/* Fonts are served from this site, so no visitor data goes to a font provider */
@font-face { font-family: "Inter Tight"; font-weight: 400; font-display: swap; src: url(fonts/inter-tight-latin-400-normal.woff2) format("woff2"); }
@font-face { font-family: "Inter Tight"; font-weight: 500; font-display: swap; src: url(fonts/inter-tight-latin-500-normal.woff2) format("woff2"); }
@font-face { font-family: "JetBrains Mono"; font-weight: 400; font-display: swap; src: url(fonts/jetbrains-mono-latin-400-normal.woff2) format("woff2"); }
@font-face { font-family: Inter; font-weight: 900; font-style: italic; font-display: swap; src: url(fonts/inter-latin-900-italic.woff2) format("woff2"); }
@font-face { font-family: Questrial; font-weight: 400; font-display: swap; src: url(fonts/questrial-latin-400-normal.woff2) format("woff2"); }
:root { --black: #0b0b0b; --bone: #efeee9; --ink: #111; --grey: #9b9b97; --grey-l: #6c6b66; --accent: #ff6600; --gut: clamp(16px, 2.2vw, 32px); --cell: clamp(28px, 4vw, 56px); }
* { box-sizing: border-box; margin: 0; padding: 0; }
/* No blue flash when tapping or clicking; keyboard users still get a visible focus ring */
* { -webkit-tap-highlight-color: transparent; }
:focus:not(:focus-visible) { outline: none; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 16px; }
body { background: var(--black); color: #fff; font-family: "Inter Tight", "Helvetica Neue", Arial, sans-serif; font-size: 16px; line-height: 1.5; -webkit-font-smoothing: antialiased; }
html:lang(zh) body { font-family: "Inter Tight", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif; }
a { color: inherit; text-decoration: none; }
img { display: block; }
.cap { display: block; font-size: 13px; font-weight: 500; letter-spacing: .04em; text-transform: uppercase; white-space: nowrap; }
html:lang(zh) .cap { letter-spacing: 0; font-size: 14px; }
h1, h2, h3 { font-weight: 400; letter-spacing: -0.035em; line-height: 1.04; }
html:lang(zh) h1, html:lang(zh) h2, html:lang(zh) h3 { letter-spacing: 0; line-height: 1.2; }
.cq { container-type: inline-size; min-width: 0; }
.one { white-space: nowrap; }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
.btn:disabled { cursor: default; opacity: .7; }
.btn { display: inline-flex; align-items: center; justify-content: center; height: 44px; padding: 0 18px; border-radius: 6px; font: 500 14px/1 "Inter Tight", sans-serif; white-space: nowrap; border: 1px solid transparent; cursor: pointer; transition: background .15s, color .15s, border-color .15s; }
.btn-bone { background: var(--bone); color: var(--ink); }
.btn-bone:hover { background: #fff; }
.btn-line { border-color: rgba(255,255,255,0.3); color: #fff; }
.btn-line:hover { background: rgba(255,255,255,0.08); }
.btn-ink { background: var(--ink); color: #fff; }
.btn-ink:hover { background: #2a2a2a; }
.btn-ghost { border-color: #8a8883; color: var(--ink); }
.btn-ghost:hover { background: rgba(17,17,17,0.05); }
.form-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.form-actions .btn { gap: 10px; }
.form-actions svg { width: 16px; height: 16px; flex: none; }

/* Page to page: the browser cross-fades between the site's pages and the new page eases up a little, while
   the header stays put. Browsers without view transitions simply load the page as before. */
@view-transition { navigation: auto; }
header { view-transition-name: site-header; }
::view-transition-old(root) { animation: vt-out .2s ease both; }
::view-transition-new(root) { animation: vt-in .45s cubic-bezier(.2,.7,.2,1) both; }
@keyframes vt-out { to { opacity: 0; } }
@keyframes vt-in { from { opacity: 0; transform: translateY(12px); } }
@media (prefers-reduced-motion: reduce) { ::view-transition-group(*), ::view-transition-old(*), ::view-transition-new(*) { animation: none !important; } }

/* Header: plain black bar */
header { position: relative; z-index: 50; }
.bar { position: relative; height: 72px; display: flex; align-items: center; gap: 16px; padding: 0 var(--gut); }
.logo { display: inline-flex; align-items: baseline; white-space: nowrap; line-height: 1; }
.logo b { font-family: Inter, sans-serif; color: var(--accent); font-weight: 900; font-style: italic; font-size: 26px; letter-spacing: -0.06em; margin-right: 1px; }
.logo span { font-family: Questrial, sans-serif; font-style: italic; color: #cfcfcb; font-size: 20px; }
header .logo b { font-size: 34px; }
header .logo span { font-size: 26px; }
nav { display: none; gap: clamp(28px, 3.2vw, 52px); position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%); font-size: 14px; white-space: nowrap; }
nav a { color: #e8e8e4; transition: color .2s; }
nav a:hover { color: var(--grey); }
.bar-end { margin-left: auto; display: flex; align-items: center; gap: 8px; }
.lang { display: flex; align-items: center; gap: 8px; height: 36px; padding: 0 10px; border-radius: 6px; border: 0; background: none; font: 13px "Inter Tight", sans-serif; color: #e8e8e4; cursor: pointer; white-space: nowrap; }
.lang:hover { background: rgba(255,255,255,0.08); }
.lang svg { width: 15px; height: 15px; }
html:lang(zh) .lang .l-en, html:not(:lang(zh)) .lang .l-zh { display: none; }
.bar .btn { height: 36px; padding: 0 14px; font-size: 13px; }
.menu-btn { display: flex; width: 36px; height: 36px; align-items: center; justify-content: center; border: 0; border-radius: 6px; background: none; color: #fff; cursor: pointer; }
.menu-btn svg { width: 20px; height: 20px; }
@media (min-width: 1000px) { nav { display: flex; } .menu-btn { display: none; } }
@media (max-width: 999px) {
  nav { display: grid; gap: 0; position: absolute; left: calc(var(--gut) / -2); right: calc(var(--gut) / -2); top: 100%; transform: none; font-size: 18px; white-space: normal;
    background: var(--black) linear-gradient(rgba(255,255,255,.12), rgba(255,255,255,.12)) no-repeat calc(var(--gut) / 2) 0 / 1px 100%;
    clip-path: inset(0 0 100% 0); visibility: hidden; transition: clip-path .45s cubic-bezier(.2,.7,.2,1), visibility 0s .45s; }
  nav::after { content: ""; position: absolute; top: 0; bottom: 0; right: calc(var(--gut) / 2); width: 1px; background: rgba(255,255,255,.12); }
  header.open nav { clip-path: inset(0 0 -1px 0); visibility: visible; transition: clip-path .45s cubic-bezier(.2,.7,.2,1), visibility 0s; }
  nav a { padding: 18px calc(var(--gut) / 2 + var(--cell)); border-bottom: 1px solid rgba(255,255,255,.16); opacity: 0; transform: translateY(-8px); transition: opacity .3s, transform .4s cubic-bezier(.2,.7,.2,1), color .2s; }
  header.open nav a { opacity: 1; transform: none; }
  header.open nav a:nth-child(1) { transition-delay: .08s; }
  header.open nav a:nth-child(2) { transition-delay: .13s; }
  header.open nav a:nth-child(3) { transition-delay: .18s; }
  header.open nav a:nth-child(4) { transition-delay: .23s; }
}
.menu-btn { position: relative; }
.menu-btn svg { transition: opacity .2s, transform .3s cubic-bezier(.2,.7,.2,1); }
.menu-btn .x { position: absolute; opacity: 0; transform: rotate(-90deg); }
header.open .menu-btn .bars { opacity: 0; transform: rotate(90deg); }
header.open .menu-btn .x { opacity: 1; transform: none; }
@media (max-width: 479px) { .bar .btn { display: none; } }
@media (max-width: 999px) { .bar .bar-end { margin-right: calc(var(--cell) - var(--gut) / 2 - 8px); } }
@media (max-width: 399px) { .bar { gap: 6px; } .bar .bar-end { padding-left: 8px; margin-right: 0; } .lang { padding: 0 6px; } }
@media (max-width: 359px) { header .logo b { font-size: 29px; } header .logo span { font-size: 22px; } .bar { gap: 8px; } .bar .bar-end { padding-left: 8px; gap: 2px; margin-right: 0; } .lang { padding: 0 6px; } }
/* Header in the grid: a line under the bar from rail to rail, and dividers closing off the logo and the actions */
.bar { margin: 0 calc(var(--gut) / 2); padding: 0 calc(var(--gut) / 2); }
.bar::after { content: ""; position: absolute; left: calc(var(--gut) / -2); right: calc(var(--gut) / -2); bottom: 0; height: 1px; background: rgba(255,255,255,.16); pointer-events: none; }
.bar > .logo { align-self: stretch; padding: 15px var(--cell) 0 0; margin-left: calc(var(--cell) - var(--gut) / 2); border-right: 1px solid rgba(255,255,255,.16); }
.bar-end { align-self: stretch; padding-left: calc(var(--cell) - 10px); margin-right: calc(var(--cell) - var(--gut) / 2); border-left: 1px solid rgba(255,255,255,.16); }
/* Once you scroll, the header floats as an inset bar between the rails. 12px + 60px keeps its 72px, so nothing jumps. */
header { position: sticky; top: 0; }
header.scrolled { padding-top: 12px; background-image: none; }
header.scrolled .bar { height: 60px; background: var(--black); border: 1px solid rgba(255,255,255,.16); border-radius: 8px; }
header.scrolled .bar::after { display: none; }
header.scrolled .bar > .logo { padding-top: 9px; }
@media (max-width: 999px) { header.scrolled nav { left: -1px; right: -1px; top: calc(100% + 6px); border: 1px solid rgba(255,255,255,.16); border-radius: 8px; background-image: none; } header.scrolled nav::after { display: none; } }
@media (prefers-reduced-motion: no-preference) { header { transition: padding .25s cubic-bezier(.4,0,.2,1); } .bar { transition: height .25s cubic-bezier(.4,0,.2,1), background-color .25s, border-color .25s; } .bar > .logo { transition: padding .25s cubic-bezier(.4,0,.2,1); } }

/* Footer: link columns with monospace labels, and the legal row */
footer { background: var(--black); padding: clamp(48px, 6vw, 80px) calc(var(--gut) / 2 + var(--cell)) 0; }
.foot { max-width: 1360px; margin-left: auto; margin-right: auto; }
.foot { display: grid; grid-template-columns: 1fr 1fr; gap: 40px 24px; }
@media (max-width: 599px) { .foot { grid-template-columns: 1fr; gap: 36px; } .foot-col a, .foot-col span:not(.mcap), .foot address { font-size: 15px; } }
@media (min-width: 1000px) { .foot { grid-template-columns: 1fr 1fr 1.2fr 1.3fr; column-gap: clamp(64px, 6.5vw, 120px); } }
.mcap { display: block; margin-bottom: 16px; font: 400 12px/1 "JetBrains Mono", ui-monospace, Consolas, monospace; letter-spacing: .08em; color: var(--grey); white-space: nowrap; }
html:lang(zh) .mcap { font-family: "JetBrains Mono", "PingFang SC", "Microsoft YaHei", monospace; letter-spacing: .04em; font-size: 13px; }
.foot-col a, .foot-col span:not(.mcap) { display: block; font-size: 17px; color: #e8e8e4; padding: 4px 0; }
.foot-col span:not(.mcap) { color: var(--grey); }
.foot-col a:hover, .foot address a:hover, .legal a:hover { color: var(--grey); }
.foot address { font-style: normal; font-size: 17px; line-height: 2; color: #e8e8e4; }
.legal { margin: clamp(40px, 5vw, 64px) calc(var(--cell) * -1) 0; padding: 16px var(--cell); position: relative; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 32px; font-size: 13px; color: var(--grey); }
.legal::before { content: ""; position: absolute; left: calc(var(--gut) / -2); right: calc(var(--gut) / -2); top: 0; height: 1px; background: var(--gh); }
.legal > div { display: flex; flex-wrap: wrap; gap: 8px 24px; }
.legal span:first-child { color: #fff; }

/* Blueprint grid: a thin rail down each page margin, a line where each section starts, and a small cross
   where they meet. Lines stay out of the content; inside the services they frame each band and its split.
   White on the black sections, ink on the bone ones. Drawn as backgrounds so nothing extra sits in the page. */
header, header, main, footer {
  --gl: rgba(255,255,255,.12); --gh: rgba(255,255,255,.22); --gm: rgba(255,255,255,.4); --rx: calc(var(--gut) / 2);
  background-image: linear-gradient(var(--gm), var(--gm)), linear-gradient(var(--gm), var(--gm)), linear-gradient(var(--gm), var(--gm)), linear-gradient(var(--gm), var(--gm)),
    linear-gradient(var(--gl), var(--gl)), linear-gradient(var(--gl), var(--gl)), linear-gradient(var(--gh), var(--gh));
  background-size: 11px 1px, 1px 6px, 11px 1px, 1px 6px, 1px 100%, 1px 100%, 100% 1px;
  background-position: calc(var(--rx) - 5px) 0, var(--rx) 0, calc(100% - var(--rx) + 5px) 0, calc(100% - var(--rx)) 0, var(--rx) 0, calc(100% - var(--rx)) 0, 0 0;
  background-repeat: no-repeat;
}
main { --gl: rgba(17,17,17,.13); --gh: rgba(17,17,17,.2); --gm: rgba(17,17,17,.45); }
header, .first { background-image: linear-gradient(var(--gl), var(--gl)), linear-gradient(var(--gl), var(--gl)); background-size: 1px 100%, 1px 100%; background-position: var(--rx) 0, calc(100% - var(--rx)) 0; }


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

/* Legal pages: bone reading area between the black header and footer */
main { background: var(--bone); color: var(--ink); }
html:lang(zh) [data-l="en"], html:not(:lang(zh)) [data-l="zh"] { display: none !important; }
.lg-top { container-type: inline-size; padding: clamp(32px, 4vw, 56px) var(--gut) clamp(48px, 6vw, 96px); }
.crumb { color: var(--grey-l); }
.crumb a { text-decoration: underline; text-underline-offset: 3px; }
.crumb a:hover { color: var(--ink); }
.lg-kicker { margin-top: clamp(48px, 7vw, 120px); color: var(--grey-l); }
.lg-top h1 { margin-top: 14px; font-size: clamp(40px, 10cqi, 128px); white-space: nowrap; }
.eff { display: inline-block; margin-top: 28px; padding: 8px 10px; border: 1px solid #cfcdc5; border-radius: 4px; font: 400 12px/1 "JetBrains Mono", ui-monospace, Consolas, monospace; letter-spacing: .08em; color: var(--grey-l); white-space: nowrap; }
html:lang(zh) .eff { font-family: "JetBrains Mono", "PingFang SC", "Microsoft YaHei", monospace; letter-spacing: .04em; font-size: 13px; }
.lg-body { display: grid; gap: 40px; padding: 0 var(--gut) clamp(80px, 9vw, 150px); }
.toc { display: none; }
@media (min-width: 1000px) {
  .lg-body { grid-template-columns: 240px minmax(0, 1fr); gap: clamp(48px, 6vw, 120px); }
  .toc { display: block; position: sticky; top: 32px; align-self: start; }
}
.toc .cap { color: var(--grey-l); margin-bottom: 12px; }
.toc ol { list-style: none; }
.toc a { display: flex; gap: 12px; padding: 5px 0; font-size: 14px; color: var(--grey-l); white-space: nowrap; transition: color .2s; }
.toc a:hover, .toc a.on { color: var(--ink); }
.toc .n, article .n { font: 400 12px/1.6 "JetBrains Mono", ui-monospace, Consolas, monospace; letter-spacing: .08em; color: var(--grey-l); }
article { container-type: inline-size; min-width: 0; max-width: 46rem; }
article section { scroll-margin-top: 24px; }
article section + section { margin-top: clamp(40px, 5vw, 64px); }
article h2 { display: flex; align-items: baseline; gap: 14px; font-size: clamp(18px, 6.2cqi, 30px); line-height: 1.15; letter-spacing: -0.025em; white-space: nowrap; }
article p, article li { margin-top: 14px; font-size: 16px; line-height: 1.65; color: #2c2c2a; }
article ul { padding-left: 20px; }
article li { margin-top: 8px; }
article a { text-decoration: underline; text-underline-offset: 3px; }
.motion-btn { border: 0; padding: 0; background: none; font: inherit; color: inherit; cursor: pointer; }
.nf { margin-top: 32px; }
.motion-btn:hover { color: #fff; }
html.still .sg-ping { animation: none; }