:root{--color-primary: #1a73e8;--color-primary-hover: #1557b0;--color-danger: #d93025;--color-danger-hover: #b3261e;--color-bg: #f8f9fa;--color-surface: #ffffff;--color-border: #dadce0;--color-text: #202124;--color-text-secondary: #5f6368;--color-overlay: rgba(0, 0, 0, .5);--header-height: 56px;--toolbar-width: 56px;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .1);--shadow-md: 0 2px 8px rgba(0, 0, 0, .15);--shadow-lg: 0 4px 16px rgba(0, 0, 0, .2);--radius-sm: 4px;--radius-md: 8px;--radius-lg: 12px}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html,body{height:100%;overflow:hidden}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,sans-serif;color:var(--color-text);background:var(--color-bg);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#app{height:100%;display:flex;flex-direction:column}button{cursor:pointer;border:none;background:none;font:inherit;color:inherit}button:disabled{cursor:not-allowed;opacity:.5}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:8px 16px;border-radius:var(--radius-sm);font-size:14px;font-weight:500;transition:background-color .15s,box-shadow .15s}.btn-primary{background:var(--color-primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--color-primary-hover)}.btn-outline{border:1px solid var(--color-border);background:var(--color-surface)}.btn-outline:hover:not(:disabled){background:var(--color-bg)}.btn-danger{background:var(--color-danger);color:#fff}.btn-danger:hover:not(:disabled){background:var(--color-danger-hover)}.btn-icon{width:40px;height:40px;padding:0;border-radius:var(--radius-sm)}.btn-icon:hover:not(:disabled){background:#0000000f}.btn-icon.active{background:#1a73e81f;color:var(--color-primary)}