.mmbu-tool-panel {
    display: flex;
    flex-direction: column;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    min-height: 520px;
}

.mmbu-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-muted, #f9fafb);
}

.mmbu-toolbar-left { display: flex; align-items: center; gap: 8px; }

.mmbu-title {
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 6px;
}

.mmbu-title i { color: #6366f1; }

.mmbu-badge {
    font-size: 0.68rem;
    font-weight: 600;
    padding: 2px 7px;
    border-radius: 10px;
    background: rgba(99, 102, 241, 0.1);
    color: #6366f1;
}

.mmbu-toolbar-right { display: flex; gap: 6px; }

.mmbu-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 5px 10px;
    font-size: 0.78rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    cursor: pointer;
}

.mmbu-btn-primary {
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    border-color: transparent;
    color: #fff !important;
}

.mmbu-canvas-wrap {
    padding: 16px;
    overflow: auto;
    background: radial-gradient(circle at 50% 50%, #eef2ff 0%, #f8fafc 70%);
}

.mmbu-board {
    position: relative;
    width: 100%;
    max-width: 720px;
    height: 480px;
    margin: 0 auto;
}

.mmbu-bubble {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    border-radius: 50%;
    font-weight: 600;
    line-height: 1.3;
    padding: 8px;
    border: 2px solid rgba(255, 255, 255, 0.8);
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.15);
    transition: transform 0.2s, box-shadow 0.2s;
    word-break: break-word;
}

.mmbu-bubble:focus {
    outline: none;
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.25);
    transform: scale(1.05);
    z-index: 10;
}

.mmbu-bubble-center {
    width: 140px;
    height: 140px;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-size: 0.95rem;
    color: #fff;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    z-index: 5;
}

.mmbu-bubble-center:focus {
    transform: translate(-50%, -50%) scale(1.05);
}

.mmbu-bubble-lg {
    width: 100px;
    height: 100px;
    font-size: 0.82rem;
    color: #3730a3;
    background: #c7d2fe;
}

.mmbu-bubble-md {
    width: 84px;
    height: 84px;
    font-size: 0.76rem;
    color: #4338ca;
    background: #ddd6fe;
}

.mmbu-bubble-sm {
    width: 68px;
    height: 68px;
    font-size: 0.68rem;
    color: #5b21b6;
    background: #ede9fe;
}

.mmbu-pos-1  { left: 8%;  top: 12%; }
.mmbu-pos-2  { left: 28%; top: 4%;  }
.mmbu-pos-3  { left: 58%; top: 6%;  }
.mmbu-pos-4  { left: 78%; top: 18%; }
.mmbu-pos-5  { left: 86%; top: 42%; }
.mmbu-pos-6  { left: 72%; top: 68%; }
.mmbu-pos-7  { left: 48%; top: 78%; }
.mmbu-pos-8  { left: 22%; top: 72%; }
.mmbu-pos-9  { left: 4%;  top: 48%; }
.mmbu-pos-10 { left: 18%; top: 28%; }
@media (max-width: 640px) {
    .mmbu-board { height: 520px; max-width: 100%; }
    .mmbu-bubble-lg { width: 80px; height: 80px; font-size: 0.72rem; }
    .mmbu-bubble-md { width: 70px; height: 70px; font-size: 0.68rem; }
    .mmbu-bubble-sm { width: 58px; height: 58px; font-size: 0.62rem; }
}