:root{--bg:#f8fafc;--card:#fff;--muted:#475569;--text:#0f172a;--accent:#2563eb;--accent2:#7c3aed;--danger:#dc2626;--border:#e2e8f0}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.45 system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Noto Sans,sans-serif}
.mo-wrap{max-width:1100px;margin:2rem auto;padding:1rem}
.header{display:flex;flex-wrap:wrap;gap:1rem;align-items:center;justify-content:space-between}
.title{font-size:clamp(1.2rem,2.5vw,2rem);font-weight:800;color:var(--accent)}
.subtitle{color:var(--muted);font-size:.98rem}
.card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:1rem;box-shadow:0 6px 18px rgba(2,6,23,.05)}
.controls{display:grid;grid-template-columns:repeat(4,1fr);gap:.75rem}
@media (max-width:780px){.controls{grid-template-columns:1fr 1fr}}
label{display:block;font-size:.8rem;color:var(--muted);margin-bottom:.25rem}
select,input[type="number"],button{width:100%;background:#fff;border:1px solid var(--border);color:var(--text);border-radius:12px;padding:.6rem .7rem}
button.ghost{background:#fff;border:1px dashed var(--border)}
.legend{display:flex;flex-wrap:wrap;gap:.6rem;align-items:center;color:var(--muted)}
.dot{width:10px;height:10px;border-radius:50%}
.dot.sigma{background:var(--accent)}.dot.pi{background:var(--accent2)}.dot.star{background:var(--danger)}
.diagram-wrap{position:relative;height:560px;background:#f1f5f9;border:1px solid var(--border);border-radius:12px}
.axis{position:absolute;left:50%;transform:translateX(-50%);top:10px;bottom:10px;width:2px;background:linear-gradient(180deg,#cbd5e1,#e2e8f0)}
svg{width:100%;height:100%}
.level{stroke:#94a3b8;stroke-width:1.5;shape-rendering:geometricPrecision}
.mo{stroke-width:2.5}
.mo.sigma{stroke:var(--accent)}.mo.pi{stroke:var(--accent2)}.mo.antibond{stroke-dasharray:6 5}
.label{font-size:12px;fill:#334155}
.e-line{stroke:#0f172a;stroke-width:2;stroke-linecap:square}
.tests{margin-top:1rem}
.tests pre{background:#f8fafc;border:1px solid var(--border);padding:.75rem;border-radius:12px;max-height:220px;overflow:auto}