PrivateGPT Workbench Style Guide

This guide defines the visual and UX direction for PrivateGPT Workbench. It complements the product requirements in docs/PRD.md.

The goal is to keep the implementation simple while aligning the demonstrator with the public-facing PrivateGPT/Zylon visual language.

Reference Assets

Use these repo-local images as visual references:

The PrivateGPT logo should be embedded directly in ./index.html as inline SVG so the page does not depend on an external logo asset at runtime.

Design Intent

PrivateGPT Workbench should feel like a polished local AI workspace, not a generic admin console and not a marketing landing page.

The interface should communicate:

• Local-first AI utility.
• Technical power without intimidating non-technical users.
• A premium, public-brand-aligned experience.
• Simplicity and directness.

The product surface remains:

Sidebar
  Context
  New Chat
  Chat list
  API Debugger
  Settings
  GitHub
  Not for Production

Main
  Context screen
  or
  API Debugger screen
  or
  Settings screen
  or
  Chat screen

Visual Language

Use a dark, atmospheric workspace:

• Deep navy, charcoal, black, muted amber, and subtle purple/brown tones.
• Radial or blended gradients across the full viewport.
• A fine grain/noise texture over the background.
• Frosted glass panels with blur, light borders, and soft shadows.
• White primary text and muted gray secondary text.
• Small blue/orange/purple gradient accents inspired by the PrivateGPT/Zylon orb.

Avoid:

• Flat admin-dashboard gray.
• Marketing hero sections.
• Large decorative cards unrelated to function.
• Bright white page backgrounds.
• Excessive purple/blue gradient dominance.
• Heavy component-library appearance.

Layout

App Shell

Follow the structure in primary-chat-layout.png.

Recommended dimensions:

• Sidebar width: 286px (--sidebar variable).
• Main content max width for chat: 860px.
• Composer width: aligned to chat content width.
• Full viewport height.
• No separate header bar unless needed.

The background should remain visible around and through glass surfaces.

Sidebar

The sidebar should be a vertical frosted-glass panel.

Content:

PrivateGPT logo

Context
New Chat

Chats
  Chat title
  Chat title
  Chat title

API Debugger
Settings
GitHub
Not for Production

Requirements:

• Place the PrivateGPT logo at the top-left. In the single-file app, use the inline embedded SVG.
• Keep navigation compact and readable.
• Active item uses a brighter glass state.
• Chat rows should truncate long titles.
• No projects, folders, or chat grouping.
• Place API Debugger above Settings at the bottom of the sidebar.
• Place Settings below API Debugger in the bottom sidebar group.
• Place the GitHub repository widget below Settings.
• Place the Not for Production disclosure below the GitHub widget.
• Avoid making the sidebar feel like an enterprise admin menu.
• The chat list fills all available vertical space between the nav buttons and the bottom group, using flex: 1 1 0 and min-height: 0.
• Apply scroll-aware top/bottom fade masks to the chat list using CSS mask-image with --fade-top-stop/--fade-bot-stop custom properties, updated on scroll.

Main Chat

The chat view should be centered and spacious.

Message behavior:

• User messages align right.
• Assistant messages align left.
• Bubbles use translucent glass fills.
• Assistant messages may include a small gradient orb/avatar.
• User messages may use a subtle avatar or label.
• Citations should appear inline as compact superscript-like markers or small chips.
• Tool activity should appear as subdued inline status blocks, not large cards.
• Apply scroll-aware top/bottom fade masks to the messages list using the same mask-image pattern as the chat list.

Composer

Use chat-tools-composer.png as the main composer reference.

The composer should include:

• Large text input area.
• Send icon button on the right.
• Compact controls below the textarea:
  • Model selector (custom glass dropdown — see Model Selector section).
  • Refresh models icon button.
  • Thinking toggle button.
  • Tools selector button opening the Tools menu.

The Tools control should expose chat-specific toggles:

• Documents
• Web
• Databases
• MCP
• Skills
• Custom Tools

Selected context items can appear as compact chips.

Context Screen

The Context screen defines what the assistant can access. It should look like a source manager, not a settings page.

Sections:

Documents
Databases
Web
MCP
Skills
Custom Tools

Use context-knowledge-base.png as the reference for:

• Glass list rows.
• File/source icons.
• Type badges.
• Status metadata.
• Overflow menus.
• Nested or grouped rows where useful.

Documents

Rows should show:

• Icon.
• Name.
• Collection.
• File type badge, such as PDF, DOCX, CSV, HTML.
• Status, such as Indexed, Processing, Failed.
• Overflow menu: Preview, Search, Delete.

The Collection field is in Settings, not in the Documents panel. It applies globally to all document operations.

Databases

Rows should show:

• Database icon.
• Friendly name.
• Host or short connection label.
• Schema/table metadata if available.
• Overflow menu: Edit, Test, Delete.

Web, MCP, Skills, Custom Tools

Use the same row/card language:

• Name.
• Description or provider.
• Configuration summary.
• Overflow actions.

The Web section is informational only. Do not collect provider credentials in Workbench; web provider and API key configuration belongs in the PrivateGPT backend.

Custom Tools should not be hidden behind an "Advanced" label. They are a first-class Context section.

Settings Screen

Settings owns Workbench-level connection configuration:

• PrivateGPT API base URL.
• Optional HTTP Basic auth (username and password fields displayed side by side).
• Optional system prompt.
• Optional workspace instructions for the current branded experience.
• Use citations toggle.
• Collection — the active document collection name used for all document operations and chat requests. This belongs in Settings, not in the Documents panel.
• Appearance controls for brand copy, palette, and optional visible sections.
• A control to rerun onboarding.
• Test API and Save buttons.
• Clear local data.

Onboarding Overlay

The first-run onboarding should feel like a guided setup sheet rather than a wizard from an enterprise admin console.

• Present it as a large glass overlay above the existing app shell so the user can feel that they are configuring the actual workspace.
• Step 1 should emphasize clarity and confidence: URL, auth, collection, then a simple checklist showing whether models, collection, and skills responded.
• Step 2 should feel lighter and optional: a prompt-driven generator plus editable result form on one side and a live preview tile on the other.
• The optional customization step should use the same visual language as Settings so the user understands both surfaces write to the same variables.
• GitHub / Zylon references are part of the demo identity and should not be removable through appearance customization.

API Debugger

API Debugger appears as a sidebar destination above Settings.

It is session-level, live-only, and ephemeral.

Recommended layout:

Timeline list | Event detail panel

Use the same glass styling, but make it denser and more technical than Chat.

API Debugger should show:

• API requests.
• API responses.
• Errors.
• Redacted request headers.

API Debugger events must not persist across page reloads.

Both the timeline panel and the detail panel must have min-width: 0 so long URLs truncate instead of overflowing the panel.

Not For Production Disclosure

The sidebar includes a compact Not for Production button below the GitHub widget.

Visual treatment:

• Same sidebar row rhythm as the GitHub widget.
• Slight warm/danger tint so it reads as an important disclosure without looking like an error.
• Info icon plus text label.

Clicking it opens a glass-style modal. The title should be:

This demonstrator is not intended for Production use

Keep the body concise, with four merged bullets covering browser localStorage secrets, lack of access control, visible debugger data, and browser-executed custom tools. End with links to Zylon (https://zylon.ai) and the demo booking page (https://cal.com/zylon/demo?source=privategptui).

GitHub Widget

The sidebar includes a clickable GitHub widget below Settings.

Requirements:

• Link to https://github.com/zylon-ai/private-gpt.
• Show the GitHub icon, label, star icon, and live star count when available.
• If the star fetch fails, keep the widget usable and show a neutral Stars label.

URL Hash Navigation

The app uses hash-based navigation so reloading restores the current view.

Hash format:

syncHash() calls history.replaceState at the end of every render() call. restoreFromHash() runs at startup before the first render and on hashchange events for browser back/forward support.

Components

Glass Surface

All main panels share one glass treatment via a shared CSS selector group:

.settings-card,
.context-panel,
.debug-panel,
.composer,
.message-bubble,
.menu-panel,
.model-dropdown,
.modal-card {
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.14), rgba(255, 255, 255, 0.055));
  border: 1px solid var(--border);
  box-shadow: 0 18px 60px rgba(0, 0, 0, 0.28);
  backdrop-filter: blur(22px);
  -webkit-backdrop-filter: blur(22px);
}

Floating panels (modal card, tools menu, model dropdown) override with a light translucent frost, very heavy blur, heavier at the bottom:

.modal-card,
.menu-panel,
.model-dropdown {
  background: linear-gradient(to bottom,
    rgba(255, 255, 255, 0.14) 0%,
    rgba(255, 255, 255, 0.26) 100%
  );
  backdrop-filter: blur(72px) saturate(1.6);
  -webkit-backdrop-filter: blur(72px) saturate(1.6);
}

The white-glass tint stays light (translucent, not opaque); the blur(72px) defocuses the background enough to make text readable; the gradient is heavier at the bottom for visual grounding.

The modal backdrop itself uses a moderate blur:

.modal-backdrop {
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

Background

:root {
  --bg: #090b12;
  --text: #f7f7fb;
  --muted: rgba(255, 255, 255, 0.58);
  --muted-strong: rgba(255, 255, 255, 0.74);
  --faint: rgba(255, 255, 255, 0.36);
  --glass: rgba(255, 255, 255, 0.1);
  --glass-soft: rgba(255, 255, 255, 0.07);
  --glass-strong: rgba(255, 255, 255, 0.16);
  --border: rgba(255, 255, 255, 0.24);
  --border-soft: rgba(255, 255, 255, 0.14);
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.38);
  --danger: #ff9f9f;
  --ok: #91e8bd;
  --warn: #ffd18a;
  --accent: #f0a247;
  --blue: #70b7ff;
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --sidebar: 286px;
}

body {
  background:
    radial-gradient(circle at 17% 78%, rgba(36, 125, 190, 0.58), transparent 36%),
    radial-gradient(circle at 83% 16%, rgba(212, 148, 63, 0.38), transparent 31%),
    radial-gradient(circle at 53% 42%, rgba(92, 50, 116, 0.34), transparent 40%),
    linear-gradient(135deg, #081427 0%, #15121c 42%, #130b05 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.24;
  background-image:
    radial-gradient(rgba(255,255,255,0.18) 0.65px, transparent 0.65px);
  background-size: 3px 3px;
  mix-blend-mode: overlay;
}

Model Selector

Replace the native <select> with a custom glass dropdown:

• A ghost-button showing a CPU icon, the current model name (truncated), and an animated chevron.
• Clicking opens a .model-dropdown panel positioned above the composer.
• The dropdown lists all models as .model-option rows with a checkmark on the active selection.
• Close on outside click or Escape.
• The .model-dropdown is in the shared glass group and gets the stronger frost override.

Tools Menu

The Tools popup (.menu-panel) is structured with section groups:

Knowledge
  Documents  [toggle]
  Web        [toggle]

Databases    [group title]
  item       [toggle]

MCP          [group title]
  ...

Skills       [group title]
  ...

Custom Tools [group title]
  ...

Each group uses .menu-group and .menu-group-title (small uppercase label). Toggle rows inside the menu are borderless with hover highlight only, distinguishing them from Settings card toggle rows which retain a border.

Toggle Switches

All input[type="checkbox"] elements are styled as custom pill toggles — no native appearance:

• Pill track: 34 × 20px, rounded.
• Knob: 12px circle, vertically centered.
• Off state: muted white track and knob.
• On state: blue tint track (rgba(80, 150, 255, 0.32)) with a bright knob (rgba(150, 205, 255, 0.96)).
• Smooth left transition on the knob (not transform: translateX).

Thinking Button

The Extended Thinking toggle in the composer uses:

• A ghost-button with a zap icon and the label Thinking.
• Inactive: standard ghost button appearance with purple hover hint.
• Active: purple border, purple-tinted background, soft glow, and purple-tinted icon.

.thinking-chip.active {
  border-color: rgba(130, 80, 230, 0.55);
  background: rgba(100, 55, 200, 0.18);
  color: rgba(200, 165, 255, 0.95);
  box-shadow: 0 0 14px rgba(120, 70, 220, 0.18);
}

Buttons And Chips

Buttons and chips should feel like part of the glass environment:

• Thin border.
• Translucent fill.
• Slightly brighter hover.
• Clear active state with scale(0.97) press feedback.
• Icons where useful.

Use icons for:

• Send.
• Search.
• Files/collection.
• Tools.
• Database.
• More menu.
• Delete.
• Refresh/test.
• CPU (model selector).
• Chevron-down (model selector dropdown indicator).
• Check (selected item in model dropdown).
• Zap (thinking toggle).

If no icon library is used, inline SVGs are acceptable, but keep them minimal.

Menus And Overlays

Use search-overlay.png as reference.

Requirements:

• Glass overlay panel with the stronger frost treatment.
• Strong border.
• Soft shadow.
• Large readable input for search-like overlays.
• Compact pill filters where needed.
• Results as clean rows.

Both .menu-panel and .model-dropdown share the same glass + stronger-frost override as .modal-card.

Scroll Fades

Apply a top/bottom scroll-aware fade mask to any scrollable list that may overflow:

.scrollable-wrap {
  --fade-top-stop: 0px;
  --fade-bot-stop: 0px;
  mask-image: linear-gradient(
    to bottom,
    transparent 0,
    black var(--fade-top-stop),
    black calc(100% - var(--fade-bot-stop)),
    transparent 100%
  );
}

Update --fade-top-stop and --fade-bot-stop via JavaScript on scroll. Applied to:

• .chat-list-wrap — sidebar chat list (22px stops).
• .messages — main message list (28px stops).

Typography

Use a modern sans-serif stack:

font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

Guidelines:

• Primary text: high contrast white.
• Secondary text: muted white/gray.
• Avoid oversized hero typography.
• Chat text should be comfortably readable.
• Context/debugger text can be denser.
• Do not use negative letter spacing.
• Do not scale font sizes with viewport width.

Responsive Behavior

Desktop is the primary target for v1.

Minimum behavior:

• At narrow widths, sidebar can collapse or become an overlay.
• Chat composer remains usable.
• Text must not overflow buttons, chips, or rows.
• Context rows should wrap metadata rather than clipping important labels.

Implementation Constraints

The visual system should not require a frontend framework.

Preferred implementation:

• Single static ./index.html.
• Vanilla CSS variables.
• Small reusable CSS classes.
• Repeated HTML templates are acceptable.
• No design system extraction required.

The styling should support the PRD's simplicity requirement: polished enough for a public-facing demo, but not architected like a long-term product frontend.