:root{--color-primary: #646cff;--color-primary-hover: #5558dd;--color-primary-light: #e8e8ff;--color-bg-main: #f8f9fa;--color-bg-toolbar: #ffffff;--color-bg-canvas: #ffffff;--color-border: #e0e0e0;--color-border-hover: #b0b0b0;--color-text: #333333;--color-text-light: #666666;--color-text-muted: #999999;--color-shadow: rgba(0, 0, 0, .08);--color-shadow-hover: rgba(0, 0, 0, .12);--spacing-xs: 4px;--spacing-sm: 8px;--spacing-md: 12px;--spacing-lg: 16px;--spacing-xl: 20px;--radius-sm: 6px;--radius-md: 8px;--radius-lg: 12px;--radius-xl: 16px;--radius-full: 9999px;--shadow-sm: 0 1px 2px var(--color-shadow);--shadow-md: 0 2px 8px var(--color-shadow);--shadow-lg: 0 4px 16px var(--color-shadow);--transition-fast: .15s ease;--transition-base: .2s ease;--transition-slow: .3s ease;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,sans-serif;line-height:1.5;font-weight:400;font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}a{font-weight:500;color:var(--color-primary);text-decoration:inherit;transition:color var(--transition-base)}a:hover{color:var(--color-primary-hover)}body{margin:0;min-width:320px;min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,sans-serif;background-color:var(--color-bg-main);color:var(--color-text)}#root{width:100vw;height:100vh;margin:0;padding:0}h1{font-size:3.2em;line-height:1.1}button{border-radius:var(--radius-md);border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;font-family:inherit;background-color:var(--color-bg-toolbar);color:var(--color-text);cursor:pointer;transition:all var(--transition-base)}button:hover:not(:disabled){background-color:var(--color-bg-main)}button:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}button:disabled{opacity:.5;cursor:not-allowed}.canvas-container{flex:1;width:100%;height:100%;position:relative;overflow:hidden;background-color:var(--color-bg-canvas);background-image:linear-gradient(var(--color-border) 1px,transparent 1px),linear-gradient(90deg,var(--color-border) 1px,transparent 1px);background-size:20px 20px;background-position:-1px -1px}.whiteboard-canvas{display:block;cursor:crosshair;touch-action:none}.toolbar{width:60px;background-color:var(--color-bg-toolbar);border-right:1px solid var(--color-border);display:flex;flex-direction:column;justify-content:space-between;position:relative;overflow:visible;box-shadow:var(--shadow-md);margin:var(--spacing-md);margin-right:0;border-radius:var(--radius-lg);padding:var(--spacing-sm) 0}.toolbar-main{display:flex;flex-direction:column;padding:var(--spacing-xs) 0;gap:var(--spacing-xs)}.tool-wrapper{position:relative;display:flex;justify-content:center}.tool-btn{width:44px;height:44px;padding:0;background-color:transparent;border:none;border-radius:var(--radius-md);cursor:pointer;font-size:20px;color:var(--color-text);transition:all var(--transition-base);display:flex;align-items:center;justify-content:center;position:relative}.tool-btn:hover:not(:disabled){background-color:var(--color-bg-main);transform:scale(1.05)}.tool-btn.active{background-color:var(--color-primary-light);color:var(--color-primary)}.tool-btn:active:not(:disabled){transform:scale(.98)}.tool-btn:disabled{opacity:.4;cursor:not-allowed}.tool-icon{font-size:22px;line-height:1;display:flex;align-items:center;justify-content:center}.shapes-menu{position:absolute;left:calc(100% + var(--spacing-sm));top:0;background-color:var(--color-bg-toolbar);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:var(--spacing-xs);box-shadow:var(--shadow-lg);z-index:1000;min-width:140px;animation:slideIn var(--transition-fast)}@keyframes slideIn{0%{opacity:0;transform:translate(-8px)}to{opacity:1;transform:translate(0)}}.shape-option{width:100%;padding:var(--spacing-sm) var(--spacing-md);background-color:transparent;border:none;border-radius:var(--radius-sm);cursor:pointer;font-size:14px;text-align:left;transition:all var(--transition-base);display:flex;align-items:center;gap:var(--spacing-sm);color:var(--color-text);margin-bottom:2px}.shape-option:last-child{margin-bottom:0}.shape-option:hover{background-color:var(--color-bg-main);transform:translate(2px)}.shape-option.active{background-color:var(--color-primary-light);color:var(--color-primary)}.shape-icon{font-size:16px;width:20px;display:inline-flex;align-items:center;justify-content:center}.toolbar-footer{display:flex;flex-direction:column;padding:var(--spacing-xs) 0;gap:var(--spacing-xs);border-top:1px solid var(--color-border);align-items:center;padding-top:var(--spacing-sm);margin-top:var(--spacing-sm)}.color-separator{width:32px;height:1px;background-color:var(--color-border);margin:var(--spacing-xs) 0}.color-indicator{width:32px;height:32px;border:2px solid var(--color-border);border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-base);background-color:currentColor;box-shadow:var(--shadow-sm)}.color-indicator:hover{transform:scale(1.1);box-shadow:var(--shadow-md);border-color:var(--color-border-hover)}@media(max-width:768px){.toolbar{width:56px;margin:var(--spacing-sm)}.tool-btn{width:40px;height:40px}.tool-icon{font-size:18px}}.color-label{position:relative;cursor:pointer}.color-input-hidden{position:absolute;opacity:0;width:100%;height:100%;top:0;left:0;cursor:pointer;border:none;padding:0}.width-menu{position:absolute;left:calc(100% + 8px);top:0;background:#fff;border:1px solid #e0e0e0;border-radius:10px;padding:12px;box-shadow:0 4px 20px #0000001f;z-index:100;min-width:160px;display:flex;flex-direction:column;gap:8px}.width-label{font-size:12px;color:#666;font-weight:500}.width-slider{width:100%;accent-color:#4a6cf7;cursor:pointer}.width-presets{display:flex;gap:6px;align-items:center;justify-content:space-between;margin-top:4px}.width-preset{flex:1;padding:6px 4px;border:1px solid #e0e0e0;border-radius:6px;background:#f8f8f8;cursor:pointer;display:flex;align-items:center;justify-content:center;min-height:32px;transition:background .15s,border-color .15s}.width-preset:hover,.width-preset.active{border-color:#4a6cf7;background:#eef1ff}.width-btn{display:flex;align-items:center;justify-content:center}.clear-btn{opacity:.7}.clear-btn:hover{opacity:1;background:#fff0f0}.header{background-color:var(--color-bg-toolbar);border-bottom:1px solid var(--color-border);padding:var(--spacing-sm) var(--spacing-lg);position:relative;z-index:100;box-shadow:var(--shadow-sm);margin:var(--spacing-md);margin-bottom:0;border-radius:var(--radius-lg)}.header-content{display:flex;justify-content:space-between;align-items:center;max-width:100%}.header-left{display:flex;align-items:center;gap:var(--spacing-md);flex:1}.header-logo{font-size:18px;font-weight:600;color:var(--color-text);display:flex;align-items:center;gap:var(--spacing-xs)}.board-name-input{padding:var(--spacing-sm) var(--spacing-md);border:1px solid transparent;border-radius:var(--radius-md);font-size:14px;font-weight:500;outline:none;transition:all var(--transition-base);background-color:transparent;max-width:200px;color:var(--color-text)}.board-name-input:hover{background-color:var(--color-bg-main)}.board-name-input:focus{border-color:var(--color-primary);background-color:var(--color-bg-toolbar);box-shadow:0 0 0 3px var(--color-primary-light)}.header-menu-btn{width:32px;height:32px;border:none;border-radius:var(--radius-md);background-color:transparent;cursor:pointer;font-size:20px;display:flex;align-items:center;justify-content:center;transition:all var(--transition-base);color:var(--color-text)}.header-menu-btn:hover{background-color:var(--color-bg-main);transform:scale(1.05)}.header-right{display:flex;gap:var(--spacing-sm);align-items:center}.header-btn{width:36px;height:36px;border:1px solid var(--color-border);border-radius:var(--radius-md);background-color:var(--color-bg-toolbar);cursor:pointer;font-size:18px;transition:all var(--transition-base);display:flex;align-items:center;justify-content:center;color:var(--color-text)}.header-btn:hover{border-color:var(--color-border-hover);background-color:var(--color-bg-main);transform:translateY(-1px);box-shadow:var(--shadow-sm)}.profile-button{width:36px;height:36px;border:none;border-radius:var(--radius-full);background-color:transparent;cursor:pointer;padding:0;display:flex;align-items:center;justify-content:center;transition:transform var(--transition-base)}.profile-button:hover{transform:scale(1.05)}.profile-icon{width:32px;height:32px;border-radius:var(--radius-full);background-color:var(--color-primary);border:2px solid var(--color-bg-toolbar);box-shadow:var(--shadow-sm);transition:box-shadow var(--transition-base)}.profile-button:hover .profile-icon{box-shadow:var(--shadow-md)}.present-button,.share-button{padding:var(--spacing-sm) var(--spacing-lg);border:1px solid var(--color-border);border-radius:var(--radius-md);background-color:var(--color-bg-toolbar);cursor:pointer;font-size:14px;font-weight:500;transition:all var(--transition-base);display:flex;align-items:center;gap:var(--spacing-sm);color:var(--color-text)}.present-button:hover,.share-button:hover{border-color:var(--color-border-hover);background-color:var(--color-bg-main);transform:translateY(-1px);box-shadow:var(--shadow-sm)}.share-button{background-color:var(--color-primary);color:#fff;border-color:var(--color-primary)}.share-button:hover{background-color:var(--color-primary-hover);border-color:var(--color-primary-hover);box-shadow:var(--shadow-md)}@media(max-width:768px){.header{margin:var(--spacing-sm);padding:var(--spacing-sm) var(--spacing-md)}.header-left{gap:var(--spacing-sm)}.header-logo{font-size:16px}.board-name-input{max-width:120px;font-size:13px}.header-right{gap:var(--spacing-xs)}.header-btn{width:32px;height:32px;font-size:16px}.present-button,.share-button{padding:var(--spacing-sm) var(--spacing-md);font-size:13px}}.zoom-controls{position:fixed;bottom:var(--spacing-xl);right:var(--spacing-xl);display:flex;align-items:center;background-color:var(--color-bg-toolbar);border:1px solid var(--color-border);border-radius:var(--radius-full);padding:var(--spacing-xs);gap:2px;box-shadow:var(--shadow-lg);z-index:50}.zoom-button,.zoom-minimap,.zoom-help{width:36px;height:36px;border:none;background-color:transparent;cursor:pointer;font-size:18px;font-weight:500;border-radius:var(--radius-full);transition:all var(--transition-base);display:flex;align-items:center;justify-content:center;color:var(--color-text)}.zoom-button:hover,.zoom-minimap:hover,.zoom-help:hover{background-color:var(--color-bg-main);transform:scale(1.1)}.zoom-button:active{background-color:var(--color-border);transform:scale(.95)}.zoom-display{min-width:60px;height:36px;border:none;background-color:transparent;cursor:pointer;font-size:13px;font-weight:600;border-radius:var(--radius-full);transition:all var(--transition-base);color:var(--color-text);padding:0 var(--spacing-sm)}.zoom-display:hover{background-color:var(--color-bg-main);transform:scale(1.05)}.zoom-divider{width:1px;height:24px;background-color:var(--color-border);margin:0 var(--spacing-xs)}.zoom-minimap,.zoom-help{font-size:16px}@media(max-width:768px){.zoom-controls{bottom:var(--spacing-lg);right:var(--spacing-lg);padding:var(--spacing-xs)}.zoom-button,.zoom-minimap,.zoom-help{width:32px;height:32px;font-size:16px}.zoom-display{min-width:55px;height:32px;font-size:12px}}.app{display:flex;flex-direction:column;height:100vh;width:100vw;overflow:hidden;background-color:var(--color-bg-main)}.app-content{display:flex;flex:1;overflow:hidden;gap:0}@media(max-width:768px){.app-content{flex-direction:column}}