:root{
  --bg:#0f172a;          /* page background (dark slate) */
  --panel:#111827;       /* panels/cards */
  --text:#e5e7eb;        /* light text */
  --muted:#94a3b8;       /* muted text */
  --brand:#60a5fa;       /* soft blue */
  --brand-strong:#3b82f6;
  --border:#1f2937;
}

*{box-sizing:border-box}
html,body{margin:0;padding:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text)}
a{color:var(--brand);text-decoration:none}
a:hover{color:var(--brand-strong)}
.container{max-width:1100px;margin:0 auto;padding:0 16px}
.narrow{max-width:800px}

.nav{position:sticky;top:0;background:#0b1225;border-bottom:1px solid var(--border);z-index:100}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{font-weight:700;font-size:20px;color:#dbeafe}
.nav-links a{margin-left:16px;color:#cbd5e1}
.nav-links a.active,.nav-links a:hover{color:#fff}

.layout{display:grid;grid-template-columns:1fr 280px;gap:24px;padding:32px 0}
.content h1{margin:0 0 8px 0;font-size:32px}
.lead{color:var(--muted);margin:0 0 20px 0}
.mt{margin-top:28px}
.bullets{margin:10px 0 0 18px;color:#cbd5e1}
.bullets li{margin:6px 0}

.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:16px}
.card{background:var(--panel);border:1px solid var(--border);border-radius:14px;padding:16px;box-shadow:0 1px 2px rgba(0,0,0,.2)}
.card h3{margin:0 0 8px 0}

.sidebar{position:relative}
.sidebar-title{font-weight:600;margin-bottom:10px;color:#bfdbfe}
.btn{display:block;text-align:center;padding:12px 14px;margin-bottom:10px;border:1px solid var(--border);border-radius:12px;background:#0b1225;color:#e5e7eb}
.btn:hover{background:#101935}
.btn.primary{background:linear-gradient(180deg,#60a5fa,#3b82f6);border:none;color:#0b1225;font-weight:700}
.btn.primary:hover{filter:brightness(1.05)}

.form{background:var(--panel);border:1px solid var(--border);border-radius:14px;padding:18px}
.form label{display:block;margin:12px 0}
.form span{display:block;margin-bottom:6px;color:#cbd5e1}
.form input,.form textarea{
  width:100%;padding:10px;border-radius:10px;border:1px solid var(--border);
  background:#0b1225;color:#e5e7eb;outline:none
}
.form input:focus,.form textarea:focus{border-color:var(--brand)}

.alert{padding:12px 14px;border-radius:12px;margin:12px 0;font-weight:600}
.alert.success{background:#052e1e;color:#bfffe3;border:1px solid #0f5132}
.alert.error{background:#2a0f12;color:#ffd1d6;border:1px solid #842029}

.footer{border-top:1px solid var(--border);padding:18px 0;margin-top:24px;color:#9ca3af}
@media (max-width:980px){.cards{grid-template-columns:1fr}}
@media (max-width:860px){
  .layout{grid-template-columns:1fr}
  .sidebar{order:-1;margin-bottom:12px}
}