*{margin:0;padding:0;box-sizing:border-box}:root{--primary-color:#6366f1;--primary-dark:#4f46e5;--secondary-color:#10b981;--secondary-dark:#059669;--background:#f8fafc;--surface:#fff;--text-primary:#1e293b;--text-secondary:#64748b;--border:#e2e8f0;--border-focus:#cbd5e1;--shadow:rgba(0,0,0,.1);--shadow-lg:rgba(0,0,0,.15)}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh;padding:2rem;color:var(--text-primary)}.container{max-width:1200px;margin:0 auto}header{text-align:center;color:#fff;margin-bottom:3rem}header h1{font-size:2.5rem;font-weight:700;margin-bottom:.5rem;text-shadow:2px 2px 4px rgba(0,0,0,.2)}.subtitle{font-size:1.1rem;opacity:.95}.main-content{display:grid;grid-template-columns:1fr 1fr;grid-gap:2rem;gap:2rem;margin-bottom:2rem}section{background:var(--surface);border-radius:12px;padding:2rem;box-shadow:0 10px 25px var(--shadow-lg)}section h2{font-size:1.5rem;color:var(--text-primary)}.input-group,.output-group,section h2{margin-bottom:1.5rem}label{display:block;margin-bottom:.5rem;font-weight:600;color:var(--text-secondary);font-size:.9rem;text-transform:uppercase;letter-spacing:.5px}textarea{width:100%;padding:1rem;border:2px solid var(--border);border-radius:8px;font-family:Monaco,Menlo,Ubuntu Mono,monospace;font-size:.95rem;resize:vertical;transition:all .3s ease;background:var(--background);color:var(--text-primary)}textarea:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 3px rgba(99,102,241,.1)}textarea[readonly]{background:var(--background);cursor:default}.textarea-wrapper{position:relative;display:inline-block;width:100%}.copy-button{position:absolute;top:.75rem;right:.75rem;padding:.5rem .75rem;border:none;border-radius:6px;background:var(--surface);color:var(--text-secondary);font-size:1.1rem;cursor:pointer;transition:all .2s ease;box-shadow:0 2px 4px rgba(0,0,0,.1);z-index:10;line-height:1;display:flex;align-items:center;justify-content:center;min-width:2.5rem}.copy-button:hover{background:var(--primary-color);color:#fff;transform:scale(1.05);box-shadow:0 4px 8px rgba(99,102,241,.3)}.copy-button:active{transform:scale(.95)}.btn{padding:.75rem 1.5rem;border:none;border-radius:8px;font-size:1rem;font-weight:600;cursor:pointer;transition:all .3s ease;text-transform:uppercase;letter-spacing:.5px;margin-bottom:1.5rem}.btn-primary{background:var(--primary-color);color:#fff}.btn-primary:hover{background:var(--primary-dark);transform:translateY(-2px);box-shadow:0 4px 12px rgba(99,102,241,.4)}.btn-secondary{background:var(--secondary-color);color:#fff}.btn-secondary:hover{background:var(--secondary-dark);transform:translateY(-2px);box-shadow:0 4px 12px rgba(16,185,129,.4)}.btn-outline{background:transparent;color:var(--primary-color);border:2px solid var(--primary-color)}.btn-outline:hover{background:var(--primary-color);color:#fff}.stats{display:flex;gap:2rem;padding-top:1rem;border-top:1px solid var(--border)}.stat-item{display:flex;flex-direction:column}.stat-label{font-size:.85rem;color:var(--text-secondary);margin-bottom:.25rem}.stat-item span:last-child{font-size:1.1rem;font-weight:700;color:var(--primary-color)}.tree-section{margin-top:2rem}#tree-info,#tree-info p{margin-bottom:1rem}#tree-info p{color:var(--text-secondary)}code{padding:.2rem .5rem;border-radius:4px;font-size:.9rem;color:var(--primary-color)}.tree-display,code{background:var(--background);font-family:Monaco,Menlo,Ubuntu Mono,monospace}.tree-display{border:2px solid var(--border);border-radius:8px;padding:1.5rem;font-size:.85rem;white-space:pre-wrap;max-height:400px;overflow-y:auto}.hidden{display:none}.error{color:#ef4444;background:#fee2e2;border-left:4px solid #ef4444}.error,.success{padding:1rem;border-radius:8px;margin-top:1rem}.success{color:var(--secondary-dark);background:#d1fae5;border-left:4px solid var(--secondary-dark)}.tabs{display:flex;gap:.5rem;margin-bottom:1rem;border-bottom:2px solid var(--border)}.tab{padding:.5rem 1rem;background:transparent;color:var(--text-secondary);font-size:.9rem;font-weight:600;cursor:pointer;transition:all .3s ease;border:none;border-bottom:2px solid transparent;margin-bottom:-2px;text-transform:uppercase;letter-spacing:.5px}.tab.active,.tab:hover:not(:disabled){color:var(--primary-color);background:var(--background)}.tab.active{border-bottom-color:var(--primary-color)}.tab:disabled{opacity:.5;cursor:not-allowed}@media (max-width:768px){.main-content{grid-template-columns:1fr}header h1{font-size:2rem}.stats{flex-direction:column;gap:1rem}.tabs{flex-wrap:wrap}.tab{font-size:.85rem;padding:.4rem .8rem}}