:root{
  --bg:#ffffff;
  --card:#ffffff;
  --muted:#6b7280;
  --primary:#2563eb;
  --accent:#06b6d4;
  --glass: rgba(37,99,235,0.06);
  --radius:12px;
  --shadow: 0 8px 28px rgba(15,23,42,0.06);
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;font-family:Inter,system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial;
  background:linear-gradient(180deg,#f8fafc,#eef2ff);
  color:#07203a;
  -webkit-font-smoothing:antialiased;
  padding:18px;
}

/* layout */
.app{max-width:1200px;margin:0 auto;display:grid;grid-template-columns:260px 1fr;gap:20px;align-items:start;}
.sidebar{background:var(--card);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow);border:1px solid rgba(2,6,23,0.03)}
.logo{display:flex;gap:10px;align-items:center;margin-bottom:8px}
.logo .mark{width:44px;height:44px;border-radius:10px;background:linear-gradient(135deg,var(--primary),var(--accent));display:grid;place-items:center;color:white;font-weight:800}
.logo h3{margin:0;font-size:16px}
.small{font-size:13px;color:var(--muted)}

/* nav */
.nav{display:flex;flex-direction:column;gap:8px;margin-top:12px}
.nav button{background:transparent;border:0;padding:10px;border-radius:10px;text-align:left;cursor:pointer;font-weight:600;color:#0b2b3b}
.nav button.active{background:linear-gradient(90deg, rgba(37,99,235,0.08), rgba(6,182,212,0.04));box-shadow:0 6px 18px rgba(37,99,235,0.06)}

/* sidebar quick */
.quick{margin-top:14px;background:linear-gradient(180deg,rgba(2,6,23,0.01),transparent);padding:12px;border-radius:10px;border:1px solid rgba(2,6,23,0.03)}

/* main */
.main{min-height:720px;background:transparent}
.header{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:12px}
.search input{padding:10px 12px;border-radius:10px;border:1px solid rgba(2,6,23,0.06);width:420px;background:transparent}
.controls{display:flex;gap:10px;align-items:center}
.btn{background:linear-gradient(90deg,var(--primary),var(--accent));color:white;padding:10px 14px;border-radius:10px;border:0;cursor:pointer;font-weight:700;box-shadow:0 8px 18px rgba(37,99,235,0.12)}

.container{display:grid;grid-template-columns:1fr 360px;gap:18px}

/* cards */
.card{background:var(--card);border-radius:12px;padding:14px;box-shadow:var(--shadow);border:1px solid rgba(2,6,23,0.03)}

/* challenge list */
.challenge{display:flex;align-items:center;gap:10px;padding:12px;border-radius:10px;border:1px solid rgba(2,6,23,0.03);background:linear-gradient(180deg,rgba(6,182,212,0.02),transparent)}
.challenge h4{margin:0}
.meta{flex:1}

/* rules editor */
.form-row{display:flex;gap:8px;align-items:center;margin-bottom:8px}
.form-row input, .form-row select, textarea{padding:8px;border-radius:8px;border:1px solid rgba(2,6,23,0.06);width:100px}
textarea{width:100%;min-height:100px;padding:10px}

/* leaderboard */
.leader{display:flex;flex-direction:column;gap:8px}
.lb-row{display:flex;justify-content:space-between;align-items:center;padding:10px;border-radius:8px;border:1px solid rgba(2,6,23,0.03)}

/* challenge builder modal */
.modal{position:fixed;left:0;top:0;right:0;bottom:0;display:none;align-items:center;justify-content:center;background:rgba(12,20,40,0.4);z-index:60}
.modal .panel{width:980px;background:var(--card);padding:18px;border-radius:12px;box-shadow:0 30px 80px rgba(12,20,40,0.2);display:grid;grid-template-columns:1fr 360px;gap:16px}
.steps{display:flex;gap:8px;margin-bottom:12px}
.step{padding:8px 10px;border-radius:999px;background:rgba(2,6,23,0.03);font-weight:700;color:var(--muted)}

/* responsive */
@media (max-width:1000px){.app{grid-template-columns:1fr;}.container{grid-template-columns:1fr}.search input{width:200px}}

/* small helpers */
.kpi{font-weight:800;font-size:18px}
.note{background:linear-gradient(90deg,rgba(37,99,235,0.06),rgba(6,182,212,0.04));padding:8px;border-radius:8px;color:#08304b}
@media (max-width: 768px) 
{
  body{
    padding: 05px !important;
  }
}