Matrix digital rain · grok-4.7
Output saved · Stopped by an API error Cost / run $0.1058 Runtime 87.2s
A model request failed and its retries ran out. The output is the HTML saved before that.
Prompt for this run
Build an animated Matrix-style digital rain effect on a full-screen black canvas. Use HTML, CSS, and JavaScript as needed. Write it to `index.html` in the current working directory using your file tools. Inline your own CSS and JavaScript. Do not use external assets, CDNs, or network requests. No third-party libraries are provided. Required behavior: - Draw multiple independently moving columns of green katakana glyphs, each with a brighter leading character and a fading trail. - Vary column speed and start position. Recycle columns after they leave the bottom so the effect continues without accumulating off-screen state. - Provide Pause/Resume and Restart. Pause freezes the animation; Restart resets the columns and clears previous trails. - Resize the canvas and column layout to fit the viewport without stretching an old screenshot or leaving an uncovered strip. - Use locally available fonts and procedural drawing; no external fonts or images. Choose glyphs, brightness, and timing freely. Verify: Sample the animation at several moments to inspect independently moving columns, brighter leading glyphs, and fading trails. Pause and resume to check that the image freezes and continues, then use Restart and check that old trails are cleared.
TAKE IT TO CODE
A single self-contained HTML file — copy it and open in any browser, or reuse the prompt with your own pi-agent run.
RUN
METRICS
Transcript · 21 messages
Build an animated Matrix-style digital rain effect on a full-screen black canvas. Use HTML, CSS, and JavaScript as needed. Write it to `index.html` in the current working directory using your file tools. Inline your own CSS and JavaScript. Do not use external assets, CDNs, or network requests. No third-party libraries are provided. Required behavior: - Draw multiple independently moving columns of green katakana glyphs, each with a brighter leading character and a fading trail. - Vary column speed and start position. Recycle columns after they leave the bottom so the effect continues without accumulating off-screen state. - Provide Pause/Resume and Restart. Pause freezes the animation; Restart resets the columns and clears previous trails. - Resize the canvas and column layout to fit the viewport without stretching an old screenshot or leaving an uncovered strip. - Use locally available fonts and procedural drawing; no external fonts or images. Choose glyphs, brightness, and timing freely. Verify: Sample the animation at several moments to inspect independently moving columns, brighter leading glyphs, and fading trails. Pause and resume to check that the image freezes and continues, then use Restart and check that old trails are cleared.
thinking
I'll build a self-contained Matrix rain page and then check the animation, pause, and restart in the browser.
/tmp/job-cmWCnL/index.html (6480 bytes)Successfully wrote to /tmp/job-cmWCnL/index.html
thinking
{"action":"reload"}Frame 1, +0ms
[Browser image supplied to model]
{"console":["warning: An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing."],"dom":"PAUSE\nRESTART\nRUNNING","images":"attached"}
thinking
The screen is black. Columns start at random negative Y positions, so some should be visible. A device pixel ratio bug is causing columns to start too far above the screen. The random Y offset uses canvas.height in device pixels, but the coordinate system expects CSS pixels. The screenshot may have been captured before the first animation frame executed. The frame function initializes lastTs without drawing anything, so the initial frame could be blank.
The first frame is black, so I’m checking whether glyphs are actually drawing and which fonts are available.
{"command":"fc-list : family | sort -u | head -80; echo '---'; fc-list :lang=ja family | head -20; echo '---dpr check later'"}Bitstream Charter Courier 10 Pitch FreeMono FreeSans FreeSerif IPAGothic,IPAゴシック IPAPGothic,IPA Pゴシック Liberation Mono Liberation Sans Liberation Sans Narrow Liberation Serif Loma Noto Color Emoji Noto Sans CJK HK Noto Sans CJK JP Noto Sans CJK KR Noto Sans CJK SC Noto Sans CJK TC Noto Sans Mono CJK HK Noto Sans Mono CJK JP Noto Sans Mono CJK KR Noto Sans Mono CJK SC Noto Sans Mono CJK TC Noto Serif CJK HK Noto Serif CJK JP Noto Serif CJK KR Noto Serif CJK SC Noto Serif CJK TC Unifont Unifont CSUR Unifont Upper Unifont\-JP WenQuanYi Zen Hei Mono,文泉驛等寬正黑,文泉驿等宽正黑 WenQuanYi Zen Hei Sharp,文泉驛點陣正黑,文泉驿点阵正黑 WenQuanYi Zen Hei,文泉驛正黑,文泉驿正黑 --- Noto Serif CJK JP Noto Serif CJK KR Noto Serif CJK HK Noto Serif CJK SC Noto Serif CJK TC Unifont\-JP Noto Sans Mono CJK SC Noto Sans Mono CJK TC Noto Sans Mono CJK JP Noto Sans Mono CJK HK Noto Sans Mono CJK KR IPAGothic,IPAゴシック WenQuanYi Zen Hei Mono,文泉驛等寬正黑,文泉驿等宽正黑 IPAPGothic,IPA Pゴシック Noto Sans CJK HK Noto Sans CJK KR WenQuanYi Zen Hei Sharp,文泉驛點陣正黑,文泉驿点阵正黑 Noto Sans CJK JP Noto Sans CJK SC Noto Sans CJK TC ---dpr check later
thinking
The font stack may lack katakana glyphs. Canvas font fallback might not match CSS behavior. I'll switch to "Noto Sans Mono CJK JP" or "IPAGothic" for proper CJK support. I also need to fix the canvas height mismatch, start columns already on screen so the rain isn't black at first, and delay motion sampling. I'll use window.innerHeight for y initialization instead of canvas.height. Columns will be distributed across the viewport so the rain appears immediately. Shadow blur is acceptable. Pause and restart logic are already correct, and resize properly clears and resets the canvas.
{"path":"/tmp/job-cmWCnL/index.html","edits":[{"oldText":" const FONT = \"ui-monospace, \\\"DejaVu Sans Mono\\\", \\\"Liberation Mono\\\", Successfully replaced 2 block(s) in /tmp/job-cmWCnL/index.html.
thinking
{"action":"reload"}Frame 1, +0ms
[Browser image supplied to model]
{"console":["warning: An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing."],"dom":"PAUSE\nRESTART\nRUNNING","images":"attached"}
thinking
{"action":"motion","delta":600}Frame 1, +0ms
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Frame 2, +583ms
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Frame 3, +1154ms
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Frame 4, +1724ms
[Browser image supplied to model]
{"console":["warning: An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing."],"dom":"PAUSE\nRESTART\nRUNNING","images":"attached"}
thinking
Columns are moving independently with brighter heads and fading trails. A large empty gap persists in the center across frames. It may be random clustering from uneven start heights, but it looks unusually consistent. The math shows 80 columns packed tightly across the width. Random y positions should keep every head visible, so the center gap is puzzling.
{"action":"click","x":48,"y":772}Frame 1, +0ms
[Browser image supplied to model]
{"console":["warning: An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing."],"dom":"RESUME\nRESTART\nPAUSED","images":"attached"}
thinking
{"action":"motion","delta":500}Frame 1, +0ms
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Frame 2, +552ms
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Frame 3, +1101ms
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Frame 4, +1642ms
[Browser image supplied to model]
{"console":["warning: An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing."],"dom":"RESUME\nRESTART\nPAUSED","images":"attached"}
thinking
{"action":"click","x":52,"y":772}Frame 1, +0ms
[Browser image supplied to model]
{"console":["warning: An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing."],"dom":"PAUSE\nRESTART\nRUNNING","images":"attached"}