Create initial landing page with user interest form

I would like to create a landing page using index_2.html at the root of the repository with the following elements.

Navigation

• This is a landing page so no navigation is necessary for now.
• The main hero section should have the following tagline:
  • Product Name: dev++
  • Slogan: The best way to Learn\nIs to Launch
• Underneath the hero section a couple feature highlights (to be filled in later)
• Under the feature highlights a form with the following:
  • Name
  • Email
  • Coding experience - slider with options 1 year, 5 years, 10 years, 20 years
  • AI tools used for coding - checkboxes with options Chatbots (ChatGPT, Gemini), IDEs (Cursor, Windsurf), Coding Agents (Claude Code, Codex), Vibe coding (Lovable, v0, Replit)
  • AI tool expertise - for each box checked, a slider with options (novice, intermediate, expert)
  • A submit button which does basic form validation and POSTs the data which will go to a script that appends it to a Google Sheet.
    • On submission, add a spinner icon after the text in the button, post to a URL, update the icon to a checkmark or exclamation point depending on if the response is 2xx.
• A Python function which writes the form data into a Google Sheet. This script will be hosted on a server capable of executing Python.

从仓库根目录的 index_2.html 开始，梳理所要求的 hero、功能亮点、表单字段、验证、提交状态和 POST 行为。然后确定用于将表单数据写入 Google Sheet 的 Python 函数应放在哪里，以及托管的 endpoint 将如何与页面连接。完成的标准是落地页和表单能够端到端正常工作，包括成功和失败反馈。