TITLE: ORION-7 — a CRT mainframe that boots itself and answers your commands

PROMPT: Build a single self-contained HTML page that is a fictional mainframe terminal on a CRT. Palette: black-green #020604 ground, phosphor #39ff88, mint #0affc3, amber warning #ffb000, dim green #06281a. Everything is ui-monospace 14–16px, uppercase headings, phosphor text-shadow 0 0 7px rgba(57,255,136,.42). Layout: a fixed full-viewport .room with a dark radial ambient; inside it one .crt cabinet (flex column, rounded clamp(12px,1.6vw,26px), plastic gradient, deep drop shadow) holding a .screen (flex column, radial-gradient tube face, inset shadows, 1px phosphor inner border) and a .controls strip with an "Orion Systems" plate, four status LEDs and a power button. The screen contains, in order: a header bar (Host ORION-7, Uptime, Load, state) with a phosphor gradient wash and a bottom hairline; a .main grid of two panels (1.55fr / 1fr) — left the event log with its own scrollbar styling, right the telemetry panel with four gauges (CPU, Memory, Network, Tape I/O) each a label row plus a 7px bordered track and a gradient fill, then a hand-authored 44-character box-drawing ASCII sector map with nodes [+] [#] [~] [*] connected by ═ and ║ runs, padded in JS to a fixed width so every column aligns; then the command line (prompt orion-7:~$, mirrored text span, blinking block caret, transparent absolutely-positioned input). Over everything: a repeating-linear-gradient scanline layer (1px dark per 3px), a 16%-height phosphor sweep bar animating translateY over 7.5s, and a glass layer with a radial vignette plus a diagonal highlight. Motion and behaviour: a typing queue types twelve BIOS lines character by character with 2–10ms jitter and a 45–125ms pause between lines, so the machine reaches ONLINE about 3.5 seconds in, then the state machine flips BOOTING → ONLINE, lights the LEDs, enables the input and starts ambient traffic (a new log line every 1.25s from a pool of relay messages and amber warnings), gauge drift every 780ms with >82% turning a gauge amber, an uptime clock every second, and a horizontal sync wobble every 9–15s. Commands: help, status, map, clear, reboot, uptime, whoami, with Tab completion over that list and ArrowUp/ArrowDown history. Holding the power button for 900ms fills a conic-gradient ring via a --hold custom property and fires a 1.15s degauss animation (scaleY collapse to .008, overshoot to 1.07) before replaying the whole boot. prefers-reduced-motion: reduce removes the sweep, wobble, degauss, caret blink, LED blink, line flash and gauge transition, and slows the ambient intervals. One inline style block, one inline script IIFE at the end of body, zero external references, and the substring "http" must never appear.

DESCRIPTION: A phosphor terminal that behaves like a machine rather than a picture of one. It starts dark and boots itself: twelve BIOS lines type themselves out at an uneven, hand-feeling speed, then the state chip flips to Online, three green LEDs light, and the room comes alive — relay traffic scrolls into the log with a green flash on every new line, four gauges drift and occasionally turn amber, and the whole tube occasionally slips sideways for half a second like a mis-tuned vertical hold. A 44-character box-drawing sector map sits in the telemetry panel, its nodes and connectors aligned to the character. The command line is real: type help and you get a command list, status prints a subsystem summary, map redraws and briefly lights the map amber, clear wipes the log, reboot cold-starts the machine with a full degauss collapse. Everything is wrapped in scanlines, a slow phosphor sweep, and a glass vignette that keeps the corners dark, and the only light in the room is the tube itself.

TECHNIQUES:
- Typing queue with per-character jitter and variable inter-line pauses driving a small BOOTING / ONLINE / REBOOTING state machine
- Hand-authored box-drawing ASCII map padded to a fixed 42-character content width in JS so every column aligns
- repeating-linear-gradient scanlines plus a translating phosphor sweep bar and a radial vignette glass layer
- Phosphor text-shadow on every log line, with amber and mint variants for warnings and echoes
- Line-append flash animation, blinking block caret, blinking LED keyframes
- Gauges as bordered tracks with gradient fills, eased width transitions, alarm state at >82% switching the fill and label to amber
- Conic-gradient power ring masked into an annulus, filled by a --hold custom property over a 900ms rAF hold timer
- CSS degauss keyframes collapsing the tube with scaleY to .008 then overshooting to 1.07, replayed on every reboot
- Mirrored command text span behind a transparent absolutely-positioned input, with Tab completion and a command history stack

INTERACTION:
- Type a command and press Enter: help, status, map, clear, reboot, uptime, whoami all execute; anything else answers "unknown command: x -- try help"
- Press Tab: completes the current word against the command list and appends a space
- Press ArrowUp / ArrowDown: walks the command history
- Click anywhere in the tube: returns focus to the command line
- Hold the power button for 900ms: an amber ring fills around it, then the tube degausses (scaleY collapse and overshoot) and the machine cold-boots again; releasing early cancels
- Focus the power button and press Enter or Space: reboots immediately
- Watch: new log lines flash in every 1.25s, gauges drift every 780ms, the fourth LED lights amber when CPU or network exceeds 78%, the tube wobbles every 9–15s, the scanline sweep crosses the screen every 7.5s
- prefers-reduced-motion: reduce: sweep, wobble, degauss, caret blink, LED blink, line flash and gauge transitions are all disabled and ambient intervals are slowed