:root{--bg:#fafafa;--panel:#ffffff;--panel-2:#f5f5f5;--border:#e4e4e7;--border-strong:#d4d4d8;--text:#18181b;--muted:#71717a;--accent:#2563eb;--accent-soft:#eff6ff;--ok:#047857;--ok-soft:#ecfdf5;--warn:#b45309;--warn-soft:#fffbeb;--mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;--sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;--radius:10px}*{box-sizing:border-box}body,html{margin:0;padding:0}body{font-family:var(--sans);background:var(--bg);color:var(--text);line-height:1.5;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}.page{max-width:660px;margin:0 auto;padding:56px 20px 96px}.title{font-size:1.5rem;font-weight:600;letter-spacing:-.01em;margin:0 0 4px}.subtitle{color:var(--muted);font-size:.95rem;margin:0 0 28px}.card{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:20px}.card+.card{margin-top:16px}.label{display:block;font-size:.8rem;font-weight:600;color:var(--muted);text-transform:uppercase;letter-spacing:.04em;margin-bottom:8px}.eq-input{width:100%;font-family:var(--mono);font-size:1rem;padding:12px 14px;border:1px solid var(--border-strong);border-radius:8px;background:var(--panel-2);color:var(--text)}.eq-input:focus{outline:2px solid var(--accent);outline-offset:1px;background:var(--panel)}.examples{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}.chip{font-family:var(--mono);font-size:.78rem;padding:5px 10px;border:1px solid var(--border);border-radius:999px;background:var(--panel);color:var(--muted);cursor:pointer}.chip:hover{border-color:var(--accent);color:var(--accent)}.hint{color:var(--muted);font-size:.85rem;margin:10px 0 0}.error{color:var(--warn);background:var(--warn-soft);border:1px solid #fde68a;border-radius:8px;padding:10px 12px;font-size:.88rem;margin:12px 0 0}.vars{display:flex;flex-direction:column;gap:10px}.var-row{display:grid;grid-template-columns:auto 1fr 1.4fr;align-items:center;grid-gap:12px;gap:12px}.var-radio{display:inline-flex;align-items:center;gap:6px;font-size:.82rem;color:var(--muted);white-space:nowrap;cursor:pointer}.var-name{font-size:.98rem;font-weight:600}.var-input,.var-name{font-family:var(--mono)}.var-input{width:100%;font-size:.95rem;padding:9px 11px;border:1px solid var(--border-strong);border-radius:8px;background:var(--panel);color:var(--text)}.var-input:focus{outline:2px solid var(--accent);outline-offset:1px}.var-input--target{background:var(--accent-soft);border-color:#bfdbfe}.solve-btn{margin-top:18px;width:100%;font-size:.98rem;font-weight:600;padding:12px 16px;border:none;border-radius:8px;background:var(--accent);color:#fff;cursor:pointer}.solve-btn:disabled{background:var(--border-strong);color:var(--muted);cursor:not-allowed}.result-value{font-family:var(--mono);font-size:2rem;font-weight:600;letter-spacing:-.01em;word-break:break-all}.result-target{color:var(--muted);font-family:var(--mono);font-size:1rem}.result-meta{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:14px}.badge{font-size:.78rem;font-weight:600;padding:4px 10px;border-radius:999px}.badge--direct{background:var(--accent-soft);color:var(--accent)}.badge--iter{background:var(--panel-2);color:var(--muted)}.badge--ok{background:var(--ok-soft);color:var(--ok)}.badge--warn{background:var(--warn-soft);color:var(--warn)}.detail{margin-top:12px;font-size:.82rem;color:var(--muted);font-family:var(--mono)}.detail span{margin-right:16px}.gm-back{position:fixed;bottom:12px;left:14px;z-index:99999;font:500 12px/1 system-ui,-apple-system,sans-serif;color:#94a3b8;text-decoration:none;opacity:.55;transition:opacity .2s}.gm-back:hover{opacity:1}