Text Before HTML:

We are building a book reading app with the following features:
 - Customizable fonts (we'll allow the user to choose a font from a set of options)
 - Dark mode option
 - Progress bar to show the current reading progress
 - Easy chapter navigation (list of chapters, current chapter highlighted)

 We'll use Tailwind CSS for styling and include a simple JavaScript for interactivity.

 Design Inspiration:
 We'll take inspiration from the provided template in terms of layout and aesthetics, but we'll adapt it for a book reader.
 We'll use a clean, modern design with a focus on readability.

 Color Scheme:
 We'll define a light and dark theme. For the light theme, we'll use:
   - Background: light gray (e.g., #f8f9fa)
   - Text: dark gray (e.g., #212529)
   - Accent: a calming color for highlights (e.g., #4a6fa5)

 For the dark theme:
   - Background: dark gray (e.g., #212529)
   - Text: light gray (e.g., #f8f9fa)
   - Accent: a lighter shade of the same accent color (e.g., #6d9dc5)

 We'll also include a progress bar that shows the percentage of the book read.

 Structure:
   - Header: App title and theme toggle (dark mode)
   - Main Content:
        * A section for the book cover (centered, large)
        * A section for the book title and author
        * A progress bar
        * A list of chapters (with current chapter highlighted)
        * The book content (as a long text, we'll use lorem ipsum for placeholder)
   - Footer: Maybe a status bar or copyright

 We'll also include a way to change the font (via a dropdown or buttons) but note: the font change might be limited by the content being long.

 Steps:

 1. Set up the HTML structure with Tailwind via CDN.
 2. Define custom styles for light and dark themes in a style tag (using CSS variables).
 3. Create the header with the app title and dark mode toggle.
 4. Create the main content area:
      - Book cover (placeholder image or a div with background)
      - Book title and author
      - Progress bar (using a div with a background that changes width)
      - Chapter list (ul with li, and mark the current chapter)
      - Book content (a div with a long text, we'll use lorem ipsum)
 5. Add a footer.

 6. JavaScript for:
      - Toggling dark mode (change the class on the body and update the theme)
      - Updating the progress bar when the user scrolls (if we want to simulate progress)
      - Highlighting the current chapter in the list (if we have multiple pages)

 However, note: the progress bar might be fixed to the top? We can have a fixed header and the content below.

 Let's design:

   - The book content should be long, so we'll have a fixed height for the reading area and scrollable.

 We'll break the main content into:

   

     

        
 
        
        
Book Title
        
Author Name
     

     

        

          

        
        
30% complete
     

     

        
Chapters
        

          

            
            Chapter 1: Introduction
          
          ... 
        
     

     

        
     
   

 7. For the font customization, we can have a dropdown in the header or in the settings. Since the template had a mobile menu, we can add a button in the header to open a modal with font options.

 However, note: the template had a complex hero section. We are not building that. We are building a reading app.

 Let's simplify:

   Header: 
     - App name: "Book Reader"
     - Dark mode toggle (sun/moon icon)
     - Font selection dropdown (or a button to open a menu with font options)

   We'll have a few font options: 
        - System default
        - Serif (like Georgia, Times)
        - Sans-serif (like Arial, Helvetica)
        - Monospace (like Courier)

 8. We'll use the same approach for the dark mode as the template: a class "dark" on the body.

 9. We'll write JavaScript to handle:
      - Toggling the dark mode
      - Changing the font for the entire app (we'll set the font-family on the body)

 10. We'll also include a script to set the current year in the footer.

 Implementation:

   We'll create a modal for font selection that appears when the font button is clicked.

   The modal will have buttons for each font family.

   We'll set the font-family on the body and update the button states.

 11. We'll also make the progress bar update as the user scrolls. We can do this by:

      - Setting the height of the book content to a fixed value (so we know the total height)
      - On scroll, calculate the percentage and update the progress bar.

 12. For the chapter navigation, we can have an array of chapter titles and then when a chapter is clicked, we scroll to that section.

 However, note: the content is long and we are using lorem ipsum. We don't have real anchors. We can simulate by having each chapter as a section with an id? But we are not breaking the content into sections. Alternatively, we can have a separate list of chapters that when clicked, scrolls to the corresponding section? But we don't have sections.

 Since we are using a long text, we can break it into sections by chapter? Or we can have a separate div for each chapter? 

 Alternatively, we can have:

   

     
...
     
...
   

 But the problem is that the content is long and we don't have real content. We are using lorem ipsum.

 We'll simulate by having 5 chapters, each with a heading and a paragraph of lorem ipsum.

   

     

        
Chapter 1: Introduction
        
...
     
     ... 
   

 Then when a chapter in the list is clicked, we scroll to that id.

 13. We'll also highlight the current chapter in the list (the one that is in view).

 14. We'll use IntersectionObserver to track which chapter is in view.

 Given the complexity, we'll start with a simpler version and then add the chapter navigation.

 Let's code step by step.

 Note: We are not using the exact template, but we are inspired by its clean design and animations.

 We'll include the same animation for the book cover? Maybe not, but we can have a fade-in for the content.

 We'll also include the same approach for the theme toggle (using a class and CSS variables).

 Let's define the CSS variables for light and dark themes.

 We'll define:

   :root {
     --bg-primary-light: #f8f9fa;
     --text-primary-light: #212529;
     --text-secondary-light: #6c757d;
     --accent-light: #4a6fa5;
     --border-light: #dee2e6;
     --card-bg-light: #ffffff;
     --header-bg-light: rgba(248, 249, 250, 0.8);
   }

   .dark {
     --bg-primary-dark: #212529;
     --text-primary-dark: #f8f9fa;
     --text-secondary-dark: #adb5bd;
     --accent-dark: #6d9dc5;
     --border-dark: #495057;
     --card-bg-dark: #343a40;
     --header-bg-dark: rgba(33, 37, 41, 0.8);
   }

   body {
     background-color: var(--bg-primary-light);
     color: var(--text-primary-light);
   }

   .dark body {
     background-color: var(--bg-primary-dark);
     color: var(--text-primary-dark);
   }

   ... and so on.

 We'll also define the progress bar and other elements accordingly.

 Let's code accordingly.


# Book Reader App with Tailwind CSS

I'll create a modern book reading app with customizable fonts, dark mode, progress tracking, and chapter navigation. The design will be clean and focused on readability.

Generated HTML Page:

Text After HTML:

## Key Features Implemented

1. **Customizable Fonts**:
   - Three font styles: Sans, Serif, and Display
   - Interactive selector with visual indicator
   - Real-time font change applied to entire app

2. **Dark Mode Option**:
   - Toggle switch with moon/sun icons
   - Smooth transition between themes
   - Custom color variables for both modes

3. **Progress Tracking**:
   - Visual progress bar with percentage indicator
   - Simulated progress update every 3 seconds
   - Chapter-based navigation

4. **Chapter Navigation**:
   - Collapsible chapter list with active state highlighting
   - Page range indicators for each chapter
   - Click navigation to different chapters

5. **Reading Experience**:
   - Clean typography with proper spacing
   - Blockquote styling for important quotes
   - Responsive layout for all screen sizes
   - Reading settings controls

6. **Modern UI Design**:
   - Clean, minimalist interface focused on content
   - Subtle animations and transitions
   - Card-based layout with rounded corners
   - Consistent color scheme with accent colors

The design uses a teal/teal color scheme that's easy on the eyes for extended reading sessions, with proper contrast in both light and dark modes. The layout is fully responsive and provides an excellent reading experience across devices.