:root{
  --bg:#f8fafc;--card:#fff;--ink:#0f172a;--ink2:#475569;--muted:#64748b;--line:#e2e8f0;
  --brand:#4f46e5;--brand-d:#4338ca;--brand-l:#eef2ff;--ok:#059669;--ok-l:#ecfdf5;--warn:#d97706;--warn-l:#fffbeb;--err:#dc2626;--err-l:#fef2f2;
  --r:14px;--shadow:0 1px 2px rgba(15,23,42,.05),0 8px 24px rgba(15,23,42,.06);
  --font:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:var(--font);background:var(--bg);color:var(--ink);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;background:#f1f5f9;border:1px solid var(--line);padding:.1em .4em;border-radius:6px;font-size:.88em;word-break:break-word}
pre{background:#0f172a;color:#e2e8f0;padding:16px 18px;border-radius:12px;overflow:auto;font-size:.85rem;line-height:1.55}
pre code{background:none;border:0;padding:0;color:inherit}
.wrap{max-width:1080px;margin:0 auto;padding:0 24px}
.muted{color:var(--muted)}.small{font-size:.85rem}

/* nav */
.nav{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.9);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;height:66px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.15rem;color:var(--ink)!important;text-decoration:none!important}
.logo{width:36px;height:36px;border-radius:11px;background:var(--brand);color:#fff;display:grid;place-items:center;box-shadow:0 6px 16px rgba(79,70,229,.3)}
.logo svg{width:20px;height:20px}
.nav-links{display:flex;align-items:center;gap:26px;font-size:.92rem;font-weight:500}
.nav-links a{color:var(--ink2)}.nav-links a:hover,.nav-links a.active{color:var(--brand);text-decoration:none}
.nav-links a.active{font-weight:700}
@media(max-width:760px){.nav-links a:not(.btn){display:none}}

/* buttons */
.btn{display:inline-flex;align-items:center;gap:8px;background:var(--brand);color:#fff!important;font-weight:600;padding:10px 20px;border-radius:12px;border:0;cursor:pointer;font-size:.92rem;text-decoration:none!important;box-shadow:0 6px 16px rgba(79,70,229,.25);transition:.15s;font-family:inherit}
.btn:hover{background:var(--brand-d);transform:translateY(-1px)}
.btn.lg{padding:14px 28px;font-size:1.05rem;border-radius:14px}
.btn.ghost{background:#fff;color:var(--ink)!important;border:1px solid var(--line);box-shadow:none}
.btn.ghost:hover{background:#f8fafc}
.btn.danger{background:var(--err);box-shadow:none}
.btn.sm{padding:6px 12px;font-size:.82rem;border-radius:9px;box-shadow:none}
.btn:disabled{opacity:.55;cursor:not-allowed;transform:none}

/* hero + sections */
.hero{background:radial-gradient(900px 400px at 50% -10%,#e0e7ff 0%,#fff 70%);border-bottom:1px solid var(--line);padding:88px 0 80px;text-align:center}
.pill{display:inline-flex;gap:8px;align-items:center;background:var(--brand-l);color:var(--brand);border:1px solid #c7d2fe;font-weight:600;font-size:.82rem;padding:6px 14px;border-radius:999px}
.hero h1{font-size:clamp(2.4rem,6vw,4.4rem);line-height:1.08;letter-spacing:-.03em;margin:22px 0 18px;font-weight:800}
.hero h1 span{color:var(--brand)}
.hero p.lead{font-size:1.2rem;color:var(--ink2);max-width:640px;margin:0 auto 32px}
.hero .cta{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
section.block{padding:72px 0}
section.block.alt{background:#fff;border-block:1px solid var(--line)}
.h2{font-size:2rem;letter-spacing:-.02em;margin:0 0 10px;font-weight:800;text-align:center}
.sub{color:var(--ink2);text-align:center;max-width:620px;margin:0 auto 40px}
.grid{display:grid;gap:22px}.g3{grid-template-columns:repeat(3,1fr)}.g2{grid-template-columns:repeat(2,1fr)}
@media(max-width:860px){.g3,.g2{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--line);border-radius:20px;padding:28px;box-shadow:0 1px 2px rgba(15,23,42,.03)}
.card h3{margin:14px 0 8px;font-size:1.15rem}.card p{margin:0;color:var(--ink2)}
.ico{width:48px;height:48px;border-radius:14px;display:grid;place-items:center;background:var(--brand-l);color:var(--brand)}
.ico svg{width:24px;height:24px}
.ico.g{background:var(--ok-l);color:var(--ok)}.ico.p{background:#f5f3ff;color:#7c3aed}.ico.a{background:var(--warn-l);color:var(--warn)}
.steps{counter-reset:s;display:grid;gap:16px;max-width:760px;margin:0 auto}
.step{display:flex;gap:16px;background:#fff;border:1px solid var(--line);border-radius:16px;padding:20px}
.step:before{counter-increment:s;content:counter(s);flex:none;width:34px;height:34px;border-radius:50%;background:var(--brand);color:#fff;font-weight:700;display:grid;place-items:center}
.step h4{margin:0 0 4px}.step p{margin:0;color:var(--ink2)}

/* prose pages */
.page{padding:56px 0 80px}
.prose{max-width:820px;margin:0 auto}
.prose h1{font-size:2.4rem;letter-spacing:-.025em;margin:0 0 6px;font-weight:800}
.prose .meta{color:var(--muted);margin-bottom:28px}
.prose h2{font-size:1.45rem;margin:38px 0 10px;letter-spacing:-.01em;scroll-margin-top:90px}
.prose h3{font-size:1.1rem;margin:24px 0 6px}
.prose p,.prose li{color:var(--ink2)}
.prose ul,.prose ol{padding-left:22px}.prose li{margin:4px 0}
.prose table{width:100%;border-collapse:collapse;margin:14px 0;font-size:.92rem}
.prose th,.prose td{border:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top}
.prose th{background:#f1f5f9;color:var(--ink)}
.callout{border:1px solid #c7d2fe;background:var(--brand-l);border-radius:14px;padding:14px 18px;margin:18px 0;color:#3730a3}
.callout.warn{border-color:#fde68a;background:var(--warn-l);color:#92400e}
.toc{background:#fff;border:1px solid var(--line);border-radius:14px;padding:16px 22px;margin:18px 0 8px}
.toc a{display:block;padding:2px 0}

/* footer */
footer{border-top:1px solid var(--line);background:#fff;padding:36px 0;color:var(--muted);font-size:.9rem}
footer .wrap{display:flex;gap:18px;justify-content:space-between;flex-wrap:wrap;align-items:center}
footer nav{display:flex;gap:20px;flex-wrap:wrap}footer a{color:var(--ink2)}

/* message pages (OAuth result, errors) */
.center-page{min-height:100vh;display:grid;place-items:center;padding:24px;background:radial-gradient(800px 380px at 50% -10%,#e0e7ff,var(--bg))}
.msg-card{background:#fff;border:1px solid var(--line);border-radius:24px;box-shadow:var(--shadow);padding:40px;max-width:480px;width:100%;text-align:center}
.msg-card h1{font-size:1.6rem;margin:16px 0 10px}
.msg-body{color:var(--ink2)}
.msg-icon{width:64px;height:64px;border-radius:50%;display:grid;place-items:center;margin:0 auto;font-size:1.9rem;font-weight:700}
.msg-icon.ok{background:#d1fae5;color:var(--ok)}.msg-icon.err{background:#fee2e2;color:var(--err)}