 0; background: none; font: inherit; color: var(--gray); text-decoration: none; cursor: pointer; }
.download .fine a:hover, .download .fine button:hover { color: var(--zhu); }

footer { padding: 28px 0 40px; border-top: 1px solid var(--line); font-size: 13.5px; color: var(--faint); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 10px 26px; }
footer nav { display: flex; flex-wrap: wrap; gap: 8px 22px; margin-left: auto; }
footer a { text-decoration: none; }
footer a:hover { color: var(--ink); }

/* Responsive */

@media (max-width: 900px) {
  .dl-grid, .limits-grid { grid-template-columns: minmax(0, 1fr); }
  .limits-band { padding: 120px 0; }
  .limits-band::before { background: linear-gradient(to bottom, #fff 0, #eef1f1 90px, #eef1f1 calc(100% - 90px), #fff 100%); }
  .pass { width: min(100%, 420px); margin: 0 auto; }
  .decide-grid { grid-template-columns: minmax(0, 1fr); }
  .desk { margin-top: 24px; }
}
/* Narrow windows and portrait tablets keep the two columns; the section
   links leave the header, and the seal moves to the middle of the narrower
   column. */
@media (max-width: 1060px) {
  .nav .hide-sm { display: none; }
}
@media (max-width: 900px), (max-aspect-ratio: 1 / 1) {
  .hero-image .plate { transform: translateX(clamp(calc(100cqw - 100%), calc(50cqw - 73.6%), 0px)); }
}

/* Phones: the header on white, a shorter band of the photograph, then the
   title, the button and only then the three points, so the download is on
   the first screen. */
@media (max-width: 700px) {
  .hero { grid-template-columns: minmax(0, 1fr); min-height: 0; }
  .hero-image { grid-row: 1; grid-column: 1; height: clamp(240px, 42svh, 420px); }
  .hero-text { grid-column: 1; padding: 0 var(--gutter) 56px; }
  .statement { display: contents; }
  .statement h1 { order: 1; margin-top: 30px; }
  .statement .sub { order: 2; margin-top: 16px; }
  .intro { order: 3; margin: 24px 0 0; }
  .statement .points { order: 4; margin-top: 30px; }
  .hero { padding-top: 64px; }
  .nav { position: absolute; top: 20px; left: var(--gutter); right: var(--gutter); z-index: 2; }
}
@media (max-width: 560px) {
  .ctas { gap: 10px 22px; }
  .statement .points li b { display: block; }
  .statement .points li b + .sep { display: none; }
  .desk { grid-template-columns: minmax(0, 1fr); }
  .slip { aspect-ratio: auto; min-height: 168px; }
  .slip { padding-right: 124px; }
  .limits li { grid-template-columns: 44px minmax(0, 1fr); }
  .assure li, :lang(en) .assure li { grid-template-columns: minmax(0, 1fr); gap: 2px; }
  .slip .imp { left: auto; right: 18px; bottom: 18px; width: 92px; margin-left: 0; }
}

/* Touch screens: small links get a finger-sized hit area from an invisible
   pseudo-element, so neither the layout nor the underlines move. */
@media (pointer: coarse) {
  .nav a, .cta-alt, .link, .hub-copy, .assure .star, .download .fine a, .download .fine button, footer a { position: relative; }
  .nav a::before, .cta-alt::before, .link::before, .hub-copy::before, .assure .star::before, .download .fine a::before, .download .fine button::before, footer a::before { content: ""; position: absolute; inset: -10px -6px; }
}