.whiteboard-header {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    align-items: flex-start;
    margin-bottom: 0.75rem;
}

.whiteboard-header__actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.whiteboard-name-label {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    font-size: 0.9rem;
    color: var(--muted);
}

.whiteboard-name-label input {
    min-width: 160px;
}

.whiteboard-layout {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 0.75rem;
    align-items: stretch;
}

.whiteboard-toolbar {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 0.75rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    height: fit-content;
    position: sticky;
    top: 1rem;
}

.whiteboard-toolbar__group {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.whiteboard-tool {
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--fg);
    border-radius: 10px;
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    transition: background 120ms ease, box-shadow 120ms ease, border-color 120ms ease;
}

.whiteboard-tool.active {
    background: var(--accent-soft);
    color: var(--accent-contrast);
    border-color: var(--accent);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.whiteboard-colors {
    display: flex;
    gap: 0.4rem;
}

.whiteboard-color {
    width: 32px;
    height: 32px;
    border-radius: 10px;
    border: 1px solid var(--border);
    background: var(--swatch);
    cursor: pointer;
    box-shadow: inset 0 0 0 2px rgba(0,0,0,0.04);
}

.whiteboard-color.is-active {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.whiteboard-toolbar__hint {
    line-height: 1.35;
}

.whiteboard-surface {
    position: relative;
    background: var(--card-bg);
    border: 1px dashed var(--border);
    border-radius: 16px;
    min-height: 540px;
    overflow: hidden;
    isolation: isolate;
}

.whiteboard-stage {
    width: 100%;
    height: 100%;
    position: relative;
    cursor: crosshair;
}

.whiteboard-grid {
    position: absolute;
    inset: 0;
    background-image: linear-gradient(to right, rgba(0,0,0,0.05) 1px, transparent 1px), linear-gradient(to bottom, rgba(0,0,0,0.05) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.5;
    pointer-events: none;
    z-index: 1;
}

[data-theme="dark"] .whiteboard-grid {
    background-image: linear-gradient(to right, rgba(255,255,255,0.08) 1px, transparent 1px), linear-gradient(to bottom, rgba(255,255,255,0.08) 1px, transparent 1px);
}

.whiteboard-content {
    position: absolute;
    inset: 0;
    transform-origin: 0 0;
    z-index: 2;
}

.whiteboard-cursors {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 4;
}

.whiteboard-zoom {
    font-weight: 600;
}

.whiteboard-item {
    position: absolute;
    border-radius: 10px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
    touch-action: none;
    user-select: none;
}

.whiteboard-item__body {
    padding: 0.75rem;
    min-width: 140px;
    min-height: 120px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.whiteboard-item textarea {
    border: 1px solid var(--border);
    border-radius: 8px;
    resize: none;
    background: rgba(255,255,255,0.65);
    padding: 0.5rem;
    min-height: 80px;
    font: inherit;
}

[data-theme="dark"] .whiteboard-item textarea {
    background: rgba(0,0,0,0.25);
}

.whiteboard-item__footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.85rem;
    color: var(--muted);
}

.whiteboard-handle {
    position: absolute;
    width: 16px;
    height: 16px;
    right: -8px;
    bottom: -8px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: nwse-resize;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

.whiteboard-line {
    position: absolute;
    transform-origin: 0 50%;
    height: 4px;
    background: var(--fg);
    border-radius: 999px;
}

.whiteboard-line__arrow {
    position: absolute;
    right: -6px;
    top: 50%;
    width: 12px;
    height: 12px;
    transform: translateY(-50%) rotate(45deg);
    border-top: 3px solid currentColor;
    border-right: 3px solid currentColor;
}

.whiteboard-shape {
    position: absolute;
    border: 2px solid rgba(0,0,0,0.25);
    background: rgba(0,0,0,0.03);
}

[data-theme="dark"] .whiteboard-shape {
    border-color: rgba(255,255,255,0.35);
    background: rgba(255,255,255,0.05);
}

.whiteboard-shape--circle {
    border-radius: 999px;
}

.whiteboard-cursor {
    position: absolute;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.25rem 0.5rem;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 999px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    font-size: 0.85rem;
    transform: translate(-35%, -70%);
    pointer-events: none;
    white-space: nowrap;
}

.whiteboard-cursor__dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: currentColor;
}

.whiteboard-lock-hint {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.whiteboard-lock-hint::before {
    content: '⏳';
}

.whiteboard-task-btn {
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--fg);
    border-radius: 8px;
    padding: 0.3rem 0.55rem;
    cursor: pointer;
    font-size: 0.85rem;
}

.whiteboard-task-btn:hover {
    border-color: var(--accent);
}

.whiteboard-surface.is-panning {
    cursor: grabbing;
}

@media (max-width: 960px) {
    .whiteboard-layout {
        grid-template-columns: 1fr;
    }

    .whiteboard-toolbar {
        position: relative;
        top: 0;
    }
}