Chart Prompts

Restyle my chart in the "Escalation Tiers" 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 support-operations review on a dark charcoal screen. Calm pastel lines, a small ladder diagram that explains the tiers, and one decisive vertical rule marking when the process changed.

Colors (use these exact values):
- Background: #18181B charcoal. Ladder blocks: #222226 with a 1.2px border in the tier color at 55% opacity. Ladder rails and rungs: #3F3F46.
- Series: #93C5FD pale blue (first tier), #A78BFA violet (second tier), #FDA4AF rose (third tier).
- Ink #F4F4F5, secondary #A1A1AA, gridlines #2A2A2F, baseline #52525B, event rule #E4E4E7. The post-change region is tinted white at 2.5% opacity.

Typography (Google Fonts):
- Epilogue for the title (700, 28px, #F4F4F5, stating the finding with the percent change computed from the same rounded averages the ladder shows, so the title and the figures agree) and tier keys ("L1", "L2", "L3": 700, 22px in the ladder, 17px at line ends, in the tier color).
- Atkinson Hyperlegible for everything else: subtitle 15px #A1A1AA, tier names 700 13px, before/after averages 12.5px ("8.4 → 3.6 a day", the arrow drawn as a thin stroked path since the font has no arrow glyph), tick labels 12.5px, event label 700 13px, end-value notes 11.5px, notes and source 12px.

Layout:
- 44px margins. Title and subtitle at the top.
- Ladder at the left edge, 150px wide: two vertical 3px rails with round caps and three stacked 70px blocks (radius 10) with 28px gaps, the highest tier at the top. A rung crosses each gap with a small upward chevron in #A1A1AA. Each block has a 4px tier-colored stub on its left edge, the key, the tier name and its before/after daily average. A two-line note under the ladder explains the averages.
- Plot from x 250 to 848 and y 140 to 500, end labels in the right margin.

Axes and grid:
- 1px #2A2A2F horizontal gridlines, a #52525B baseline, y ticks right-aligned. Date ticks every two weeks with 6px tick marks. No vertical grid.
- Event: a 1.4px #E4E4E7 dashed vertical rule (5 on, 4 off) rising 14px above the plot, its label just right of the rule at the top, and the region after it tinted.

Marks:
- Line chart: stepped lines (step-after, each day a flat run), 2.2px, one per tier in its color. At the right end a 3.5px dot, the tier key and its latest value, nudged apart vertically so labels never collide.
- Bar chart: stacked or grouped columns per period in the three tier colors with 1px charcoal gaps and square corners, the same event rule and tinted after-region, the ladder unchanged.

Avoid: smoothing the steps, neon glows, bright saturated colors, a boxed legend (the ladder and end labels are the legend), and more than one event rule.

When you're done, render the chart and check that the percent change in the title matches the before and after averages in the ladder, the event rule sits on the right date, the end labels do not collide, and the three pastel lines stay distinguishable where they approach each other.