pbi-report-design

# Power BI Report Design

> **Report modification requires tooling.** Two paths exist:
> 1. **`pbir` CLI (preferred)** -- use the `pbir` command and the `pbir-cli` skill. Install with `uv tool install pbir-cli` or `pip install pbir-cli`. Check availability with `pbir --version`.
> 2. **Direct JSON modification** -- if `pbir` is not available, use the `pbir-format` skill (pbip plugin) for PBIR JSON structure and patterns. Validate every change with `jq empty <file.json>`.
>
> If neither the `pbir-cli` skill nor the `pbir-format` skill is loaded, ask the user to install the appropriate plugin before proceeding with report modifications.

Best practices and guidelines for Power BI report design. Follow these guidelines strictly to avoid generic, poorly formatted reports ("Power BI Slop").

Be innovative, pushing boundaries while adhering to data visualization rules and guidelines. Work within Power BI's constraints, aiming for simplicity and effectiveness over aesthetics and decoration. Focus reports, pages, and visuals on answering specific questions and minimizing cognitive load -- not on looking "pretty and impressive".

When a user request contradicts these guidelines, push back and explain better alternatives. The goal is to inform the user of options that lead to improved outcomes.

## Core rules

1. **3-30-300 Rule:** The most important and least detailed information should be in the top-left (KPIs, cards, etc.) while the least important and most detailed information should be in the bottom-right
2. **Titles:** All report pages should have a title using a `textBox` visualType or a title in a background image added to the report page canvas
3. **Visual positioning, alignment, and spacing:** All visuals must have equal spacing between them and equal spacing between the edge of the page (the margin). If visuals are unaligned or this spacing is unequal, fix it to ensure alignment and equal spacing
4. **Themes:** Reports should use a theme that differs from the default Power BI themes; a suggested theme is the `sqlbi` theme (see the `modifying-theme-json` skill for applying templates). Themes are preferred because they provide a set of default styles for all charts that can adhere to good design practices and brand or style guidelines
5. **Semantic Models:** Reports in Power BI are complex. They are dependant on an underlying semantic model (either in the .SemanticModel folder, called a "thick report" or a published model in Power BI/Fabric, called a "thin report"). Much of the functionality from a Power BI report comes from its semantic model design or DAX code
6. **Report extensions, or thin report measures:** It is possible to create calculation logic in Power BI report, called "thin report measures" or "visual calculations". These should be used sparingly and only for "report-specific" scenarios
7. **Visual fields:** All data visuals should have field bindings, and all field bindings should be for fields that actually exist in the model; there is no reason for visuals to exist that have no fields bound
8. **Chart selection:** Make smart choices about what visuals to use for each scenario. Visual vocabulary is essential for this skill.
9. **Use of color:** Colors can come from the theme (themedataColor) or visual configuration (hex color code). Colors should be muted and soft; colors that implicitly encode meaning (like red=bad, green=good) should be avoided unless using them for that encoding. Consider colorblindness and use accessible palettes (blues instead of greens with reds, for instance).
10. **Pre-attentive attributes:** Styles and colors should be used to steer and direct attention, and not to decorate charts. Formatting of visuals should be intentional and not purely aesthetic. Styles should where possible be stored in the theme and not in bespoke visual configuration.
11. **Fonts:** Prefer *Segoe UI* and *Segoe UI Semibold*. Do not use custom fonts, since they aren't guaranteed to render on user computers. Evaluate whether fonts are sufficiently large to be readable given the visual and page size.

## Page Layout Guidelines

### Check Page Size Before Modifying

**Always query the actual page dimensions before adding or repositioning visuals.** Do not assume a page is 1280x720 or 1920x1080 -- templates and existing reports vary. The object model validates that visuals fit within page bounds, so setting position or size without knowing the page dimensions will cause errors. Check the page's `page.json` file for `width` and `height` properties, or use the object model (`page.width`, `page.height`) to confirm dimensions first. When resizing visuals via the object model, set `width`/`height` before `x`/`y` to avoid intermediate states that exceed bounds.

### Standard Page Size

- **Width:** 1280px (default)
- **Height:** 720px (16:9 aspect ratio)
- Alternative: 1920x1080 for high-resolution displays

### Visual Spacing

- **Minimum gap between visuals:** 16px
- **Edge margins:** 24-32px from page edges
- **Consistent alignment:** Use grid-based positioning
- **Equal spacing is mandatory:** Every gap between adjacent visuals (horizontal and vertical) must be the same value. Every margin from the page edge must be the same value. Calculate positions arithmetically from (margin, gap, page_width, page_height) to guarantee alignment. If visuals are misaligned or gaps are unequal, fix immediately -- this is one of the most visible quality signals in a report.

### Detail Gradient

Arrange content following the "detail gradient":

```
+------------------+------------------+
|   KPIs/Cards     |   KPIs/Cards     |  <- Top: High-level, important
|   (Summary)      |   (Summary)      |
+------------------+------------------+
|                                     |
|   Charts/Trends                     |  <- Middle: Context, trends
|   (Analysis)                        |
|                                     |
+------------------+------------------+
|