:root {
  --bg: #FDFCFF;
  --panel: #FFFFFF;
  --panel-2: #F2F0F8;
  --border: #E5E1EF;
  --accent: #5B2EF0;
  --accent-dark: #3A1A9E;
  --text: #1B1631;
  --muted: #5F5A73;
  --success: #12A06B;
  --warn: #E6880F;
  --error: #D7344B;
  --pink: #FF8FB8;
  --orange: #FF9A3D;
  --flag-red: #D52B3F;
  --flag-blue: #2B3A8C;
  --flag-navy: #1C2766;
  --flag-white: #FFFFFF;
  --clear: transparent;
  --font-display: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans", "Apple SD Gothic Neo", "Malgun Gothic", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Hiragino Sans", "Yu Gothic", "Apple SD Gothic Neo", "Malgun Gothic", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --r-pill: 999px;
  --r-xl: 40px;
  --r-lg: 20px;
  --r-md: 14px;
  --r-sm: 10px;
  --r-focus: 6px;
  --r-phone: 26px;
  --r-glass: 22px;
  --r-row: 12px;
  --round: 50%;
  --weight-body: 400;
  --weight-medium: 600;
  --weight-bold: 700;
  --weight-heavy: 800;
  --weight-display: 900;
  --text-xs: 12px;
  --text-sm: 14px;
  --text-base: 16px;
  --text-lede: 17px;
  --text-h1: clamp(52px, 4.6vw, 66px);
  --text-h2: clamp(28px, 3vw, 40px);
  --text-h3: clamp(22px, 2.2vw, 30px);
  --tracking-display: -.03em;
  --tracking-body-heading: -.02em;
  --gutter: 48px;
  --content-max: 1392px;
  --reading-max: 880px;
  --space-section: 80px;
  --top-height: 72px;
  --notice-height: 40px;
  --shell-height: 112px;
  --anchor-space: 128px;
  --toc-anchor-space: 196px;
  --ease: cubic-bezier(.2, .7, .2, 1);
  --fast: .2s;
  --reveal-time: .35s;
  --tint-12: color-mix(in srgb, var(--accent) 12%, var(--clear));
  --accent-wash: color-mix(in srgb, var(--accent) 10%, var(--panel));
  --accent-line: color-mix(in srgb, var(--accent) 14%, var(--clear));
  --veil-color: color-mix(in srgb, var(--text) 28%, var(--clear));
  --card-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 9%, var(--clear)), inset 0 1px 0 var(--panel), 0 24px 48px -10px var(--tint-12), 0 4px 12px -4px color-mix(in srgb, var(--accent) 10%, var(--clear));
  --pill-shadow: inset 0 1px 0 color-mix(in srgb, var(--panel) 30%, var(--clear)), 0 14px 32px -10px color-mix(in srgb, var(--accent) 55%, var(--clear));
  --gradient-device: linear-gradient(135deg, var(--pink), var(--orange));
  --gradient-overview: linear-gradient(120deg, var(--accent), color-mix(in srgb, var(--accent) 45%, var(--pink)) 62%, var(--pink));
}
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: var(--anchor-space);
  scroll-behavior: smooth;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: var(--weight-body) var(--text-base)/1.6 var(--font-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
::selection { background: color-mix(in srgb, var(--accent) 20%, var(--clear)); }
a { color: inherit; text-underline-offset: .22em; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, a, summary { -webkit-tap-highlight-color: var(--accent-line); }
button { color: inherit; }
img { max-width: 100%; height: auto; }
svg { flex-shrink: 0; }
h1, h2, h3 { font-family: var(--font-display); text-wrap: balance; }
h1, .h1 {
  font-size: var(--text-h1);
  font-weight: var(--weight-display);
  line-height: 1.1;
  letter-spacing: var(--tracking-display);
  color: var(--accent-dark);
}
h2 { font-size: var(--text-h2); line-height: 1.2; letter-spacing: var(--tracking-body-heading); }
h3 { font-size: var(--text-h3); line-height: 1.3; letter-spacing: var(--tracking-body-heading); }
:lang(zh-CN) h1, :lang(zh-TW) h1, :lang(ja) h1, :lang(ko) h1 { letter-spacing: var(--tracking-body-heading); }
p { margin-block: 0 1.2em; }
h1, h2, h3 { margin-block: 0 24px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: var(--r-focus); }
[hidden] { display: none !important; }
.sr {
  position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0;
  overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0;
}
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.no-break { white-space: nowrap; }
.wrap { width: 100%; max-width: var(--content-max); margin-inline: auto; padding-inline: var(--gutter); }
.reading { max-width: var(--reading-max); margin-inline: auto; }
.sec { padding-top: var(--space-section); padding-bottom: var(--space-section); }
.grid { display: grid; gap: 24px; }
.grid > *, .hero-in > *, .feature-panel > *, .footer-grid > * { min-width: 0; }
.grid-three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-five { grid-template-columns: repeat(5, minmax(0, 1fr)); }
.muted { color: var(--muted); }
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.kicker { color: var(--accent-dark); font-size: var(--text-sm); font-weight: var(--weight-heavy); }
.panel, .card { background: var(--panel); border-radius: var(--r-lg); box-shadow: var(--card-shadow); padding: 28px; }
.panel-soft { background: var(--panel-2); border-radius: var(--r-lg); padding: 28px; }
.section-head { max-width: 760px; margin-bottom: 32px; }
.prose { overflow-wrap: break-word; }
.prose h2, .prose h3 { margin-top: 48px; }
.prose p, .prose li { line-height: 1.85; }
.prose a:not(.btn) { color: var(--accent-dark); }
code { font-family: var(--font-mono); overflow-wrap: anywhere; font-size: .9em; }
pre { max-width: 100%; overflow-x: auto; padding: 24px; background: var(--panel-2); border: 1px solid var(--border); border-radius: var(--r-md); }
pre code { overflow-wrap: normal; white-space: pre; }
.skip {
  position: absolute; left: 16px; top: -80px; z-index: 110; padding: 10px 16px;
  border-radius: var(--r-pill); background: var(--text); color: var(--panel);
  font-weight: var(--weight-bold); text-decoration: none;
}
.skip:focus { top: 12px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  min-height: 52px; padding: 12px 28px; border: 0; border-radius: var(--r-pill);
  font: var(--weight-bold) var(--text-base)/1.3 var(--font-body);
  text-decoration: none; flex-shrink: 0;
  transition: transform var(--fast) ease, box-shadow var(--fast) ease, background var(--fast) ease;
}
.btn svg { width: 18px; height: 18px; }
.btn-primary { background: var(--accent); color: var(--panel); box-shadow: var(--pill-shadow); }
.btn-primary:hover, .btn-primary.is-hover { transform: translateY(-1px); background: color-mix(in srgb, var(--accent) 88%, var(--accent-dark)); }
.btn-ghost { background: var(--panel); color: var(--accent-dark); box-shadow: inset 0 0 0 1px var(--border), 0 8px 24px -12px var(--tint-12); }
.btn-ghost:hover { transform: translateY(-1px); box-shadow: inset 0 0 0 1px var(--accent-line), 0 12px 28px -12px var(--tint-12); }
.btn-secondary { background: var(--text); color: var(--panel); white-space: nowrap; box-shadow: 0 12px 28px -14px var(--tint-12); }
.btn-secondary:hover { background: var(--accent-dark); transform: translateY(-1px); }
.btn:active, .btn.is-active { transform: translateY(1px); }
.btn:disabled, .btn[aria-disabled="true"] { opacity: .5; cursor: not-allowed; box-shadow: none; }
.btn.is-focus { outline: 2px solid var(--accent); outline-offset: 3px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 32px; }
.badge {
  display: inline-flex; align-items: center; gap: 8px; min-height: 32px;
  margin: 0; padding: 6px 14px 6px 12px; border-radius: var(--r-pill);
  background: color-mix(in srgb, var(--panel) 82%, var(--clear));
  backdrop-filter: blur(8px);
  box-shadow: inset 0 0 0 1px var(--accent-line), 0 6px 18px -10px var(--tint-12);
  font: var(--weight-medium) 13px/1.4 var(--font-body); color: var(--accent-dark);
}
.badge-dot { width: 8px; height: 8px; flex: none; border-radius: var(--round); background: var(--success); box-shadow: 0 0 0 3px color-mix(in srgb, var(--success) 18%, var(--clear)); }
.tag {
  display: inline-flex; align-items: center; min-height: 22px; padding: 3px 9px;
  border-radius: var(--r-pill); font: var(--weight-bold) 11px/1.4 var(--font-body);
  background: var(--panel-2); color: var(--muted); max-width: 100%; overflow: hidden; overflow-wrap: anywhere;
}
.tag-iepl { background: color-mix(in srgb, var(--accent) 11%, var(--panel)); color: var(--accent-dark); }
.tag-relay { background: var(--panel-2); color: var(--muted); }
.tag-direct { background: color-mix(in srgb, var(--orange) 16%, var(--panel)); color: color-mix(in srgb, var(--orange) 42%, var(--text)); }
#site-header { position: sticky; top: 0; z-index: 70; }
.notice {
  position: relative; display: flex; align-items: center; justify-content: center; gap: 20px;
  min-height: var(--notice-height); padding: 8px 64px; background: var(--panel-2);
  border-bottom: 1px solid var(--border); font: var(--weight-medium) 13.5px/1.4 var(--font-body); color: var(--text);
}
.notice p { margin: 0; }
.notice a { font-weight: var(--weight-heavy); letter-spacing: .02em; text-decoration-thickness: 1.5px; text-underline-offset: 5px; }
.notice a:hover { color: var(--accent-dark); }
.notice-x {
  position: absolute; right: 20px; top: 50%; display: grid; place-items: center;
  width: 24px; height: 24px; margin-top: -12px; padding: 0; border: 0;
  border-radius: var(--round); background: var(--text); color: var(--panel);
}
.notice-x svg { width: 10px; height: 10px; }
.top {
  position: relative; z-index: 75;
  background: color-mix(in srgb, var(--panel) 84%, var(--clear));
  -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.top-in { display: flex; align-items: center; gap: 40px; height: var(--top-height); flex-wrap: nowrap; }
.brand {
  display: inline-flex; align-items: center; gap: 10px; flex: none;
  text-decoration: none; font: var(--weight-display) 20px/1 var(--font-display);
  letter-spacing: -.02em; color: var(--accent-dark);
}
.brand img { width: 34px; height: 34px; flex: none; display: block; }
.desktop-nav { flex: 1; min-width: 0; }
.nav-links { display: flex; align-items: center; gap: 4px; margin: 0; padding: 0; list-style: none; }
.nav-links a {
  display: flex; align-items: center; justify-content: center; min-height: 38px;
  padding: 9px 15px; border-radius: var(--r-pill); font: var(--weight-medium) 15px/1.2 var(--font-body);
  color: var(--muted); text-decoration: none; white-space: nowrap;
  transition: background var(--fast) ease, color var(--fast) ease;
}
.nav-links a:hover { color: var(--text); background: var(--panel-2); }
.nav-links a[aria-current="page"] {
  color: var(--accent-dark); font-weight: var(--weight-heavy); background: var(--accent-wash);
  box-shadow: inset 0 0 0 1px var(--accent-line), inset 0 1px 0 var(--panel);
}
.top-end { display: flex; align-items: center; gap: 12px; margin-left: auto; flex-shrink: 0; }
.language { position: relative; }
.lang {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  min-width: 44px; width: auto; height: 38px; padding: 0 12px; border: 0;
  border-radius: var(--r-pill); background: var(--panel-2); color: var(--text);
  font: var(--weight-medium) 14px/1 var(--font-body);
}
.lang span { white-space: nowrap; }
.lang svg { width: 16px; height: 16px; color: var(--muted); }
.lang .caret { font-size: 11px; color: var(--muted); }
.language-panel {
  position: absolute; top: calc(100% + 12px); right: 0; z-index: 90; width: 180px;
  padding: 8px; border: 1px solid var(--border); border-radius: var(--r-md);
  background: var(--panel); box-shadow: var(--card-shadow);
}
.language-panel a { display: flex; align-items: center; min-height: 44px; padding: 10px 12px; border-radius: var(--r-sm); text-decoration: none; font-size: var(--text-sm); }
.language-panel a:hover, .language-panel a[aria-current="true"] { background: var(--panel-2); color: var(--accent-dark); }
.login {
  display: inline-flex; align-items: center; justify-content: center; min-height: 42px;
  padding: 10px 24px; border-radius: var(--r-pill); background: var(--accent); color: var(--panel);
  font: var(--weight-heavy) 15px/1.2 var(--font-body); text-decoration: none; white-space: nowrap;
  box-shadow: inset 0 1px 0 color-mix(in srgb, var(--panel) 28%, var(--clear)), 0 10px 24px -10px color-mix(in srgb, var(--accent) 60%, var(--clear));
}
.login:hover { transform: translateY(-1px); }
.menu-button {
  display: none; align-items: center; justify-content: center; flex-direction: column; gap: 5px;
  min-width: 44px; min-height: 44px; padding: 10px; border: 1px solid var(--border);
  border-radius: var(--r-sm); background: var(--panel); color: var(--accent-dark);
}
.menu-line { display: block; width: 20px; height: 2px; background: currentColor; transition: transform var(--fast) ease; }
.menu-button[aria-expanded="true"] .menu-line:first-child { transform: translateY(7px) rotate(45deg); }
.menu-button[aria-expanded="true"] .menu-line:nth-child(2) { opacity: 0; }
.menu-button[aria-expanded="true"] .menu-line:last-child { transform: translateY(-7px) rotate(-45deg); }
.drawer {
  position: fixed; top: var(--shell-height); right: 0; bottom: 0; z-index: 73;
  width: min(420px, 100%); height: calc(100dvh - var(--shell-height));
  max-height: calc(100dvh - var(--shell-height)); overflow-y: auto; overscroll-behavior: contain;
  padding: 20px var(--gutter) 32px; background: var(--panel); border-left: 1px solid var(--border);
}
.drawer .nav-links { flex-direction: column; align-items: stretch; }
.drawer .nav-links > li { width: 100%; }
.drawer a { display: flex; align-items: center; justify-content: flex-start; width: 100%; min-height: 44px; padding: 12px 16px; border-radius: var(--r-sm); text-decoration: none; }
.drawer a:hover, .drawer a[aria-current="page"] { background: var(--accent-wash); color: var(--accent-dark); }
.drawer-languages { display: grid; border-top: 1px solid var(--border); margin-top: 16px; padding-top: 16px; }
.drawer-languages a[aria-current="true"] { color: var(--accent-dark); font-weight: var(--weight-heavy); background: var(--panel-2); }
.nav-veil {
  position: fixed; inset: var(--shell-height) 0 0; z-index: 72;
  border: 0; padding: 0; width: 100%; background: var(--veil-color);
}
.is-notice-closed { --shell-height: var(--top-height); }
html.nav-open { overflow: hidden; }
.site-footer { background: var(--panel-2); border-top: 1px solid var(--border); padding-top: 56px; padding-bottom: 32px; }
.footer-grid { display: grid; grid-template-columns: 1.25fr 1fr 1.25fr; gap: 48px; }
.footer-brand p { max-width: 340px; margin-top: 20px; color: var(--muted); font-size: var(--text-sm); }
.footer-heading { margin: 0 0 16px; font: var(--weight-heavy) var(--text-base)/1.4 var(--font-display); color: var(--accent-dark); }
.footer-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 4px 16px; margin: 0; padding: 0; list-style: none; }
.footer-links a { display: inline-flex; align-items: center; min-height: 32px; padding-block: 4px; text-decoration: none; font-size: var(--text-sm); color: var(--muted); overflow-wrap: anywhere; }
.footer-links a:hover, .footer-bottom a:hover { color: var(--accent-dark); text-decoration: underline; }
.footer-languages { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 32px; }
.footer-languages a { display: inline-flex; align-items: center; min-height: 32px; font-size: var(--text-sm); text-decoration: none; }
.footer-languages [aria-current="true"] { color: var(--accent-dark); font-weight: var(--weight-heavy); }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px; border-top: 1px solid var(--border); margin-top: 24px; padding-top: 24px; font-size: var(--text-xs); color: var(--muted); }
.footer-bottom p { margin: 0; }
.footer-legal { display: flex; flex-wrap: wrap; gap: 20px; }
.footer-legal a { display: inline-flex; align-items: center; min-height: 24px; }
.reveal { transition: opacity var(--reveal-time) ease, transform var(--reveal-time) ease; }
.reveal.pending { opacity: 0; transform: translateY(16px); }
.reveal.shown { opacity: 1; transform: none; }
#server-status { position: static; display: block; min-height: 80px; max-width: 100%; overflow: hidden; margin-block: 24px; }
#server-status > * { min-width: 0; max-width: 100%; }
#server-status + * { margin-top: 32px; }
.decorated, .stripe-halo-host { position: relative; overflow-x: clip; }
.stripe-halo { position: absolute; inset: 0; pointer-events: none; max-width: 100%; }
@media (max-width: 1320px) {
  .top-in { gap: 20px; }
  .nav-links a { padding-inline: 10px; font-size: var(--text-sm); }
  .top-end { gap: 8px; }
}
@media (max-width: 1120px) {
  .desktop-nav { display: none; }
  .menu-button { display: inline-flex; }
  .top-end { margin-left: auto; }
}
@media (min-width: 1121px) {
  .drawer, .nav-veil { display: none !important; }
}
@media (max-width: 768px) {
  :root { --gutter: 24px; --space-section: 56px; --text-h1: clamp(28px, 5.2vw, 40px); }
  .grid-three { grid-template-columns: 1fr; }
  .grid-five { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-brand { grid-column: 1 / -1; }
  .notice { font-size: 11px; gap: 10px; padding-inline: 24px 48px; }
  .notice-x { right: 12px; }
}
@media (max-width: 640px) {
  :root { --gutter: 16px; }
  .no-break { white-space: normal; }
  .tilt, .tilt-card, .tilt-content { transform: none; }
  .decorated, .stripe-halo-host, .stripe-halo { max-width: 100%; }
  .top-in { gap: 8px; }
  .brand { font-size: 17px; gap: 6px; }
  .brand img { width: 28px; height: 28px; }
  .top-end { margin-left: auto; gap: 6px; }
  .login { min-height: 40px; padding: 10px 14px; font-size: 13px; }
  .lang { padding-inline: 8px; font-size: 11px; gap: 4px; }
  .lang svg, .lang .caret { display: none; }
  .menu-button { min-width: 44px; }
  .panel, .card, .panel-soft { padding: 22px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-brand { grid-column: auto; }
  .notice { gap: 8px; font-size: 10px; }
  .notice a { flex-shrink: 0; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition-duration: 0s !important; }
  .reveal, .reveal.pending { opacity: 1; transform: none; }
}