.builder-layout {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    max-width: 1000px;
    margin: 0 auto;
}
.canvas-panel {
    position: relative;
    background: #000;
    border-radius: 12px;
    overflow: hidden;
    width: 100%;
    aspect-ratio: 1 / 1;
    max-height: 80vh;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    cursor: crosshair;
}
.palette-panel {
    background: rgba(30, 41, 59, 0.85);
    border: 1px solid #334155;
    border-radius: 16px;
    padding: 1.5rem;
    color: #f8fafc;
    position: sticky;
    bottom: 10px;
    z-index: 100;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}
.palette-panel.unpinned {
    position: relative;
    bottom: auto;
}
.parts-grid {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}
.part-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(15, 23, 42, 0.8);
    border: 2px solid #334155;
    border-radius: 12px;
    padding: 0.8rem;
    cursor: pointer;
    transition: all 0.2s;
    color: #cbd5e1;
    min-width: 90px;
}
.part-btn:hover {
    background: rgba(30, 41, 59, 1);
    border-color: #475569;
}
.part-btn.active {
    border-color: #3b82f6;
    background: rgba(59, 130, 246, 0.1);
    color: #3b82f6;
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.3);
}
.part-icon {
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
}
.part-label {
    font-size: 0.8rem;
    font-weight: 600;
}
.play-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    align-items: center;
}
.play-controls button, #btn-save, #btn-load {
    padding: 0 1rem;
    height: 42px;
    font-size: 0.95rem;
    font-weight: 700;
    border-radius: 8px;
    white-space: nowrap;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}
#btn-pin {
    display: flex;
}
@media (max-width: 768px) {
    .palette-panel {
        position: relative !important;
        bottom: auto !important;
    }
    #btn-pin {
        display: none !important;
    }
    .play-controls {
        flex-wrap: wrap;
    }
}
.canvas-instructions {
    font-size: 0.9rem;
    color: #94a3b8;
    background: rgba(15, 23, 42, 0.5);
    padding: 1rem;
    border-radius: 8px;
    line-height: 1.6;
}