:root{--font:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;--bg:#000;--card:#111113;--ink:#f5f5f7;--gray:#98989d;--line:#26262a;--link:#2997ff;--nav:rgba(0,0,0,.72)}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:84px}
body{font-family:var(--font);background:var(--bg);color:var(--ink);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--link);text-decoration:none}a:hover{text-decoration:underline}
.top{position:sticky;top:0;z-index:20;background:var(--nav);backdrop-filter:saturate(180%) blur(20px);-webkit-backdrop-filter:saturate(180%) blur(20px);border-bottom:1px solid var(--line)}
.top-in{max-width:1080px;margin:0 auto;height:52px;padding:0 22px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{font-weight:700;font-size:16px;letter-spacing:-.01em;color:var(--ink)}.brand:hover{text-decoration:none}
.switch{display:flex;gap:4px;overflow-x:auto;scrollbar-width:none}
.switch a{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--gray);padding:6px 12px;border-radius:980px;white-space:nowrap}
.switch a img{width:18px;height:18px;border-radius:5px}
.switch a:hover{color:var(--ink);text-decoration:none}
.switch a[aria-current]{background:rgba(var(--acc),.14);color:var(--ink);font-weight:600}
@media(max-width:640px){.switch a span,.switch{display:none}}
main{max-width:1080px;margin:0 auto;padding:0 22px 80px}
.hero{text-align:center;padding:72px 0 44px}
.hero .app{margin:0 auto 22px;border-radius:22.5%;box-shadow:0 20px 40px -14px rgba(var(--acc),.55),0 0 0 1px rgba(0,0,0,.06)}
.eyebrow{font-size:15px;font-weight:600;color:rgb(var(--acc));letter-spacing:.02em;margin-bottom:6px}
h1{font-size:clamp(2.4rem,6vw,4rem);font-weight:700;letter-spacing:-.04em;line-height:1.05}
.lead{max-width:680px;margin:18px auto 0;font-size:clamp(1.05rem,2vw,1.3rem);color:var(--gray);line-height:1.5}
.meta{list-style:none;display:flex;flex-wrap:wrap;gap:8px 10px;justify-content:center;margin-top:28px}
.meta li{font-size:13px;color:var(--gray);background:var(--card);border:1px solid var(--line);border-radius:980px;padding:6px 14px}
.meta b{color:var(--ink);font-weight:600;margin-right:6px}
.glance{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-bottom:56px}
.g{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:22px}
.g small{font-size:12px;color:var(--gray);text-transform:uppercase;letter-spacing:.06em;font-weight:600}
.g strong{display:block;font-size:1.6rem;letter-spacing:-.03em;margin:6px 0 4px;color:rgb(var(--acc))}
.g p{font-size:14px;color:var(--gray);line-height:1.45}
.layout{display:grid;grid-template-columns:240px 1fr;gap:48px;align-items:start}
.toc{position:sticky;top:76px;display:flex;flex-direction:column;gap:2px;font-size:14px}
.toc b{font-size:12px;text-transform:uppercase;letter-spacing:.06em;color:var(--gray);margin-bottom:8px}
.toc a{color:var(--gray);padding:6px 12px;border-left:2px solid var(--line);border-radius:0 8px 8px 0}
.toc a:hover{color:var(--ink);text-decoration:none}
.toc a.on{color:var(--ink);border-left-color:rgb(var(--acc));background:rgba(var(--acc),.08);font-weight:600}
.doc section{background:var(--card);border:1px solid var(--line);border-radius:26px;padding:34px;margin-bottom:18px}
.doc h2{display:flex;align-items:center;gap:14px;font-size:1.5rem;letter-spacing:-.03em;margin-bottom:16px;line-height:1.2}
.doc h2 span{flex:none;width:34px;height:34px;border-radius:50%;display:grid;place-items:center;font-size:14px;background:rgba(var(--acc),.14);color:rgb(var(--acc))}
.doc p{margin-bottom:12px;color:var(--ink)}
.doc ul{margin:0 0 12px 1.2em}.doc li{margin-bottom:8px}
code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.85em;background:rgba(127,127,127,.15);padding:2px 7px;border-radius:6px}
.kv dt{font-weight:600;margin-top:14px}.kv dd{color:var(--gray);margin:2px 0 0}
.perms{display:grid;gap:12px;margin-top:8px}
.perm{border:1px solid var(--line);border-radius:18px;padding:18px 20px;background:rgba(127,127,127,.04)}
.perm-h{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px 14px;margin-bottom:8px}
.perm h3{font-size:1.05rem;letter-spacing:-.02em}
.perm p{font-size:15px;margin-bottom:6px}
.perm .safe{color:var(--gray)}.perm b{color:var(--ink)}
.contact{display:grid;gap:10px;margin-top:8px}
.contact div{display:flex;flex-wrap:wrap;gap:4px 14px;padding:14px 18px;border:1px solid var(--line);border-radius:16px}
.contact b{min-width:90px;color:var(--gray);font-weight:600;font-size:14px}
.foot{max-width:1080px;margin:0 auto;padding:30px 22px 50px;border-top:1px solid var(--line);color:var(--gray);font-size:13px}
.foot p{margin-bottom:6px}
.index{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:16px;margin-top:12px}
.ic{background:var(--card);border:1px solid var(--line);border-radius:26px;padding:34px 24px;text-align:center;color:var(--ink);transition:transform .35s cubic-bezier(.2,.8,.2,1),box-shadow .35s}
.ic:hover{transform:translateY(-6px);box-shadow:0 30px 60px -24px rgba(var(--acc),.5);text-decoration:none}
.ic img{margin:0 auto 18px;border-radius:22.5%}
.ic h2{font-size:1.4rem;letter-spacing:-.03em}.ic p{color:var(--gray);font-size:14px;margin:2px 0 14px}.ic span{color:var(--link);font-size:14px}
@media(max-width:900px){.layout{grid-template-columns:1fr}.toc{display:none}.doc section{padding:24px}}
@media print{.top,.toc{display:none}body{background:#fff}.doc section{border:0;padding:0;break-inside:avoid}}

/* ===== v2: cinematic dark hero, motion, icons ===== */
.top{background:rgba(0,0,0,.6);border-bottom-color:rgba(255,255,255,.1)}
.brand{color:#f5f5f7}
.switch a{color:rgba(245,245,247,.7)}.switch a:hover{color:#fff}
.switch a[aria-current]{background:rgba(255,255,255,.14);color:#fff}
.bar{position:fixed;top:0;left:0;right:0;height:3px;z-index:50}
.bar i{display:block;height:100%;transform-origin:0 50%;transform:scaleX(0);background:linear-gradient(90deg,rgb(var(--acc)),#fff)}
.herowrap{position:relative;overflow:hidden;background:#000;color:#f5f5f7;margin-top:-52px;padding-top:52px}
.herowrap::after{content:"";position:absolute;left:0;right:0;bottom:0;height:120px;background:linear-gradient(transparent,var(--bg));opacity:0}
.glow{position:absolute;border-radius:50%;filter:blur(90px);pointer-events:none}
.glow.g1{width:640px;height:640px;left:50%;top:-260px;margin-left:-320px;background:rgba(var(--acc),.38);animation:drift 14s ease-in-out infinite alternate}
.glow.g2{width:420px;height:420px;right:-120px;top:120px;background:rgba(var(--acc),.18);animation:drift 18s ease-in-out infinite alternate-reverse}
@keyframes drift{to{transform:translate(40px,30px) scale(1.12)}}
.herowrap .hero{position:relative;z-index:2;max-width:1080px;margin:0 auto;padding:84px 22px 120px}
.herowrap h1{background:linear-gradient(180deg,#fff 30%,rgba(255,255,255,.62));-webkit-background-clip:text;background-clip:text;color:transparent;font-size:clamp(3rem,8vw,5.5rem)}
.herowrap .eyebrow{color:rgb(var(--acc));filter:brightness(1.35);letter-spacing:.14em;text-transform:uppercase;font-size:13px}
.sub{font-size:clamp(1.1rem,2.4vw,1.5rem);font-weight:500;color:rgba(245,245,247,.6);margin-top:6px;letter-spacing:-.01em}
.herowrap .lead{color:rgba(245,245,247,.72)}
.herowrap .meta li{background:rgba(255,255,255,.08);border-color:rgba(255,255,255,.14);color:rgba(245,245,247,.7);backdrop-filter:blur(12px)}
.herowrap .meta b{color:#fff}
.appwrap{position:relative;width:104px;height:104px;margin:0 auto 26px;animation:float 5s ease-in-out infinite}
@keyframes float{50%{transform:translateY(-10px)}}
.appwrap .app{position:relative;width:104px;height:104px;margin:0;box-shadow:0 30px 60px -14px rgba(var(--acc),.7),0 0 0 1px rgba(255,255,255,.14)}
.ring{position:absolute;inset:-16px;border-radius:32%;background:conic-gradient(from 0deg,rgba(var(--acc),0),rgba(var(--acc),.9),rgba(var(--acc),0) 60%);animation:spin 6s linear infinite;filter:blur(14px);opacity:.75}
@keyframes spin{to{transform:rotate(360deg)}}
main{position:relative;z-index:3}
.glance{margin-top:-64px}
.g{position:relative;overflow:hidden;box-shadow:0 20px 50px -28px rgba(0,0,0,.4);transition:transform .4s cubic-bezier(.2,.8,.2,1),box-shadow .4s}
.g::before{content:"";position:absolute;inset:0 0 auto 0;height:3px;background:linear-gradient(90deg,rgb(var(--acc)),transparent)}
.g:hover{transform:translateY(-6px);box-shadow:0 30px 60px -24px rgba(var(--acc),.55)}
.gi{display:grid;place-items:center;width:38px;height:38px;border-radius:12px;background:rgba(var(--acc),.14);color:rgb(var(--acc));margin-bottom:14px}
.gi svg,.pi svg{width:20px;height:20px}
.pt{display:flex;align-items:center;gap:12px}
.pi{flex:none;display:grid;place-items:center;width:38px;height:38px;border-radius:12px;background:rgba(var(--acc),.14);color:rgb(var(--acc))}
.perm{transition:transform .35s cubic-bezier(.2,.8,.2,1),border-color .35s,background .35s}
.perm:hover{transform:translateX(4px);border-color:rgba(var(--acc),.6);background:rgba(var(--acc),.05)}
.doc h2 span{background:linear-gradient(135deg,rgb(var(--acc)),rgba(var(--acc),.55));color:#fff;box-shadow:0 8px 18px -8px rgb(var(--acc))}
.doc section{box-shadow:0 1px 2px rgba(0,0,0,.03)}
html.js .rv{opacity:0;transform:translateY(26px);transition:opacity .8s cubic-bezier(.2,.8,.2,1) var(--d,0ms),transform .8s cubic-bezier(.2,.8,.2,1) var(--d,0ms)}
html.js .rv.in{opacity:1;transform:none}
.idx .herowrap .hero{padding-bottom:110px}
.index{margin-top:-60px;position:relative}
.ic{background:var(--card);box-shadow:0 20px 50px -28px rgba(0,0,0,.4)}
.ic img{box-shadow:0 18px 34px -12px rgba(var(--acc),.6)}
@media(prefers-reduced-motion:reduce){.appwrap,.ring,.glow{animation:none}html.js .rv{opacity:1;transform:none;transition:none}}

/* logo in top bar */
.brand{display:flex;align-items:center;gap:10px}
.brand .logo{width:26px;height:26px;border-radius:7px;box-shadow:0 0 0 1px rgba(255,255,255,.12)}

/* ===== theme switch + light theme ===== */
:root{color-scheme:dark}
html[data-theme="light"]{color-scheme:light;--bg:#fbfbfd;--card:#fff;--ink:#1d1d1f;--gray:#6e6e73;--line:#dcdce1;--link:#0066cc;--nav:rgba(251,251,253,.75)}
.theme-btn{width:32px;height:32px;flex:none;border-radius:50%;border:1px solid rgba(255,255,255,.18);background:rgba(255,255,255,.06);color:#f5f5f7;display:grid;place-items:center;cursor:pointer;transition:background .25s,transform .3s}
.theme-btn:hover{background:rgba(255,255,255,.14);transform:rotate(18deg)}
.theme-btn svg{width:17px;height:17px;grid-area:1/1}
.theme-btn .i-moon{display:none}
html[data-theme="light"] .theme-btn .i-sun{display:none}
html[data-theme="light"] .theme-btn .i-moon{display:block}
html[data-theme="light"] .theme-btn{border-color:rgba(0,0,0,.16);background:rgba(0,0,0,.04);color:#1d1d1f}
html[data-theme="light"] .top{background:rgba(251,251,253,.78);border-bottom-color:rgba(0,0,0,.08)}
html[data-theme="light"] .brand{color:#1d1d1f}
html[data-theme="light"] .brand .logo{box-shadow:0 0 0 1px rgba(0,0,0,.1)}
html[data-theme="light"] .switch a{color:#6e6e73}
html[data-theme="light"] .switch a:hover{color:#1d1d1f}
html[data-theme="light"] .switch a[aria-current]{background:rgba(var(--acc),.12);color:#1d1d1f}
html[data-theme="light"] .herowrap{background:#fbfbfd;color:#1d1d1f}
html[data-theme="light"] .herowrap h1{background:linear-gradient(180deg,#1d1d1f 30%,#6e6e73);-webkit-background-clip:text;background-clip:text;color:transparent}
html[data-theme="light"] .herowrap .eyebrow{filter:brightness(.8)}
html[data-theme="light"] .sub{color:#6e6e73}
html[data-theme="light"] .herowrap .lead{color:#515154}
html[data-theme="light"] .herowrap .meta li{background:#fff;border-color:rgba(0,0,0,.1);color:#6e6e73}
html[data-theme="light"] .herowrap .meta b{color:#1d1d1f}
html[data-theme="light"] .glow.g1{background:rgba(var(--acc),.22)}
html[data-theme="light"] .glow.g2{background:rgba(var(--acc),.12)}
html[data-theme="light"] .appwrap .app{box-shadow:0 30px 60px -14px rgba(var(--acc),.5),0 0 0 1px rgba(0,0,0,.08)}
html[data-theme="light"] .g,html[data-theme="light"] .doc section{box-shadow:0 16px 40px -28px rgba(0,0,0,.25)}