Design memo

Design Memo

Purpose

This is the default output format for plans and designs. When a user requests any plan, design, architecture proposal, implementation approach, decision record, or review document, offer to produce it as an HTML design memo. For simple or quick plans, ask whether they would prefer plain text. Default to HTML for non-trivial plans involving multiple components or architectural decisions.

The output is a single standalone HTML file with inline CSS and JavaScript, readable as both a scrollable presentation and a long-form design memo. It includes enough implementation detail that reviewers can evaluate the design without reading the chat transcript.

Output

• Create or update a single standalone .html file.
• Keep the file self-contained: inline CSS and JavaScript only.
• Do not depend on external fonts, scripts, CSS frameworks, image assets, or CDN libraries.
• Use semantic HTML sections so the document reads well as both a presentation and a long-form design memo.
• Include enough implementation detail that the presentation can be reviewed without reading the chat transcript.

Output Location

• If the user specifies an output directory, use that location. Examples: plans/, docs/, architecture/, or a fully specified file path.
• If the user does not specify a location, suggest design-memos/ as the default directory for HTML design memos.
• If design-memos/ already exists, place the output file there by default.
• If design-memos/ does not exist, ask the user whether to create it or choose another location.
• Never create a new output directory without user confirmation.

Output File Naming

Name output files using the pattern <topic>-design-memo.html, where <topic> is a lowercase, hyphenated summary of the subject matter. Examples:

• cdn-migration-design-memo.html
• auth-flow-design-memo.html
• database-sharding-design-memo.html

Visual Direction

• Use a Tufte-inspired editorial layout:
  • Serif typography for headings and narrative text.
  • Restrained tables with strong horizontal rules.
  • Margin-note style callouts for caveats, rationale, and important review notes.
  • Wide content when detail is dense, but avoid a generic slide-deck look.
• Use a cinematic palette when requested. If no palette is specified, default to an Arrival-inspired Denis Villeneuve palette:
  • Foggy slate / mist gray backgrounds.
  • Charcoal ink for text.
  • Muted olive and amber for structure.
  • Blue-gray accents for progress and technical emphasis.
• Avoid copyrighted imagery or film stills. Use color, spacing, and atmosphere only.

Default Palette Variables

Use these as the default Arrival-inspired palette unless the user requests a different mood:

:root {
  --paper: #cfd4cf;
  --paper-deep: #7f8985;
  --panel: #e6e6df;
  --ink: #171c1d;
  --muted: #4a5250;
  --olive: #4a4f3f;
  --amber: #9a7a55;
  --ochre: #b79b65;
  --mustard: #d6c7a4;
  --teal: #2f5557;
  --blue: #5f7f86;
  --line: #9aa39d;
  --code: #111819;
  --code-bg: #bdc8c3;
}

--muted is for secondary or supplementary text only (e.g., margin notes, captions). Never use it for essential content — use --ink instead.

Scrollytelling Interaction

Add lightweight scrollytelling affordances:

• A fixed top progress bar showing scroll progress.
• A fixed right-side section rail that acts as a persistent, floating table of contents. Each entry shows a single-key shortcut lozenge (left-aligned within the row, so the key is the first thing the eye lands on) and the section label, so a keyboard user can always see the full sequence of topics and the key that jumps to each one. The current section's entry is visually prominent and transitions smoothly as the active section changes; inactive entries remain fully readable, not just dots.
• A sticky or fixed chapter indicator with the current section number and label, positioned so it does not collide with the rail.
• Active-section transitions on both the rail entry and the slide content, such as subtle opacity, lift, or scale changes.
• Keep all interaction implemented with small vanilla JavaScript.
• Hide progress UI in print and simplify it on small screens. In print, stamp each section's Crockford shortcut character as a lozenge in the bottom-right of its page so a printed copy stays keyboard-addressable.
• Prefer scroll-snap-type: y proximity over mandatory snapping so long tables and code listings remain easy to read. Disable snapping on small screens and for users who prefer reduced motion.
• Add presentation-style keyboard shortcuts: ArrowRight, ArrowDown, PageDown, and Space advance; ArrowLeft, ArrowUp, and PageUp go back; Home and End jump to the first and last sections. Each section also has a single-key jump shortcut drawn from Crockford's Base32 alphabet (0123456789ABCDEFGHJKMNPQRSTVWXYZ — digits 0–9 followed by A–Z excluding I, L, O, and U). Section 1 maps to 0, section 2 to 1, and so on, giving up to 32 sections unique single-key shortcuts. Display this character on each rail entry's lozenge so the shortcut is always visible. Accept Crockford's standard aliases when matching key input: treat I and L as 1, and O as 0, so visually similar inputs still work. Match keys case-insensitively.

Accessibility

• Ensure all text meets WCAG 2.1 AA contrast ratios (4.5:1 for body text, 3:1 for large text) against palette backgrounds. Verify contrast when customizing the palette.
• Scrollytelling navigation dots must be keyboard-focusable (<button> elements) with visible focus indicators (outline or ring).
• Add role="navigation" and aria-label="Section navigation" to the section rail.
• Mark the progress bar with role="progressbar", aria-valuenow, aria-valuemin="0", and aria-valuemax="100".
• Use aria-current="step" on the active section dot.
• Remove aria-current from inactive dots rather than setting it to "false".
• Add aria-keyshortcuts to each rail entry, set to the Crockford Base32 character assigned to that section. Reflect the same character as the visible content of the entry's lozenge so sighted and screen-reader users see the same shortcut.
• The sticky chapter indicator should use aria-live="polite" so screen readers announce section changes.
• Ensure all content is reachable without JavaScript: all content remains visible in document order (progressive enhancement, not JavaScript-dependent rendering).
• Use prefers-reduced-motion media query to disable scroll-triggered animations for users who prefer reduced motion.
• Do not dim or transform content by default. If using inactive-section styling, add a .js class from JavaScript and scope dimming to .js section:not(.is-active) so no-JS readers get fully readable content.
• Do not capture global shortcuts while focus is in editable controls. Let focused rail buttons keep their native Enter/Space activation behavior.

Content Structure

For technical designs or plans, prefer this structure:

1. Opening decision or design thesis with the recommended path stated first.
2. Ordered behavior, architecture, or priority table.
3. Decision model / request flow / state machine.
4. Implementation draft or pseudocode.
5. Validation matrix with inputs, expected outcomes, and rationale.
6. Operational notes, such as caching, deployment, rollback, or monitoring.
7. Source/evidence inventory so reviewers can audit the analysis.
8. Confidence and caveats.
9. Appendix — Original prompt (always last). See "Appendix: Original Prompt".

Adapt the section names to the user's domain. Do not keep route inventory or background-analysis sections unless they directly support the design.

Appendix: Original Prompt

Always end the memo with an appendix section that records the prompt or instructions that initiated the design memo. Reviewers use it to see what steering the agent received without reading the chat transcript.

• Place this section last, after sources, confidence, and caveats.
• Use an eyebrow such as "Appendix" and a heading like "Original prompt".
• Quote the user's instruction verbatim inside <pre class="prompt-original"> (or another preformatted block) so whitespace and line breaks are preserved. Escape &, <, and > so the text renders literally.
• If the design emerged from a multi-turn exchange, include the substantive steering messages in chronological order — not every conversational aside, but enough that a reviewer can reconstruct the brief. Label each block with its turn (e.g., "Initial request", "Follow-up: scope clarification").
• If the prompt referenced files, attachments, or pasted artifacts that the agent treated as part of the brief, list them in a short sub-note.
• Do not paraphrase, summarize, or "improve" the wording. Fidelity matters more than polish here.
• Give the section a stable id of appendix-original-prompt so it can be deep-linked.

Deep Linking and Section Anchors

Every slide must be addressable by URL so reviewers can share a link to a specific section.

• Assign a stable id attribute to every <main> > <section>. Prefer an author-supplied id; otherwise generate one in JavaScript by slugifying the section's h1/h2 (or its .eyebrow label) and de-duplicating collisions by appending -2, -3, etc. Fall back to section-N if no text is available. Slug rules: lowercase, ASCII letters/digits/hyphens, collapse whitespace to single hyphens, trim leading/trailing hyphens, cap at ~60 characters.
• As the active section changes — whether from scrolling, the section rail, keyboard shortcuts, or programmatic navigation — update the URL hash to #<section-id> using history.replaceState(null, "", "#" + id). Use replaceState, not pushState, so the browser Back button continues to navigate between pages rather than between slides.
• Only update the hash when the active section index actually changes; do not thrash history.replaceState on every scroll tick.
• On initial page load, if window.location.hash matches an existing section id, scroll that section into view and mark it active. The browser's native anchor jump handles the initial position; the script just needs to refresh the active-section state afterwards.
• Decode the hash with decodeURIComponent before lookup, and guard against ids that do not exist (do not throw).
• Hashes are user-visible. Keep slugs human-readable: prefer #decision-model over #section-3.

Presentation Components

Use the richer presentation components from the skeleton when they help reviewers scan the memo:

• A hero/decision slide with an eyebrow, decisive title, short thesis, and the first table of ordered decisions.
• .card and .card-body wrappers for dense sections.
• .grid-2 or .grid-3 for side-by-side decision models and caveats.
• .source blocks for evidence, files reviewed, assumptions, or alternatives.
• .badge, .badge.success, .badge.warning, and .badge.danger for classifications such as "recommended", "caveat", "blocked", or "pass-through".
• .callout, .callout.warning, and .callout.danger for review-critical notes that should not be buried in prose.
• .footer source summaries at the end of evidence-heavy memos.

Code Listings

• Include syntax-highlighted code blocks for implementation drafts.
• Prefer a tiny inline highlighter or hand-authored spans over external libraries.
• If using an inline highlighter, escape HTML before assigning highlighted output to innerHTML.
• For infrastructure functions, include comments that explain the rationale for each major decision branch.
• Keep code examples realistic and directly usable, but label them as drafts when environmental details may vary.

Review Quality Bar

• Preserve the user's intended behavior and clearly identify pass-through, rewrite, fallback, and unknown/default cases.
• Make rule ordering explicit when it matters.
• Include test cases that reviewers can scan quickly.
• Include a "Sources reviewed" footer or table for review documents and design memos based on code inspection.
• Surface caveats plainly rather than burying them in prose.
• Avoid masking unknown routes or failure cases in the design unless the user explicitly asks for catch-all behavior.

HTML Implementation Notes

• Use one <section> per major step.
• Wrap sections in <main> and include a semantic <header> hero when the memo has a decision thesis.
• Add generated navigation by scanning main > section in JavaScript.
• Use CSS custom properties for the palette so future palette changes are easy.
• Validate embedded JavaScript syntax after edits.
• Keep the presentation readable when JavaScript is disabled: all content should remain visible in document order.
• Build labels from .eyebrow plus h1/h2 when available so the rail and chapter indicator are meaningful.

HTML Skeleton

Use this as a starting scaffold. Adapt the sections to match the plan content — this is a structural reference, not a rigid template. Keep the accessibility contract intact when changing the visual design.

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Design Memo — TOPIC</title>
  <script>
    document.documentElement.className += " js";
  </script>
  <style>
    :root {
      color-scheme: light;
      --paper: #cfd4cf;
      --paper-deep: #7f8985;
      --panel: #e6e6df;
      --ink: #171c1d;
      --muted: #4a5250;
      --olive: #4a4f3f;
      --amber: #9a7a55;
      --ochre: #b79b65;
      --mustard: #d6c7a4;
      --teal: #2f5557;
      --blue: #5f7f86;
      --line: #9aa39d;
      --code: #111819;
      --code-bg: #bdc8c3;
      /* Rail geometry: the slide content reserves room for 90% of the rail
         so the table of contents overlaps the slide by at most 10% of its
         width. */
      --rail-gutter: clamp(0.8rem, 2vw, 1.8rem);
      --rail-width: min(18rem, 28vw);
      /* Reserve room for 90% of the rail's width on the side it sits on, so
         the table of contents overlaps the slide by ~10% of its width. */
      --rail-reserve: calc(var(--rail-gutter) + var(--rail-width) * 0.9);
    }

    *, *::before, *::after { box-sizing: border-box; }

    body {
      margin: 0;
      font-family: Georgia, "Times New Roman", serif;
      background:
        radial-gradient(circle at 14% 0%, rgba(214, 199, 164, 0.5), transparent 28rem),
        radial-gradient(circle at 86% 8%, rgba(95, 127, 134, 0.28), transparent 30rem),
        linear-gradient(135deg, #dce0dc, var(--paper) 52%, var(--paper-deep));
      color: var(--ink);
      line-height: 1.6;
    }

    .progress-bar {
      position: fixed;
      z-index: 20;
      top: 0;
      left: 0;
      width: 100%;
      height: 0.45rem;
      background: rgba(23, 28, 29, 0.13);
    }

    .progress-bar__fill {
      width: 0;
      height: 100%;
      background: linear-gradient(90deg, var(--olive), var(--ochre), var(--amber));
      transition: width 120ms linear;
    }

    .story-rail {
      position: fixed;
      z-index: 15;
      top: 50%;
      right: var(--rail-gutter);
      display: grid;
      gap: 0.3rem;
      width: var(--rail-width);
      max-height: min(82vh, 38rem);
      overflow-y: auto;
      padding: 0.55rem;
      border: 1px solid rgba(154, 163, 157, 0.55);
      background: rgba(230, 230, 223, 0.82);
      box-shadow: 0 10px 28px rgba(23, 28, 29, 0.12);
      backdrop-filter: blur(8px);
      transform: translateY(-50%);
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    }

    .story-dot {
      display: grid;
      grid-template-columns: auto minmax(0, 1fr);
      align-items: center;
      gap: 0.6rem;
      width: 100%;
      padding: 0.32rem 0.55rem 0.32rem 0.32rem;
      border: 1px solid transparent;
      background: transparent;
      color: var(--muted);
      cursor: pointer;
      font: inherit;
      font-size: 0.8rem;
      text-align: left;
      opacity: 0.78;
      transition:
        background 220ms ease,
        border-color 220ms ease,
        color 220ms ease,
        opacity 220ms ease,
        transform 220ms ease;
    }

    .story-dot:hover {
      color: var(--ink);
      opacity: 1;
    }

    .story-dot:focus-visible {
      outline: 2px solid var(--teal);
      outline-offset: 3px;
    }

    .story-dot__key {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 1.55rem;
      height: 1.55rem;
      padding: 0 0.35rem;
      border: 1px solid var(--ink);
      border-radius: 0.55rem;
      background: var(--panel);
      color: var(--ink);
      font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
      font-size: 0.82rem;
      font-weight: 700;
      line-height: 1;
      letter-spacing: 0.02em;
      transition: background 220ms ease, color 220ms ease, border-color 220ms ease;
    }

    .story-dot__label {
      overflow: hidden;
      white-space: nowrap;
      text-overflow: ellipsis;
      letter-spacing: 0.04em;
    }

    .story-dot.is-active {
      color: var(--ink);
      opacity: 1;
      background: rgba(214, 199, 164, 0.45);
      border-color: rgba(154, 122, 85, 0.7);
      transform: translateX(-0.25rem);
    }

    .story-dot.is-active .story-dot__key {
      background: var(--olive);
      border-color: var(--olive);
      color: var(--panel);
    }

    .story-dot.is-active .story-dot__label {
      font-weight: 700;
    }

    .chapter-indicator {
      position: fixed;
      z-index: 14;
      bottom: clamp(1rem, 3vw, 2rem);
      left: clamp(1rem, 4vw, 3rem);
      display: grid;
      grid-template-columns: auto 1fr;
      gap: 0.6rem 0.85rem;
      align-items: center;
      max-width: min(28rem, calc(100vw - 7rem));
      padding: 0.75rem 0.95rem;
      border: 1px solid rgba(154, 122, 85, 0.8);
      background: rgba(230, 230, 223, 0.84);
      box-shadow: 0 10px 28px rgba(23, 28, 29, 0.14);
      backdrop-filter: blur(8px);
    }

    .chapter-indicator__number {
      color: var(--olive);
      font-size: 1.55rem;
      line-height: 1;
    }

    .chapter-indicator__label {
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      font-size: 0.72rem;
      font-weight: 800;
      letter-spacing: 0.14em;
      text-transform: uppercase;
    }

    .chapter-indicator__rule {
      grid-column: 1 / -1;
      height: 1px;
      overflow: hidden;
      background: rgba(23, 28, 29, 0.18);
    }

    .chapter-indicator__rule span {
      display: block;
      width: 0;
      height: 100%;
      background: var(--ochre);
      transition: width 120ms linear;
    }

    main {
      scroll-snap-type: y proximity;
    }

    section {
      display: grid;
      min-height: 100vh;
      padding: 4.5rem clamp(1.25rem, 5vw, 6rem);
      place-items: center;
      scroll-snap-align: start;
    }

    /* When the rail is on screen, reserve room for it so the table of
       contents only overhangs the slide by ~10% of its width. */
    @media (min-width: 821px) {
      .js section {
        padding-right: var(--rail-reserve);
      }
    }

    .slide {
      width: min(1180px, 100%);
    }

    .card {
      overflow: hidden;
      border: 1px solid var(--line);
      border-top: 9px double var(--olive);
      background:
        linear-gradient(90deg, rgba(214, 199, 164, 0.26), transparent 36%),
        rgba(230, 230, 223, 0.96);
      box-shadow:
        0 1px 0 rgba(23, 28, 29, 0.18),
        0 18px 45px rgba(44, 55, 55, 0.16);
      transition: opacity 420ms ease, transform 420ms ease, box-shadow 420ms ease;
    }

    .js section:not(.is-active) .card {
      opacity: 0.76;
      transform: translateY(1.8rem) scale(0.985);
    }

    .js section.is-active .card {
      opacity: 1;
      transform: translateY(0) scale(1);
      box-shadow:
        0 1px 0 rgba(23, 28, 29, 0.18),
        0 26px 70px rgba(44, 55, 55, 0.22);
    }

    .card-body {
      display: grid;
      grid-template-columns: minmax(0, 1fr) minmax(13rem, 0.28fr);
      column-gap: clamp(2rem, 6vw, 5rem);
      padding: clamp(2rem, 4vw, 4.6rem);
    }

    .card-body > * {
      grid-column: 1;
    }

    .eyebrow {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      margin-bottom: 1.1rem;
      color: var(--teal);
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      font-size: 0.72rem;
      font-weight: 700;
      letter-spacing: 0.16em;
      text-transform: uppercase;
    }

    .eyebrow::before {
      width: 0.75rem;
      height: 0.75rem;
      border-radius: 999px;
      background: var(--ochre);
      content: "";
    }

    h1,
    h2,
    h3 {
      margin: 0;
      line-height: 1.05;
    }

    h1 {
      max-width: 820px;
      color: var(--olive);
      font-size: clamp(3rem, 7vw, 6.25rem);
      font-weight: 500;
      letter-spacing: -0.045em;
    }

    h2 {
      max-width: 780px;
      color: var(--olive);
      font-size: clamp(2.1rem, 4.6vw, 4.7rem);
      font-weight: 500;
      letter-spacing: -0.035em;
    }

    p {
      max-width: 700px;
      margin: 1.2rem 0 0;
      color: var(--muted);
      font-size: clamp(1.05rem, 1.55vw, 1.23rem);
    }

    .lead {
      max-width: 760px;
      font-size: clamp(1.25rem, 2.2vw, 1.62rem);
    }

    .grid {
      display: grid;
      gap: 1rem;
      margin-top: 2rem;
    }

    .grid-2 {
      grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .grid-3 {
      grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .source {
      padding: 1rem 1.15rem;
      border: 1px solid var(--line);
      background: rgba(230, 230, 223, 0.68);
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    }

    .source strong {
      display: block;
      margin-bottom: 0.35rem;
    }

    .callout {
      grid-column: 2;
      align-self: start;
      margin-top: 2rem;
      padding: 0.35rem 0 0.35rem 1rem;
      border-left: 3px solid var(--teal);
      color: var(--muted);
      font-size: 0.98rem;
      font-style: italic;
    }

    .callout.warning {
      border-left-color: var(--ochre);
    }

    .callout.danger {
      border-left-color: var(--olive);
    }

    table {
      width: 100%;
      border-collapse: collapse;
      margin-top: 1.8rem;
      border-top: 2px solid var(--ink);
      border-bottom: 2px solid var(--ink);
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      font-size: 0.88rem;
    }

    th, td {
      text-align: left;
      padding: 0.85rem 1rem;
      border-bottom: 1px solid var(--line);
      vertical-align: top;
    }

    th {
      background: rgba(214, 199, 164, 0.32);
      color: var(--ink);
      font-size: 0.8rem;
      letter-spacing: 0.07em;
      text-transform: uppercase;
    }

    tr:last-child td {
      border-bottom: 0;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      padding: 0.2rem 0.55rem;
      border-radius: 999px;
      background: rgba(95, 127, 134, 0.2);
      color: #355e66;
      font-size: 0.78rem;
      font-weight: 800;
      white-space: nowrap;
    }

    .badge.success {
      background: rgba(31, 63, 70, 0.18);
      color: #1f3f46;
    }

    .badge.warning {
      background: rgba(214, 199, 164, 0.42);
      color: #5e4a2e;
    }

    .badge.danger {
      background: rgba(154, 122, 85, 0.28);
      color: var(--olive);
    }

    code,
    pre {
      border-radius: 10px;
      background: var(--code-bg);
      color: var(--code);
      font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
    }

    code {
      padding: 0.15rem 0.4rem;
      font-size: 0.92em;
    }

    pre {
      overflow-x: auto;
      margin: 1.6rem 0 0;
      padding: 1.2rem 1.35rem;
      border: 1px solid var(--line);
      border-left: 6px solid var(--blue);
      font-size: 0.9rem;
      line-height: 1.55;
      white-space: pre-wrap;
    }

    .code-js {
      position: relative;
      background:
        linear-gradient(90deg, rgba(95, 127, 134, 0.17), transparent 44%),
        var(--code-bg);
    }

    .code-js::before {
      position: absolute;
      top: 0.65rem;
      right: 0.85rem;
      color: var(--muted);
      content: "JavaScript";
      font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      font-size: 0.68rem;
      font-weight: 700;
      letter-spacing: 0.12em;
      text-transform: uppercase;
    }

    .tok-keyword { color: var(--olive); font-weight: 700; }
    .tok-boolean { color: var(--teal); font-weight: 700; }
    .tok-string { color: #6b5537; }
    .tok-regex { color: #3a6670; }
    .tok-function { color: var(--teal); font-weight: 700; }
    .tok-comment { color: var(--muted); font-style: italic; }

    .prompt-original {
      border-left-color: var(--ochre);
      background: rgba(214, 199, 164, 0.28);
      color: var(--ink);
      font-family: Georgia, "Times New Roman", serif;
      font-size: 1rem;
      white-space: pre-wrap;
    }

    .footer {
      margin-top: 2rem;
      color: var(--muted);
      font-size: 0.9rem;
    }

    @media print {
      @page {
        size: letter;
        margin: 0;
      }

      .progress-bar,
      .story-rail,
      .chapter-indicator {
        display: none;
      }

      body {
        margin: 0;
        /* Horizontal padding only — vertical headroom lives on each section
           so the top inset repeats on every page, not just the first. */
        padding: 0 0.7in;
        background: var(--paper);
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<body>
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  <nav class="story-rail" aria-label="Section navigation"></nav>

  <aside class="chapter-indicator" aria-live="polite">
    <span class="chapter-indicator__number">01</span>
    <span class="chapter-indicator__label">Decision</span>
    <span class="chapter-indicator__rule"><span></span></span>
  </aside>

  <main>
    <section id="decision">
      <div class="slide">
        <div class="card">
          <header class="card-body">
            <div class="eyebrow">Decision</div>
            <h1>State the recommended design in one sentence</h1>
            <p class="lead">
              Lead with the decision, then explain why it preserves the intended
              behavior and which alternatives were rejected.
            </p>
            <table>
              <thead>
                <tr>
                  <th>Priority</th>
                  <th>Rule</th>
                  <th>Outcome</th>
                  <th>Rationale</th>
                </tr>
              </thead>
              <tbody>
                <tr>
                  <td>1</td>
                  <td><code>critical-path</code></td>
                  <td><span class="badge success">Recommended</span></td>
                  <td>Summarize the highest-priority behavior first.</td>
                </tr>
                <tr>
                  <td>2</td>
                  <td><code>fallback</code></td>
                  <td><span class="badge warning">Caveat</span></td>
                  <td>Make defaults and unknown cases explicit.</td>
                </tr>
              </tbody>
            </table>
            <div class="callout warning">
              Use callouts for details reviewers must notice before approving.
            </div>
          </header>
        </div>
      </div>
    </section>

    <section id="decision-model">
      <div class="slide">
        <div class="card">
          <div class="card-body">
            <div class="eyebrow">Decision model</div>
            <h2>Show the request flow or state machine</h2>
            <div class="grid grid-2">
              <div class="source">
                <strong>1. First branch</strong>
                <span>Describe the condition, expected behavior, and owner.</span>
              </div>
              <div class="source">
                <strong>2. Second branch</strong>
                <span>Describe pass-through, rewrite, fallback, or rejection.</span>
              </div>
              <div class="source">
                <strong>3. Known-good path</strong>
                <span>Explain the normal successful path.</span>
              </div>
              <div class="source">
                <strong>4. Unknown/default path</strong>
                <span>Explain how unknown inputs fail safely.</span>
              </div>
            </div>
            <div class="callout">
              Rule ordering matters. Present ordered behavior before code.
            </div>
          </div>
        </div>
      </div>
    </section>

    <section id="implementation">
      <div class="slide">
        <div class="card">
          <div class="card-body">
            <div class="eyebrow">Implementation draft</div>
            <h2>Include realistic pseudocode or configuration</h2>
            <pre class="code-js" data-lang="js">function chooseBehavior(input) {
  // Preserve protected or externally-owned paths first.
  if (shouldPassThrough(input)) {
    return "pass-through";
  }

  // Then handle known application-owned routes.
  if (isKnownApplicationPath(input)) {
    return "rewrite";
  }

  // Unknown paths should fail explicitly unless catch-all behavior is required.
  return "not-found";
}</pre>
            <div class="callout">
              Label drafts when environment-specific names or APIs may vary.
            </div>
          </div>
        </div>
      </div>
    </section>

    <section id="validation">
      <div class="slide">
        <div class="card">
          <div class="card-body">
            <div class="eyebrow">Validation</div>
            <h2>Provide a scan-friendly validation matrix</h2>
            <table>
              <thead>
                <tr>
                  <th>Input</th>
                  <th>Expected outcome</th>
                  <th>Reason</th>
                </tr>
              </thead>
              <tbody>
                <tr>
                  <td><code>known-good</code></td>
                  <td>Success path</td>
                  <td>Confirms the intended behavior.</td>
                </tr>
                <tr>
                  <td><code>unknown</code></td>
                  <td>Explicit failure or fallback</td>
                  <td>Prevents accidental masking of errors.</td>
                </tr>
              </tbody>
            </table>
          </div>
        </div>
      </div>
    </section>

    <section id="operations">
      <div class="slide">
        <div class="card">
          <div class="card-body">
            <div class="eyebrow">Operations</div>
            <h2>Document deployment, caching, rollback, and monitoring</h2>
            <div class="grid grid-3">
              <div class="source"><strong>Deploy</strong><span>How the change rolls out.</span></div>
              <div class="source"><strong>Rollback</strong><span>How to return to the prior behavior.</span></div>
              <div class="source"><strong>Observe</strong><span>Signals that confirm success or failure.</span></div>
            </div>
          </div>
        </div>
      </div>
    </section>

    <section id="sources-and-caveats">
      <div class="slide">
        <div class="card">
          <div class="card-body">
            <div class="eyebrow">Sources and caveats</div>
            <h2>Close with evidence, confidence, and follow-ups</h2>
            <div class="grid grid-2">
              <div class="source">
                <strong>High confidence</strong>
                <span>Summarize the files, APIs, traces, or docs reviewed.</span>
              </div>
              <div class="source">
                <strong>Main caveat</strong>
                <span>State the riskiest unknown plainly.</span>
              </div>
            </div>
            <div class="footer">
              Sources reviewed: <code>path/to/file</code>, <code>path/to/test</code>,
              and <code>relevant documentation</code>.
            </div>
          </div>
        </div>
      </div>
    </section>

    <section id="appendix-original-prompt">
      <div class="slide">
        <div class="card">
          <div class="card-body">
            <div class="eyebrow">Appendix</div>
            <h2>Original prompt</h2>
            <p class="lead">
              Verbatim record of the instructions that initiated this memo, so
              reviewers can see the steering the agent received.
            </p>
            <pre class="prompt-original">Paste the user's original prompt here, with whitespace and line breaks preserved. Escape &amp;, &lt;, and &gt; so the text renders literally. For multi-turn briefs, include each substantive steering message in order, labeled by turn.</pre>
          </div>
        </div>
      </div>
    </section>
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