Chart Prompts

Restyle my chart in the "Fan Chart" 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: an exhibit in a central bank's monetary policy report. Sober, technical and precise: a numbered chart, a blue-gray panel, graded blue uncertainty bands and careful notes.

Colors (use these exact values):
- Page: #FFFFFF. Plot panel: #EEF3F8 with white 1.2px gridlines.
- Primary line: #0A2F5C (navy).
- Uncertainty bands, darkest to lightest: #3F76B5 (30 percent), #86A9D3 (60 percent), #C3D5EB (90 percent).
- Title ink #1B2530; secondary text and dividers #5A6B7F; header rule #D6DFEA.

Typography (Google Fonts):
- IBM Plex Sans throughout, tabular figures for numbers.
- Exhibit number ("Chart 2.4") 15px 700 navy, followed on the same line by a 1px #D6DFEA rule to the right margin.
- Title 26px 600 #1B2530, stating the finding. Subtitle 16px 400 #5A6B7F with measure, unit, frequency and what the bands are.
- Axis labels 14px #5A6B7F; forecast-period years 500 weight in navy. Legend 13px. Notes 12px, with the report name in italic at the bottom right.

Layout:
- 64px margins. Exhibit number at y 50, title at y 86, subtitle at y 114.
- Panel from x 72 to x 900, y 140 to y 492, no border. Y labels right-aligned just left of the panel.
- A legend inside the panel at top left, in an area the data doesn't reach: line swatches for the actual series and the central projection, then three 20 x 12 band swatches labelled 30%, 60%, 90% and "projection bands".
- Below the panel: a one-line note explaining the bands, then "Source: ..." at left and the report name at right.

Axes and grid:
- Horizontal white gridlines only, at each whole unit; the zero line 1px #5A6B7F.
- Year labels centered under each year's span, with 5px ticks at year boundaries.
- A 1px #5A6B7F vertical divider at the start of the forecast, full panel height, labelled "Outturn" (13px 500 #5A6B7F, right of it aligned end) and "Forecast" (13px 600 navy) at the top.

Marks:
- Line chart: history as a 2.6px navy stepped line (step-after, square corners) for rates that change in discrete moves, or a plain 2.6px line for continuous series. From the last actual point, the fan: three smooth closed bands (90 percent drawn first, then 60, then 30) whose half-widths grow with the square root of the horizon, all pinching to zero width at the last actual point. A 1.6px navy dashed (5 on, 4 off) central projection runs through the middle. Mark the last actual value with a navy dot (r 4.5, 1.5px white ring) and its value in 15px 700 navy placed clear of the line.
- Bar chart: navy square-cornered bars for actual periods; forecast-period bars in #86A9D3 with thin #3F76B5 whisker ranges (30 percent range as a thick 6px segment, 90 percent as a 1.5px line) on top, split by the same Forecast divider.

Avoid: rounded corners, drop shadows, bright non-blue colors, a boxed legend outside the panel, and fans that start with nonzero width.

When you're done, render the chart and check that the bands are nested and graded from dark center to light edge, the stepped line never slopes, the divider sits exactly at the first forecast period, and the title's number matches the central projection.