:root{--bg: #faf6f4;--panel: #ffffff;--accent: #c1272d;--accent-soft: #f4ebe8;--border: #eee0db;--border-strong: #d4c4be;--text: #2a1f1f;--muted: #6a5a5a;--mono: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;--serif: "Iowan Old Style", "Palatino", Georgia, serif}*{box-sizing:border-box}html,body,#root{margin:0;padding:0;min-height:100%}body{background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;font-size:14px;line-height:1.45}.app{max-width:1500px;margin:0 auto;padding:28px 24px 60px}header{text-align:center;margin-bottom:4px}header h1{margin:0;font-size:30px;font-weight:600;letter-spacing:-.01em}header .subtitle{color:var(--muted);margin:6px auto 20px;max-width:900px;font-size:15px;font-style:italic}header .subtitle a{color:var(--accent);text-decoration:none;border-bottom:1px dotted currentColor}header .subtitle a:hover{border-bottom-style:solid}footer{margin-top:36px;color:var(--muted);font-size:12.5px;text-align:center}footer a{color:var(--accent);text-decoration:none}footer a:hover{text-decoration:underline}.controls{background:var(--panel);border-radius:14px;padding:20px 22px;margin-bottom:24px;border:1px solid var(--border);box-shadow:0 1px 2px #3c1e1e08}.settings-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:22px 32px;align-items:start}.control-group{display:flex;flex-direction:column;gap:8px;min-width:0}.control-label{font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);font-weight:600}.segmented{display:inline-flex;border:1px solid var(--border-strong);border-radius:8px;overflow:hidden;background:#fff;width:fit-content;max-width:100%;box-shadow:0 1px #3c1e1e05}.segmented button{background:transparent;border:none;border-right:1px solid var(--border-strong);padding:6px 14px;cursor:pointer;color:var(--text);font-size:13px;font-family:inherit;transition:background-color .12s ease;white-space:nowrap}.segmented button:last-child{border-right:none}.segmented button:hover:not(.active){background:var(--accent-soft)}.segmented button.active{background:var(--accent);color:#fff}.segmented button:focus-visible{outline:2px solid var(--accent);outline-offset:-2px;position:relative;z-index:1}.control-hint{font-size:12.5px;color:var(--muted);line-height:1.5;min-height:2.6em}.divider{border:none;border-top:1px solid var(--border);margin:18px 0 14px}.math-input{display:flex;flex-direction:column;gap:10px}.formula-row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.formula-row label{display:flex;align-items:center;gap:8px;flex:1;min-width:280px}.formula-label{font-family:var(--serif);font-style:italic;font-size:16px;white-space:nowrap;color:var(--text)}.formula-row input{flex:1;padding:7px 12px;font-family:var(--mono);font-size:13px;border:1px solid var(--border-strong);border-radius:6px;background:#fbf8f6;color:var(--text)}.formula-row input:focus{outline:none;border-color:var(--accent);background:#fff;box-shadow:0 0 0 3px #c1272d1f}button.primary{background:var(--accent);color:#fff;border:none;padding:7px 18px;border-radius:6px;cursor:pointer;font-size:13px;font-family:inherit;font-weight:500}button.primary:hover{filter:brightness(1.05)}.presets{display:flex;gap:6px;flex-wrap:wrap;align-items:center}.presets-label{color:var(--muted);font-size:11px;text-transform:uppercase;letter-spacing:.08em;font-weight:600;margin-right:6px}.presets button{background:var(--accent-soft);color:var(--text);border:1px solid transparent;padding:4px 10px;border-radius:5px;font-size:12.5px;cursor:pointer;font-family:inherit;transition:background-color .12s ease,border-color .12s ease}.presets button:hover{background:#ebd9d4;border-color:var(--border-strong)}.footnote{color:var(--muted);font-size:12px;line-height:1.5}.footnote code{font-family:var(--mono);background:var(--accent-soft);padding:1px 5px;border-radius:3px;font-size:11.5px}.error{color:var(--accent);font-size:13px;font-family:var(--mono);background:var(--accent-soft);padding:6px 10px;border-radius:4px}.brush-controls{display:flex;align-items:center;gap:14px;flex-wrap:wrap}.brush-controls button{background:var(--accent-soft);color:var(--text);border:1px solid var(--border-strong);padding:6px 14px;border-radius:6px;cursor:pointer;font-family:inherit;font-size:13px}.brush-controls button:hover{background:#ebd9d4}.panels{display:flex;align-items:center;gap:14px;justify-content:center;flex-wrap:wrap}.panel{background:var(--panel);border-radius:14px;padding:14px;border:1px solid var(--border);text-align:center;box-shadow:0 1px 2px #3c1e1e08}.panel canvas{display:block;border-radius:10px;background:#fff7f4}.panel-title{display:flex;flex-direction:column;align-items:center;gap:2px;margin-bottom:10px;font-family:var(--serif)}.panel-title .bold{font-weight:700;font-size:20px;font-style:italic}.panel-title .formula{font-size:13px;color:var(--muted);font-style:italic}.symbol{font-size:40px;font-weight:300;color:var(--muted);font-family:var(--serif);padding:0 4px}