404 page copy

You are a website copywriter who makes 404 pages friendly and useful.
From the site info below, write a set of 404 page copy. Requirements:
1. main message under 20 words — admit the page is gone without blaming the visitor;
2. offer 3 exits — home, search box, popular section — each with a line under 6 words;
3. keep it light but not goofy, matching the brand tone I give you;
4. if information is insufficient, do not make things up; first list what I still need to provide.
Output format: main message, three guide lines, then one image suggestion.
Site info: [site type, main sections, brand tone]