:root {
  --bg: #ffffff;
  --bg-panel: #f6f7fb;
  --bg-panel-2: #eff0f8;
  --border: #e5e7ef;
  --accent: #0a5cff;
  --accent-dark: #0042cc;
  --text: #111318;
  --text-muted: #5d6272;
  --success: #1f9d6b;
  --warn: #c58a12;
  --error: #d63a3a;
  --on-accent: #ffffff;
  --glow-pink: #f4c9e6;
  --glow-lilac: #cdc6fa;
  --glow-sky: #bcd3ff;
  --screen-blue: #5b8dff;
  --dot-final: #8b7cf6;
  --canvas-ink: #8d94e2;
  --canvas-ink-soft: #c2c6f2;
  --device-edge: #2b2e37;
  --device-edge-hi: #4b4f5c;
  --island: #0c0d11;
  --glass: rgba(255,255,255,.5);
  --glass-strong: rgba(255,255,255,.82);
  --glass-line: rgba(255,255,255,.92);
  --veil: rgba(255,255,255,.6);
  --ink-line: rgba(17,19,24,.07);
  --accent-soft: rgba(10,92,255,.08);
  --accent-ring: rgba(10,92,255,.26);
  --scrim: rgba(17,19,24,.24);
  --clear: transparent;
  --shadow-float: 0 30px 56px -34px rgba(66,74,168,.42);
  --shadow-chip: 0 10px 22px -14px rgba(66,74,168,.5);
  --shadow-none: none;

  --font-display: 'Inter','Noto Sans SC','Noto Sans JP','Noto Sans KR','PingFang SC','Hiragino Sans','Microsoft YaHei',system-ui,sans-serif;
  --font-body: 'Inter','Noto Sans SC','Noto Sans JP','Noto Sans KR','PingFang SC','Hiragino Sans','Microsoft YaHei',system-ui,sans-serif;
  --font-mono: 'JetBrains Mono',ui-monospace,'SF Mono',Menlo,Consolas,monospace;
  --weight-regular: 400;
  --weight-medium: 500;
  --weight-strong: 600;
  --size-body: 16px;
  --size-small: 13.5px;
  --size-caption: 12px;
  --size-h1: clamp(34px,3.35vw,48px);
  --size-h2: clamp(26px,2.5vw,36px);
  --size-h3: 23px;
  --tracking-display: -.02em;

  --r-canvas: 36px;
  --r-cell: 22px;
  --r-panel: 18px;
  --r-btn: 14px;
  --r-sm: 10px;
  --r-shot: 10px;
  --r-pill: 999px;
  --r-circle: 50%;
  --r-logo: 30%;
  --r-phone: 26px;
  --r-phone-screen: 23px;
  --r-tablet-screen: 16px;
  --r-mobile-canvas: 28px;
  --r-tiny: 2px;

  --rail: 1376px;
  --reading: 880px;
  --header-content: 1280px;
  --gutter: 48px;
  --topbar-h: 76px;
  --section-space: 160px;
  --panel-pad: 36px;
  --line: 1px;
  --focus-width: 2px;
  --ease: cubic-bezier(.2,.7,.2,1);
  --duration: .2s;
  --reveal-duration: .65s;
  --layer-header: 40;
  --layer-menu: 42;
  --layer-fab: 30;
  --layer-tip: 60;
}

*, *::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(--size-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
[hidden] { display: none !important; }
img, svg { max-width: 100%; }
img { height: auto; }
svg { flex-shrink: 0; vertical-align: middle; }
button, input, select, textarea { font: inherit; }
button, summary, a { -webkit-tap-highlight-color: var(--accent-soft); }
button { cursor: pointer; }
a { color: inherit; text-underline-offset: .22em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible {
  outline: var(--focus-width) solid var(--accent);
  outline-offset: 3px;
  border-radius: var(--r-sm);
}
::selection { background: var(--accent); color: var(--on-accent); }
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: var(--weight-regular); text-wrap: balance; }
h1 { margin: 0 0 24px; font-size: var(--size-h1); line-height: 1.16; letter-spacing: var(--tracking-display); }
h2 { margin: 0 0 20px; font-size: var(--size-h2); line-height: 1.25; letter-spacing: var(--tracking-display); }
h3 { margin: 0 0 16px; font-size: var(--size-h3); line-height: 1.35; }
p { margin: 0 0 20px; }
strong { font-weight: var(--weight-strong); }
code, pre, kbd { font-family: var(--font-mono); }
code { overflow-wrap: anywhere; font-size: .88em; }
pre {
  max-width: 100%;
  min-width: 0;
  margin: 24px 0;
  padding: 22px;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  border: var(--line) solid var(--border);
  border-radius: var(--r-panel);
  background: var(--bg-panel);
  color: var(--text);
  font-size: 13px;
  line-height: 1.8;
  tab-size: 2;
}
pre code { font-size: inherit; overflow-wrap: normal; word-break: normal; white-space: pre; }
blockquote { margin-inline: 0; }
:where(main, section, article, aside, nav, div, li) { min-width: 0; }
:where(section, article)[id] { scroll-margin-top: 24px; }
.rail, .wrap {
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.reading { max-width: calc(var(--reading) + var(--gutter) * 2); }
.section { padding-top: var(--section-space); }
.section-last { padding-bottom: var(--section-space); }
.section-head { max-width: 760px; margin: 0 auto 48px; text-align: center; }
.section-head h2 { color: var(--accent); }
.section-head p { color: var(--text-muted); margin-bottom: 0; }
.prose { line-height: 1.85; }
.prose h2 { margin-top: 64px; }
.prose h3 { margin-top: 36px; }
.prose li + li { margin-top: 10px; }
.prose a { color: var(--accent-dark); }
.prose :where(div, section, article) { min-width: 0; max-width: 100%; }
.muted { color: var(--text-muted); }
.accent { color: var(--accent); }
.mono { font-family: var(--font-mono); }
.keep-word { white-space: nowrap; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}
.skip-link {
  position: absolute;
  top: 8px;
  left: var(--gutter);
  z-index: var(--layer-tip);
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  background: var(--accent);
  color: var(--on-accent);
  border-radius: var(--r-sm);
}
.skip-link:focus {
  width: auto;
  height: auto;
  padding: 10px 16px;
  overflow: visible;
  clip-path: none;
  white-space: normal;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  max-width: 100%;
  padding: 12px 26px;
  border: 0;
  border-radius: var(--r-btn);
  background: var(--bg-panel);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: var(--weight-medium);
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  transition: background-color var(--duration) var(--ease), transform var(--duration) var(--ease);
}
.btn svg { width: 18px; height: 18px; }
.btn:hover { transform: translateY(-1px); text-decoration: none; }
.btn-solid { background: var(--accent); color: var(--on-accent); }
.btn-solid:hover, .btn-solid.is-hover { background: var(--accent-dark); color: var(--on-accent); }
.btn-line {
  background: var(--bg);
  color: var(--accent);
  box-shadow: inset 0 0 0 var(--line) var(--accent);
}
.btn-line:hover { background: var(--accent-soft); color: var(--accent-dark); }
.btn-soft { background: var(--bg-panel); color: var(--text); }
.btn:disabled, .btn[aria-disabled="true"] {
  background: var(--bg-panel-2);
  color: var(--text-muted);
  box-shadow: var(--shadow-none);
  cursor: not-allowed;
  transform: none;
}
.btn.is-focus { outline: var(--focus-width) solid var(--accent); outline-offset: 3px; }
.card, .panel {
  padding: var(--panel-pad);
  border-radius: var(--r-canvas);
  background: var(--bg-panel);
  color: var(--text);
}
.card p:last-child, .panel p:last-child { margin-bottom: 0; }
.card-hover { transition: transform var(--duration) var(--ease); }
.card-hover:hover { transform: translateY(-2px); }
.card-white { background: var(--bg); color: var(--text); border: var(--line) solid var(--border); }
.soft-field {
  position: relative;
  overflow-x: clip;
  background: linear-gradient(135deg,var(--glow-pink),var(--glow-lilac) 55%,var(--glow-sky));
  color: var(--text);
}
.grid-two { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 24px; }
.stack { display: grid; gap: 24px; }

.topbar { position: relative; z-index: var(--layer-header); height: var(--topbar-h); background: var(--bg); color: var(--text); }
.header-rail {
  width: 100%;
  max-width: min(100%,calc(var(--header-content) + var(--gutter) * 2));
  height: 100%;
  margin-inline: auto;
  padding-inline: var(--gutter);
  display: flex;
  align-items: center;
  gap: 24px;
}
.brand { display: inline-flex; align-items: center; gap: 12px; flex-shrink: 0; text-decoration: none; }
.brand-mark { display: block; width: 34px; height: 34px; flex-shrink: 0; border-radius: var(--r-logo); }
.brand-placeholder {
  background: linear-gradient(140deg,var(--glow-sky),var(--glow-lilac) 55%,var(--glow-pink));
  color: var(--text);
  box-shadow: inset 0 0 0 var(--line) var(--border);
}
.brand-name { font-size: 17px; font-weight: var(--weight-medium); letter-spacing: -.01em; }
.desktop-nav { margin-left: auto; min-width: 0; }
.nav-list { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; gap: 4px; }
.nav-list > li > a, .nav-more > summary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 40px;
  padding: 8px 14px;
  border-radius: var(--r-pill);
  color: var(--text);
  font-size: 15px;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
}
.nav-list > li > a:hover, .nav-more > summary:hover { background: var(--bg-panel); color: var(--text); }
.nav-list a[aria-current="page"], .nav-more.has-current > summary { color: var(--accent); }
.nav-more { position: relative; }
.nav-more > summary { list-style: none; }
.nav-more > summary::-webkit-details-marker { display: none; }
.chev { width: 12px; height: 12px; color: var(--text-muted); transition: transform var(--duration) var(--ease); }
.nav-more[open] .chev { transform: rotate(180deg); }
.more-panel, .language-panel {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  width: 272px;
  max-width: calc(100vw - var(--gutter) * 2);
  padding: 10px;
  border-radius: var(--r-panel);
  background: var(--bg);
  color: var(--text);
  box-shadow: inset 0 0 0 var(--line) var(--border),var(--shadow-float);
}
.more-panel a, .language-panel a {
  display: block;
  min-height: 44px;
  padding: 10px 12px;
  border-radius: var(--r-sm);
  text-decoration: none;
}
.more-panel a:hover, .language-panel a:hover { background: var(--bg-panel); color: var(--text); }
.more-group-label { display: block; padding: 6px 12px 8px; color: var(--text-muted); font-size: 12px; letter-spacing: .04em; }
.more-title { display: block; font-size: 15px; }
.more-desc { display: block; margin-top: 2px; font-size: 13px; color: var(--text-muted); white-space: normal; }
.header-tools { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.language-control { position: relative; padding-left: 20px; border-left: var(--line) solid var(--border); }
.lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 40px;
  padding: 8px 14px;
  border: 0;
  border-radius: var(--r-pill);
  background: var(--clear);
  color: var(--text);
  font-size: 15px;
  white-space: nowrap;
}
.lang:hover { background: var(--bg-panel); color: var(--text); }
.lang svg { width: 16px; height: 16px; color: var(--text-muted); }
.lang-short { display: none; }
.language-panel { width: 190px; }
.language-panel a[aria-current="true"] { color: var(--accent); }
.menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  border: var(--line) solid var(--border);
  border-radius: var(--r-btn);
  background: var(--bg);
  color: var(--text);
}
.menu-toggle svg { width: 20px; height: 20px; }
.mobile-drawer, .menu-veil { display: none; }
.preview-mobile { display: none; margin-left: auto; position: relative; }
.preview-mobile summary { padding: 10px 14px; min-height: 44px; border-radius: var(--r-pill); border: var(--line) solid var(--border); cursor: pointer; }

.site-footer {
  margin-top: var(--section-space);
  padding-top: 64px;
  padding-bottom: 100px;
  border-top: var(--line) solid var(--border);
  background: var(--bg);
  color: var(--text);
}
.footer-grid { display: grid; grid-template-columns: 1.45fr 1fr 1.2fr 1fr; gap: 48px; }
.footer-brand p { max-width: 30em; margin-top: 20px; color: var(--text-muted); font-size: 14px; }
.footer-heading { margin-bottom: 16px; font-size: 15px; font-weight: var(--weight-medium); }
.footer-links { margin: 0; padding: 0; list-style: none; }
.footer-links li + li { margin-top: 8px; }
.footer-links a { display: inline-block; padding-block: 4px; color: var(--text-muted); font-size: 14px; text-decoration: none; }
.footer-links a:hover { color: var(--accent); }
.footer-bottom { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 16px 32px; margin-top: 48px; padding-top: 24px; border-top: var(--line) solid var(--border); color: var(--text-muted); font-size: 12px; }
.footer-bottom p { margin: 0; }
.legal-links { display: flex; flex-wrap: wrap; gap: 12px 20px; }

.reveal { opacity: 1; transform: none; }
html.reveal-ready .reveal:not(.shown) { opacity: 0; transform: translateY(18px); }
html.reveal-ready .reveal { transition: opacity var(--reveal-duration) var(--ease),transform var(--reveal-duration) var(--ease); }
.reveal.shown { opacity: 1; transform: none; }

@media (max-width:1180px) {
  .nav-list > li > a, .nav-more > summary, .lang { padding-inline: 11px; }
  .header-rail { gap: 16px; }
}
@media (max-width:1100px) {
  .desktop-nav { display: none; }
  .header-tools { margin-left: auto; }
  .language-control { border-left: 0; padding-left: 0; }
  .menu-toggle { display: inline-flex; }
  .mobile-drawer {
    position: absolute;
    z-index: var(--layer-menu);
    top: var(--topbar-h);
    left: 0;
    right: 0;
    max-height: calc(100dvh - var(--topbar-h));
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: 16px var(--gutter) 28px;
    border-top: var(--line) solid var(--border);
    border-bottom: var(--line) solid var(--border);
    background: var(--bg);
    color: var(--text);
  }
  .mobile-drawer:not([hidden]) { display: block; }
  .mobile-drawer ul { margin: 0; padding: 0; list-style: none; }
  .mobile-drawer a { display: flex; width: 100%; align-items: center; min-height: 48px; padding: 12px 16px; border-radius: var(--r-sm); text-decoration: none; }
  .mobile-drawer a:hover { background: var(--bg-panel); color: var(--text); }
  .mobile-drawer a[aria-current] { color: var(--accent); }
  .drawer-label { margin: 16px 0 4px; padding-inline: 16px; color: var(--text-muted); font-size: 12px; }
  .menu-veil:not([hidden]) { display: block; position: fixed; inset: var(--topbar-h) 0 0; z-index: 1; border: 0; background: var(--scrim); color: var(--text); cursor: default; }
  .preview-tools { display: none; }
  .preview-mobile { display: block; }
}
@media (max-width:980px) {
  :root { --gutter: 20px; --topbar-h: 64px; --panel-pad: 28px; }
  .footer-grid { grid-template-columns: repeat(2,minmax(0,1fr)); gap: 36px; }
}
@media (max-width:768px) {
  :root { --size-h1: clamp(24px,5vw,30px); --size-h2: clamp(25px,5vw,30px); }
}
@media (max-width:640px) {
  :root { --gutter: 20px; --panel-pad: 24px; }
  .brand-name { min-width: 0; font-size: 14px; line-height: 1.3; overflow-wrap: anywhere; }
  .header-rail > .brand { min-width: 0; flex-shrink: 1; }
  .brand { gap: 8px; }
  .brand-mark { width: 30px; height: 30px; }
  .header-rail { gap: 8px; }
  .header-tools { gap: 4px; margin-left: auto; }
  .lang { min-width: 44px; min-height: 44px; padding-inline: 8px; }
  .lang-full, .lang .globe { display: none; }
  .lang-short { display: inline; }
  .grid-two, .footer-grid { grid-template-columns: minmax(0,1fr); }
  .footer-grid { gap: 32px; }
  .section-head { margin-bottom: 32px; }
  .tilt, [data-tilt] { transform: none !important; }
  .card, .panel { border-radius: var(--r-mobile-canvas); }
  pre { padding: 16px; font-size: 12px; }
}
@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; }
  .btn:hover, .card-hover:hover { transform: none; }
}
@media print {
  .topbar, .dl-fab, .wx-open-tip, .menu-veil { display: none !important; }
  .reveal, html.reveal-ready .reveal:not(.shown) { opacity: 1; transform: none; }
  .site-footer { margin-top: 40px; }
}