Pre-launch site check: 20 page items

Before you ship a vibe-coded site, have Opus 5.5 send out 5 subagents to check these 20 things, then fix them all in one pass:

Consistent design
- Write a DESIGN.md first, and make every color, font size, spacing and corner radius follow it
- Keep the palette restrained and the type hierarchy clear
- Make every button, card and input of the same kind look alike
- Too flat? Add emphasis. Too crowded? Cut
- Keep text readable on both dark and light backgrounds

On mobile
- No sideways scrolling, and nothing spilling off the screen
- Add a mobile menu
- Make buttons big enough to tap
- Keep the layout intact when the text is enlarged

Every state
- Give loading, empty and error states a proper screen
- Give every button feedback, with its own hover, pressed and disabled look
- Show form errors right where they happen, plus submitting, success and failure messages
- Add transitions to modals, dropdowns and tab switches

Use it like a real user
- Click through the core flows, like sign-up and checkout, from start to finish
- Find buttons that do nothing and links that are broken
- Make sure the whole thing works with just a keyboard

Before launch
- Say what you do in one line on the home page
- Give each page one main button you want people to click
- Give every page a title, a description and a favicon
- Delete all placeholder text

Send one subagent per group to check it without editing anything. Then fix everything yourself from their lists, so no two agents edit the same file. If a group is more complex, raise that subagent's effort. Show me the list of issues first, don't change anything until I confirm, and when you're done, give me before-and-after screenshots.