:root {
  --bg: #FFFFFF;
  --bg-panel: #F6F7F9;
  --bg-panel-2: #EEF0F4;
  --border: #E3E6EC;
  --accent: #0F5BE6;
  --accent-dark: #0A3FA8;
  --text: #12161F;
  --text-muted: #5B6474;
  --success: #1E9E5A;
  --warn: #C98300;
  --error: #D93838;
  --amber: #F59E42;
  --magenta: #D946C8;
  --violet: #6B5CF0;
  --on-accent: #FFFFFF;
  --on-accent-soft: rgba(255,255,255,.86);
  --on-accent-veil: rgba(255,255,255,.16);
  --on-dark: #FFFFFF;
  --clear: transparent;
  --accent-tint: rgba(15,91,230,.08);
  --accent-ring: rgba(15,91,230,.16);
  --frame-tint: rgba(15,91,230,.10);
  --frame-tint-soft: rgba(107,92,240,.10);
  --line-amber: rgba(245,158,66,.34);
  --line-pink: rgba(217,70,200,.24);
  --line-blue: rgba(15,91,230,.20);
  --veil: rgba(18,22,31,.32);
  --mask-solid: #12161F;
  --grad-tri: linear-gradient(90deg,var(--amber) 0%,var(--magenta) 52%,var(--violet) 100%);
  --grad-brand: linear-gradient(180deg,var(--accent),var(--accent-dark));
  --shadow-hi: 0 1px 2px rgba(18,22,31,.06),0 14px 32px -10px rgba(18,22,31,.14),0 44px 90px -28px rgba(18,22,31,.24);
  --shadow-mid: 0 1px 2px rgba(18,22,31,.05),0 10px 24px -10px rgba(18,22,31,.14),0 28px 56px -26px rgba(18,22,31,.20);
  --shadow-low: 0 1px 2px rgba(18,22,31,.05),0 8px 20px -12px rgba(18,22,31,.14);
  --shadow-pill: 0 2px 4px rgba(18,22,31,.10),0 12px 26px -10px rgba(18,22,31,.38);
  --shadow-cta: 0 1px 2px rgba(10,63,168,.25),0 12px 26px -10px rgba(15,91,230,.55);
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --radius-xs: 8px;
  --radius-row: 14px;
  --radius-code: 20px;
  --radius-phone: 34px;
  --radius-screen: 28px;
  --radius-line: 2px;
  --radius-pill: 999px;
  --radius-round: 50%;
  --font-display: "Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-body: "Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono: "JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --fs-tiny: 11px;
  --fs-code-mini: 11.5px;
  --fs-xs: 12px;
  --fs-control: 12.5px;
  --fs-sm: 13px;
  --fs-setting: 13.5px;
  --fs-label: 14px;
  --fs-nav: 15px;
  --fs-body: 16px;
  --fs-lede: 17px;
  --fs-subtitle: 20px;
  --fs-h3: 22px;
  --fs-h2: 28px;
  --fs-section: clamp(24px,2.6vw,36px);
  --fs-h1: clamp(34px,3.35vw,48px);
  --fs-hero: clamp(26px,3.35vw,48px);
  --fs-h1-mobile: clamp(24px,4.5vw,30px);
  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;
  --weight-display: 800;
  --tracking-display: -.02em;
  --tracking-brand: -.01em;
  --tracking-button: -.005em;
  --tracking-label: .02em;
  --gutter: 32px;
  --content-width: 1184px;
  --reading-width: 816px;
  --header-height: 68px;
  --duration: .2s;
  --reveal-duration: .55s;
  --ease: ease;
}

*,*::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(--bg); color: var(--text); font-family: var(--font-body); font-size: var(--fs-body); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button,input,select,textarea { font: inherit; }
button { cursor: pointer; }
button,a,input,summary { -webkit-tap-highlight-color: var(--accent-ring); }
button { color: inherit; }
button:disabled { cursor: not-allowed; }
img,svg { vertical-align: middle; }
img { max-width: 100%; height: auto; }
h1,h2,h3,h4,p,figure,pre { margin: 0; }
h1,h2,h3 { font-family: var(--font-display); font-weight: var(--weight-display); letter-spacing: var(--tracking-display); line-height: 1.25; text-wrap: balance; }
h1 { font-size: var(--fs-h1); line-height: 1.14; }
h2 { font-size: var(--fs-section); }
h3 { font-size: var(--fs-h3); font-weight: var(--weight-bold); }
ul,ol { padding-inline-start: 1.5em; }
[hidden] { display: none !important; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }
::selection { background: var(--accent-ring); color: var(--text); }
code,kbd,pre { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; }
pre { max-width: 100%; min-width: 0; overflow-x: auto; padding: 24px; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--bg-panel); color: var(--text); font-size: var(--fs-label); line-height: 1.75; tab-size: 2; }
pre code { overflow-wrap: normal; word-break: normal; white-space: pre; }
.wrap { width: 100%; max-width: calc(var(--content-width) + var(--gutter) * 2); margin-inline: auto; padding-inline: var(--gutter); }
.reading { max-width: calc(var(--reading-width) + var(--gutter) * 2); }
.section { padding-top: 80px; padding-bottom: 80px; }
.section-head { margin-bottom: 32px; }
.section-head p { max-width: 700px; margin-top: 14px; color: var(--text-muted); }
.center { text-align: center; }
.nowrap { white-space: nowrap; }
.muted { color: var(--text-muted); }
.mono { font-family: var(--font-mono); }
.text-link { color: var(--accent); font-weight: var(--weight-semibold); text-underline-offset: .25em; }
.text-link:hover { color: var(--accent-dark); text-decoration: underline; }
.eyebrow { margin-bottom: 8px; color: var(--accent); font-size: var(--fs-sm); font-weight: var(--weight-semibold); }
.grad-text { background: var(--grad-tri); color: var(--clear); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: var(--clear); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.ico { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; flex-shrink: 0; }
.ico-fill { fill: currentColor; flex-shrink: 0; }
.grid { display: grid; gap: 24px; }
.grid-two { grid-template-columns: repeat(2,minmax(0,1fr)); }
.grid-three { grid-template-columns: repeat(3,minmax(0,1fr)); }
.grid > *, .flex-row > *, .footer-grid > *, .feature-panel > * { min-width: 0; }
.flex-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.panel { padding: 40px; border-radius: var(--radius-xl); background: var(--bg-panel); color: var(--text); }
.card { padding: 28px; border: 1px solid var(--frame-tint); border-radius: var(--radius-lg); background: var(--bg); color: var(--text); box-shadow: var(--shadow-mid); min-width: 0; }
.card p { margin-top: 12px; color: var(--text-muted); }
.btn { display: inline-flex; justify-content: center; align-items: center; gap: 9px; min-height: 50px; padding: 10px 26px; border: 1.5px solid var(--clear); border-radius: var(--radius-pill); font-size: var(--fs-body); font-weight: var(--weight-semibold); letter-spacing: var(--tracking-button); line-height: 1.5; text-align: center; transition: transform var(--duration) var(--ease),background var(--duration) var(--ease),box-shadow var(--duration) var(--ease); }
.btn .ico { width: 18px; height: 18px; stroke-width: 2; }
.btn-primary { background: var(--accent); color: var(--on-accent); box-shadow: var(--shadow-cta); }
.btn-primary:hover,.btn-primary.is-hover { background: var(--accent-dark); color: var(--on-accent); transform: translateY(-1px); }
.btn-primary:active,.btn-primary.is-pressed { transform: translateY(1px); box-shadow: var(--shadow-low); }
.btn-ghost { background: var(--bg); color: var(--accent); border-color: var(--accent); box-shadow: var(--shadow-low); }
.btn-ghost:hover,.btn-ghost.is-hover { background: var(--accent-tint); color: var(--accent-dark); transform: translateY(-1px); }
.btn-subtle { background: var(--bg-panel-2); color: var(--text); }
.btn:disabled,.btn[aria-disabled="true"] { background: var(--bg-panel-2); color: var(--text-muted); border-color: var(--border); box-shadow: none; transform: none; }
.btn.is-focus { outline: 3px solid var(--accent); outline-offset: 4px; }
.cta-row { display: flex; justify-content: center; gap: 14px; flex-wrap: wrap; margin-top: 24px; }
.prose { min-width: 0; }
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote { margin-block: 1.2em; }
.prose h2 { margin-top: 2.4em; margin-bottom: .7em; }
.prose h3 { margin-top: 1.7em; margin-bottom: .6em; }
.prose li + li { margin-top: .5em; }
.prose a { color: var(--accent); text-decoration: underline; text-underline-offset: .2em; }
.prose :not(pre) > code { padding: .12em .35em; border-radius: var(--radius-xs); background: var(--bg-panel); color: var(--text); font-size: .9em; }
.prose > :first-child { margin-top: 0; }
.decorated { position: relative; overflow-x: clip; }
.reveal { opacity: 1; transform: none; }
html.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(16px); }
html.reveal-ready .reveal { transition: opacity var(--reveal-duration) var(--ease),transform var(--reveal-duration) var(--ease); }

.topbar { position: relative; z-index: 50; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--bg-panel-2); }
.topbar-in { position: relative; max-width: min(100%,calc(1280px + var(--gutter) * 2)); min-height: var(--header-height); margin-inline: auto; padding-inline: var(--gutter); display: flex; align-items: center; gap: 20px; }
.brand { display: inline-flex; align-items: center; gap: 10px; margin-right: auto; flex-shrink: 0; font-family: var(--font-display); font-size: var(--fs-body); font-weight: var(--weight-bold); letter-spacing: var(--tracking-brand); }
.brand-mark { display: block; width: 32px; height: 32px; flex-shrink: 0; }
.tabs { min-width: 0; }
.tabs ul { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 2px; }
.tab { position: relative; display: flex; align-items: center; min-height: var(--header-height); padding-inline: 16px; color: var(--text-muted); font-size: var(--fs-nav); font-weight: var(--weight-medium); white-space: nowrap; transition: color var(--duration) var(--ease); }
.tab:hover { color: var(--text); }
.tab[aria-current="page"] { color: var(--text); font-weight: var(--weight-semibold); }
.tab[aria-current="page"]::after { content: ""; position: absolute; left: 16px; right: 16px; bottom: -1px; height: 2px; border-radius: var(--radius-line); background: var(--accent); color: var(--on-accent); }
.nav-tools { display: flex; align-items: center; gap: 12px; flex-shrink: 0; margin-left: 8px; padding-left: 20px; border-left: 1px solid var(--border); height: 26px; }
.lang-wrap { position: relative; }
.lang { display: inline-flex; align-items: center; gap: 6px; min-height: 36px; padding: 6px 12px 6px 10px; border: 1px solid var(--border); border-radius: var(--radius-pill); background: var(--bg); color: var(--text-muted); font-size: var(--fs-label); white-space: nowrap; }
.lang .ico { width: 16px; height: 16px; }
.lang:hover { border-color: var(--accent-ring); color: var(--text); }
.lang-short { display: none; }
.lang-menu { position: absolute; top: calc(100% + 14px); right: 0; width: 192px; padding: 8px; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--bg); color: var(--text); box-shadow: var(--shadow-mid); z-index: 5; }
.lang-menu a { display: flex; align-items: center; min-height: 44px; padding: 10px 14px; border-radius: var(--radius-sm); }
.lang-menu a:hover,.lang-menu a[aria-current="true"] { background: var(--accent-tint); color: var(--accent-dark); }
.nav-cta { display: inline-flex; align-items: center; justify-content: center; min-height: 40px; padding: 8px 18px; border-radius: var(--radius-pill); background: var(--accent); color: var(--on-accent); box-shadow: var(--shadow-cta); font-size: var(--fs-label); font-weight: var(--weight-semibold); white-space: nowrap; transition: background var(--duration) var(--ease),transform var(--duration) var(--ease); }
.nav-cta:hover { background: var(--accent-dark); color: var(--on-accent); transform: translateY(-1px); }
.menu-toggle { display: none; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; padding: 8px; border: 1px solid var(--border); border-radius: var(--radius-pill); background: var(--bg); color: var(--text); }
.mobile-nav { position: absolute; top: 100%; left: 0; right: 0; padding: 16px var(--gutter) 24px; max-height: calc(100dvh - var(--header-height)); overflow-y: auto; overscroll-behavior: contain; background: var(--bg); color: var(--text); border-bottom: 1px solid var(--border); box-shadow: var(--shadow-mid); z-index: 3; }
.mobile-nav a { display: flex; align-items: center; width: 100%; min-height: 48px; padding: 12px 16px; border-radius: var(--radius-sm); }
.mobile-nav a:hover,.mobile-nav a[aria-current] { background: var(--accent-tint); color: var(--accent-dark); }
.mobile-languages { margin-top: 12px; border-top: 1px solid var(--border); padding-top: 12px; }
.nav-veil { position: fixed; inset: var(--header-height) 0 0; z-index: 40; border: 0; border-radius: 0; background: var(--veil); color: var(--text); }

.site-footer { margin-top: 80px; padding-top: 56px; padding-bottom: 96px; border-top: 1px solid var(--border); background: var(--bg); color: var(--text); }
.footer-grid { display: grid; grid-template-columns: 1.3fr .8fr 1.5fr .8fr; gap: 40px; }
.footer-brand p { max-width: 310px; margin-top: 18px; color: var(--text-muted); font-size: var(--fs-label); }
.footer-title { margin-bottom: 14px; font-size: var(--fs-label); font-weight: var(--weight-bold); }
.footer-links { list-style: none; margin: 0; padding: 0; }
.footer-links a { display: inline-block; padding-block: 6px; color: var(--text-muted); font-size: var(--fs-label); }
.footer-links a:hover { color: var(--accent); text-decoration: underline; }
.footer-searches { display: flex; flex-wrap: wrap; gap: 6px 14px; align-content: start; }
.footer-searches li { min-width: 0; }
.footer-bottom { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--border); color: var(--text-muted); font-size: var(--fs-sm); }

@media (min-width: 961px) {
  .mobile-nav { display: none !important; }
}
@media (max-width: 1100px) {
  .topbar-in { gap: 10px; }
  .tab { padding-inline: 10px; }
  .nav-tools { gap: 8px; padding-left: 12px; }
}
@media (max-width: 960px) {
  .tabs { display: none; }
  .nav-tools { margin-left: auto; border-left: 0; padding-left: 0; }
  .menu-toggle { display: inline-flex; }
  .footer-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media (max-width: 768px) {
  h1 { font-size: var(--fs-h1-mobile); }
  .grid-three { grid-template-columns: minmax(0,1fr); }
}
@media (max-width: 640px) {
  :root { --gutter: 18px; }
  .wrap,.topbar-in { padding-inline: var(--gutter); }
  .topbar-in { gap: 8px; }
  .brand { gap: 8px; font-size: var(--fs-label); }
  .brand-mark { width: 28px; height: 28px; }
  .nav-tools { margin-left: auto; gap: 6px; }
  .nav-tools .nav-cta { display: none; }
  .lang-full { display: none; }
  .lang-short { display: inline; }
  .lang { min-height: 40px; padding-inline: 9px; }
  .lang .ico { display: none; }
  .section { padding-top: 48px; padding-bottom: 48px; }
  .panel { padding: 28px 22px; }
  .card { padding: 24px 20px; }
  .grid-two,.footer-grid { grid-template-columns: minmax(0,1fr); }
  .footer-grid { gap: 28px; }
  .site-footer { margin-top: 48px; }
  .tilt,[data-tilt] { transform: none !important; }
  pre { padding: 18px; font-size: var(--fs-sm); }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,*::before,*::after { animation: none !important; transition: none !important; }
  html.reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
}