:root{
  --sidebar-w: 320px;
  --bg: #0f1113;
  --panel: #0b0d0f;
  --muted: #98a0a6;
  --accent: #7aa2ff;
}

/* Reset + enforce two-column layout to avoid stacking */
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%;width:100%;font-family:system-ui,-apple-system,"Segoe UI",Roboto, "Helvetica Neue", Arial;background:var(--bg);color:#e9eef6}
#app{
  display:flex !important;
  flex-direction:row !important;
  height:100vh !important;
  width:100vw !important;
  overflow:hidden !important;
}

/* Sidebar (left) */
#sidebar{
  flex:0 0 var(--sidebar-w) !important;
  width:var(--sidebar-w) !important;
  min-width:var(--sidebar-w) !important;
  max-width:var(--sidebar-w) !important;
  background:linear-gradient(180deg,var(--panel),#0a0b0c);
  border-right:1px solid rgba(255,255,255,0.03);
  padding:20px;
  display:flex;
  flex-direction:column;
  gap:14px;
  z-index:20;
  overflow:auto;
}

/* Brand */
.brand{display:flex;align-items:center;gap:10px}
.logo{width:36px;height:36px;border-radius:8px;background:#111315;display:flex;align-items:center;justify-content:center;font-size:18px}
.title{font-weight:600;font-size:16px;color:#fff}

/* Controls */
.controls{display:flex;flex-direction:column;gap:12px}
.control label{display:block;font-size:13px;color:var(--muted);margin-bottom:8px}
.control input[type="range"]{width:100%}
.control input[type="number"]{width:100%;padding:6px 8px;border-radius:6px;border:1px solid rgba(255,255,255,0.04);background:#0d0f11;color:#eaf0ff}
.values{display:flex;justify-content:space-between;align-items:center;font-size:13px;color:var(--muted);margin-top:6px}
.values strong{color:#fff}

/* Buttons row */
.row{display:flex;gap:8px}
.btn{
  flex:1;
  background:#141617;
  color:#eaf0ff;
  border:1px solid rgba(255,255,255,0.04);
  padding:8px 10px;
  border-radius:8px;
  cursor:pointer;
  font-size:13px;
}
.btn:active{transform:translateY(1px)}
.hint{font-size:13px;color:var(--muted)}
.hint ul{padding-left:18px;margin-top:6px}

/* Footer / legend */
.footer{margin-top:auto;font-size:13px;color:var(--muted)}
.legend{display:flex;align-items:center;gap:8px}
.dot{width:12px;height:12px;border-radius:50%}
.dot.nucleus{background:#ff6b6b}

/* Canvas container (right) */
#canvas-container{
  flex:1 1 auto !important;
  min-width:0 !important;
  background:#000;
  position:relative;
  overflow:hidden;
  display:flex;
  align-items:stretch;
  justify-content:stretch;
}

/* p5 canvas fill */
#canvas-container canvas{width:100% !important;height:100% !important;display:block;}

/* Small tweak for very narrow screens */
@media (max-width:420px){
  :root{--sidebar-w:260px}
  #sidebar{padding:12px}
  .title{font-size:14px}
}