## Task
Complete the HTML structure by adding the missing Tailwind CSS classes to meet the layout requirements.
- **Grid container**: Define a grid with three columns and a gap of 1rem (16px) between items;
- **First item**: Span across two columns;
- **Second item**: Span across one column;
- **Third item**: Span across all three columns.

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

- For the grid container, use `grid grid-cols-3 gap-4`;
- For the first item, use `col-span-2`;
- For the second item, use `col-span-1`;
- For the third item, use `col-span-3`.

PCFET0NUWVBFIGh0bWw+CjxodG1sIGxhbmc9ImVuIj4KICA8aGVhZD4KICAgIDxtZXRhIGNoYXJzZXQ9IlVURi04IiAvPgogICAgPG1ldGEgbmFtZT0idmlld3BvcnQiIGNvbnRlbnQ9IndpZHRoPWRldmljZS13aWR0aCwgaW5pdGlhbC1zY2FsZT0xLjAiIC8+CiAgICA8dGl0bGU+Q2hhbGxlbmdlOiBHcmlkIFV0aWxpdGllcyAtIFNvbHV0aW9uPC90aXRsZT4KICAgIDxzY3JpcHQgc3JjPSJodHRwczovL2Nkbi50YWlsd2luZGNzcy5jb20iPjwvc2NyaXB0PgogIDwvaGVhZD4KICA8Ym9keT4KICAgIDxkaXYgY2xhc3M9ImdyaWQgZ3JpZC1jb2xzLTMgZ2FwLTQiPgogICAgICA8ZGl2IGNsYXNzPSJjb2wtc3Bhbi0yIGJnLWJsdWUtNzAwIHAtNCI+SXRlbSAxPC9kaXY+CiAgICAgIDxkaXYgY2xhc3M9ImNvbC1zcGFuLTEgYmctZ3JlZW4tNzAwIHAtNCI+SXRlbSAyPC9kaXY+CiAgICAgIDxkaXYgY2xhc3M9ImNvbC1zcGFuLTMgYmctcmVkLTcwMCBwLTQiPkl0ZW0gMzwvZGl2PgogICAgPC9kaXY+CiAgPC9ib2R5Pgo8L2h0bWw+

Learn to style websites efficiently using Tailwind CSS, a utility-first framework for rapid UI development. Discover how to set up Tailwind and apply utility classes for colors, typography, borders, and shadows. Build and style essential components like buttons, cards, and forms. Master layout techniques using spacing, flexbox, and grid utilities. Create responsive designs and customize Tailwind to match your project needs.

Meet Tailwind CSS, a utility-first framework known for its flexibility and efficiency in web styling. Discover the key benefits and the utility-first philosophy. Additionally, explore the simple installation methods using CDN or npm/yarn.

Discover the foundational elements of Tailwind CSS, including an understanding of utility classes and their application to HTML elements. Delve into essential styling techniques such as setting colors, borders, shadows, and typography utilities.

Dive into practical applications focusing on creating and styling Buttons, Forms, and Cards. Through hands-on challenges, you’ll master building these essential UI components, enhancing your skills with real-world examples.

Explore Tailwind CSS’s essential spacing utilities, covering how to apply margin and padding to your elements. You’ll also learn to utilize flexbox utilities to control layout with display settings, flex direction, and both horizontal and vertical alignment. Additionally, you’ll dive into grid utilities to create simple yet powerful grid layouts, mastering the setup of grid containers and items.

Discover how to customize Tailwind CSS to meet your project’s design requirements and create adaptable layouts for various devices.

Challenge: Grid Layout Mastery

Task