:root{
  --color-page:#E9EFFA;
  --color-surface:#F6F9FF;
  --color-surface-strong:#DCE5F5;
  --color-border:#C3D0E8;
  --color-accent:#F5A300;
  --color-accent-dark:#C77F00;
  --color-text:#131C2E;
  --color-muted:#4C5A75;
  --color-success:#1E8E5A;
  --color-warning:#B45309;
  --color-error:#C2372E;
  --color-white:#FFFFFF;
  --color-flag-red:#CE3D3D;
  --color-flag-blue:#2C4C96;
  --color-overlay:rgba(19,28,46,.42);
  --color-dot:rgba(76,90,117,.16);
  --color-dot-strong:rgba(76,90,117,.30);
  --color-shadow:rgba(19,28,46,.07);
  --color-shadow-lift:rgba(19,28,46,.11);
  --font-display:'Inter','Noto Sans SC','Noto Sans JP','Noto Sans KR',-apple-system,'PingFang SC','Hiragino Sans','Malgun Gothic',sans-serif;
  --font-body:'Inter','Noto Sans SC','Noto Sans JP','Noto Sans KR',-apple-system,'PingFang SC','Hiragino Sans','Malgun Gothic',sans-serif;
  --font-mono:'JetBrains Mono','SFMono-Regular',Consolas,'Liberation Mono',Menlo,monospace;
  --radius-sm:12px;
  --radius-md:18px;
  --radius-card:26px;
  --radius-pill:999px;
  --shadow-card:0 10px 28px var(--color-shadow);
  --shadow-lift:0 16px 36px var(--color-shadow-lift);
  --content-width:1320px;
  --header-height:62px;
  --gutter:34px;
  --focus-width:2px;
  --toc-offset:82px;
  --transition-fast:150ms ease;
  --transition-base:240ms ease;
}
*,
*::before,
*::after{box-sizing:border-box}
html{
  min-width:320px;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-height) + 16px);
}
html.nav-open{overflow:hidden}
body{
  margin:0;
  min-width:320px;
  min-height:100%;
  overflow-x:clip;
  color:var(--color-text);
  background-color:var(--color-page);
  background-image:radial-gradient(var(--color-dot) 1.1px,transparent 1.5px);
  background-size:26px 26px;
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img,svg,video{display:block;max-width:100%}
img{height:auto}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
a{color:inherit;text-decoration:none}
p,h1,h2,h3,h4,ul,ol,figure,blockquote{margin-top:0}
p{margin-bottom:1em}
ul,ol{padding-left:1.35em}
code,kbd,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{
  max-width:100%;
  overflow-x:auto;
  padding:18px;
  border:1px solid var(--color-border);
  border-radius:var(--radius-sm);
  background:var(--color-text);
  color:var(--color-surface);
  -webkit-overflow-scrolling:touch;
}
table{border-collapse:collapse}
button,a,summary,[role="tab"],select{
  -webkit-tap-highlight-color:transparent;
}
a:focus-visible,
button:focus-visible,
summary:focus-visible,
select:focus-visible,
input:focus-visible,
textarea:focus-visible,
[role="tab"]:focus-visible{
  outline:var(--focus-width) solid var(--color-accent-dark);
  outline-offset:3px;
}
.wrap{
  width:100%;
  max-width:var(--content-width);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.section{
  padding-top:88px;
  padding-bottom:88px;
}
.section-head{
  max-width:780px;
  margin-bottom:36px;
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:8px;
  min-height:28px;
  padding:4px 13px;
  border:1px solid var(--color-border);
  border-radius:var(--radius-pill);
  background:var(--color-surface-strong);
  color:var(--color-muted);
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:700;
  letter-spacing:.12em;
}
.eyebrow-dot{
  width:7px;
  height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--color-success);
}
.no-break{white-space:nowrap}
h1,h2,h3,h4{
  color:var(--color-text);
  font-family:var(--font-display);
  text-wrap:balance;
}
h1{
  margin-bottom:20px;
  font-size:clamp(52px,5.2vw,72px);
  font-weight:900;
  line-height:1.1;
  letter-spacing:-.015em;
}
h2{
  margin-bottom:16px;
  font-size:clamp(34px,4vw,52px);
  font-weight:900;
  line-height:1.14;
  letter-spacing:-.01em;
}
h3{
  margin-bottom:10px;
  font-size:22px;
  font-weight:800;
  line-height:1.3;
}
.lead{
  color:var(--color-muted);
  font-size:clamp(18px,2vw,22px);
  line-height:1.65;
}
.text-muted{color:var(--color-muted)}
.mono{font-family:var(--font-mono)}
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  min-width:24px;
  min-height:48px;
  padding:12px 30px;
  border:1.5px solid transparent;
  border-radius:var(--radius-pill);
  font-family:var(--font-display);
  font-size:15px;
  font-weight:800;
  line-height:1.2;
  letter-spacing:.02em;
  transition:transform var(--transition-fast),background-color var(--transition-fast),border-color var(--transition-fast),color var(--transition-fast);
}
.btn:hover{transform:translateY(-2px)}
.btn-primary{
  border-color:var(--color-accent);
  background:var(--color-accent);
  color:var(--color-text);
}
.btn-primary:hover{
  border-color:var(--color-accent-dark);
  background:var(--color-accent-dark);
}
.btn-secondary{
  border-color:var(--color-text);
  background:transparent;
  color:var(--color-text);
}
.btn-secondary:hover{background:var(--color-surface-strong)}
.btn-soft{
  border-color:var(--color-border);
  background:var(--color-surface-strong);
}
.btn-small{
  min-height:40px;
  padding:9px 20px;
  font-size:13px;
}
.button-row{
  display:flex;
  flex-wrap:wrap;
  gap:12px;
}
.panel,
.card{
  min-width:0;
  border:1px solid var(--color-border);
  border-radius:var(--radius-card);
  background:var(--color-surface);
  box-shadow:var(--shadow-card);
}
.card{
  padding:26px;
  transition:transform var(--transition-base),box-shadow var(--transition-base);
}
.card:hover{
  transform:translateY(-3px);
  box-shadow:var(--shadow-lift);
}
.badge,
.tag{
  display:inline-flex;
  align-items:center;
  gap:7px;
  max-width:100%;
  min-height:28px;
  padding:4px 12px;
  overflow:hidden;
  border:1px solid var(--color-border);
  border-radius:var(--radius-pill);
  background:var(--color-surface-strong);
  color:var(--color-muted);
  font-size:12px;
  font-weight:700;
  text-overflow:ellipsis;
}
.badge-dot{
  width:7px;
  height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--color-success);
}
.reveal{
  transition:opacity 560ms ease,transform 560ms ease;
}
.reveal.pending{
  opacity:0;
  transform:translateY(16px);
}
.reveal.shown{
  opacity:1;
  transform:none;
}

/* Shared header */
.site-head{
  position:relative;
  z-index:1100;
  border-bottom:1px solid var(--color-border);
  background:var(--color-surface);
}
.head-in{
  position:relative;
  z-index:100;
  display:flex;
  align-items:center;
  gap:22px;
  height:var(--header-height);
}
.brand{
  display:inline-flex;
  align-items:center;
  gap:9px;
  min-width:max-content;
  min-height:44px;
}
.brand img{
  width:30px;
  height:30px;
  flex:0 0 auto;
}
.brand-copy{
  display:flex;
  align-items:baseline;
  gap:7px;
}
.brand-name{
  font-family:var(--font-display);
  font-size:19px;
  font-weight:900;
  letter-spacing:.04em;
}
.brand-local{
  color:var(--color-muted);
  font-size:12px;
  font-weight:600;
}
.desktop-nav{
  display:flex;
  align-items:center;
  gap:3px;
  min-width:0;
}
.desktop-nav a,
.nav-link{
  display:inline-flex;
  align-items:center;
  gap:6px;
  min-height:36px;
  padding:7px 10px;
  border-radius:var(--radius-pill);
  color:var(--color-muted);
  font-size:13px;
  font-weight:650;
  white-space:nowrap;
  transition:color var(--transition-fast),background-color var(--transition-fast);
}
.desktop-nav a:hover,
.desktop-nav a.is-active,
.nav-link:hover,
.nav-link.is-active{
  background:var(--color-surface-strong);
  color:var(--color-text);
}
.desktop-nav a.is-active{font-weight:800}
.nav-icon{
  width:15px;
  height:15px;
  flex:0 0 auto;
}
.head-tools{
  display:flex;
  align-items:center;
  gap:9px;
  margin-left:auto;
  flex:0 0 auto;
}
.lang-control{position:relative}
.lang-button{
  display:inline-flex;
  align-items:center;
  gap:5px;
  min-height:36px;
  padding:6px 10px;
  border:0;
  border-radius:var(--radius-pill);
  background:transparent;
  color:var(--color-muted);
  font-size:13px;
  font-weight:700;
}
.lang-menu{
  position:absolute;
  top:calc(100% + 8px);
  right:0;
  z-index:110;
  display:none;
  width:168px;
  padding:7px;
  border:1px solid var(--color-border);
  border-radius:var(--radius-md);
  background:var(--color-surface);
  box-shadow:var(--shadow-lift);
}
.lang-control.is-open .lang-menu{display:block}
.lang-menu a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:8px 11px;
  border-radius:var(--radius-sm);
  font-size:13px;
}
.lang-menu a:hover,
.lang-menu a[aria-current="true"]{background:var(--color-surface-strong)}
.login-link{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:38px;
  padding:7px 19px;
  border:1.5px solid var(--color-text);
  border-radius:var(--radius-pill);
  font-size:13px;
  font-weight:800;
}
.login-link:hover{
  background:var(--color-text);
  color:var(--color-surface);
}
.menu-toggle{
  display:none;
  align-items:center;
  justify-content:center;
  min-width:44px;
  min-height:44px;
  padding:0;
  border:0;
  border-radius:var(--radius-pill);
  background:transparent;
}
.menu-toggle svg{width:22px;height:22px}
.mobile-drawer{
  position:fixed;
  top:var(--header-height);
  left:0;
  right:0;
  z-index:130;
  display:none;
  max-height:calc(100dvh - var(--header-height));
  overflow-y:auto;
  overscroll-behavior:contain;
  padding:10px var(--gutter) 18px;
  border-top:1px solid var(--color-border);
  border-bottom:1px solid var(--color-border);
  background:var(--color-surface);
}
.mobile-drawer.is-open{display:block}
.mobile-drawer a{
  display:flex;
  align-items:center;
  gap:10px;
  width:100%;
  min-height:46px;
  padding:11px 12px;
  border-radius:var(--radius-sm);
  color:var(--color-muted);
  font-size:15px;
  font-weight:700;
}
.mobile-drawer a:hover,
.mobile-drawer a.is-active{
  background:var(--color-surface-strong);
  color:var(--color-text);
}
.drawer-label{
  margin:14px 12px 5px;
  color:var(--color-muted);
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.13em;
}
.nav-veil{
  position:fixed;
  inset:var(--header-height) 0 0;
  z-index:90;
  display:none;
  background:var(--color-overlay);
}
.nav-veil.is-open{display:block}

/* Shared footer */
.site-footer{
  margin-top:72px;
  border-top:1px solid var(--color-border);
  background:var(--color-surface);
}
.footer-grid{
  display:grid;
  grid-template-columns:1.25fr 1fr 1.25fr .8fr;
  gap:34px;
  padding-top:56px;
  padding-bottom:40px;
}
.footer-brand p{
  max-width:36ch;
  margin-top:16px;
  color:var(--color-muted);
  font-size:14px;
}
.footer-title{
  margin-bottom:14px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:800;
  letter-spacing:.12em;
}
.footer-links{
  display:grid;
  gap:7px;
}
.footer-links a{
  display:inline-flex;
  align-items:center;
  min-height:30px;
  color:var(--color-muted);
  font-size:13px;
}
.footer-links a:hover{color:var(--color-text)}
.footer-bottom{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:20px;
  padding-top:20px;
  padding-bottom:24px;
  border-top:1px dashed var(--color-border);
  color:var(--color-muted);
  font-size:12px;
}
.footer-legal{
  display:flex;
  flex-wrap:wrap;
  gap:18px;
}
.footer-legal a{min-height:24px}

/* Long-form content */
.prose{
  min-width:0;
  color:var(--color-text);
}
.prose p,
.prose li{color:var(--color-muted)}
.prose h2{margin-top:2em}
.prose h3{margin-top:1.65em}
.prose a{
  color:var(--color-text);
  text-decoration:underline;
  text-decoration-color:var(--color-accent-dark);
  text-underline-offset:3px;
}
.prose img{border-radius:var(--radius-md)}
.prose blockquote{
  margin-inline:0;
  padding:20px 24px;
  border-left:4px solid var(--color-accent);
  border-radius:0 var(--radius-md) var(--radius-md) 0;
  background:var(--color-surface);
}
body:has(.toc-tabs) section[id]{
  scroll-margin-top:var(--toc-offset);
}

@media (max-width:1120px){
  .desktop-nav a{padding-inline:7px;font-size:12px}
  .desktop-nav .nav-icon{display:none}
  .brand-local{display:none}
}
@media (max-width:900px){
  :root{--gutter:24px}
  .desktop-nav{display:none}
  .head-tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .lang-control>.lang-button,
  .lang-control>.lang-menu{display:none}
  .footer-grid{grid-template-columns:1.2fr 1fr 1fr}
  .footer-grid>div:last-child{grid-column:2/4}
}
@media (max-width:768px){
  h1{font-size:clamp(34px,9.5vw,40px);line-height:1.12;letter-spacing:-.01em}
  h2{font-size:clamp(28px,7vw,38px)}
  .section{padding-top:64px;padding-bottom:64px}
  .card:hover{transform:none}
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-grid>div:last-child{grid-column:auto}
}
@media (max-width:640px){
  :root{--gutter:16px}
  body{background-size:22px 22px}
  .wrap{padding-inline:var(--gutter)}
  .head-in{gap:8px}
  .brand-copy{gap:0}
  .brand-local{display:none}
  .login-link{padding-inline:14px}
  .mobile-drawer{padding-block:6px 10px}
  .mobile-drawer a{min-height:36px;padding-block:4px}
  .drawer-label{margin-top:4px}
  .button-row .btn{width:100%}
  h1 .no-break,
  h2 .no-break{white-space:normal}
  .footer-grid{grid-template-columns:1fr;gap:28px}
  .footer-grid>div:last-child{grid-column:auto}
  .footer-bottom{align-items:flex-start;flex-direction:column}
  .tilt-card,
  [data-tilt]{transform:none!important}
}
@media (max-width:380px){
  .brand-name{font-size:17px}
  .brand img{width:27px;height:27px}
  .login-link{padding-inline:11px}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,
  .reveal.pending,
  .card,
  .btn{transition:none!important;opacity:1!important;transform:none!important}
}