:root{--sidebar:#111827;--primary:#1d4ed8;--bg:#f3f4f6;--card:#fff}body{background:var(--bg);font-size:14px}.app-shell{display:flex;min-height:100vh}.sidebar{width:245px;background:var(--sidebar);color:#fff;flex-shrink:0}.brand{font-size:26px;line-height:1.05;font-weight:800;padding:24px 22px;border-bottom:1px solid rgba(255,255,255,.08)}.brand span{font-size:16px;color:#9ca3af}.sidebar nav{padding:12px}.sidebar a{display:block;color:#d1d5db;text-decoration:none;padding:10px 12px;border-radius:8px;margin-bottom:2px}.sidebar a:hover,.sidebar a.active{background:#243044;color:#fff}.content{flex:1;min-width:0}.topbar{height:64px;background:#fff;border-bottom:1px solid #e5e7eb;display:flex;align-items:center;justify-content:space-between;padding:0 24px;position:sticky;top:0;z-index:5}.stat-card{border:0;box-shadow:0 1px 4px rgba(0,0,0,.06)}h1{font-size:28px;margin-bottom:20px}.mail-preview{white-space:pre-wrap;background:#f8fafc;border:1px solid #e5e7eb;padding:12px;border-radius:8px;max-width:700px}.login-bg{background:linear-gradient(135deg,#0f172a,#1d4ed8)}.table td,.table th{vertical-align:middle}@media(max-width:900px){.app-shell{display:block}.sidebar{width:auto}.sidebar nav{display:flex;overflow:auto}.sidebar a{white-space:nowrap}.topbar{position:static}}