*,*::before,*::after{box-sizing:border-box}
body{margin:0}
.app{
  --background:#ffffff; --foreground:#09090b;
  --card:#ffffff; --card-foreground:#09090b;
  --primary:#f59e0b; --primary-foreground:#451a03;
  --secondary:#f4f4f5; --secondary-foreground:#18181b;
  --muted:#f4f4f5; --muted-foreground:#71717a;
  --accent:#f4f4f5; --accent-foreground:#18181b;
  --border:#e4e4e7; --input:#e4e4e7; --ring:#f59e0b;
  --brand:#b45309;
  --fill-bg:rgba(245,158,11,.10); --fill-bd:rgba(245,158,11,.45);
  --shadow-xs:0 1px 2px 0 rgb(0 0 0 / .05);
  --shadow-sm:0 1px 3px 0 rgb(0 0 0 / .1), 0 1px 2px -1px rgb(0 0 0 / .1);
  background:var(--background); color:var(--foreground);
  font-family:ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  font-size:16px; line-height:1.5; -webkit-font-smoothing:antialiased;
  font-feature-settings:"cv02","cv03","cv04";
}
html.dark .app{
  --background:#09090b; --foreground:#fafafa;
  --card:#09090b; --card-foreground:#fafafa;
  --primary:#fbbf24; --primary-foreground:#451a03;
  --secondary:#27272a; --secondary-foreground:#fafafa;
  --muted:#27272a; --muted-foreground:#a1a1aa;
  --accent:#27272a; --accent-foreground:#fafafa;
  --border:#27272a; --input:#27272a; --ring:#fbbf24;
  --brand:#fbbf24;
  --fill-bg:rgba(251,191,36,.12); --fill-bd:rgba(251,191,36,.40);
}
.app.zh{ font-family:ui-sans-serif,system-ui,-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif; }
.app.zh p,.app.zh li{ line-height:1.75; }
.app.zh h1,.app.zh h2{ letter-spacing:normal; }
body{background:#ffffff}
html.dark body{background:#09090b}

a{color:inherit;text-decoration:none}
a:hover{color:var(--brand)}
h1,h2,h3,h4,p,ul,ol{margin:0}
ul{padding:0;list-style:none}

.container{width:100%;max-width:1280px;margin:0 auto;padding:0 24px}
.section{padding:96px 0}
.section-lg{padding:128px 0}
.section-sm{padding:64px 0}
.section-muted{background:var(--muted)}
/* zinc's stock muted-foreground on muted is 4.40:1 in light mode — lift to zinc-600 (7.0:1) */
html:not(.dark) .app .section-muted{--muted-foreground:#52525b}
html:not(.dark) .app .tabs{--muted-foreground:#52525b}
.split,.split-a,.split-b{display:grid;gap:64px}
.split{grid-template-columns:1fr 1fr}
.split-a{grid-template-columns:1.25fr 1fr}
.split-b{grid-template-columns:1fr 1.15fr}
.footgrid{display:grid;grid-template-columns:1.4fr repeat(4,1fr);gap:40px}

/* type ramp — tailwind scale as used by the blocks */
.h1{font-size:60px;line-height:1.05;font-weight:700;letter-spacing:-.025em;text-wrap:balance}
.h2{font-size:36px;line-height:1.1;font-weight:600;letter-spacing:-.02em;text-wrap:balance}
.h3{font-size:20px;line-height:1.4;font-weight:600}
.h4{font-size:18px;line-height:1.4;font-weight:600}
.lead{font-size:20px;line-height:1.6;color:var(--muted-foreground);text-wrap:pretty}
.body{font-size:16px;line-height:1.65;color:var(--muted-foreground);text-wrap:pretty}
.sm{font-size:14px;line-height:1.6;color:var(--muted-foreground)}
.xs{font-size:12px;line-height:1.5;color:var(--muted-foreground)}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace}
.eyebrow{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--brand);font-weight:500}
.fg{color:var(--foreground)}
.mutedfg{color:var(--muted-foreground)}

/* placeholder token — every unverified fact on this canvas */
.fill{display:inline-block;font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;font-size:.88em;line-height:1.4;color:var(--brand);background:var(--fill-bg);border:1px dashed var(--fill-bd);border-radius:4px;padding:0 5px;white-space:nowrap;vertical-align:baseline}

/* button — h-9/px-4, lg h-10/px-6, rounded-md 6px, text-sm/500 */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;white-space:nowrap;border-radius:6px;font-size:14px;font-weight:500;height:36px;padding:0 16px;border:1px solid transparent;cursor:pointer;transition:all .15s ease;font-family:inherit}
.btn-lg{height:40px;padding:0 24px}
.btn-sm{height:32px;padding:0 12px;gap:6px}
.btn-primary{background:var(--primary);color:var(--primary-foreground)}
.btn-primary:hover{background:var(--primary);opacity:.9;color:var(--primary-foreground)}
.btn-outline{border-color:var(--border);background:var(--background);color:var(--foreground);box-shadow:var(--shadow-xs)}
.btn-outline:hover{background:var(--accent);color:var(--accent-foreground)}
.btn-ghost{background:transparent;color:var(--foreground)}
.btn-ghost:hover{background:var(--accent);color:var(--accent-foreground)}
.btn-block{width:100%}

/* card — rounded-xl 12px, 1px border, shadow-sm, p-6 */
.card{background:var(--card);color:var(--card-foreground);border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow-sm)}
.card-p{padding:24px}
.card-hi{border-color:var(--primary);box-shadow:var(--shadow-sm),0 0 0 1px var(--primary)}

/* badge — rounded-full px-2 py-0.5 text-xs/500 */
.badge{display:inline-flex;align-items:center;gap:4px;border-radius:9999px;border:1px solid var(--border);padding:2px 8px;font-size:12px;line-height:16px;font-weight:500;color:var(--foreground);white-space:nowrap}
.badge-primary{border-color:transparent;background:var(--primary);color:var(--primary-foreground)}
.badge-secondary{border-color:transparent;background:var(--secondary);color:var(--secondary-foreground)}

.sep{height:1px;width:100%;background:var(--border);border:0}
.rowline{border-bottom:1px solid var(--border)}

.grid{display:grid}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.g5{grid-template-columns:repeat(5,minmax(0,1fr))}
.g6{grid-template-columns:repeat(6,minmax(0,1fr))}
.flex{display:flex}
.col{flex-direction:column}
.mid{align-items:center}
.between{justify-content:space-between}

/* table — text-sm, rows border-b, head muted */
.tbl{width:100%;border-collapse:collapse;font-size:14px}
.tbl th{text-align:left;font-weight:500;color:var(--muted-foreground);padding:12px 16px;border-bottom:1px solid var(--border);white-space:nowrap}
.tbl td{padding:16px;border-bottom:1px solid var(--border);vertical-align:middle;color:var(--foreground)}
.tbl tr:last-child td{border-bottom:0}

/* tabs — h-9 bg-muted rounded-lg p-[3px]; trigger rounded-md */
.tabs{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:3px;border-radius:8px;background:var(--muted)}
.tab{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:30px;padding:0 14px;border-radius:6px;border:1px solid transparent;font-size:14px;font-weight:500;color:var(--muted-foreground);cursor:pointer;font-family:inherit;background:transparent;transition:all .15s ease;white-space:nowrap}
.tab-on{background:var(--background);color:var(--foreground);box-shadow:var(--shadow-sm)}
html.dark .app .tab-on{border-color:var(--input);background:var(--background)}

/* accordion-style faq item */
.faq-item{border-bottom:1px solid var(--border);padding:20px 0}
.faq-q{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;font-size:15px;font-weight:500}
.faq-a{padding-top:8px;font-size:14px;line-height:1.7;color:var(--muted-foreground);max-width:78ch}

.icon-tile{display:inline-flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:8px;background:var(--secondary);color:var(--foreground);flex:none}
.dot{width:6px;height:6px;border-radius:9999px;background:var(--primary);flex:none}

.navbar{position:relative;z-index:2;border-bottom:1px solid var(--border);background:var(--background)}
.navrow{display:flex;align-items:center;justify-content:space-between;height:64px}
.navlinks{display:flex;align-items:center;gap:28px;font-size:14px;font-weight:500}
.navlinks a{color:var(--muted-foreground)}
.navlinks a:hover{color:var(--foreground)}
.navlinks a.on{color:var(--foreground)}

.gridbg{position:absolute;inset:0;pointer-events:none;
  background-image:linear-gradient(to right,var(--border) 1px,transparent 1px),linear-gradient(to bottom,var(--border) 1px,transparent 1px);
  background-size:64px 64px;
  -webkit-mask-image:radial-gradient(ellipse 70% 60% at 50% 0%,#000 30%,transparent 78%);
  mask-image:radial-gradient(ellipse 70% 60% at 50% 0%,#000 30%,transparent 78%);
  opacity:.7}

.footer{border-top:1px solid var(--border);padding:64px 0 40px}
.footcol h5{font-size:13px;font-weight:600;margin-bottom:14px;letter-spacing:.01em}
.footcol a{display:block;font-size:14px;color:var(--muted-foreground);padding:5px 0}

/* ---- site chrome (MODE === 'site') ---- */
.skip{position:absolute;left:-9999px;top:0;z-index:50;background:var(--primary);color:var(--primary-foreground);padding:10px 16px;border-radius:0 0 6px 0;font-size:14px;font-weight:500}
.skip:focus{left:0;color:var(--primary-foreground)}
.navbar{position:sticky;top:0}
.iconbtn{display:inline-flex;align-items:center;justify-content:center;width:32px;height:32px;border-radius:6px;border:1px solid var(--border);background:var(--background);color:var(--foreground);cursor:pointer;padding:0}
.iconbtn:hover{background:var(--accent)}
.i-moon{display:none}
html.dark .app .i-sun{display:none}
html.dark .app .i-moon{display:inline-flex}
.langsw{font-variant-numeric:tabular-nums}
#navToggle{display:none}
.footph{display:block;padding:5px 0}
.footph .fill{font-size:13px}
:where(a,button,summary,.btn):focus-visible{outline:2px solid var(--ring);outline-offset:2px;border-radius:4px}
.faq-item{list-style:none}
.faq-item>summary{cursor:pointer;list-style:none}
.faq-item>summary::-webkit-details-marker{display:none}
.faq-item>summary svg{transition:transform .18s ease;flex:none;margin-top:3px}
.faq-item[open]>summary svg{transform:rotate(180deg)}
@media (prefers-reduced-motion:reduce){
  *{transition:none!important;animation:none!important}
  html{scroll-behavior:auto}
  html.js [data-reveal]{opacity:1!important;transform:none!important}
}

/* ---- motion ---- */
html{scroll-behavior:smooth}

.card{transition:border-color .25s ease,box-shadow .25s ease,transform .25s cubic-bezier(.2,.7,.2,1)}
.card:hover{transform:translateY(-2px);box-shadow:0 10px 26px -14px rgba(0,0,0,.30),0 2px 6px -2px rgba(0,0,0,.10)}
html.dark .app .card:hover{box-shadow:0 10px 30px -14px rgba(0,0,0,.75)}
.icon-tile{transition:transform .28s cubic-bezier(.2,.7,.2,1),background-color .22s ease}
.card:hover .icon-tile{transform:scale(1.07) rotate(-3deg)}

.btn{transition:background-color .18s ease,color .18s ease,border-color .18s ease,box-shadow .18s ease,opacity .18s ease,transform .14s ease}
.btn:hover{transform:translateY(-1px)}
.btn:active{transform:translateY(0) scale(.985)}
.btn svg{transition:transform .22s cubic-bezier(.2,.7,.2,1)}
.btn:hover svg:last-child{transform:translateX(3px)}

.navlinks a{position:relative;transition:color .18s ease}
.navlinks a::after{content:"";position:absolute;left:0;right:0;bottom:-7px;height:2px;border-radius:2px;background:var(--primary);transform:scaleX(0);transform-origin:left;transition:transform .24s cubic-bezier(.2,.7,.2,1)}
.navlinks a:hover::after,.navlinks a.on::after{transform:scaleX(1)}

.tbl tbody tr{transition:background-color .18s ease}
.tbl tbody tr:hover{background:var(--muted)}
.footcol a{transition:color .18s ease,transform .2s cubic-bezier(.2,.7,.2,1)}
.footcol a:hover{transform:translateX(3px)}
.fill{transition:background-color .2s ease,border-color .2s ease}
.tab{transition:background-color .2s ease,color .2s ease,box-shadow .2s ease}
.faq-a{overflow:hidden}
.faq-item>summary{transition:color .18s ease}
.faq-item>summary:hover{color:var(--brand)}
.iconbtn{transition:background-color .18s ease,border-color .18s ease,transform .16s ease}
.iconbtn:active{transform:scale(.92)}
.iconbtn svg{transition:transform .4s cubic-bezier(.2,.7,.2,1)}
.iconbtn:hover svg{transform:rotate(20deg)}
#navToggle svg{transition:transform .28s cubic-bezier(.2,.7,.2,1)}

.navbar{transition:box-shadow .25s ease,background-color .25s ease}
.navbar.scrolled{box-shadow:0 1px 0 var(--border),0 8px 22px -16px rgba(0,0,0,.4)}

/* colour-theme crossfade, only while the switch is firing */
html.theming *,html.theming *::before,html.theming *::after{transition:background-color .3s ease,border-color .3s ease,color .3s ease,fill .3s ease,box-shadow .3s ease!important}

/* scroll reveal — gated on html.js so artboards and no-JS clients render fully visible */
html.js [data-reveal]{opacity:0;transform:translateY(18px)}
html.js [data-reveal].is-in{opacity:1;transform:none;transition:opacity .6s cubic-bezier(.2,.7,.2,1),transform .6s cubic-bezier(.2,.7,.2,1)}
@keyframes acDrift{from{background-position:0 0,0 0}to{background-position:64px 64px,64px 64px}}
html.js .gridbg{animation:acDrift 28s linear infinite}

@media (max-width:900px){
  .h1{font-size:40px}.h2{font-size:28px}.lead{font-size:17px}
  .g3,.g4,.g5{grid-template-columns:repeat(1,minmax(0,1fr))}
  .g6{grid-template-columns:repeat(2,minmax(0,1fr))}
  .g2{grid-template-columns:repeat(1,minmax(0,1fr))}
  .split,.split-a,.split-b{grid-template-columns:1fr;gap:40px}
  .footgrid{grid-template-columns:repeat(2,1fr);gap:32px}
  .section,.section-lg{padding:64px 0}
  .container{padding:0 20px}
  .card-p{padding:20px}
  .tbl th,.tbl td{padding:10px 8px}
  #navToggle{display:inline-flex}
  .navrow{height:56px}
  .navbar .navlinks{display:flex;flex-direction:column;align-items:flex-start;gap:14px;position:absolute;left:0;right:0;top:56px;background:var(--background);border-bottom:1px solid var(--border);padding:18px 20px;z-index:9;opacity:0;visibility:hidden;transform:translateY(-10px);transition:opacity .22s ease,transform .24s cubic-bezier(.2,.7,.2,1),visibility .24s}
  .navbar.open .navlinks{opacity:1;visibility:visible;transform:none}
  .navbar.open #navToggle svg{transform:rotate(90deg)}
  .navrow>div:first-child{gap:12px}
  .langsw,.navbar .btn-ghost{display:none}
}
@media (max-width:560px){
  .h1{font-size:32px}.h2{font-size:24px}
  .section-lg{padding:48px 0}
}