/* ==========================================================================
   VPNUJ — base.css
   Design tokens, reset, typography, layout shell, buttons, header, footer,
   reveal transition, responsive guards.
   ========================================================================== */

:root{
  /* ---- surfaces ---- */
  --bg:#FCFCFD;
  --bg-panel:#FFFFFF;
  --bg-panel-2:#F1F2F4;
  --border:#E3E4E8;
  --border-strong:#D3D5DC;
  --border-hi:rgba(255,255,255,.90);
  --white:#FFFFFF;

  /* ---- text ---- */
  --text:#121316;
  --text-muted:#5F6470;
  --text-soft:#8A8F9A;

  /* ---- accent & semantics ---- */
  --accent:#C2410C;
  --accent-dark:#8F2F08;
  --accent-line:rgba(194,65,12,.32);
  --accent-soft:rgba(194,65,12,.08);
  --accent-soft-2:rgba(194,65,12,.14);
  --success:#157F4E;
  --warn:#A96A12;
  --error:#B3261E;

  /* ---- ink surfaces ---- */
  --ink:#14161B;
  --ink-2:#1C1F26;
  --ink-3:#0C0E12;
  --ink-line-hi:rgba(255,255,255,.16);
  --ink-text:rgba(255,255,255,.94);
  --ink-muted:rgba(255,255,255,.60);
  --ink-faint:rgba(255,255,255,.30);
  --ink-halo:rgba(255,255,255,.09);
  --space-blue:#26386B;

  /* ---- flags ---- */
  --flag-red:#BF3A33;
  --flag-blue:#2B3F7C;
  --flag-white:#FFFFFF;

  /* ---- atmosphere ---- */
  --atmo-warm:rgba(194,65,12,.055);
  --atmo-ink:rgba(20,22,27,.030);
  --atmo-zero:rgba(252,252,253,0);
  --glow-1:rgba(194,65,12,.14);
  --glow-2:rgba(194,65,12,.04);
  --glow-0:rgba(194,65,12,0);
  --glow-sun:rgba(194,65,12,.42);
  --glow-sun-2:rgba(194,65,12,.12);
  --glow-sun-0:rgba(194,65,12,0);
  --halo-accent:rgba(194,65,12,.16);
  --veil:rgba(18,19,22,.44);
  --grid-line:rgba(20,22,27,.055);

  /* ---- shadows ---- */
  --shadow-xs:0 1px 2px rgba(18,19,22,.05);
  --shadow-sm:0 2px 6px rgba(18,19,22,.06), 0 12px 26px -18px rgba(194,65,12,.35);
  --shadow-search:0 1px 2px rgba(18,19,22,.04), 0 26px 46px -30px rgba(194,65,12,.45);
  --shadow-ink:0 10px 22px -12px rgba(18,19,22,.55);
  --shadow-ink-hover:0 16px 30px -14px rgba(18,19,22,.55);
  --shadow-sky:0 40px 76px -40px rgba(194,65,12,.18), 0 2px 4px rgba(18,19,22,.06);
  --shadow-float:0 18px 36px -18px rgba(18,19,22,.28);
  --shadow-card:0 1px 2px rgba(18,19,22,.04), 0 18px 34px -26px rgba(194,65,12,.30);
  --shadow-card-hover:0 2px 4px rgba(18,19,22,.05), 0 26px 44px -28px rgba(194,65,12,.42);

  /* ---- geometry ---- */
  --r-xs:8px;
  --r-sm:12px;
  --r-md:16px;
  --r-lg:18px;
  --r-xl:26px;
  --r-pill:999px;

  /* ---- type ---- */
  --font-display:"Inter","Noto Sans SC",-apple-system,"Segoe UI","Hiragino Sans","Malgun Gothic",sans-serif;
  --font-body:"Inter","Noto Sans SC",-apple-system,"Segoe UI","Hiragino Sans","Malgun Gothic",sans-serif;
  --font-mono:"JetBrains Mono","Noto Sans SC",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  /* ---- spacing scale (8px grid) ---- */
  --sp-1:4px;
  --sp-2:8px;
  --sp-3:12px;
  --sp-4:16px;
  --sp-5:24px;
  --sp-6:32px;
  --sp-7:48px;
  --sp-8:64px;
  --sp-9:96px;

  /* ---- layout ---- */
  --maxw:1360px;
  --gutter:28px;
  --header-h:66px;
  --measure:72ch;

  /* ---- motion ---- */
  --ease:cubic-bezier(.2,.7,.3,1);
  --dur-fast:.18s;
  --dur:.28s;
}

/* ==========================================================================
   Reset
   ========================================================================== */

*,*::before,*::after{box-sizing:border-box;}

html{
  overflow-x:clip;
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-h) + 16px);
}

html.nav-open{overflow:hidden;}

body{
  margin:0;
  background:var(--bg);
  color:var(--text);
  font-family:var(--font-body);
  font-size:15px;
  line-height:1.5;
  overflow-x:clip;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

a{color:inherit;}

ul,ol{margin:0;padding:0;list-style:none;}

svg{display:block;}

img{max-width:100%;height:auto;}

button,input,select,textarea{font:inherit;color:inherit;}

hr{border:0;border-top:1px solid var(--border);margin:var(--sp-5) 0;}

::selection{background:var(--accent-soft-2);color:var(--text);}

/* keyboard focus ring — never removed without replacement */
:where(a,button,summary,input,select,textarea,[tabindex]):focus-visible{
  outline:2px solid var(--accent);
  outline-offset:2px;
  border-radius:var(--r-xs);
}

/* ==========================================================================
   Typography
   ========================================================================== */

h1,h2,h3,h4{
  font-family:var(--font-display);
  color:var(--text);
  letter-spacing:-.02em;
  text-wrap:balance;
}

h1{
  margin:0;
  font-size:clamp(52px,5.2vw,72px);
  line-height:1.06;
  font-weight:800;
  letter-spacing:-.035em;
}

h2{
  margin:0;
  font-size:clamp(26px,2.6vw,34px);
  line-height:1.16;
  font-weight:800;
}

h3{
  margin:0;
  font-size:19px;
  line-height:1.32;
  font-weight:700;
}

h4{
  margin:0;
  font-size:15px;
  line-height:1.4;
  font-weight:700;
  letter-spacing:-.01em;
}

p{margin:0;}

.lede{
  font-size:17px;
  line-height:1.62;
  color:var(--text-muted);
  max-width:var(--measure);
}

.lede strong{color:var(--text);font-weight:600;}

.muted{color:var(--text-muted);}
.soft{color:var(--text-soft);}

.mono{
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.02em;
}

.accent-text{color:var(--accent);}
.accent-key{color:var(--accent);font-weight:inherit;}

/* Chinese keyword guard: 2–4 hanzi only, released on narrow screens */
.no-break{white-space:nowrap;}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:7px;
  margin:0;
  font-family:var(--font-mono);
  font-size:11.5px;
  font-weight:600;
  letter-spacing:.06em;
  color:var(--text-soft);
}

.eyebrow::before{
  content:"";
  width:5px;height:5px;border-radius:50%;
  background:var(--accent);
  flex:none;
}

.eyebrow.no-dot::before{display:none;}

/* ==========================================================================
   Layout shell
   ========================================================================== */

.shell,
.wrap{
  width:100%;
  max-width:var(--maxw);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.sec{padding-block:clamp(48px,6.5vw,88px);}
.sec-tight{padding-block:clamp(32px,4vw,56px);}

.section-head{
  display:flex;
  flex-direction:column;
  gap:10px;
  max-width:760px;
  margin-bottom:var(--sp-6);
}

.section-head p{color:var(--text-muted);font-size:15.5px;line-height:1.65;}

.grid{display:grid;gap:var(--sp-4);}
.grid > *{min-width:0;}

.cols-2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr));}
.cols-3{grid-template-columns:repeat(auto-fit,minmax(240px,1fr));}
.cols-4{grid-template-columns:repeat(auto-fit,minmax(200px,1fr));}

.stack{display:flex;flex-direction:column;gap:var(--sp-4);}
.row{display:flex;flex-wrap:wrap;align-items:center;gap:var(--sp-3);}

.page{
  position:relative;
  min-height:100vh;
  background-image:linear-gradient(180deg,var(--atmo-warm) 0%,var(--atmo-ink) 46%,var(--atmo-zero) 92%);
  background-repeat:no-repeat;
  background-size:100% 100%;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  height:46px;
  padding:0 26px;
  border-radius:var(--r-pill);
  font-size:15px;
  font-weight:600;
  text-decoration:none;
  border:1px solid transparent;
  white-space:nowrap;
  flex-shrink:0;
  transition:transform var(--dur-fast) var(--ease),
             box-shadow var(--dur-fast) var(--ease),
             background-color var(--dur-fast) var(--ease),
             border-color var(--dur-fast) var(--ease),
             color var(--dur-fast) var(--ease);
}

.btn-primary{
  background:var(--text);
  color:var(--white);
  box-shadow:var(--shadow-ink);
}
.btn-primary:hover{background:var(--ink-2);transform:translateY(-2px);box-shadow:var(--shadow-ink-hover);}
.btn-primary svg{width:13px;height:13px;flex:none;}
/* buttons keep their own colors inside prose/link contexts */
.btn.btn-primary,
.btn.btn-primary:hover,
.btn.btn-primary:focus-visible{color:var(--white);}
.prose a.btn,
.prose a.btn:hover{text-decoration:none;}

.btn-ghost{
  background:var(--bg-panel);
  color:var(--text);
  border-color:var(--border);
  box-shadow:var(--shadow-xs);
}
.btn-ghost:hover{transform:translateY(-2px);border-color:var(--border-strong);box-shadow:var(--shadow-sm);}

.btn-quiet{
  background:var(--bg-panel-2);
  color:var(--text);
  border-color:transparent;
}
.btn-quiet:hover{background:var(--border);transform:translateY(-1px);}

.btn-sm{height:38px;padding:0 18px;font-size:13.5px;}
.btn-block{width:100%;}

.btn[disabled],
.btn[aria-disabled="true"]{
  opacity:.55;
  pointer-events:none;
  box-shadow:none;
}

/* ==========================================================================
   Chips / badges / status dots
   ========================================================================== */

.pill{
  display:inline-flex;
  align-items:center;
  gap:7px;
  max-width:100%;
  height:32px;
  padding:0 14px;
  border-radius:var(--r-pill);
  background:var(--bg-panel);
  border:1px solid var(--border);
  font-size:12.5px;
  color:var(--text-muted);
  box-shadow:var(--shadow-xs);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

.pill .dot{
  width:5px;height:5px;border-radius:50%;
  background:var(--accent);
  flex:none;
}

.pill.is-current{color:var(--text);border-color:var(--accent-line);}

.badge{
  display:inline-flex;
  align-items:center;
  gap:8px;
  max-width:100%;
  padding:6px 13px;
  border-radius:var(--r-pill);
  background:var(--bg-panel);
  border:1px solid var(--border);
  font-size:12.5px;
  color:var(--text-muted);
  box-shadow:var(--shadow-xs);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

.badge .dot{
  width:6px;height:6px;border-radius:50%;
  background:var(--accent);
  box-shadow:0 0 0 3px var(--halo-accent);
  flex:none;
}

.badge-ink{
  background:rgba(255,255,255,.06);
  border-color:var(--ink-line-hi);
  color:var(--ink-text);
  box-shadow:none;
}

.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  max-width:100%;
  min-height:24px;
  padding:0 10px;
  border-radius:var(--r-pill);
  border:1px solid var(--border);
  background:var(--bg-panel);
  font-family:var(--font-mono);
  font-size:11.5px;
  color:var(--text-muted);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

.tag-accent{border-color:var(--accent-line);color:var(--accent-dark);background:var(--accent-soft);}

.dot-live{
  width:6px;height:6px;border-radius:50%;
  background:var(--accent);
  box-shadow:0 0 0 3px var(--halo-accent);
  flex:none;
}

.dot-ok{width:6px;height:6px;border-radius:50%;background:var(--success);flex:none;}
.dot-warn{width:6px;height:6px;border-radius:50%;background:var(--warn);flex:none;}

/* ==========================================================================
   Panels & cards
   ========================================================================== */

.panel{
  position:relative;
  min-width:0;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-lg);
  box-shadow:var(--shadow-card);
}

.panel-flat{
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-lg);
  box-shadow:none;
}

.panel-ink{
  position:relative;
  min-width:0;
  overflow:hidden;
  color:var(--ink-text);
  background:linear-gradient(180deg,var(--ink-2) 0%,var(--ink) 54%,var(--ink-3) 100%);
  border-radius:var(--r-xl);
  box-shadow:inset 0 1px 0 var(--ink-line-hi),var(--shadow-sky);
}

.panel-ink h2,
.panel-ink h3{color:var(--white);}

.panel-body{padding:var(--sp-5);}

.card-hover{
  transition:transform var(--dur-fast) var(--ease),
             box-shadow var(--dur-fast) var(--ease),
             border-color var(--dur-fast) var(--ease);
}

.card-hover:hover{
  transform:translateY(-2px);
  border-color:var(--border-strong);
  box-shadow:var(--shadow-card-hover);
}

.hairline{
  position:relative;
}
.hairline::after{
  content:"";
  position:absolute;
  inset:0 0 auto;
  height:1px;
  background:linear-gradient(90deg,transparent,var(--border-hi),transparent);
  pointer-events:none;
}

/* ==========================================================================
   Header (injected by header.js — see design-summary for the DOM contract)
   ========================================================================== */

.site-head,
#site-header{position:relative;z-index:50;}

.head-inner{
  display:flex;
  align-items:center;
  gap:22px;
  height:var(--header-h);
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:9px;
  text-decoration:none;
  flex:none;
}

.brand-mark{width:26px;height:26px;flex:none;}

.brand-word{
  font-family:var(--font-display);
  font-size:16px;
  font-weight:800;
  letter-spacing:-.02em;
  color:var(--text);
}

.brand-zh{
  font-size:12px;
  font-weight:500;
  letter-spacing:.04em;
  color:var(--text-muted);
  padding-left:1px;
}

.main-nav{
  display:flex;
  align-items:center;
  gap:2px;
  margin-right:auto;
}

.main-nav > ul{
  display:flex;
  align-items:center;
  gap:2px;
  list-style:none;
  margin:0;
  padding:0;
}

.main-nav li{list-style:none;}

.nav-link{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:8px 12px;
  border-radius:var(--r-pill);
  font-size:13.5px;
  font-weight:500;
  color:var(--text-muted);
  text-decoration:none;
  white-space:nowrap;
  background:transparent;
  border:0;
  cursor:pointer;
  transition:color var(--dur-fast) var(--ease),background-color var(--dur-fast) var(--ease);
}

.nav-link:hover{color:var(--text);background:var(--bg-panel-2);}
.nav-link.is-active{color:var(--text);font-weight:600;}
.nav-link.is-active::before{
  content:"";
  width:5px;height:5px;border-radius:50%;
  background:var(--accent);
  flex:none;
}

.nav-more{position:relative;}
.nav-more-btn{cursor:pointer;}
.nav-more .chev{width:10px;height:10px;color:var(--text-soft);transition:transform .2s var(--ease);}
.nav-more:hover .chev,
.nav-more:focus-within .chev{transform:rotate(180deg);}

.more-panel{
  position:absolute;
  top:calc(100% + 8px);
  left:0;
  min-width:186px;
  display:flex;
  flex-direction:column;
  gap:2px;
  padding:6px;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-md);
  box-shadow:var(--shadow-float);
  z-index:70;
  opacity:0;
  visibility:hidden;
  transform:translateY(-6px);
  transition:opacity .2s var(--ease),transform .2s var(--ease),visibility .2s;
}

.nav-more:hover .more-panel,
.nav-more:focus-within .more-panel,
.nav-more.is-open .more-panel{
  opacity:1;
  visibility:visible;
  transform:translateY(0);
}

.more-panel a{
  display:flex;
  align-items:center;
  width:100%;
  min-height:36px;
  padding:8px 12px;
  border-radius:var(--r-xs);
  font-size:13px;
  color:var(--text-muted);
  text-decoration:none;
  transition:background-color .15s var(--ease),color .15s var(--ease);
}

.more-panel a:hover{background:var(--bg-panel-2);color:var(--text);}

.head-actions{
  display:flex;
  align-items:center;
  gap:16px;
  flex:none;
}

.lang{
  display:inline-flex;
  align-items:center;
  gap:5px;
  font-size:12.5px;
  color:var(--text-muted);
}
.lang svg{width:10px;height:10px;color:var(--text-soft);}

/* language dropdown (header.js) */
.lang-switch{position:relative;}
.lang-btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:5px;
  min-height:32px;
  padding:0 9px;
  border:1px solid transparent;
  border-radius:var(--r-pill);
  background:transparent;
  font-size:12.5px;
  color:var(--text-muted);
  cursor:pointer;
  white-space:nowrap;
  transition:background-color var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease);
}
.lang-btn:hover{background:var(--bg-panel-2);color:var(--text);}
.lang-btn .chev{width:10px;height:10px;color:var(--text-soft);transition:transform .2s var(--ease);}
.lang-switch.is-open .lang-btn .chev{transform:rotate(180deg);}

.lang-menu{
  position:absolute;
  right:0;
  top:calc(100% + 8px);
  min-width:158px;
  display:none;
  flex-direction:column;
  gap:2px;
  padding:6px;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-md);
  box-shadow:var(--shadow-float);
  z-index:70;
}

.lang-switch.is-open .lang-menu{display:flex;}

.lang-menu a{
  display:flex;
  align-items:center;
  width:100%;
  min-height:36px;
  padding:8px 12px;
  border-radius:var(--r-xs);
  font-size:13px;
  color:var(--text-muted);
  text-decoration:none;
}
.lang-menu a:hover{background:var(--bg-panel-2);color:var(--text);}
.lang-menu a[aria-current="true"]{color:var(--text);font-weight:600;}

/* language dropdown — header.js markup (.lang trigger + sibling .lang-panel, toggled via [hidden]) */
.head-actions{position:relative;}
.lang{cursor:pointer;}
.lang-panel{
  position:absolute;
  right:0;
  top:calc(100% + 8px);
  min-width:158px;
  display:flex;
  flex-direction:column;
  gap:2px;
  padding:6px;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-md);
  box-shadow:var(--shadow-float);
  z-index:70;
}
.lang-panel[hidden]{display:none;}
.lang-panel a,
.lang-item{
  display:flex;
  align-items:center;
  width:100%;
  min-height:36px;
  padding:8px 12px;
  border-radius:var(--r-xs);
  font-size:13px;
  color:var(--text-muted);
  text-decoration:none;
}
.lang-panel a:hover,
.lang-item:hover{background:var(--bg-panel-2);color:var(--text);}
.lang-panel a[aria-current="true"],
.lang-item[aria-current="true"]{color:var(--text);font-weight:600;}

/* drawer list/link classes (header.js markup) */
.drawer-list{display:grid;gap:2px;margin:0;padding:0;list-style:none;}
.drawer-link{
  display:flex;
  width:100%;
  align-items:center;
  min-height:48px;
  padding:10px 12px;
  border-radius:var(--r-sm);
  font-size:15px;
  font-weight:500;
  color:var(--text);
  text-decoration:none;
}
.drawer-link:hover,
.drawer-link:focus-visible{background:var(--bg-panel-2);}
.drawer-link.is-active{color:var(--accent-dark);font-weight:600;}
.drawer-langs{margin-top:2px;}

.btn-login{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  height:34px;
  padding:0 17px;
  border-radius:var(--r-pill);
  background:var(--text);
  color:var(--white);
  font-size:13px;
  font-weight:600;
  text-decoration:none;
  white-space:nowrap;
  box-shadow:var(--shadow-ink);
  transition:transform var(--dur-fast) var(--ease),box-shadow var(--dur-fast) var(--ease),background-color var(--dur-fast) var(--ease);
}

.btn-login:hover{background:var(--ink-2);transform:translateY(-1px);box-shadow:var(--shadow-ink-hover);}

/* mobile toggle */
.nav-toggle{
  display:none;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap:5px;
  min-width:44px;
  min-height:44px;
  padding:0;
  border:1px solid var(--border);
  border-radius:var(--r-pill);
  background:var(--bg-panel);
  color:var(--text);
  cursor:pointer;
  box-shadow:var(--shadow-xs);
}

.nav-toggle span{
  display:block;
  width:16px;
  height:2px;
  border-radius:2px;
  background:currentColor;
  transition:transform .2s var(--ease);
}

html.nav-open .nav-toggle span:nth-child(1){transform:translateY(3.5px) rotate(45deg);}
html.nav-open .nav-toggle span:nth-child(2){transform:translateY(-3.5px) rotate(-45deg);}

/* drawer + veil (opaque panel, full-row links) */
.drawer-veil{
  display:none;
  position:fixed;
  inset:var(--header-h) 0 0;
  z-index:55;
  background:var(--veil);
}

html.nav-open .drawer-veil{display:block;}

.nav-drawer,
.drawer{
  display:none;
  position:fixed;
  left:0;
  right:0;
  top:var(--header-h);
  bottom:0;
  z-index:60;
  max-height:calc(100dvh - var(--header-h));
  overflow-y:auto;
  overscroll-behavior:contain;
  padding:14px var(--gutter) 32px;
  background:var(--bg-panel);
  border-top:1px solid var(--border);
}

html.nav-open .nav-drawer,
html.nav-open .drawer{display:block;}

.nav-drawer ul,
.drawer ul{display:grid;gap:2px;margin:0;padding:0;list-style:none;}

.nav-drawer a,
.drawer a{
  display:flex;
  width:100%;
  align-items:center;
  min-height:48px;
  padding:10px 12px;
  border-radius:var(--r-sm);
  font-size:15px;
  font-weight:500;
  color:var(--text);
  text-decoration:none;
}

.nav-drawer a:hover,
.nav-drawer a:focus-visible,
.drawer a:hover,
.drawer a:focus-visible{background:var(--bg-panel-2);}
.nav-drawer a.is-active,
.drawer a.is-active{color:var(--accent-dark);font-weight:600;}

.nav-drawer .drawer-group,
.drawer .drawer-group{
  margin-top:14px;
  padding-top:12px;
  border-top:1px solid var(--border);
}

.nav-drawer .drawer-label,
.drawer .drawer-label,
.drawer .drawer-title{
  display:block;
  padding:6px 12px 4px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  color:var(--text-soft);
}

.drawer .drawer-title{margin:14px 0 0;}

/* ==========================================================================
   Footer (injected by footer.js)
   ========================================================================== */

.site-foot{
  position:relative;
  margin-top:var(--sp-8);
  padding-block:var(--sp-7) var(--sp-5);
  background:var(--bg-panel);
  border-top:1px solid var(--border);
}

.site-foot::before{
  content:"";
  position:absolute;
  left:0;right:0;top:-1px;
  height:1px;
  background:linear-gradient(90deg,transparent,var(--accent-line),transparent);
  pointer-events:none;
}

.foot-grid{
  display:grid;
  grid-template-columns:minmax(0,1.5fr) minmax(0,.8fr) minmax(0,.8fr) minmax(0,1.1fr);
  gap:var(--sp-6);
}

.foot-brand{
  display:inline-flex;
  align-items:center;
  gap:9px;
  text-decoration:none;
  color:var(--text);
}

.foot-tagline{
  margin-top:12px;
  max-width:36ch;
  font-size:13.5px;
  line-height:1.65;
  color:var(--text-muted);
}

.foot-title{
  display:flex;
  align-items:center;
  gap:7px;
  margin:0 0 10px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:600;
  letter-spacing:.1em;
  color:var(--text-soft);
}

.foot-title::before{
  content:"";
  width:5px;height:5px;border-radius:50%;
  background:var(--accent);
  flex:none;
}

.foot-links{display:grid;gap:2px;margin:0;padding:0;list-style:none;}

.foot-links a{
  display:inline-flex;
  align-items:center;
  min-height:32px;
  font-size:13.5px;
  color:var(--text-muted);
  text-decoration:none;
  transition:color var(--dur-fast) var(--ease);
}

.foot-links a:hover{color:var(--accent-dark);}

.foot-hot{display:flex;flex-wrap:wrap;gap:8px;margin:0;padding:0;list-style:none;}

.foot-hot a{
  display:inline-flex;
  align-items:center;
  max-width:100%;
  min-height:26px;
  padding:0 10px;
  border-radius:var(--r-pill);
  border:1px solid var(--border);
  background:var(--bg-panel-2);
  font-size:11.5px;
  color:var(--text-muted);
  text-decoration:none;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
  transition:color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}

.foot-hot a:hover{color:var(--accent-dark);border-color:var(--accent-line);}

.foot-langs{display:flex;flex-wrap:wrap;gap:6px 14px;margin:12px 0 0;padding:0;list-style:none;}

.foot-langs a{
  display:inline-flex;
  align-items:center;
  min-height:26px;
  font-size:12.5px;
  color:var(--text-muted);
  text-decoration:none;
}

.foot-langs a[aria-current="true"]{color:var(--text);font-weight:600;}
.foot-langs a:hover{color:var(--accent-dark);}

.foot-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:10px 20px;
  margin-top:var(--sp-6);
  padding-top:var(--sp-4);
  border-top:1px solid var(--border);
  font-size:12px;
  color:var(--text-soft);
}

.foot-legal{display:flex;flex-wrap:wrap;gap:6px 18px;margin:0;padding:0;list-style:none;}

.foot-legal a{
  display:inline-flex;
  align-items:center;
  min-height:24px;
  color:var(--text-muted);
  text-decoration:none;
}

.foot-legal a:hover{color:var(--accent-dark);}

/* ==========================================================================
   Reveal (visibility owned by reveal.js — default is visible)
   ========================================================================== */

.reveal{transition:opacity .5s var(--ease),transform .5s var(--ease);}

.reveal.pending{
  opacity:0;
  transform:translateY(16px);
}

/* ==========================================================================
   Utilities & narrow-screen guards
   ========================================================================== */

.sr-only{
  position:absolute;
  width:1px;height:1px;
  margin:-1px;padding:0;
  overflow:hidden;
  clip:rect(0 0 0 0);
  white-space:nowrap;
  border:0;
}

.skip-link{
  position:absolute;
  left:var(--sp-4);
  top:-60px;
  z-index:200;
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:0 16px;
  border-radius:var(--r-pill);
  background:var(--text);
  color:var(--white);
  font-size:13px;
  font-weight:600;
  text-decoration:none;
  transition:top var(--dur-fast) var(--ease);
}

.skip-link:focus-visible{top:10px;}

/* inline code / long tokens must never break the 375px layout */
code,kbd,samp{
  font-family:var(--font-mono);
  font-size:.92em;
  overflow-wrap:anywhere;
  word-break:break-word;
}

pre{
  max-width:100%;
  overflow-x:auto;
  -webkit-overflow-scrolling:touch;
  padding:var(--sp-4);
  border:1px solid var(--border);
  border-radius:var(--r-md);
  background:var(--bg-panel-2);
  font-family:var(--font-mono);
  font-size:12.5px;
  line-height:1.6;
}

pre code{overflow-wrap:normal;word-break:normal;white-space:pre;}

/* decorative tilt is cancelled on narrow screens */
.tilt{transform:rotate(-.45deg);}

/* line-status mount: in-flow, clipped, normal spacing to the next sibling */
#server-status{
  position:relative;
  display:block;
  max-width:100%;
  overflow:hidden;
  margin-block:var(--sp-6);
}

#server-status > *{max-width:100%;}
#server-status + *{margin-top:var(--sp-6);}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width:1180px){
  h1{letter-spacing:-.03em;}
}

@media (max-width:980px){
  .main-nav{display:none;}
  .nav-toggle{display:inline-flex;}
  .head-actions{margin-left:auto;}
  .foot-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--sp-5);}
  .lede{font-size:16px;}
}

@media (max-width:768px){
  h1{font-size:clamp(28px,8vw,40px);letter-spacing:-.02em;}
  h2{font-size:clamp(22px,5.4vw,28px);}
  h3{font-size:17.5px;}
}

@media (max-width:640px){
  :root{--gutter:18px;}

  .no-break{white-space:normal;}
  .tilt{transform:none;}

  .brand-zh{display:none;}
  .lang-switch{display:none;}
  .head-inner{gap:12px;}
  .head-actions{gap:10px;}

  .btn{height:44px;font-size:14px;padding:0 20px;}
  .btn-sm{height:38px;padding:0 16px;font-size:13px;}

  .foot-grid{grid-template-columns:minmax(0,1fr);gap:var(--sp-5);}
  .foot-bottom{flex-direction:column;align-items:flex-start;}
  .site-foot{padding-block:var(--sp-6) var(--sp-5);}
}

@media (max-width:400px){
  .brand-word{font-size:15px;}
  .btn{padding:0 16px;}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *{transition:none !important;animation:none !important;}
  .reveal,
  .reveal.pending{opacity:1;transform:none;}
}

/* lh:local-harden:start */
:is(h1,h2,h3,h4){text-wrap:balance}
:is(p,li,dd,dt,figcaption,blockquote,td,th){text-wrap:pretty}
html[lang|="ko"] body{word-break:keep-all;overflow-wrap:break-word}
html[lang|="ja"] :is(h1,h2,h3,h4){word-break:auto-phrase}
.lh-tscroll{overflow-x:auto;max-width:100%;-webkit-overflow-scrolling:touch}
@media (max-width:640px){.lh-tscroll :is(th,td){min-width:5.5em}}
@supports (animation-timeline:scroll()){
  .float-cta{animation:lh-fab-in linear both;animation-timeline:scroll(root);animation-range:0 70vh}
}
@keyframes lh-fab-in{0%,45%{opacity:0;visibility:hidden}100%{opacity:1;visibility:visible}}
/* lh:local-harden:end */