:root {
  --c-bg: #ffffff;
  --c-panel: #f7f6f3;
  --c-panel-2: #efede8;
  --c-line: #e7e4de;
  --c-line-strong: #d6d2ca;
  --c-accent: #f57328;
  --c-accent-2: #e8483c;
  --c-accent-dark: #c4521a;
  --c-text: #1d1c1a;
  --c-muted: #6b6862;
  --c-ok: #3aa95a;
  --c-ok-ink: #2b7f45;
  --c-ok-soft: rgba(58,169,90,.12);
  --c-warn: #e39a1b;
  --c-err: #e5484d;
  --c-err-ink: #b8343a;
  --c-err-soft: rgba(229,72,77,.11);
  --c-on-accent: #ffffff;
  --c-accent-a06: rgba(245,115,40,.05);
  --c-accent-a12: rgba(245,115,40,.12);
  --c-accent-a16: rgba(245,115,40,.16);
  --c-accent-a30: rgba(245,115,40,.30);
  --c-accent-a00: rgba(245,115,40,0);
  --c-accent2-a10: rgba(232,72,60,.10);
  --c-accent2-a00: rgba(232,72,60,0);
  --c-white-a80: rgba(255,255,255,.8);
  --c-white-a00: rgba(255,255,255,0);
  --c-veil: rgba(29,28,26,.24);
  --c-cta-ink: #151411;

  --grad-accent: linear-gradient(100deg,var(--c-accent) 0%,var(--c-accent-2) 100%);
  --grad-canvas:
    radial-gradient(ellipse 70% 62% at 82% 86%,var(--c-accent-a30) 0%,var(--c-accent-a12) 38%,var(--c-accent-a00) 72%),
    radial-gradient(ellipse 46% 40% at 18% 8%,var(--c-accent2-a10) 0%,var(--c-accent2-a00) 70%),
    linear-gradient(160deg,var(--c-bg) 0%,var(--c-panel) 46%,var(--c-panel) 100%);
  --grad-scan: linear-gradient(90deg,var(--c-accent-a16),var(--c-accent-a06));

  --font-display: "Inter","Noto Sans SC",-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-body: "Inter","Noto Sans SC",-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-mono: "JetBrains Mono",ui-monospace,"SF Mono",Menlo,Consolas,monospace;
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;
  --text-xs: 12px;
  --text-sm: 14px;
  --text-base: 16px;
  --text-lede: 17px;
  --text-h1: clamp(34px,2.2vw + 14px,46px);
  --text-h2: clamp(26px,2vw + 10px,38px);
  --text-h3: clamp(19px,1vw + 12px,24px);
  --tracking-heading: -.02em;
  --leading-body: 1.6;

  --r-panel: 32px;
  --r-board: 28px;
  --r-card: 20px;
  --r-sm: 12px;
  --r-xs: 6px;
  --r-shot: 10px;
  --r-pill: 999px;
  --r-circle: 50%;
  --r-tabline: 2px;

  --shadow-soft: 0 1px 2px rgba(29,28,26,.05),0 6px 18px rgba(29,28,26,.05);
  --shadow-board: 0 1px 2px rgba(29,28,26,.04),0 14px 34px -10px rgba(29,28,26,.12),0 44px 90px -28px rgba(196,82,26,.26);
  --shadow-float: 0 2px 4px rgba(29,28,26,.05),0 20px 44px -12px rgba(196,82,26,.32);
  --shadow-cta: inset 0 1px 0 rgba(255,255,255,.28),0 12px 26px -10px rgba(232,72,60,.55);
  --shadow-cta-hover: inset 0 1px 0 rgba(255,255,255,.28),0 16px 32px -10px rgba(232,72,60,.6);

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
  --space-9: 96px;
  --row: 56px;
  --topbar-h: 72px;
  --status-h: 36px;
  --wrap: 1280px;
  --reading: 800px;
  --gutter: 24px;
  --canvas-bleed: max(24px,calc((100vw - var(--wrap)) / 2));
  --duration-fast: .2s;
  --duration-reveal: .65s;
  --ease-out: cubic-bezier(.2,.7,.3,1);
  --z-header: 40;
  --z-fab: 30;
}

*,*::before,*::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 24px; }
html.nav-open { overflow: hidden; }
body {
  margin: 0;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-normal);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }
button,input,select,textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; }
img,svg { max-width: 100%; }
img { display: block; }
svg { flex-shrink: 0; }
p,h1,h2,h3,h4,figure,blockquote { margin: 0; }
ul,ol { margin: 0; padding: 0; list-style: none; }
h1,h2,h3,h4 {
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  letter-spacing: var(--tracking-heading);
  text-wrap: balance;
  overflow-wrap: break-word;
}
h1 { font-size: var(--text-h1); line-height: 1.16; }
h2 { font-size: var(--text-h2); line-height: 1.25; }
h3 { font-size: var(--text-h3); line-height: 1.35; }
code,kbd,pre { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre {
  max-width: 100%;
  overflow-x: auto;
  padding: 20px;
  background: var(--c-panel);
  color: var(--c-text);
  border: 1px solid var(--c-line);
  border-radius: var(--r-sm);
  font-size: var(--text-sm);
  line-height: 1.8;
  overscroll-behavior-inline: contain;
}
pre code { white-space: pre; overflow-wrap: normal; word-break: normal; }
:focus-visible { outline: 2px solid var(--c-accent-dark); outline-offset: 3px; border-radius: var(--r-xs); }
::selection { background: var(--c-accent-a30); color: var(--c-text); }
[hidden] { display: none !important; }
.wrap {
  width: 100%;
  max-width: calc(var(--wrap) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { width: 100%; max-width: calc(var(--reading) + var(--gutter) * 2); margin-inline: auto; padding-inline: var(--gutter); }
.grid-2 { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 28px; }
.grid-3 { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 24px; }
.grid-2 > *,.grid-3 > *, .wrap > *, .reading > * { min-width: 0; }
.section { padding-top: var(--space-9); padding-bottom: var(--space-9); }
.section-head { margin-bottom: 36px; }
.section-head > * + * { margin-top: 16px; }
.section-head.center { text-align: center; max-width: 760px; margin-inline: auto; }
.panel { background: var(--c-panel); color: var(--c-text); border: 1px solid var(--c-line); border-radius: var(--r-panel); padding: var(--space-8); }
.card { min-width: 0; background: var(--c-bg); color: var(--c-text); border: 1px solid var(--c-line); border-radius: var(--r-card); box-shadow: var(--shadow-soft); padding: 28px; }
.card > * + * { margin-top: 16px; }
.muted { color: var(--c-muted); }
.small { font-size: var(--text-sm); }
.mono { font-family: var(--font-mono); }
.keep { white-space: nowrap; }
.hl { background: var(--grad-accent); -webkit-background-clip: text; background-clip: text; color: transparent; -webkit-text-fill-color: transparent; }
.text-link { color: var(--c-accent-dark); text-decoration: underline; text-underline-offset: .2em; }
.prose { min-width: 0; line-height: 1.85; }
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote { margin-block: 20px; }
.prose h2 { margin-top: 56px; margin-bottom: 24px; scroll-margin-top: 24px; }
.prose h3 { margin-top: 32px; margin-bottom: 16px; }
.prose ul { list-style: disc; padding-left: 1.4em; }
.prose ol { list-style: decimal; padding-left: 1.5em; }
.prose li + li { margin-top: 8px; }
.prose a:not(.btn):not(.store-button) { color: var(--c-accent-dark); text-decoration: underline; text-underline-offset: .2em; }
.prose :not(pre) > code { background: var(--c-panel); color: var(--c-text); padding: 2px 5px; border-radius: var(--r-xs); font-size: .88em; }
.skip { position: absolute; left: 16px; top: -80px; z-index: 100; padding: 8px 14px; border-radius: var(--r-pill); background: var(--c-text); color: var(--c-bg); font-size: var(--text-sm); }
.skip:focus { top: 12px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }

.btn {
  display: inline-flex; justify-content: center; align-items: center; gap: 10px;
  min-height: 52px; max-width: 100%; padding: 12px 24px;
  border: 1px solid var(--c-white-a00); border-radius: var(--r-pill);
  font-size: 15px; font-weight: var(--weight-semibold); line-height: 1.4;
  text-align: center;
  transition: transform var(--duration-fast),box-shadow var(--duration-fast),border-color var(--duration-fast);
}
.btn svg { width: 18px; height: 18px; }
.btn-primary { background: var(--grad-accent); color: var(--c-cta-ink); box-shadow: var(--shadow-cta); }
.btn-primary:hover,.btn-primary.is-hover { transform: translateY(-1px); box-shadow: var(--shadow-cta-hover); }
.btn-primary:active { transform: translateY(0); }
.btn-ghost { background: var(--c-bg); color: var(--c-text); border-color: var(--c-line); box-shadow: var(--shadow-soft); }
.btn-ghost:hover,.btn-ghost.is-hover { border-color: var(--c-line-strong); }
.btn:disabled,.btn[aria-disabled="true"] { background: var(--c-panel-2); color: var(--c-muted); box-shadow: none; transform: none; border-color: var(--c-line); }
.btn.is-focus { outline: 2px solid var(--c-accent-dark); outline-offset: 3px; }
.cta-row { margin-top: 34px; display: flex; flex-wrap: wrap; align-items: center; gap: 14px; }

.topbar { height: var(--topbar-h); border-bottom: 1px solid var(--c-line); background: var(--c-bg); color: var(--c-text); position: relative; z-index: var(--z-header); }
.topbar-in {
  height: 100%; width: 100%;
  max-width: min(100%,calc(1280px + var(--gutter) * 2));
  margin-inline: auto; padding-inline: var(--gutter);
  display: flex; align-items: center; gap: 0;
}
.brand { display: inline-flex; align-items: center; gap: 12px; flex-shrink: 0; font-weight: var(--weight-bold); font-size: var(--text-base); letter-spacing: -.01em; }
.brand-mark { width: 34px; height: 34px; flex-shrink: 0; border-radius: var(--r-circle); border: 1px solid var(--c-line); background: var(--c-panel); color: var(--c-text); box-shadow: var(--shadow-soft); }
.brand-name { white-space: nowrap; }
.tabs { margin-left: auto; height: 100%; min-width: 0; }
.tabs ul { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: clamp(18px,2.3vw,34px); height: 100%; }
.tabs li { height: 100%; }
.tabs a { position: relative; height: 100%; display: inline-flex; align-items: center; font-size: 15px; font-weight: var(--weight-medium); color: var(--c-muted); white-space: nowrap; transition: color var(--duration-fast); }
.tabs a::after { content: ""; position: absolute; left: 0; right: 0; bottom: -1px; height: 2px; border-radius: var(--r-tabline); background: var(--grad-accent); transform: scaleX(0); transition: transform .25s; }
.tabs a:hover { color: var(--c-text); }
.tabs a:hover::after { transform: scaleX(.4); }
.tabs a[aria-current="page"] { color: var(--c-text); font-weight: var(--weight-semibold); }
.tabs a[aria-current="page"]::after { transform: scaleX(1); }
.header-tools { display: flex; align-items: center; gap: 8px; margin-left: 32px; flex-shrink: 0; }
.language-control { position: relative; }
.lang { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 36px; padding: 7px 14px; border: 1px solid var(--c-line); border-radius: var(--r-pill); background: var(--c-bg); color: var(--c-text); font-size: var(--text-sm); white-space: nowrap; }
.lang svg { width: 16px; height: 16px; color: var(--c-muted); }
.lang-short { display: none; }
.lang-caret { font-size: 11px; color: var(--c-muted); }
.lang:hover { border-color: var(--c-line-strong); }
.language-list { position: absolute; right: 0; top: calc(100% + 10px); width: 200px; padding: 8px; border: 1px solid var(--c-line); border-radius: var(--r-card); background: var(--c-bg); color: var(--c-text); box-shadow: var(--shadow-soft); z-index: 5; }
.language-list a { display: flex; align-items: center; min-height: 44px; padding: 10px 14px; border-radius: var(--r-sm); }
.language-list a:hover,.language-list a[aria-current="true"] { background: var(--c-panel); color: var(--c-text); }
.menu-toggle { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; padding: 10px; border: 1px solid var(--c-line); border-radius: var(--r-sm); background: var(--c-bg); color: var(--c-text); }
.menu-toggle svg { width: 22px; height: 22px; }
.mobile-drawer { display: none; }
.nav-veil { position: fixed; inset: var(--topbar-h) 0 0; background: var(--c-veil); color: var(--c-text); border: 0; width: 100%; z-index: -1; }
.site-footer { background: var(--c-panel); color: var(--c-text); border-top: 1px solid var(--c-line); padding-top: 64px; padding-bottom: 28px; }
.footer-grid { display: grid; grid-template-columns: 1.3fr .8fr 1.2fr .7fr; gap: 40px; }
.footer-grid > * { min-width: 0; }
.footer-about p { margin-top: 18px; max-width: 28em; font-size: var(--text-sm); color: var(--c-muted); }
.footer-title { font-size: var(--text-sm); font-weight: var(--weight-semibold); margin-bottom: 18px; letter-spacing: 0; }
.footer-links { display: grid; gap: 6px; }
.footer-links a { display: inline-block; padding-block: 5px; font-size: var(--text-sm); overflow-wrap: anywhere; color: var(--c-muted); }
.footer-links a:hover { color: var(--c-accent-dark); text-decoration: underline; text-underline-offset: .2em; }
.footer-bottom { margin-top: 44px; padding-top: 24px; border-top: 1px solid var(--c-line); display: flex; flex-wrap: wrap; gap: 12px 24px; justify-content: space-between; font-size: var(--text-xs); color: var(--c-muted); }
.footer-legal { display: flex; flex-wrap: wrap; gap: 20px; }
.reveal { opacity: 1; transform: none; }
.reveal-ready .reveal { opacity: 0; transform: translateY(18px); transition: opacity var(--duration-reveal) var(--ease-out),transform var(--duration-reveal) var(--ease-out); }
.reveal-ready .reveal.shown { opacity: 1; transform: none; }

@media (max-width:1100px) {
  .tabs { display: none; }
  .header-tools { margin-left: auto; }
  .menu-toggle { display: inline-flex; }
  .mobile-drawer:not([hidden]) {
    display: block; position: absolute; left: 0; right: 0; top: 100%;
    max-height: calc(100dvh - var(--topbar-h)); overflow-y: auto;
    overscroll-behavior: contain;
    padding: 16px var(--gutter) 24px; border-bottom: 1px solid var(--c-line);
    background: var(--c-bg); color: var(--c-text); box-shadow: var(--shadow-soft); z-index: 3;
  }
  .mobile-drawer a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 16px; border-radius: var(--r-sm); }
  .mobile-drawer a[aria-current] { background: var(--c-panel); color: var(--c-text); font-weight: var(--weight-semibold); }
  .drawer-languages { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--c-line); }
  .footer-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media (max-width:768px) {
  h1 { font-size: 28px; }
  .grid-3 { grid-template-columns: 1fr; }
  .section { padding-top: 56px; padding-bottom: 56px; }
  .panel { padding: 32px 24px; }
}
@media (max-width:640px) {
  :root { --gutter: 16px; --canvas-bleed: 16px; }
  .grid-2 { grid-template-columns: minmax(0,1fr); }
  .brand { font-size: 12px; gap: 8px; }
  .brand-mark { width: 28px; height: 28px; }
  .header-tools { margin-left: auto; gap: 6px; }
  .lang { min-height: 44px; padding: 8px 10px; gap: 4px; }
  .lang svg,.lang-full { display: none; }
  .lang-short { display: inline; }
  .lang-caret { font-size: 10px; }
  .language-list { width: 184px; }
  .card { padding: 22px; }
  .panel { padding: 28px 20px; }
  .tilt,.float-card,[data-tilt] { transform: none !important; }
  .footer-grid { gap: 32px 24px; }
  .footer-about { grid-column: 1 / -1; }
  .footer-grid .brand { font-size: var(--text-base); }
  .footer-bottom { display: block; }
  .footer-bottom > * + * { margin-top: 12px; }
}
@media (prefers-reduced-motion:reduce) {
  html { scroll-behavior: auto; }
  *,*::before,*::after { animation: none !important; transition: none !important; }
  .reveal-ready .reveal { opacity: 1; transform: none; }
}