Chart Prompts

Restyle my chart in the "Herd Health" style described below. Keep my data, chart type, title meaning and units; change only the presentation. Use the charting library this project already uses (plain SVG if there is none). If the library can't express a detail, draw it in a custom layer instead of dropping it. Measurements assume a 960 x 600 chart; scale them proportionally.

Mood: a farm veterinarian's quarterly herd report printed on straw-tinted paper. Earthy, sturdy and plain spoken, with slab serif type and square-cut stacked bars.

Colors (use these exact values):
- Page: #F7F3E8 (straw off-white).
- Series, bottom to top of the stack: #B55A30 (rust), #5B7FA3 (dusty blue), #8A8F3C (olive), #C2BCAF (warm gray, for "other").
- Ink: #2E2A22 for the title, totals, baseline, masthead rule and event marker. Secondary text #6E675A. Gridlines and footer rule #E2DACA.

Typography (Google Fonts):
- Roboto Slab for everything. Masthead 11.5px 600 uppercase with 1.8px letter-spacing in #6E675A; title 28px 700 ink stating the finding with the percent change; subtitle 14px 400 #6E675A with measure, unit and before/after averages.
- Legend 13.5px 500 ink; axis ticks 12.5 to 13px #6E675A; stack totals 13px 700 ink; event note 13px 700 headline plus 12px 400 detail; footer 12px.

Layout:
- 48px side margins. A 3px ink rule across the top at y 36, masthead under it, then title and subtitle.
- Legend directly under the subtitle: 14px square swatches with labels, in stack order, left aligned.
- Plot from x 88 to 912, y 212 to 520. A thin #E2DACA footer rule at y 556 with an explanatory note left and the source right.

Axes and grid:
- 1px #E2DACA horizontal gridlines every 10 units, tick labels left of the plot, a small unit label ("Cases") above them. A 1.5px ink baseline. Category labels 22px below the baseline. No vertical gridlines.

Marks:
- Bar chart: stacked vertical bars 40px wide with square corners, segments separated by a 1.2px #F7F3E8 hairline. Bold total above each stack, 8px clear. Mark an intervention with a 1.5px ink dashed vertical line (4 on, 3 off) between periods, with a boxed note (1px ink border, straw fill) at the top right of the line. Draw short 1px dotted rules (ink at 45%, 2 on 3 off) at the period averages before and after the event, drawn beneath the stack totals: give each total a 6px straw halo so a rule never strikes through a number.
- Line chart: one 2.5px line per condition in the same four colors with square 5px markers, stacked area is optional at 85% opacity; keep the same dashed event line and boxed note, and label each line at its right end in 12px 600 in its color.

Avoid: rounded corners, gradients, shadows, bright or saturated greens, a boxed chart frame, and a legend placed far from the title.

When you're done, render the chart and check that the stack totals and the before/after averages match the data, the title's percent change is arithmetically right, the event box does not cover any total, and the gray segment remains distinct from the olive.