:root{
  --bg:#f6f8fb;
  --nav:#ffffff;
  --panel:#ffffff;
  --text:#0f172a;
  --muted:#64748b;
  --accent:#0ea5a4;
  --accent2:#22c55e;
  --border:rgba(15,23,42,.12);
}

html,body{height:100%}
body{margin:0;font:16px/1.6 system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text)}
a{color:inherit}
.sr-only{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}

.shell{min-height:100vh;display:grid;grid-template-columns:280px 1fr}

.left-nav{background:var(--nav);border-right:1px solid var(--border);padding:16px;position:sticky;top:0;height:100vh;overflow:auto}
#logo img{display:block;height:36px;width:auto}
.nav-tagline{margin-top:10px;color:var(--muted);font-size:14px}
.nav-list{list-style:none;margin:14px 0 0;padding:0;display:flex;flex-direction:column;gap:8px}
.nav-list a{display:block;padding:10px 10px;border-radius:12px;text-decoration:none}
.nav-list li.active a{background:rgba(14,165,164,.12);font-weight:800}

.stage{display:grid;grid-template-rows:auto 1fr auto;min-height:100vh}
.stage-header{padding:14px 16px;border-bottom:1px solid var(--border);background:linear-gradient(90deg,rgba(14,165,164,.10),rgba(34,197,94,.08))}
.header-ads{max-width:720px}

.stage-main{padding:18px 16px}
.panel{background:var(--panel);border:1px solid var(--border);border-radius:18px;padding:16px;box-shadow:0 10px 26px rgba(15,23,42,.08)}

.stage-aside{padding:0 16px 18px}
.slot{background:var(--panel);border:1px dashed rgba(15,23,42,.26);border-radius:18px;padding:12px}

.container{max-width:1120px;margin:0 auto;padding:0 16px}
#footer{border-top:1px solid var(--border);padding:16px 0;background:rgba(255,255,255,.70)}
#footer .social{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:10px}
#footer .social a{display:inline-flex;align-items:center;justify-content:center;width:38px;height:38px;border-radius:12px;border:1px solid var(--border);background:#fff}
#footer p{margin:0;color:var(--muted)}

@media (max-width: 980px){
  .shell{grid-template-columns:1fr}
  .left-nav{position:relative;height:auto}
}