:root{
  --bg:#e6f7ff; --panel:#ffffff; --accent:#0b78d1; --danger:#e74c3c;
  --glass: rgba(255,255,255,0.8);
  --muted:#6b7280;
  --shadow: 0 6px 18px rgba(11,120,209,0.12);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}
*{box-sizing:border-box}
html,body{height:100%; margin:0; background:linear-gradient(180deg,#e6fbff 0%, #c5eefe 100%); color:#032a3b}
.oc-wrapper{max-width:1200px;margin:18px auto;padding:18px}
.oc-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:12px}
.oc-header h1{margin:0;font-size:1.6rem;letter-spacing:0.3px}
.oc-header-actions{display:flex;gap:8px;align-items:center}
.oc-header-actions button, .oc-header-actions a{background:var(--panel);border:1px solid rgba(0,0,0,0.06);padding:8px 10px;border-radius:8px;cursor:pointer;box-shadow:var(--shadow)}
.open-hub{ text-decoration:none;color:inherit }

.oc-main{display:grid;grid-template-columns:1fr 320px;gap:16px}
.oc-canvas-wrap{background:linear-gradient(180deg, #bfe9ff, #9fdfff);border-radius:12px;padding:12px;box-shadow:var(--shadow);display:flex;align-items:center;justify-content:center}
canvas{display:block;width:100%;height:auto;border-radius:8px;background:linear-gradient(180deg,rgba(255,255,255,0.03),transparent);}

.oc-ui{display:flex;flex-direction:column;gap:12px}
.panel{background:var(--panel);padding:12px;border-radius:12px;box-shadow:0 6px 18px rgba(2,6,23,0.06)}
.stat{display:flex;justify-content:space-between;align-items:center;padding:6px 0;border-bottom:1px dashed rgba(0,0,0,0.04)}
.stat:last-child{border-bottom:none}
.stat strong{font-size:0.85rem;color:var(--muted)}
.stat div{font-size:1.2rem;font-weight:700;color:var(--accent)}

.upgrades h3{margin:0 0 8px 0}
.upgrade-list{display:flex;flex-direction:column;gap:8px}
.upgrade-btn{padding:8px;border-radius:8px;border:1px solid rgba(0,0,0,0.06);background:linear-gradient(180deg,#ffffff,#f6fbff);cursor:pointer}
.upgrade-btn:disabled{opacity:0.5;cursor:not-allowed}
.save-note{margin-top:8px;color:var(--muted);font-size:0.9rem}

.tips ul{margin:8px 0 0 16px;padding:0;color:var(--muted);font-size:0.9rem}
.tips h4{margin:0 0 6px 0}

.oc-footer{margin-top:12px;text-align:center;color:var(--muted)}
@media (max-width:1000px){
  .oc-main{grid-template-columns:1fr 300px}
}
@media (max-width:820px){
  .oc-wrapper{padding:12px}
  .oc-main{grid-template-columns:1fr;align-items:start}
  .oc-ui{order:2}
}