Interactive Pie Chart Python Sankey Heatmap Infographic

Data visualization infographic titled "Heatmap Example" using a SANKEY FLOW as the dominant visual element to show trend movement through a pipeline over time. Create a clean editorial data journalism illustration, FT / Bloomberg-grade chart aesthetics, vector-clean infographic layout in a monochrome ink palette: deep black, charcoal, slate gray, warm off-white background, subtle gray gridlines, high contrast typography, calm analytical mood. The main graphic should be a left-to-right Sankey pipeline with 5 sequential stages labeled in English: "Input", "Processing", "Analysis", "Output", "Adoption". Encode a trend across 4 time periods with clearly separated flow bands and precise labels: "Q1", "Q2", "Q3", "Q4". Use realistic illustrative values that increase over time, for example total flow volumes labeled "120", "145", "168", "196" at each period, with branch losses and gains visible between stages. Include sharp axis labels and tick marks in English by adding a subtle top or bottom reference scale labeled "Illustrative volume" with ticks at "0", "50", "100", "150", "200" and a secondary timeline axis labeled "Quarter" with ticks "Q1", "Q2", "Q3", "Q4". Ensure no misleading axis truncation or scale manipulation.

Add 4 key insight callouts placed around the chart, each with a small simple icon and English text exactly rendered as follows: 1) headline number "196" with interpretation "Q4 total flow is the highest level in the year" and a small upward arrow icon; 2) headline number "+63%" with interpretation "Output volume rises from 76 in Q1 to 124 in Q4" and a small pipeline icon; 3) headline number "22" with interpretation "Average loss narrows in late-stage processing by Q4" and a small filter icon; 4) headline number "81%" with interpretation "Adoption captures most output by the end of the period" and a small check-circle icon. Add compact annotations on selected bands such as "Illustrative increase", "Stable transition", and "Late-stage conversion improves".

Because the topic is "heatmap example" while the chosen archetype is Sankey, integrate a subtle supporting mini-panel or background reference strip that echoes heatmap logic without overpowering the Sankey: a small grayscale matrix labeled "Intensity reference" with rows "Stage 1", "Stage 2", "Stage 3", "Stage 4" and columns "Q1", "Q2", "Q3", "Q4", showing darker cells over time. Keep this secondary and clearly subordinate to the Sankey.

Typography should be crisp, newsroom-style, with sharp English labels, legends, captions, and numeric tags. Add a concise legend in English: "Flow volume", "Retention", "Drop-off", "Illustrative trend". Add a small source / data-note strip at the bottom in English reading exactly: "Data note: Illustrative example. Figures are plausible mock values for demonstration only." Avoid any fake authoritative source. All text MUST be written in English (array). Every heading, label, caption, legend and metric name in the image must be in English — not English. Spell each English word correctly using English characters and diacritics. Numbers stay as digits, no fake authoritative sources cited, no watermarks Numbers labeled "illustrative" unless the user supplied specific sourced data. No fake authoritative sources cited (do not invent "Source: Reuters 2025" — use "Illustrative example" instead). No misleading axis truncation or scale manipulation.