Hover to expand - panel displays message preview

Key features

• Permanent right navigation rail - a slender vertical rail on the right side of the screen, with an indicator line for each user message, consistent with the folded state of the official website
• 1:1 replica of the DeepSeek Harness (DSH) plug-in on the "Conversation Navigation Bar" on the right side of the DeepSeek official website - bringing the ScrollNav interface and interaction of the official web version of chat.deepseek.com into your DSH Web chat interface.
• Layout/CSS1:1 transplantation of official website ScrollNav (extracted from official main.css, namespaced with dsct_ prefix)
• Hover to expand - the panel displays a message preview and highlights the current reading position in real time as you scroll (brand blue)