/* Modern dark coding theme */
:root{
  --bg:#0b0f16;
  --panel:#0f1720;
  --muted:#94a3b8;
  --accent:#6ee7b7;
  --accent-2:#60a5fa;
  --glass: rgba(255,255,255,0.03);
  --glass-2: rgba(255,255,255,0.02);
  --danger:#fb7185;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}
*{box-sizing:border-box}
html,body,#app{height:100%}
body{
  margin:0;
  background:linear-gradient(180deg,var(--bg),#061016 60%);
  color:#e6eef8;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  display:flex;justify-content:center;align-items:stretch;
  padding:20px;
}

/* Topbar */
.topbar{
  position:fixed;left:0;right:0;top:0;height:56px;
  display:flex;align-items:center;justify-content:space-between;padding:0 20px;
  background:linear-gradient(90deg, rgba(255,255,255,0.02), transparent);
  border-bottom:1px solid rgba(255,255,255,0.02);
  z-index:50;color:var(--muted);
}
.brand{font-weight:700;color:var(--accent-2)}
.userbox{display:flex;gap:10px;align-items:center}
.chip{background:var(--glass);padding:6px 10px;border-radius:999px;font-size:12px;color:var(--muted)}
.username{font-weight:600;color:#dbeafe}

/* Main container */
.container{
  width:1100px;max-width:calc(100% - 40px);margin:80px auto 40px;
}

/* Panels */
.panel{background:linear-gradient(180deg,var(--panel), #071125);border-radius:12px;padding:20px;box-shadow:0 6px 30px rgba(2,6,23,0.6);border:1px solid rgba(255,255,255,0.02)}
.auth-grid{display:flex;gap:20px;flex-wrap:wrap}
.card{background:var(--glass);padding:16px;border-radius:10px;min-width:260px}
.card h3{margin:0 0 10px;color:var(--accent)}
input,textarea{width:100%;padding:10px;border-radius:8px;border:1px solid rgba(255,255,255,0.03);background:transparent;color:inherit;outline:none;margin:6px 0;font-family:inherit}
textarea{min-height:160px;font-family:monospace;resize:vertical}

/* Buttons */
.btn{background:transparent;border:1px solid rgba(255,255,255,0.06);padding:8px 12px;border-radius:8px;color:inherit;cursor:pointer}
.btn.primary{background:linear-gradient(90deg,var(--accent),var(--accent-2));border:none;color:#02203a;font-weight:700}
.btn.small{padding:6px 8px;font-size:13px}
.btn-row{display:flex;gap:8px;margin-top:10px}

/* Game layout */
.game-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px}
.level-info{display:flex;gap:18px;align-items:center;color:var(--muted)}
.controls{display:flex;gap:8px}

.game-body{display:flex;gap:20px}
.left-panel{width:360px}
.stage{flex:1;display:flex;flex-direction:column;align-items:center;gap:10px}
#grid-wrap{background:var(--glass-2);padding:16px;border-radius:10px;border:1px solid rgba(255,255,255,0.02);min-height:340px;display:flex;align-items:center;justify-content:center;width:100%}
#grid{display:grid;gap:6px;}

/* Grid cells */
.cell{width:48px;height:48px;background:linear-gradient(180deg,#051622,#0b2633);border-radius:8px;display:flex;align-items:center;justify-content:center;position:relative;overflow:hidden;box-shadow:inset 0 -6px 12px rgba(0,0,0,0.3)}
.cell.obstacle{background:linear-gradient(180deg,#2a2430,#1b1a1d)}
.cell.start{background:linear-gradient(180deg,#0b7238,#063f22)}
.cell.goal{background:linear-gradient(180deg,#1652b4,#07294a)}
.robot{
  position:absolute;width:60%;height:60%;border-radius:10px;background:linear-gradient(180deg,#9be7c4,#4aa3ff);display:flex;align-items:center;justify-content:center;color:#02203a;font-weight:700;transform-origin:center;transition:transform 220ms linear;
  box-shadow:0 6px 18px rgba(0,0,0,0.5);
}
.robot .eye{width:8px;height:8px;background:#02203a;border-radius:50%}

/* message */
.message{padding:12px 16px;border-radius:8px;background:linear-gradient(90deg,#0b1220,#071428);border:1px solid rgba(255,255,255,0.03)}

/* Hints and leaderboard */
.hints .panel-block, .leaderboard .panel-block{margin-top:12px}
.leaderboard ol{padding-left:18px;color:var(--muted)}

/* Responsive */
@media (max-width:980px){
  .container{width:100%}
  .game-body{flex-direction:column}
  .left-panel{width:100%}
  .cell{width:40px;height:40px}
}

/* small niceties */
.footnote{margin-top:12px;color:var(--muted);text-align:center;font-size:13px;padding:6px}
.radio-row{display:flex;gap:8px;align-items:center}