/* Main layout structure */
#whiteboard {
    width: 100vw;
    height: 100vh;
    position: relative;
    overflow: auto;
    background: var(--bg-image), #1a1a1a;
    background-attachment: fixed;
    background-size: cover;
    background-position: center;
}

#grid {
    position: relative;
    width: 2000px;
    height: 2000px;
    min-width: 100%;
    min-height: 100%;
    background-image: radial-gradient(circle, rgba(255,255,255,0.035) var(--grid-dot-size), transparent var(--grid-dot-size));
    background-size: var(--grid-spacing) var(--grid-spacing);
    background-position: 0 0;
}


/* Expand space buttons */
.expand-space-btn {
    position: fixed;
    z-index: 100;
    background: rgba(0, 0, 0, 0.6);
    border: none;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    backdrop-filter: blur(10px);
}

.expand-space-btn:hover {
    background: rgba(0, 0, 0, 0.8);
    transform: scale(1.1);
}

.expand-space-btn svg {
    color: white;
}

.expand-right {
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
}

.expand-right:hover {
    transform: translateY(-50%) scale(1.1);
}

.expand-bottom {
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
}

.expand-bottom:hover {
    transform: translateX(-50%) scale(1.1);
}