docs: Enhance READMEs with detailed information, download instructions, and updated screenshots, including a new privacy image.

README.md

@@ -1,13 +1,39 @@
-# Caption Trans
+<p align="center"><a href="https://github.com/cddqssc/Caption-Trans"><img src="assets/images/app_icon.png" alt="Caption Trans" width="100" /></a></p>
+<h3 align="center">Caption Translator</h3>
+<p align="center">
+  <a href="https://mit-license.org/"><img src="https://img.shields.io/badge/License-MIT-blue.svg" alt="License: MIT"></a>
+</p>
+<p align="center">
+  <a href="README.md"><img alt="English" src="https://img.shields.io/badge/English-d9d9d9"></a>
+  <a href="README_zh.md"><img alt="中文(简体)" src="https://img.shields.io/badge/中文(简体)-d9d9d9"></a>
+</p>
 
-[中文版](README_zh.md)
+# What is Caption Trans?
+Import videos, extract subtitles, and use AI to translate them into the target language.
+Supports: Google Gemini (tested), OpenAI, DeepSeek, Ollama, and other OpenAI-compatible API services.
 
-## App Screenshot
-![App Screenshot](screenshots/screenshot_en.jpg)
+# Download
+Supports macOS (Apple Silicon) and Windows.
 
-A one-stop video subtitle translation tool. It extracts subtitles locally using Whisper and accurately translates them into the target language using LLM.
-Currently, it supports OpenAI, Google Gemini, DeepSeek, Ollama, and other API services compatible with the OpenAI interface.
+Please go to [Releases](https://github.com/cddqssc/Caption-Trans/releases) to download.
 
-## License
+## ⚠️ How to open on macOS
+1. Double-click the app. It will be blocked by the system because it has not been signed with an Apple developer certificate.
+2. Go to **System Settings** > **Privacy & Security**.
+3. Scroll down to the Security section and click **"Open Anyway"** next to the app's block message.
+4. Enter your Mac password and click **"Open"**. 
+*(You only need to do this once.)*
 
+# App Screenshot
+<img src="screenshots/screenshot_en.jpg" alt="App Screenshot" width="500">
+
+# Tips
+Currently, only the Gemini API has been tested. **gemini-2.5-flash-lite** is recommended.
+
+It balances speed and quality, and the price is relatively low. It can also translate sensitive content.
+
+For models above Gemini 3, translating sensitive content may return an empty result, and the price is higher.
+
+# License
 [MIT License](LICENSE)
+

README_zh.md

@@ -1,13 +1,38 @@
-# Caption Trans
+<p align="center"><a href="https://github.com/cddqssc/Caption-Trans"><img src="assets/images/app_icon.png" alt="Caption Trans" width="100" /></a></p>
+<h3 align="center">Caption Translator</h3>
+<p align="center">
+  <a href="https://mit-license.org/"><img src="https://img.shields.io/badge/License-MIT-blue.svg" alt="License: MIT"></a>
+</p>
+<p align="center">
+  <a href="README.md"><img alt="English" src="https://img.shields.io/badge/English-d9d9d9"></a>
+  <a href="README_zh.md"><img alt="中文(简体)" src="https://img.shields.io/badge/中文(简体)-d9d9d9"></a>
+</p>
 
-[English Version](README.md)
+# 什么是 Caption Trans？
+导入视频，提取视频字幕，使用 AI 翻译字幕为目标语言。
+支持：Google Gemini（已测试）、OpenAI、DeepSeek、Ollama 等兼容 OpenAI 的 API 服务。
 
-## 应用截图
-![应用截图](screenshots/screenshot_zh.jpg)
+# 下载
+支持 macOS（M系列芯片）和 Windows。
 
-一站式视频字幕翻译软件。通过本地 Whisper 提取字幕，并使用 AI 将其准确翻译为目标语言。
-目前支持OpenAI、Google Gemini、DeepSeek、Ollama 等兼容 OpenAI 的 API 服务。
+请到 [Releases](https://github.com/cddqssc/Caption-Trans/releases) 下载。
 
-## 开源协议
+## ⚠️ 如何在 macOS 上正常打开应用
+1. 双击打开应用，由于目前尚未配置 Apple 开发者证书，会被系统拦截。
+2. 进入 Mac 的 **系统设置** > **隐私与安全性**。
+3. 向下滚动，在“安全性”板块找到拦截提示，点击旁边的**“仍要打开”**。
+4. 验证 Mac 密码后，在最终弹窗中点击**“打开”**即可。
+*（此操作仅需执行一次，后续可直接双击运行。）*
 
+# 应用截图
+<img src="screenshots/screenshot_zh.jpg" alt="应用截图" width="500">
+
+# 使用心得
+目前仅测试了 gemini api，推荐使用**gemini-2.5-flash-lite**。
+
+它能兼顾速度和质量，价格也比较便宜。并且能翻译敏感内容。
+
+gemini-3 以上的模型，翻译敏感内容会返回空，价格也比较贵。
+
+# 开源协议
 [MIT License](LICENSE)