:root{--fold-color: #2563eb;--cut-color: #ea580c;--result-color: #059669;--unfolded-color: #e11d48;--error-color: #b91c1c;--border: #e2e8f0;--bg-panel: #ffffff;--bg-sidebar: #f8fafc;--bg-canvas: #1e2230;--text-primary: #0f172a;--text-secondary: #64748b;--radius: 8px;font-family:IBM Plex Sans,Noto Sans TC,system-ui,sans-serif;color:var(--text-primary)}body{margin:0;background:var(--bg-canvas)}.layout{height:100dvh;display:grid;grid-template-rows:48px 1fr 32px;grid-template-columns:188px 1fr 252px}.topBar{grid-column:1 / -1;display:flex;align-items:center;gap:6px;padding:0 12px;background:#0f172a;border-bottom:1px solid #1e293b;color:#f1f5f9}.topBar h1{font-size:15px;font-weight:700;margin:0 8px 0 0;color:#f1f5f9;letter-spacing:-.3px}.topBarSpacer{flex:1}.leftPanel{display:flex;flex-direction:column;background:var(--bg-sidebar);border-right:1px solid var(--border);overflow-y:auto}.centerCanvas{overflow:hidden;position:relative;background:var(--bg-canvas)}.rightPanel{display:flex;flex-direction:column;background:var(--bg-sidebar);border-left:1px solid var(--border);overflow:hidden}.statusBar{grid-column:1 / -1;display:flex;align-items:center;justify-content:space-between;padding:0 14px;background:#0f172a;border-top:1px solid #1e293b;font-size:12px;color:#94a3b8}.statusInstruction{color:#cbd5e1;display:flex;align-items:center;gap:6px}.statusError{color:#fca5a5}.toolBtn{width:100%;display:flex;align-items:center;gap:9px;padding:9px 12px;border:none;border-left:3px solid transparent;background:transparent;cursor:pointer;font-size:13px;font-family:inherit;text-align:left;box-sizing:border-box;color:var(--text-secondary);transition:background .1s,color .1s}.toolBtn:hover{background:#f1f5f9;color:var(--text-primary)}.toolBtn.active{background:#eff6ff;border-left-color:var(--fold-color);color:var(--fold-color);font-weight:500}.toolOptions{padding:12px;border-top:1px solid var(--border);display:flex;flex-direction:column;gap:8px}.toolOptions label{display:grid;gap:4px;font-size:12px;color:var(--text-secondary);font-weight:500}.symFoldDivider{height:1px;background:var(--border);margin:2px 0}.toolOptions input,.toolOptions select{border:1px solid var(--border);border-radius:6px;padding:6px 9px;background:#fff;font-family:inherit;font-size:13px;color:var(--text-primary);transition:border-color .15s}.toolOptions input:focus,.toolOptions select:focus{outline:none;border-color:var(--fold-color)}.canvas{width:100%;height:100%;display:block}.paper{fill:#fff;stroke:#cbd5e1;stroke-width:1;filter:drop-shadow(0 4px 16px rgba(0,0,0,.35))}.resultCut{fill:var(--unfolded-color);fill-opacity:.65;stroke:#9f1239;stroke-width:1}.foldGuide{stroke:var(--fold-color);stroke-width:1.5;stroke-dasharray:4 3;opacity:.8}.foldHistory{stroke:#94a3b8;stroke-width:.75;stroke-dasharray:3 3}.cutGuide{fill:#2563eb14;stroke:var(--fold-color);stroke-width:1.5}.cutOverlay{fill:#ea580c33;stroke:var(--cut-color);stroke-width:1;stroke-dasharray:3 2}.freehandGuide{stroke:#9a3412;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:3 2}.polygonGuide{stroke:#065f46;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round;stroke-dasharray:3 2}.foldedResult{fill:#10b981;fill-opacity:.45;stroke:#047857;stroke-width:.75}.iconBtn{display:inline-flex;align-items:center;gap:5px;border:1px solid var(--border);border-radius:6px;padding:5px 10px;background:#fff;cursor:pointer;font-size:12px;font-family:inherit;color:var(--text-primary);white-space:nowrap;transition:background .1s,border-color .1s}.iconBtn:hover:not(:disabled){background:#f8fafc;border-color:#94a3b8}.iconBtn:disabled{opacity:.38;cursor:default}.topBar .iconBtn{background:#1e293b;border-color:#334155;color:#cbd5e1}.topBar .iconBtn:hover:not(:disabled){background:#334155;border-color:#475569;color:#f1f5f9}.paperSizePill{display:inline-flex;align-items:center;gap:5px;font-size:12px;padding:4px 10px;border:1px solid #334155;border-radius:20px;cursor:pointer;background:#1e293b;color:#94a3b8;font-family:inherit;transition:background .1s,color .1s}.paperSizePill:hover{background:#334155;color:#e2e8f0}.paperSizeForm{display:flex;align-items:center;gap:6px;font-size:12px;color:#94a3b8}.paperSizeForm input{width:48px;border:1px solid #334155;border-radius:5px;padding:3px 6px;background:#1e293b;color:#f1f5f9;font-family:inherit;font-size:12px}.exportWrap{position:relative}.exportMenu{position:absolute;top:calc(100% + 6px);right:0;background:#1e293b;border:1px solid #334155;border-radius:var(--radius);box-shadow:0 8px 24px #0006;min-width:175px;z-index:20}.exportMenuItem{display:block;width:100%;text-align:left;padding:8px 12px;border:none;background:transparent;cursor:pointer;font-size:12px;font-family:inherit;color:#cbd5e1;border-radius:0}.exportMenuItem:first-child{border-radius:var(--radius) var(--radius) 0 0}.exportMenuItem:last-child{border-radius:0 0 var(--radius) var(--radius)}.exportMenuItem:hover{background:#334155;color:#f1f5f9}.exportMenuItem:disabled{opacity:.35;cursor:default}.resultLabel{padding:10px 12px 6px;font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary);border-bottom:1px solid var(--border)}.resultSvgWrap{flex:0 0 auto;padding:10px}.resultSvg{width:100%;aspect-ratio:1;display:block;border:1px solid var(--border);border-radius:6px;background:#f8fafc}.unfoldedPiece{fill:#10b981;fill-opacity:.45;stroke:#047857;stroke-width:.75}.stepsLabel{padding:10px 12px 6px;font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary);border-bottom:1px solid var(--border)}.stepList{padding:0;margin:0;list-style:none;overflow-y:auto;flex:1}.stepCard{display:flex;align-items:center;gap:8px;padding:7px 12px;border-bottom:1px solid var(--border);font-size:12px}.stepBadge{font-size:10px;font-weight:700;padding:2px 6px;border-radius:4px;letter-spacing:.04em;text-transform:uppercase}.stepBadge.fold{background:#dbeafe;color:#1d4ed8}.stepBadge.cut{background:#ffedd5;color:#c2410c}.stepSummary{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;color:var(--text-secondary)}.stepsEmpty{padding:16px 12px;font-size:12px;color:#94a3b8;text-align:center}.removeBtn{border:none;background:transparent;cursor:pointer;color:#cbd5e1;padding:3px 5px;font-size:13px;border-radius:4px;transition:color .1s,background .1s}.removeBtn:hover{color:var(--error-color);background:#fee2e2}.topBar select{background:#1e293b;border:1px solid #334155;color:#94a3b8;border-radius:5px;padding:3px 7px;font-size:12px;font-family:inherit;cursor:pointer}@media (max-width: 960px){.layout{grid-template-columns:1fr;grid-template-rows:48px auto auto auto 32px}.leftPanel{border-right:none;border-bottom:1px solid var(--border)}.rightPanel{border-left:none;border-top:1px solid var(--border)}}