.whiteboard-container{display:flex;flex-direction:column;width:100%;height:100%;border-radius:var(--radius-xl);overflow:hidden;box-shadow:var(--shadow-lg);animation:scaleIn .3s ease-out;background:var(--bg-primary)}.whiteboard-header{display:flex;justify-content:space-between;align-items:center;padding:12px var(--space-lg);border-bottom:1px solid var(--border-color);background:var(--bg-secondary)}.whiteboard-title{display:flex;align-items:center;gap:var(--space-sm)}.whiteboard-title h3{font-size:1rem;font-weight:700;color:var(--text-primary);margin:0}.whiteboard-title .icon{font-size:1.2rem}.badge-outline{border:1px solid var(--pink-500);color:var(--pink-500);background:transparent;padding:2px 8px;font-size:.75rem;border-radius:var(--radius-sm);margin-left:8px}.whiteboard-header .btn-close{background:transparent;border:none;font-size:1.2rem;color:var(--text-secondary);cursor:pointer;width:32px;height:32px;border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;transition:all var(--transition-fast)}.whiteboard-header .btn-close:hover{background:var(--bg-tertiary);color:var(--color-error)}.whiteboard-canvas-wrapper{flex:1;position:relative;overflow:hidden;min-height:0;--color-background: var(--bg-primary);--color-text: var(--text-primary)}.whiteboard-canvas-wrapper .excalidraw,.whiteboard-canvas-wrapper .excalidraw-container{width:100%;height:100%}.whiteboard-snapshot-bar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;padding:8px 12px;border-bottom:1px solid var(--border-color);background:var(--bg-secondary)}.whiteboard-snapshot-label{min-width:120px;flex:1;max-width:240px;padding:6px 10px;font-size:.85rem}.whiteboard-snapshot-select-wrap{display:flex;align-items:center;gap:6px;flex:1;min-width:180px}.whiteboard-snapshot-hint{font-size:.78rem;color:var(--text-secondary);white-space:nowrap}.whiteboard-snapshot-select{flex:1;min-width:0;padding:6px 10px;font-size:.85rem}.whiteboard-pdf-btn{display:inline-flex;align-items:center;gap:4px;white-space:nowrap}.whiteboard-pdf-input{display:none}.whiteboard-remote-cursor{position:absolute;pointer-events:none;transform:translate(-2px,-2px)}.whiteboard-cursor-label{position:absolute;top:16px;left:4px;font-size:.72rem;padding:2px 6px;border-radius:4px;color:#fff;white-space:nowrap;opacity:.9}.slide-uploader-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:#00000080;display:flex;justify-content:center;align-items:center;z-index:100;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);animation:fadeIn var(--transition-fast)}.slide-uploader-modal{width:90%;max-width:500px;background:var(--bg-primary);border-radius:var(--radius-xl);padding:var(--space-lg);display:flex;flex-direction:column;gap:var(--space-md);box-shadow:var(--shadow-lg)}.uploader-header{display:flex;justify-content:space-between;align-items:center}.uploader-header h3{margin:0;font-size:1.2rem}.drop-zone{border:2px dashed var(--border-color);border-radius:var(--radius-lg);padding:var(--space-2xl);text-align:center;cursor:pointer;transition:all var(--transition-normal);background:var(--bg-secondary)}.drop-zone:hover,.drop-zone.drag-active{border-color:var(--pink-400);background:var(--pink-50)}[data-theme=dark] .drop-zone:hover,[data-theme=dark] .drop-zone.drag-active{background:#ec48991a}.drop-zone-content{display:flex;flex-direction:column;align-items:center;gap:var(--space-sm);pointer-events:none}.upload-icon{font-size:3rem;opacity:.8}.upload-hint{font-size:.85rem;color:var(--text-muted)}.uploader-footer{display:flex;justify-content:space-between;align-items:center;margin-top:var(--space-sm)}.upload-note{font-size:.75rem;color:var(--text-secondary);margin:0}.drop-zone-busy{cursor:wait;opacity:.85;pointer-events:none}.slide-upload-progress{width:100%;max-width:280px;height:6px;border-radius:999px;background:var(--border-color);overflow:hidden;margin-top:var(--space-sm);position:relative}.slide-upload-progress:after{content:"";position:absolute;top:0;right:0;bottom:0;left:0;width:40%;background:linear-gradient(90deg,var(--pink-400),var(--pink-600));border-radius:inherit;animation:slide-upload-indeterminate 1.1s ease-in-out infinite}@keyframes slide-upload-indeterminate{0%{transform:translate(-100%)}to{transform:translate(350%)}}.presentation-container{display:flex;flex-direction:column;width:100%;height:100%;background:var(--bg-primary);border-radius:var(--radius-xl);overflow:hidden;box-shadow:var(--shadow-md)}.presentation-container.fullscreen{position:fixed;top:0;left:0;width:100vw;height:100vh;z-index:9999;border-radius:0}.presentation-header{display:flex;justify-content:space-between;align-items:center;padding:var(--space-sm) var(--space-md);border-bottom:1px solid var(--border-color);background:var(--bg-glass)}.presentation-title{font-size:1rem;font-weight:600;color:var(--text-primary);margin:0}.presentation-actions{display:flex;gap:var(--space-sm)}.presentation-body{flex:1;display:flex;justify-content:center;align-items:center;background:var(--bg-secondary);overflow:hidden;padding:var(--space-md)}.slide-wrapper{position:relative;max-width:100%;max-height:100%;display:flex;justify-content:center;align-items:center;box-shadow:var(--shadow-lg);border-radius:var(--radius-md);overflow:hidden;background:#fff}.slide-ink-svg{position:absolute;top:0;right:0;bottom:0;left:0;width:100%;height:100%;pointer-events:none}.slide-ink-svg.drawing{pointer-events:auto;touch-action:none;cursor:crosshair}.presentation-ink-hint{margin:0;padding:4px var(--space-md);font-size:.75rem;color:var(--text-secondary);text-align:center}.slide-image{max-width:100%;max-height:100%;object-fit:contain}.presentation-controls,.presentation-controls-student{display:flex;justify-content:space-between;align-items:center;padding:var(--space-sm) var(--space-lg);border-top:1px solid var(--border-color);background:var(--bg-glass)}.presentation-controls-student{justify-content:center;flex-wrap:wrap;gap:var(--space-md)}.presentation-follow-label{display:inline-flex;align-items:center;gap:8px;font-size:.85rem;color:var(--text-secondary);cursor:pointer;-webkit-user-select:none;user-select:none}.presentation-follow-label input{accent-color:var(--pink-500, #ec4899)}.slide-counter{font-weight:600;color:var(--text-secondary)}