:root{--bg: #f4f6fa;--panel: #ffffff;--panel-soft: #f8fafc;--border: #e8ecf3;--border-strong: #d8dee9;--text: #1f2937;--text-soft: #4b5563;--muted: #94a3b8;--accent: #3b6fff;--accent-hover: #2856e8;--accent-soft: #eef2ff;--danger: #ef4444;--success: #10b981;--shadow-sm: 0 1px 2px rgba(15, 23, 42, .04);--shadow: 0 4px 16px rgba(15, 23, 42, .06);--shadow-lg: 0 12px 32px rgba(15, 23, 42, .1);--radius: 14px;--radius-sm: 8px;--radius-pill: 999px}*{box-sizing:border-box}html{scrollbar-gutter:stable}html,body,#app{margin:0;height:100%;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Microsoft YaHei,sans-serif;font-size:14px;line-height:1.5;-webkit-font-smoothing:antialiased}h1,h2,h3,h4{margin:0;color:var(--text);font-weight:600}hr{border:0;border-top:1px solid var(--border)}button{font:inherit;font-weight:500;padding:9px 18px;border-radius:var(--radius-pill);border:1px solid var(--border-strong);background:var(--panel);color:var(--text);cursor:pointer;transition:all .15s ease;display:inline-flex;align-items:center;justify-content:center;gap:4px;white-space:nowrap}button:hover:not(:disabled){border-color:var(--accent);color:var(--accent);background:var(--accent-soft)}button:active:not(:disabled){transform:translateY(1px)}button.primary{background:var(--accent);border-color:var(--accent);color:#fff;box-shadow:0 2px 8px #3b6fff47}button.primary:hover:not(:disabled){background:var(--accent-hover);border-color:var(--accent-hover);color:#fff;box-shadow:0 4px 12px #3b6fff59}button:disabled{opacity:.45;cursor:not-allowed}input[type=number],input[type=text],input[readonly],select{font:inherit;padding:8px 12px;background:var(--panel);border:1px solid var(--border-strong);border-radius:var(--radius-sm);color:var(--text);transition:border-color .15s,box-shadow .15s;width:100%}select{appearance:none;-webkit-appearance:none;-moz-appearance:none;padding-right:36px;background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8' fill='none'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%2364748b' stroke-width='1.6' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 12px center;background-size:12px 8px}input:focus,select:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px #3b6fff26}input[readonly]{background:var(--panel-soft);color:var(--text-soft)}input[type=range]{-webkit-appearance:none;-moz-appearance:none;appearance:none;height:4px;background:var(--border-strong);border-radius:2px;outline:none;width:100%}input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;-moz-appearance:none;appearance:none;width:16px;height:16px;border-radius:50%;background:var(--accent);cursor:pointer;box-shadow:0 2px 4px #3b6fff66;border:2px solid #fff}input[type=range]::-moz-range-thumb{width:14px;height:14px;border-radius:50%;background:var(--accent);cursor:pointer;border:2px solid #fff}.panel{background:var(--panel);padding:24px;box-shadow:0 1px 3px #0f172a0a}.panel-title{font-size:15px;font-weight:600;color:var(--text);margin-bottom:16px}.checker-bg{background-color:#fff;background-image:linear-gradient(45deg,#e6e9f0 25%,transparent 25%),linear-gradient(-45deg,#e6e9f0 25%,transparent 25%),linear-gradient(45deg,transparent 75%,#e6e9f0 75%),linear-gradient(-45deg,transparent 75%,#e6e9f0 75%);background-size:16px 16px;background-position:0 0,0 8px,8px -8px,-8px 0}.stage{padding:16px;min-width:0;min-height:0;overflow:hidden;display:flex;flex-direction:column}.stage-toolbar{display:flex;align-items:center;justify-content:space-between;padding:0 8px 12px;border-bottom:1px solid var(--border);margin-bottom:12px;flex-wrap:wrap;gap:8px;flex-shrink:0}.stage-title{font-size:15px;font-weight:600}.canvas-wrap{position:relative;background:var(--panel-soft);flex:1;min-height:0;width:100%;min-width:0;box-sizing:border-box;display:flex;align-items:center;justify-content:center;overflow:hidden}.muted{color:var(--muted);font-size:13px}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-thumb{background:var(--border-strong);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--muted)}