:root{--bg:#0d0d10;--s2:#252525;--b:#333;--b2:#404040;--blue:#0a84ff;--blue2:#5aabff;--green:#30d158;--t:#f5f5f7;--dim:#a1a1a6;--muted:#8e8e93;--ff:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif}
*{box-sizing:border-box;margin:0;padding:0}
body{background:var(--bg);color:var(--t);font-family:var(--ff);font-size:14.5px;line-height:1.75}
a{color:var(--blue2);text-decoration:none}a:hover{text-decoration:underline}
.top{display:flex;align-items:center;justify-content:space-between;padding:16px 28px;border-bottom:1px solid rgba(255,255,255,.07);position:sticky;top:0;background:#0d0d10}
.logo{font-weight:800}.logo span{color:var(--blue)}
.back{font-size:12.5px;color:var(--dim)}
.doc{max-width:780px;margin:0 auto;padding:46px 24px 70px}
.doc h1{font-size:30px;font-weight:800;letter-spacing:-.5px;margin-bottom:6px}
.upd{color:var(--muted);font-size:12.5px;margin-bottom:8px}
.foot{max-width:780px;margin:0 auto;padding:0 24px 50px;font-size:12px;color:var(--muted)}
.foot a{color:var(--muted)}
@media(max-width:560px){
  .doc{padding:32px 18px 56px}
  .doc h1{font-size:24px;letter-spacing:-.3px;line-height:1.2}
  .doc h2{font-size:16.5px;margin:22px 0 6px}
  .top{padding:12px 16px}
  .back{display:inline-flex;align-items:center;min-height:40px;padding:8px 4px}
  .foot{padding:0 18px 40px;line-height:2.4;text-align:center}
  .foot a{display:inline-block;padding:8px 4px}
}
@media(max-width:400px){.doc h1{font-size:21px}}

.langsw{display:flex;align-items:center;background:var(--s2);border:1px solid var(--b2);border-radius:100px;padding:2px;gap:1px;margin-right:12px}
.langsw button{font-family:var(--ff);font-size:10.5px;font-weight:700;letter-spacing:.4px;padding:4px 9px;border-radius:100px;border:none;background:transparent;color:var(--dim);cursor:pointer;transition:background .15s,color .15s}
.langsw button:hover{color:var(--t)}
.langsw button.on{background:var(--blue);color:#fff}