/* Navigation Panel */
.navigation-panel {
    position: absolute; /* Changed to absolute positioning */
    top: 0;
    left: 0;
    width: 0;
    min-width: 0;
    overflow: hidden;
    z-index: 1000;
    height: 100vh;
    /* Use transform instead of width for GPU-accelerated animation */
    transition: width 0.15s cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 0.15s ease-out;
    opacity: 0;
    /* CSS custom properties for dynamic animation */
    --stagger-delay: 0.05s;
    --base-delay: 0.05s;
    /* Custom properties for menu item animations */
    --item-stagger-delay: 0.03s;
    --item-base-delay: 0.1s;
    /* Promote to GPU layer */
    will-change: width, opacity;
    transform: translateZ(0);
}

    .navigation-panel.open {
        min-width: 250px;
        width: 25%;
        opacity: 1;
    }

        .navigation-panel.open .menu-category {
            animation: slideInFromLeft 0.3s ease-out forwards;
            animation-delay: calc(var(--base-delay) + (counter(menu-item) - 1) * var(--stagger-delay));
        }

.navigation-menu {
    padding: 15px;
    margin-top: 40px;
    color: var(--neutral-foreground-rest);
    height: calc(100vh - 40px);
    overflow-y: auto;
    box-sizing: border-box;
    counter-reset: menu-item;
    /* Promote to GPU layer for smooth scrolling */
    transform: translateZ(0);
}

.menu-category {
    margin-bottom: 5px;
    counter-increment: menu-item;
    /* Promote to GPU layer */
    will-change: transform, opacity;
}

.category-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 12px;
    background: color-mix(in srgb, var(--accent-fill-active) 60%, transparent);
    backdrop-filter: blur(10px);
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.2s ease-out;
    border: 1px solid color-mix(in srgb, var(--accent-stroke-active) 60%, transparent);
    /* Promote to GPU layer */
    transform: translateZ(0);
}

    .category-header:hover {
        background: var(--accent-fill-hover);
        color: var( --foreground-on-accent-rest-large);
    }

.category-title {
    font-weight: 400;
    font-size: var(--font-size-medium);
}

.category-arrow {
    font-size: var(--font-size-small);
    transition: transform 0.2s;
}

    .category-arrow.expanded {
        transform: rotate(180deg);
    }

.category-items {
    padding: 5px 0;
    /* Reset counter for menu items within each category */
    counter-reset: category-item;
}

.menu-item {
    padding: 8px 10px;
    cursor: pointer;
    border-radius: 3px;
    transition: background-color 0.2s ease-out;
    margin: 2px 0;
    /* Increment counter for each menu item */
    counter-increment: category-item;
    /* Initial state for animation */
    opacity: 0;
    transform: translateY(-20px);
    /* Promote to GPU layer */
    will-change: transform, opacity;
}

/* Animate menu items when category is expanded and navigation panel is open */
.navigation-panel.open .category-items .menu-item {
    animation: slideInFromTop 0.25s ease-out forwards;
    /* Dynamic delay calculation for each menu item */
    animation-delay: calc(var(--item-base-delay) + (counter(category-item) - 1) * var(--item-stagger-delay));
}

.menu-item:hover {
    background: var(--accent-fill-hover);
    color: var( --foreground-on-accent-rest-large);
}

.item-title {
    display: block;
    font-size: var(--font-size-medium);
    font-weight: 400;
}

.item-description {
    display: block;
    font-size: var(--font-size-small);
    margin-top: 2px;
}