# Dev Log: Fix Filter Panel Layout

**Date:** 2026-02-07
**Task:** Tweak layout on Filter Panel to match pixel-perfect visual specifications.

## 1. Task Overview
The objective was to refine the CSS layout of the dashboard's "Filter Panel" to exactly match a provided visual mockup (`FilterPanel_correct.png`). The mockup specified strict vertical alignment and spacing requirements, specifically requiring a total panel height of **100px** (reduced from 102px) and precise positioning of the filter icon, sliders, checkboxes, and action buttons.

## 2. Challenges Faced
*   **Legacy CSS Constraints:** The previous implementation used a fixed height of `69px` for internal containers (`.filter-item`, `.checkboxes-wrapper`) to force alignment. This approach made it difficult to achieve the new `100px` total height requirement without creating awkward vertical gaps or misalignments.
*   **Flexbox centering vs. Fixed Spacing:** Achieving "pixel-perfect" placement using relative Flexbox centering (`align-items: center`) required removing the old fixed-height constraints on children elements and letting the parent container (`.filter-panel-open`, height: 100px) drive the alignment.
*   **Responsiveness:** The layout had a media query at `1300px` that switched the height to `auto`, causing the panel to collapse or shift unexpectedly on standard laptop screens.

## 3. Implementation Details (Solution)

To address these challenges, the following changes were made to `static/global.css` and `templates/dashboard.html`:

### A. strict Height Enforcement
*   **Global Variable:** Updated `--filter-panel-height` from `102px` to **`100px`**.
*   **CSS Class:** Set `.filter-panel-open` to strictly use `height: 100px` and `min-height: 100px`.
*   **Media Query Override:** Modified the `@media (max-width: 1300px)` block to enforce `height: 100px !important` instead of `auto`. This ensures the panel maintains its rigid structure even on smaller screens, preventing layout shifts unless a smaller breakpoint (like mobile) is triggered.

### B. Vertical Alignment & Spacing
*   **Filter Items (Sliders):**
    *   Removed fixed height.
    *   Changed `justify-content: space-between` to `center`.
    *   Reduced label `margin-bottom` to **2px** for tighter grouping with the slider.
*   **Checkboxes:**
    *   Removed fixed height.
    *   Changed alignment to `center`.
    *   Set `gap: 6px` between items.
*   **Action Buttons:**
    *   Reduced gap between buttons to **4px**.
    *   Centered vertically within the 100px container.

### C. Javascript Synchronization
*   Updated the `toggleFilterPanel` function in `dashboard.html` to set the CSS variable `--filter-panel-height` to `100px` when opening the panel, ensuring the JS state matches the CSS styling.

## 4. Verification Results
A custom Playwright script (`verification/verify_filter_panel.py`) was used to measure the rendered bounding boxes of the UI elements.

**Measured Dimensions:**
*   **Panel Height:** 100px (Exact match)
*   **Icon Spacing:** ~41px top/bottom (Centered)
*   **Button Group Spacing:** Centered vertically.

The task was **successful**. The layout now strictly adheres to the visual specifications provided.