Houston, we have a problem.
This page has drifted out of orbit. We’ll bring you back to base before the oxygen runs out.
Back to baseHTML + CSS404
Houston 404
The zero is a cratered Moon with a satellite orbiting around it. The stars shift as you move the mouse.
Settings
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Code
<!doctype html>
<html lang="es">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<meta name="robots" content="noindex" />
<title>404 · Page not found</title>
<style>
body { margin: 0; background: #000; }
.n4-houston {
--accent: #9fc3ff;
--k: 1;
position: fixed;
inset: 0;
z-index: 0;
overflow: hidden;
container-type: size;
display: grid;
place-items: center;
background: #000;
color: #f5f5f7;
font-family: -apple-system,BlinkMacSystemFont,"SF Pro Display","Inter","Segoe UI",system-ui,sans-serif;
-webkit-font-smoothing: antialiased;
text-align: center;
line-height: 1.4;
}
.n4-houston *,.n4-houston *::before,.n4-houston *::after {
box-sizing: border-box;
}
.n4-houston .n4-copy {
position: relative;
z-index: 5;
display: flex;
flex-direction: column;
align-items: center;
gap: 1.6cqmin;
width: 100%;
max-width: 680px;
padding: 0 6cqw;
}
.n4-houston .n4-title {
margin: 0;
font-size: clamp(17px,4.2cqmin,36px);
font-weight: 600;
letter-spacing: -.02em;
line-height: 1.15;
text-wrap: balance;
}
.n4-houston .n4-sub {
margin: 0;
max-width: 34em;
font-size: clamp(13px,2.4cqmin,18px);
color: #a1a1a6;
text-wrap: balance;
}
.n4-houston .n4-tag {
font: 600 clamp(10px,1.9cqmin,13px)/1 ui-monospace,"SF Mono",Menlo,Consolas,monospace;
letter-spacing: .16em;
text-transform: uppercase;
color: var(--accent);
}
.n4-houston .n4-cta {
margin-top: 1.8cqmin;
display: inline-flex;
align-items: center;
gap: .5em;
padding: .85em 1.5em;
border-radius: 999px;
background: #f5f5f7;
color: #000;
font-size: clamp(13px,2.2cqmin,16px);
font-weight: 600;
text-decoration: none;
transition: transform .3s cubic-bezier(.25,.1,.25,1),box-shadow .3s cubic-bezier(.25,.1,.25,1);
}
.n4-houston .n4-cta:hover {
transform: translateY(-2px);
box-shadow: 0 12px 32px -10px var(--accent);
}
.n4-houston .n4-cta:focus-visible {
outline: 2px solid var(--accent);
outline-offset: 3px;
}
.n4-houston .n4-stars,.n4-houston .n4-stars2 {
position: absolute;
inset: -4%;
pointer-events: none;
}
.n4-houston .n4-stars {
background-image: radial-gradient(1px 1px at 8% 12%,#fff 60%,transparent),radial-gradient(1px 1px at 22% 68%,#fff 60%,transparent),radial-gradient(1.5px 1.5px at 35% 24%,#fff 60%,transparent),radial-gradient(1px 1px at 48% 82%,#fff 60%,transparent),radial-gradient(1px 1px at 57% 9%,#fff 60%,transparent),radial-gradient(1.5px 1.5px at 66% 44%,#fff 60%,transparent),radial-gradient(1px 1px at 74% 72%,#fff 60%,transparent),radial-gradient(1px 1px at 86% 18%,#fff 60%,transparent),radial-gradient(1.5px 1.5px at 93% 58%,#fff 60%,transparent),radial-gradient(1px 1px at 14% 42%,#fff 60%,transparent),radial-gradient(1px 1px at 40% 55%,#fff 60%,transparent),radial-gradient(1px 1px at 81% 90%,#fff 60%,transparent),radial-gradient(1px 1px at 4% 88%,#fff 60%,transparent),radial-gradient(1px 1px at 62% 30%,#fff 60%,transparent);
opacity: .75;
animation: n4-houston-tw calc(5s / var(--k)) ease-in-out infinite alternate;
}
.n4-houston .n4-stars2 {
background-image: radial-gradient(2px 2px at 18% 30%,rgba(255,255,255,.9) 50%,transparent),radial-gradient(1.5px 1.5px at 72% 20%,rgba(255,255,255,.8) 50%,transparent),radial-gradient(2px 2px at 30% 85%,rgba(255,255,255,.7) 50%,transparent),radial-gradient(1.5px 1.5px at 88% 70%,rgba(255,255,255,.8) 50%,transparent),radial-gradient(2px 2px at 52% 60%,rgba(255,255,255,.6) 50%,transparent),radial-gradient(1.5px 1.5px at 6% 55%,rgba(255,255,255,.8) 50%,transparent);
opacity: .55;
animation: n4-houston-tw calc(7s / var(--k)) ease-in-out infinite alternate-reverse;
}
.n4-houston [data-depth] {
transition: transform .9s cubic-bezier(.2,.7,.2,1);
}
@keyframes n4-houston-tw {
from {
opacity: .3;
}
}
@keyframes n4-houston-spin {
to {
transform: rotate(1turn);
}
}
@keyframes n4-houston-fade {
from {
opacity: 0;
transform: translateY(10px);
}
}
@media (prefers-reduced-motion:reduce) {
.n4-houston *,.n4-houston *::before,.n4-houston *::after {
animation: none!important;
transition: none!important;
}
}
.n4-houston {
background: radial-gradient(80% 60% at 50% 40%,#0a1020,#000 72%);
}
.n4-houston .n4-num {
margin: 0 0 1cqmin;
display: flex;
align-items: center;
font-size: clamp(84px,28cqmin,280px);
font-weight: 700;
letter-spacing: -.05em;
line-height: .9;
}
.n4-houston .n4-num b {
color: #f5f5f7;
text-shadow: 0 0 .2em color-mix(in srgb,var(--accent) 30%,transparent);
}
.n4-houston .n4-o {
position: relative;
isolation: isolate;
display: grid;
place-items: center;
width: .78em;
height: .78em;
margin: 0 .06em;
}
.n4-houston .n4-moon {
position: relative;
z-index: 1;
width: .72em;
height: .72em;
border-radius: 50%;
background: radial-gradient(circle at 30% 34%,rgba(0,0,0,.28) 0 .045em,transparent .05em),radial-gradient(circle at 64% 30%,rgba(0,0,0,.22) 0 .03em,transparent .035em),radial-gradient(circle at 55% 64%,rgba(0,0,0,.25) 0 .07em,transparent .075em),radial-gradient(circle at 26% 70%,rgba(0,0,0,.18) 0 .028em,transparent .033em),radial-gradient(circle at 78% 55%,rgba(0,0,0,.2) 0 .022em,transparent .027em),radial-gradient(ellipse 40% 30% at 40% 45%,rgba(0,0,0,.12),transparent 70%),radial-gradient(circle at 35% 30%,#f2f2f4,#c7c7cc 45%,#8e8e93 75%,#5a5a5f);
box-shadow: inset -.1em -.06em .14em rgba(0,0,0,.65),0 0 .35em rgba(255,255,255,.12);
}
.n4-houston .n4-orbit {
position: absolute;
left: 50%;
top: 50%;
width: 1.5em;
height: 1.5em;
margin: -.75em 0 0 -.75em;
transform: rotate(-16deg) scaleY(.32);
pointer-events: none;
z-index: 0;
animation: n4-houston-z calc(9s / var(--k)) linear infinite;
}
.n4-houston .n4-orbit::before {
content: "";
position: absolute;
inset: 0;
border-radius: 50%;
border: .008em solid rgba(255,255,255,.2);
}
.n4-houston .n4-sat {
position: absolute;
inset: 0;
animation: n4-houston-spin calc(9s / var(--k)) linear infinite;
}
.n4-houston .n4-sat::after {
content: "";
position: absolute;
left: 50%;
top: -.035em;
width: .07em;
height: .07em;
margin-left: -.035em;
border-radius: 50%;
background: #fff;
box-shadow: 0 0 .06em .02em #fff,0 0 .22em color-mix(in srgb,var(--accent) 90%,#fff);
}
.n4-houston .n4-copy>* {
animation: n4-houston-fade calc(1s / var(--k)) cubic-bezier(.2,.7,.2,1) both;
}
.n4-houston .n4-copy>:nth-child(2) {
animation-delay: calc(.15s / var(--k));
}
.n4-houston .n4-copy>:nth-child(3) {
animation-delay: calc(.3s / var(--k));
}
.n4-houston .n4-copy>:nth-child(4) {
animation-delay: calc(.45s / var(--k));
}
@keyframes n4-houston-z {
0%,24.9% {
z-index: 0;
}
25%,74.9% {
z-index: 3;
}
75%,100% {
z-index: 0;
}
}
</style>
</head>
<body>
<main class="n4-houston">
<div class="n4-stars" data-depth="10" aria-hidden="true"></div>
<div class="n4-stars2" data-depth="26" aria-hidden="true"></div>
<div class="n4-copy">
<p class="n4-num" aria-hidden="true">
<b>4</b>
<span class="n4-o" data-depth="-14"><span class="n4-moon"></span><span class="n4-orbit"><span class="n4-sat"></span></span></span>
<b>4</b>
</p>
<h1 class="n4-title">Houston, we have a problem.</h1>
<p class="n4-sub">This page has drifted out of orbit. We’ll bring you back to base before the oxygen runs out.</p>
<a class="n4-cta" href="/">Back to base</a>
</div>
</main>
<script>
document.querySelectorAll(".n4-houston").forEach((el) => {
const layers = el.querySelectorAll("[data-depth]");
const move = (e) => {
const r = el.getBoundingClientRect();
const x = (e.clientX - r.left) / r.width - 0.5;
const y = (e.clientY - r.top) / r.height - 0.5;
layers.forEach((l) => {
const d = Number(l.dataset.depth);
l.style.transform = `translate3d(${-x * d}px, ${-y * d}px, 0)`;
});
};
el.addEventListener("pointermove", move);
});
</script>
</body>
</html>
Prompt for AI
Paste it into ChatGPT, Claude or Cursor and it will adapt the block to your project with these settings, even if you don’t use React.
More in 404
Where to use it
A 404 with a bit of humor tells visitors that someone looks after the site, even when a link is broken. “Houston, we have a problem” does that in one line, and the orbiting satellite keeps the eye busy while they read. It suits a SaaS startup, a coding bootcamp or a science podcast looking for a funny 404 page.
The stars move slightly with the mouse to add depth; on phones they just stay put and the page looks as good. Swap the pale blue for your brand color and keep the classic line, since almost everybody recognizes it.