:root{--ink:#14161C;--ink2:#3A3F4C;--muted:#6B7180;--line:#E7E4DE;--ground:#FAF9F7;--surface:#fff;--surface2:#F2EFEA;--brand:#2b7fe0;--brand-ink:#1e63c4;--brand-soft:#e3eefc;--teal:#18b7c6;--dark:#0F1117;--on-dark:#EDEFF4;--on-dark-mut:#9AA1B2;--display:"Bricolage Grotesque",ui-sans-serif,system-ui,sans-serif;--body:"Inter",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;background:var(--ground);color:var(--ink);font-family:var(--body);line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{font-family:var(--display);letter-spacing:-.02em;line-height:1.15;font-weight:800;margin:0}

/* top nav */
header.nav{position:sticky;top:0;z-index:40;background:rgba(250,249,247,.9);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav-in{max-width:1240px;margin:0 auto;display:flex;align-items:center;justify-content:space-between;padding:12px 20px}
.logo span{font-family:var(--display);font-weight:800;font-size:1.4rem;letter-spacing:-.02em}.logo .b{color:var(--brand)}
.nav-links{display:flex;align-items:center;gap:20px}.nav-links a{font-size:.92rem;color:var(--ink2);font-weight:500}.nav-links a:hover{color:var(--ink)}
.btn{display:inline-flex;align-items:center;gap:.4em;font-weight:600;font-size:.9rem;padding:.55em 1.05em;border-radius:10px;background:var(--brand);color:#fff;border:1px solid transparent;transition:.15s}
.btn:hover{background:var(--brand-ink)}

/* shell: sidebar + content */
.shell{max-width:1240px;margin:0 auto;display:grid;grid-template-columns:250px minmax(0,1fr);gap:0}
.side{position:sticky;top:57px;align-self:start;height:calc(100dvh - 57px);overflow-y:auto;border-right:1px solid var(--line);padding:22px 14px 40px}
.side .search{display:flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--surface);border-radius:10px;padding:7px 10px;margin-bottom:16px}
.side .search input{border:0;outline:0;background:transparent;font-size:.86rem;width:100%;color:var(--ink)}
.side .grp{margin-bottom:16px}
.side .grp>b{display:block;font-family:var(--display);font-size:.72rem;font-weight:800;letter-spacing:.09em;text-transform:uppercase;color:var(--muted);padding:0 8px 6px}
.side a.lnk{display:block;font-size:.9rem;color:var(--ink2);padding:6px 10px;border-radius:8px;margin:1px 0}
.side a.lnk:hover{background:var(--surface2);color:var(--ink)}
.side a.lnk.on{background:var(--brand-soft);color:var(--brand-ink);font-weight:600}
.side a.soon{color:var(--muted);opacity:.7;cursor:default}.side a.soon:after{content:"soon";float:right;font-size:.6rem;font-weight:700;background:var(--surface2);color:var(--muted);padding:2px 5px;border-radius:6px;text-transform:uppercase}

.main{padding:34px 40px 80px;min-width:0}
.art{max-width:760px}
.crumbs{font-size:.8rem;color:var(--muted);margin-bottom:14px}.crumbs a:hover{color:var(--brand)}
.art h1{font-size:2.1rem;margin:0 0 6px}
.art .lead{font-size:1.1rem;color:var(--ink2);margin:0 0 26px}
.art h2{font-size:1.35rem;margin:34px 0 12px;padding-top:8px}
.art h3{font-size:1.05rem;margin:22px 0 8px}
.art p{margin:0 0 14px;color:var(--ink2)}
.art ul,.art ol{margin:0 0 16px;padding-left:22px;color:var(--ink2)}.art li{margin:5px 0}
.art a.inl{color:var(--brand-ink);font-weight:600;text-decoration:underline;text-underline-offset:2px}
.art code{background:var(--surface2);border-radius:6px;padding:1px 6px;font-size:.86em;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}
.art strong{color:var(--ink)}
.callout{background:var(--brand-soft);border-left:3px solid var(--brand);border-radius:0 12px 12px 0;padding:13px 16px;margin:0 0 18px;font-size:.94rem}
.callout.tip{background:#e9f9f0;border-color:#35d07f}
.steps{counter-reset:s;list-style:none;padding:0;margin:0 0 18px}
.steps li{position:relative;padding:2px 0 14px 40px;counter-increment:s}
.steps li:before{content:counter(s);position:absolute;left:0;top:0;width:26px;height:26px;border-radius:50%;background:var(--brand);color:#fff;font-family:var(--display);font-weight:800;font-size:.85rem;display:flex;align-items:center;justify-content:center}
.steps li:not(:last-child):after{content:"";position:absolute;left:12.5px;top:28px;bottom:0;width:1px;background:var(--line)}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:14px;margin:6px 0 24px}
.dcard{border:1px solid var(--line);border-radius:14px;background:var(--surface);padding:16px;transition:.15s;display:block}
.dcard:hover{border-color:var(--brand);transform:translateY(-2px);box-shadow:0 14px 34px -24px rgba(20,22,28,.4)}
.dcard b{font-family:var(--display);font-size:1rem;display:block;margin-bottom:3px}
.dcard span{font-size:.84rem;color:var(--muted)}
.dcard .em{font-size:1.5rem;display:block;margin-bottom:6px}
.next{display:flex;flex-wrap:wrap;gap:12px;margin-top:34px;border-top:1px solid var(--line);padding-top:20px}
.next a{flex:1;min-width:200px;border:1px solid var(--line);border-radius:12px;padding:12px 14px;background:var(--surface)}
.next a:hover{border-color:var(--brand)}.next small{color:var(--muted);font-size:.72rem;text-transform:uppercase;letter-spacing:.06em}.next b{display:block;color:var(--brand-ink)}

.menu-btn{display:none}
@media(max-width:860px){
  .shell{grid-template-columns:1fr}
  .side{position:fixed;left:0;top:57px;z-index:50;width:270px;background:var(--surface);transform:translateX(-100%);transition:.2s;box-shadow:0 20px 60px -20px rgba(0,0,0,.4)}
  .side.open{transform:none}
  .menu-btn{display:inline-flex;align-items:center;gap:6px;font-size:.85rem;font-weight:600;color:var(--brand-ink);background:var(--brand-soft);border:0;border-radius:8px;padding:7px 11px;margin:14px 0 0 20px}
  .main{padding:18px 20px 60px}.nav-links a:not(.btn){display:none}
}
footer.ft{background:var(--dark);color:var(--on-dark-mut);margin-top:40px;padding:30px 20px;text-align:center;font-size:.85rem}
footer.ft a{color:var(--on-dark-mut);text-decoration:underline}footer.ft a:hover{color:#fff}
/* FAQ (AEO) — accordion */
.faq{margin:12px 0 4px;border:1px solid var(--line,#e6e8ee);border-radius:12px;overflow:hidden}
.faq details{border-top:1px solid var(--line,#e6e8ee)}
.faq details:first-child{border-top:0}
.faq summary{cursor:pointer;list-style:none;padding:14px 16px;font-weight:600;color:var(--ink,#1a2233);position:relative;font-size:.98rem}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";position:absolute;right:16px;top:12px;font-size:1.2rem;color:#8a90a2;transition:transform .15s}
.faq details[open] summary::after{content:"–"}
.faq details[open] summary{color:var(--brand,#2b7fe0)}
.faq details>div{padding:0 16px 15px;color:var(--mut,#4a5162);font-size:.95rem;line-height:1.6}
.faq details>div a{color:var(--brand,#2b7fe0)}