/* =========================================================================
   VPNSort · base.css
   Design tokens, reset, typography, buttons, header, footer, primitives.
   Every colour literal lives in :root — components only read tokens.
   ========================================================================= */

:root{
  /* ---------- palette ---------- */
  --bg:#FAF2E4;
  --bg-panel:#FFFCF4;
  --bg-panel2:#F1E4CC;
  --border:#E2D2B4;
  --accent:#1B4B8F;
  --accent-dark:#123561;
  --accent-soft:#2F63AE;
  --text:#2B2118;
  --text-muted:#6F5D49;
  --success:#1F7A4D;
  --warn:#A9690A;
  --error:#B3261E;
  --on-accent:#FFFFFF;

  /* ---------- warm sand scale ---------- */
  --sand-0:#FDF1DF;
  --sand-1:#F8DFC0;
  --sand-mid:#FBE9D3;
  --sand-2:#FBF2E2;
  --sand-3:#E9C79B;
  --sand-4:#EFD3AC;

  /* ---------- flag fills ---------- */
  --flag-red:#D7263D;
  --flag-red-deep:#C8102E;
  --flag-blue:#1B3A8F;
  --flag-navy:#0B2C6B;
  --flag-white:#FFFFFF;
  --flag-green:#1F7A4D;
  --flag-yellow:#EFC02F;
  --flag-gold:#DFAF26;
  --flag-black:#2B2118;

  /* ---------- accent alpha helpers ---------- */
  --accent-a00:rgba(27,75,143,0);
  --accent-a06:rgba(27,75,143,.06);
  --accent-a08:rgba(27,75,143,.08);
  --accent-a09:rgba(27,75,143,.09);
  --accent-a10:rgba(27,75,143,.10);
  --accent-a14:rgba(27,75,143,.14);
  --accent-a26:rgba(27,75,143,.26);
  --accent-a30:rgba(27,75,143,.30);
  --accent-a42:rgba(27,75,143,.42);
  --accent-a45:rgba(27,75,143,.45);
  --accent-a55:rgba(27,75,143,.55);
  --accent-a75:rgba(27,75,143,.75);
  --accent-a78:rgba(27,75,143,.78);
  --accent-a85:rgba(27,75,143,.85);
  --accent-a86:rgba(27,75,143,.86);
  --accent-a90:rgba(27,75,143,.90);

  /* ---------- ink / paper alpha helpers ---------- */
  --ink-a05:rgba(43,33,24,.05);
  --ink-a06:rgba(43,33,24,.06);
  --ink-a10:rgba(43,33,24,.10);
  --ink-a12:rgba(43,33,24,.12);
  --ink-a14:rgba(43,33,24,.14);
  --muted-a46:rgba(111,93,73,.46);
  --dot-ink:rgba(111,93,73,.062);
  --dot-ink-clear:rgba(111,93,73,0);
  --dot-strong:rgba(43,33,24,.09);
  --dot-strong-clear:rgba(43,33,24,0);

  --white-a00:rgba(255,255,255,0);
  --white-a24:rgba(255,255,255,.24);
  --white-a32:rgba(255,255,255,.32);
  --white-a36:rgba(255,255,255,.36);
  --white-a55:rgba(255,255,255,.55);
  --white-a60:rgba(255,255,255,.60);
  --white-a72:rgba(255,255,255,.72);
  --white-a78:rgba(255,255,255,.78);
  --white-a90:rgba(255,255,255,.90);
  --white-a92:rgba(255,255,255,.92);
  --white-a96:rgba(255,255,255,.96);
  --white-a98:rgba(255,255,255,.98);

  --panel-a55:rgba(255,252,244,.55);
  --panel-a60:rgba(255,252,244,.60);
  --panel-a70:rgba(255,252,244,.70);

  --warm-a62:rgba(248,223,192,.62);
  --warm-a00:rgba(248,223,192,0);
  --sand-shadow:rgba(150,105,52,.28);

  --success-a14:rgba(31,122,77,.14);
  --success-a16:rgba(31,122,77,.16);

  --panel-border:rgba(226,210,180,.92);
  --panel-border-soft:rgba(226,210,180,.94);
  --panel-border-90:rgba(226,210,180,.90);
  --border-soft:rgba(226,210,180,.62);

  --veil-ink:rgba(43,33,24,.46);
  --mask-on:#000000;

  /* ---------- fonts ---------- */
  --font-display:"Inter","Noto Sans SC","Noto Sans JP","Noto Sans KR",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-body:"Inter","Noto Sans SC","Noto Sans JP","Noto Sans KR",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","Noto Sans SC",ui-monospace,SFMono-Regular,Menlo,monospace;

  /* ---------- radii ---------- */
  --r-panel:28px;
  --r-card:20px;
  --r-node:9px;
  --r-sm:10px;
  --r-xs:6px;
  --r-pill:999px;

  /* ---------- shadows ---------- */
  --shadow-panel:inset 0 1px 0 var(--white-a92), 0 34px 90px -46px var(--accent-a42);
  --shadow-card:inset 0 1px 0 var(--white-a90), 0 18px 40px -26px var(--accent-a42), 0 1px 2px var(--ink-a05);
  --shadow-soft:inset 0 1px 0 var(--white-a90), 0 14px 30px -16px var(--accent-a42), 0 1px 2px var(--ink-a05);
  --shadow-chip:inset 0 1px 0 var(--white-a90), 0 10px 22px -12px var(--accent-a45), 0 1px 2px var(--ink-a06);

  /* ---------- spacing ---------- */
  --space-1:4px;
  --space-2:8px;
  --space-3:12px;
  --space-4:16px;
  --space-5:24px;
  --space-6:32px;
  --space-7:48px;
  --space-8:64px;
  --space-9:96px;

  /* ---------- layout ---------- */
  --wrap-max:1180px;
  --wrap-wide:1392px;
  --header-max:1440px;
  --gutter:24px;
  --header-h:64px;
  --toc-offset:104px;
  --reading-max:72ch;

  /* ---------- type scale ---------- */
  --fs-hero:clamp(38px,4.55vw,66px);
  --fs-h1:clamp(34px,4.6vw,66px);
  --fs-h2:clamp(26px,3vw,40px);
  --fs-h3:clamp(18px,1.7vw,22px);
  --fs-body:16px;
  --fs-sm:13.5px;
  --fs-xs:12.5px;
}

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

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

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

body{
  margin:0;
  background-color:var(--bg);
  background-image:
    radial-gradient(ellipse 980px 560px at 50% -10%, var(--warm-a62), var(--warm-a00) 72%),
    radial-gradient(circle, var(--dot-ink) 1px, var(--dot-ink-clear) 1.15px);
  background-size:auto, 13px 13px;
  background-repeat:no-repeat, repeat;
  color:var(--text);
  font-family:var(--font-body);
  font-size:var(--fs-body);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:clip;
}

img,svg{max-width:100%}
img{height:auto}
svg{display:block}

a{color:inherit}

button{font:inherit;color:inherit}

::selection{background:var(--accent-a14);color:var(--text)}

hr{
  border:0;
  border-top:1px solid var(--border);
  margin:var(--space-6) 0;
}

/* =========================================================================
   Focus / skip link
   ========================================================================= */

:where(a,button,summary,input,select,textarea,[tabindex]):focus-visible{
  outline:2px solid var(--accent);
  outline-offset:2px;
  border-radius:var(--r-xs);
}

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

.skip-link{
  position:absolute;
  left:var(--space-4);
  top:-60px;
  z-index:200;
  display:inline-flex;
  align-items:center;
  height:40px;
  padding:0 16px;
  border-radius:var(--r-pill);
  background:var(--accent);
  color:var(--on-accent);
  font-size:13.5px;
  font-weight:600;
  text-decoration:none;
  transition:top .18s ease;
}
.skip-link:focus-visible{top:var(--space-3)}

/* =========================================================================
   Layout helpers
   ========================================================================= */

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

.wrap--wide{max-width:var(--wrap-wide)}

.section{
  padding-top:var(--space-8);
  padding-bottom:var(--space-8);
}
.section--tight{
  padding-top:var(--space-6);
  padding-bottom:var(--space-6);
}
.section--flush-top{padding-top:0}

.stack{display:grid;gap:var(--space-4)}
.stack--lg{gap:var(--space-6)}

.grid-2,.grid-3,.grid-4{display:grid;gap:var(--space-5)}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-4{grid-template-columns:repeat(4,minmax(0,1fr))}
.grid-2 > *,.grid-3 > *,.grid-4 > *{min-width:0}

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

h1,h2,h3,h4{
  font-family:var(--font-display);
  color:var(--text);
  margin:0;
  text-wrap:balance;
}

h1{
  font-size:var(--fs-h1);
  font-weight:800;
  line-height:1.06;
  letter-spacing:-.03em;
}

h2{
  font-size:var(--fs-h2);
  font-weight:800;
  line-height:1.15;
  letter-spacing:-.025em;
}

h3{
  font-size:var(--fs-h3);
  font-weight:700;
  line-height:1.3;
  letter-spacing:-.015em;
}

h4{
  font-size:15.5px;
  font-weight:700;
  line-height:1.35;
  letter-spacing:-.01em;
}

p{margin:0 0 var(--space-4)}
p:last-child{margin-bottom:0}

strong,b{font-weight:700}

.hl{
  position:relative;
  display:inline-block;
  font-style:normal;
  color:var(--accent);
}
.hl::after{
  content:"";
  position:absolute;
  left:2px;right:2px;
  bottom:.045em;
  height:.055em;
  border-radius:.03em;
  background:var(--accent);
  opacity:.3;
}

.no-break{white-space:nowrap}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:8px;
  margin:0 0 var(--space-3);
  font-family:var(--font-mono);
  font-size:11.5px;
  font-weight:500;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--accent);
}
.eyebrow::before{
  content:"";
  width:18px;
  height:1px;
  background:var(--accent-a45);
  flex:0 0 auto;
}

.section-head{
  display:grid;
  gap:var(--space-3);
  max-width:760px;
  margin-bottom:var(--space-6);
}
.section-head--center{
  margin-inline:auto;
  text-align:center;
  justify-items:center;
}
.section-title{font-size:var(--fs-h2);font-weight:800;line-height:1.15;letter-spacing:-.025em}
.section-sub{
  font-size:15px;
  line-height:1.7;
  color:var(--text-muted);
  max-width:64ch;
}

.lede{
  font-size:17px;
  line-height:1.68;
  color:var(--text-muted);
  max-width:68ch;
}

.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.02em;
}

.text-muted{color:var(--text-muted)}
.text-accent{color:var(--accent)}

/* ---------- long-form prose ---------- */

.prose{
  max-width:var(--reading-max);
  font-size:15.5px;
  line-height:1.78;
  color:var(--text);
}
.prose > *{min-width:0}
.prose h2{
  margin-top:var(--space-7);
  margin-bottom:var(--space-3);
  font-size:clamp(23px,2.4vw,30px);
}
.prose h3{
  margin-top:var(--space-6);
  margin-bottom:var(--space-2);
  font-size:18.5px;
}
.prose h4{
  margin-top:var(--space-5);
  margin-bottom:var(--space-2);
}
.prose p{margin:0 0 var(--space-4)}
.prose ul,.prose ol{margin:0 0 var(--space-4);padding-left:22px}
.prose li{margin-bottom:8px}
.prose li::marker{color:var(--accent-a55)}
.prose a{color:var(--accent);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
.prose a:hover{text-decoration-thickness:2px}
.prose blockquote{
  margin:var(--space-5) 0;
  padding:14px 18px;
  border-left:3px solid var(--accent);
  background:var(--bg-panel2);
  border-radius:0 var(--r-sm) var(--r-sm) 0;
  color:var(--text-muted);
}
.prose img{border-radius:var(--r-sm);box-shadow:var(--shadow-soft)}

code{
  font-family:var(--font-mono);
  font-size:.92em;
  padding:1px 5px;
  border-radius:var(--r-xs);
  background:var(--bg-panel2);
  color:var(--accent-dark);
  overflow-wrap:anywhere;
  word-break:break-word;
}

pre{
  margin:0 0 var(--space-4);
  padding:var(--space-4);
  border-radius:var(--r-sm);
  background:var(--bg-panel2);
  border:1px solid var(--border);
  overflow-x:auto;
  -webkit-overflow-scrolling:touch;
  max-width:100%;
}
pre code{
  display:block;
  padding:0;
  background:transparent;
  color:var(--text);
  font-size:12.8px;
  line-height:1.7;
  white-space:pre;
  overflow-wrap:normal;
}

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

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  height:50px;
  padding:0 30px;
  border:1px solid transparent;
  border-radius:var(--r-pill);
  font-family:var(--font-display);
  font-size:15.5px;
  font-weight:700;
  letter-spacing:.01em;
  text-decoration:none;
  white-space:nowrap;
  cursor:pointer;
  transition:transform .18s ease, box-shadow .18s ease, background-color .18s ease, border-color .18s ease, color .18s ease;
}

.btn-primary{
  color:var(--on-accent);
  background:linear-gradient(180deg,var(--accent-soft) 0%,var(--accent) 52%,var(--accent-dark) 100%);
  box-shadow:inset 0 1px 0 var(--white-a32), 0 14px 26px -12px var(--accent-a78);
}
.btn-primary:hover{
  transform:translateY(-1px);
  box-shadow:inset 0 1px 0 var(--white-a36), 0 20px 34px -14px var(--accent-a86);
}

.btn-ghost{
  color:var(--text);
  background:var(--bg-panel);
  border-color:var(--border);
  box-shadow:inset 0 1px 0 var(--flag-white), 0 8px 18px -12px var(--ink-a14);
}
.btn-ghost:hover{
  transform:translateY(-1px);
  border-color:var(--accent);
  color:var(--accent);
}

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

.btn-block{width:100%}

.btn[disabled],
.btn[aria-disabled="true"]{
  opacity:.55;
  cursor:not-allowed;
  transform:none;
}

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

.chip,
.fact-pill{
  display:inline-flex;
  align-items:center;
  gap:6px;
  min-height:26px;
  max-width:100%;
  padding:0 10px;
  border-radius:var(--r-pill);
  background:var(--bg-panel);
  border:1px solid var(--border);
  box-shadow:inset 0 1px 0 var(--white-a90);
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.04em;
  color:var(--text-muted);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}
.fact-pill b{color:var(--accent);font-weight:700}

.badge{
  display:inline-flex;
  align-items:center;
  gap:5px;
  min-height:22px;
  max-width:100%;
  padding:0 9px;
  border-radius:var(--r-pill);
  background:var(--accent);
  color:var(--on-accent);
  font-family:var(--font-mono);
  font-size:10.5px;
  font-weight:500;
  letter-spacing:.06em;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}
.badge--soft{
  background:var(--accent-a10);
  color:var(--accent);
}

.status-dot{
  width:6px;
  height:6px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--success);
  box-shadow:0 0 0 3px var(--success-a14);
}
.status-dot--warn{background:var(--warn);box-shadow:0 0 0 3px var(--accent-a10)}

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

.panel{
  position:relative;
  min-width:0;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-panel);
  box-shadow:var(--shadow-panel);
  padding:var(--space-6);
}

.card{
  position:relative;
  min-width:0;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--r-card);
  box-shadow:var(--shadow-card);
  padding:var(--space-5);
}

.card--flat{box-shadow:var(--shadow-soft)}

.card-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(240px,1fr));
  gap:var(--space-5);
}
.card-grid > *{min-width:0}

/* =========================================================================
   Header
   ========================================================================= */

#site-header,
.site-header{
  position:relative;
  z-index:80;
  height:var(--header-h);
  display:flex;
  align-items:center;
}

.header-inner{
  position:relative;
  z-index:70;
  width:100%;
  max-width:var(--header-max);
  margin-inline:auto;
  padding-inline:40px;
  display:flex;
  align-items:center;
  gap:34px;
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:9px;
  flex:0 0 auto;
  text-decoration:none;
  color:var(--text);
}

.brand-logo{
  display:block;
  width:30px;
  height:30px;
  flex:0 0 auto;
}

.brand-en{
  font-family:var(--font-display);
  font-weight:800;
  font-size:17px;
  letter-spacing:-.02em;
  line-height:1;
}

.brand-zh{
  font-size:12.5px;
  font-weight:500;
  letter-spacing:.05em;
  color:var(--text-muted);
  line-height:1;
  padding-left:1px;
}

.main-nav{
  display:flex;
  align-items:center;
  margin-left:auto;
}

.nav-list{
  display:flex;
  align-items:center;
  gap:26px;
  margin:0;
  padding:0;
  list-style:none;
}
.nav-list > li{
  display:flex;
  align-items:center;
  margin:0;
  padding:0;
}

.nav-list a,
.main-nav > a{
  position:relative;
  display:inline-flex;
  align-items:center;
  padding:5px 0;
  font-size:14px;
  font-weight:500;
  color:var(--text);
  text-decoration:none;
  letter-spacing:.005em;
  transition:color .16s ease;
}
.nav-list a:hover,
.main-nav > a:hover{color:var(--accent)}

.nav-list a.is-active,
.main-nav > a.is-active{
  font-weight:700;
  color:var(--accent);
}
.nav-list a.is-active::after,
.main-nav > a.is-active::after{
  content:"";
  position:absolute;
  left:0;right:0;
  bottom:-1px;
  height:2px;
  border-radius:2px;
  background:var(--accent);
}

.header-tools{
  display:flex;
  align-items:center;
  gap:12px;
  margin-left:28px;
  flex:0 0 auto;
}

.lang-wrap{position:relative;display:inline-flex}

.lang-switch{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:5px;
  height:32px;
  padding:0 12px;
  border-radius:var(--r-pill);
  border:1px solid var(--border);
  background:var(--panel-a60);
  color:var(--text-muted);
  font-family:var(--font-body);
  font-size:12.5px;
  font-weight:500;
  cursor:pointer;
  transition:border-color .16s ease, color .16s ease;
}
.lang-switch:hover{border-color:var(--accent);color:var(--accent)}
.lang-switch .caret{font-size:9px;line-height:1;transform:translateY(-.5px)}

.lang-menu{
  position:absolute;
  top:calc(100% + 8px);
  right:0;
  z-index:90;
  display:none;
  min-width:158px;
  padding:6px;
  border-radius:var(--r-sm);
  background:var(--bg-panel);
  border:1px solid var(--border);
  box-shadow:var(--shadow-soft);
}
.lang-menu.is-open{display:block}
.lang-menu a{
  display:flex;
  align-items:center;
  width:100%;
  min-height:36px;
  padding:0 10px;
  border-radius:var(--r-xs);
  font-size:13px;
  color:var(--text);
  text-decoration:none;
}
.lang-menu a:hover{background:var(--accent-a08);color:var(--accent)}
.lang-menu a[aria-current="true"]{color:var(--accent);font-weight:700}

.login-btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:34px;
  padding:0 17px;
  border-radius:var(--r-pill);
  border:1px solid var(--accent);
  background:var(--panel-a70);
  color:var(--accent);
  font-size:13.5px;
  font-weight:600;
  letter-spacing:.01em;
  text-decoration:none;
  transition:background-color .16s ease, color .16s ease, box-shadow .16s ease;
}
.login-btn:hover{
  background:var(--accent);
  color:var(--on-accent);
  box-shadow:0 12px 22px -14px var(--accent-a90);
}

.nav-toggle{
  display:none;
  align-items:center;
  justify-content:center;
  width:44px;
  height:44px;
  padding:0;
  border-radius:var(--r-pill);
  border:1px solid var(--border);
  background:var(--panel-a70);
  cursor:pointer;
  flex:0 0 auto;
}
.nav-toggle-bars{
  display:block;
  width:18px;
  height:2px;
  border-radius:2px;
  background:var(--text);
  box-shadow:0 -6px 0 var(--text), 0 6px 0 var(--text);
  transition:background-color .16s ease;
}
html.nav-open .nav-toggle{border-color:var(--accent)}
html.nav-open .nav-toggle-bars{background:var(--accent);box-shadow:0 -6px 0 var(--accent), 0 6px 0 var(--accent)}

.mobile-nav{
  display:none;
  position:fixed;
  left:0;right:0;
  top:var(--header-h);
  z-index:60;
  padding:8px var(--gutter) 18px;
  background:var(--bg-panel);
  border-bottom:1px solid var(--border);
  box-shadow:0 26px 46px -30px var(--accent-a55);
  max-height:calc(100dvh - var(--header-h));
  overflow-y:auto;
  overscroll-behavior:contain;
  -webkit-overflow-scrolling:touch;
}
html.nav-open .mobile-nav{display:block}

.mobile-nav ul{
  list-style:none;
  margin:0;
  padding:0;
}
.mobile-nav li{margin:0;padding:0}
.mobile-nav a{
  display:flex;
  align-items:center;
  width:100%;
  min-height:48px;
  padding:0 6px;
  font-size:15px;
  font-weight:500;
  color:var(--text);
  text-decoration:none;
  border-bottom:1px solid var(--border-soft);
}
.mobile-nav a.is-active{color:var(--accent);font-weight:700}
.mobile-nav .mobile-nav-title{
  margin:14px 0 4px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.12em;
  text-transform:uppercase;
  color:var(--text-muted);
}

.nav-veil{
  display:none;
  position:fixed;
  inset:0;
  z-index:40;
  background:var(--veil-ink);
}
html.nav-open .nav-veil{display:block}
html.nav-open{overflow:hidden}

/* =========================================================================
   Footer
   ========================================================================= */

#site-footer,
.site-footer{
  position:relative;
  margin-top:var(--space-8);
  background-color:var(--bg-panel2);
  background-image:radial-gradient(circle, var(--ink-a06) 1px, var(--dot-ink-clear) 1.1px);
  background-size:14px 14px;
  border-top:1px solid var(--border);
  color:var(--text);
}

.footer-inner{
  width:100%;
  max-width:var(--wrap-max);
  margin-inline:auto;
  padding:var(--space-7) var(--gutter) var(--space-5);
}

.footer-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr 1.4fr;
  gap:var(--space-6) var(--space-6);
}
.footer-grid > *{min-width:0}

.footer-brand{display:grid;gap:var(--space-3);align-content:start}

.footer-logo{
  display:inline-flex;
  align-items:center;
  gap:9px;
  text-decoration:none;
  color:var(--text);
  font-family:var(--font-display);
  font-weight:800;
  font-size:17px;
  letter-spacing:-.02em;
}
.footer-logo img{
  display:block;
  width:30px;
  height:30px;
  flex:0 0 auto;
}

.footer-tagline{
  margin:0;
  max-width:34ch;
  font-size:13px;
  line-height:1.7;
  color:var(--text-muted);
}

.footer-fact{
  display:inline-flex;
  align-items:center;
  gap:7px;
  margin:0;
  min-height:26px;
  padding:0 10px;
  border-radius:var(--r-pill);
  background:var(--bg-panel);
  border:1px solid var(--border);
  font-family:var(--font-mono);
  font-size:10.5px;
  letter-spacing:.03em;
  color:var(--text-muted);
  width:fit-content;
  max-width:100%;
}

.footer-col{display:grid;gap:var(--space-3);align-content:start}

.footer-title{
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--accent);
}

.footer-links{
  list-style:none;
  margin:0;
  padding:0;
  display:grid;
  gap:9px;
}
.footer-links a{
  display:inline-flex;
  align-items:center;
  min-height:24px;
  font-size:13.5px;
  color:var(--text);
  text-decoration:none;
  transition:color .16s ease;
}
.footer-links a:hover{color:var(--accent)}

.footer-keywords{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-wrap:wrap;
  gap:7px;
}
.footer-keywords a{
  display:inline-flex;
  align-items:center;
  min-height:26px;
  padding:0 10px;
  border-radius:var(--r-pill);
  background:var(--bg-panel);
  border:1px solid var(--border);
  font-size:11.5px;
  color:var(--text-muted);
  text-decoration:none;
  transition:border-color .16s ease, color .16s ease;
}
.footer-keywords a:hover{border-color:var(--accent);color:var(--accent)}

.footer-lang{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  margin-top:var(--space-6);
  padding-top:var(--space-4);
  border-top:1px solid var(--border-soft);
}
.footer-lang a{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:32px;
  padding:0 13px;
  border-radius:var(--r-pill);
  background:var(--bg-panel);
  border:1px solid var(--border);
  font-size:12.5px;
  color:var(--text-muted);
  text-decoration:none;
  transition:border-color .16s ease, color .16s ease;
}
.footer-lang a:hover{border-color:var(--accent);color:var(--accent)}
.footer-lang a[aria-current="true"]{border-color:var(--accent);color:var(--accent);font-weight:700}

.footer-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:var(--space-3);
  margin-top:var(--space-4);
  padding-top:var(--space-4);
  border-top:1px solid var(--border-soft);
}

.footer-copy{
  margin:0;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.04em;
  color:var(--text-muted);
}

.footer-legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:14px;
  list-style:none;
  margin:0;
  padding:0;
}
.footer-legal a{
  display:inline-flex;
  align-items:center;
  min-height:24px;
  font-size:12px;
  color:var(--text-muted);
  text-decoration:none;
}
.footer-legal a:hover{color:var(--accent)}

/* =========================================================================
   Reveal (visibility owned by reveal.js — never hide in CSS)
   ========================================================================= */

.reveal{transition:opacity .5s ease, transform .5s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}

/* =========================================================================
   Utilities
   ========================================================================= */

.tilt{transform:rotate(-.45deg)}

.flow-hidden{overflow-x:clip}

.anchor-offset{scroll-margin-top:calc(var(--header-h) + 20px)}

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

@media (max-width:1440px){
  .header-inner{padding-inline:28px}
}

@media (max-width:1200px){
  .header-inner{gap:26px}
  .nav-list{gap:18px}
  .nav-list a,.main-nav > a{font-size:13.5px}
  .header-tools{margin-left:18px}
}

@media (max-width:1024px){
  #site-header,
  .site-header{
    position:sticky;
    top:0;
    background-color:var(--bg);
    background-image:radial-gradient(ellipse 980px 560px at 50% -10%, var(--warm-a62), var(--warm-a00) 72%);
    background-repeat:no-repeat;
  }
  .main-nav{display:none}
  .header-tools{margin-left:auto}
  .nav-toggle{display:inline-flex}
  .grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{grid-template-columns:1fr 1fr}
}

@media (max-width:900px){
  .grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}
}

@media (max-width:768px){
  h1{font-size:clamp(28px,7.4vw,40px)}
  .section{padding-top:var(--space-7);padding-bottom:var(--space-7)}
  .panel{padding:var(--space-5)}
  .grid-2{grid-template-columns:minmax(0,1fr)}
  .lede{font-size:15.5px}
}

@media (max-width:640px){
  :root{--gutter:16px}

  .no-break{white-space:normal}

  .header-inner{padding-inline:16px;gap:14px}
  .brand-zh{display:none}
  .lang-wrap{display:none}

  .grid-3,.grid-4{grid-template-columns:minmax(0,1fr)}

  .footer-grid{grid-template-columns:minmax(0,1fr);gap:var(--space-5)}
  .footer-inner{padding-top:var(--space-6)}
  .footer-bottom{flex-direction:column;align-items:flex-start}

  .tilt{transform:none}

  .btn{
    height:46px;
    padding:0 22px;
    font-size:14.5px;
  }
  .btn-sm{height:38px;padding:0 16px;font-size:13px}

  .card{padding:var(--space-4)}
  .panel{padding:var(--space-4)}
}

@media (max-width:380px){
  .header-inner{gap:10px}
  .login-btn{padding:0 13px;font-size:13px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !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 */