/*
  404 — 01: Minimal Centered Recovery, standalone HTML/CSS implementation.
  No build step, no framework, no external dependency: copy this file and
  index.html into any project and open it as-is.
*/

:root {
  --color-brand: #39ff14;
  --color-brand-foreground: #252525;
  --color-foreground: #252525;
  --color-background: #ffffff;
  --color-border: #e4e4e4;
  --color-muted-foreground: #8d8d8d;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--color-foreground);
  background: var(--color-background);
}

a {
  text-decoration: none;
  color: inherit;
}

.notfound01 {
  background: var(--color-background);
}

.notfound01__section {
  max-width: 36rem;
  margin: 0 auto;
  padding: 6rem 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

@media (min-width: 640px) {
  .notfound01__section {
    padding: 8rem 1.5rem;
  }
}

@media (min-width: 1024px) {
  .notfound01__section {
    padding: 10rem 1.5rem;
  }
}

.notfound01__badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  border: 1px solid var(--color-border);
  background: var(--color-background);
  border-radius: 999px;
  padding: 0.25rem 0.75rem;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--color-muted-foreground);
}

.notfound01__heading {
  margin: 1.5rem 0 0;
  font-size: clamp(2rem, 1.5rem + 2.2vw, 3.25rem);
  line-height: 1.1;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--color-foreground);
}

.notfound01__copy {
  margin: 1rem auto 0;
  max-width: 28rem;
  font-size: 1rem;
  line-height: 1.65;
  color: var(--color-muted-foreground);
}

@media (min-width: 640px) {
  .notfound01__copy {
    font-size: 1.125rem;
  }
}

.notfound01__cta-wrap {
  margin-top: 2.5rem;
}

.notfound01__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: 999px;
  background: var(--color-brand);
  color: var(--color-brand-foreground);
  padding: 0.75rem 1.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  transition: background-color 150ms ease;
}

.notfound01__cta:hover {
  background: color-mix(in srgb, var(--color-brand) 90%, #000);
}

.notfound01__cta-arrow {
  width: 1rem;
  height: 1rem;
  transition: transform 220ms cubic-bezier(0.16, 1, 0.3, 1);
}

.notfound01__cta:hover .notfound01__cta-arrow,
.notfound01__cta:focus-visible .notfound01__cta-arrow {
  transform: translateX(3px);
}

.notfound01__secondary {
  margin-top: 1.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-muted-foreground);
  text-underline-offset: 4px;
  transition: color 150ms ease;
}

.notfound01__secondary:hover {
  color: var(--color-foreground);
  text-decoration: underline;
}

.notfound01__badge:focus-visible,
.notfound01__cta:focus-visible,
.notfound01__secondary:focus-visible {
  outline: 2px solid var(--color-brand);
  outline-offset: 2px;
  border-radius: 4px;
}

/* Motion — disabled entirely under reduced motion; every element already
   renders at its final, fully visible state outside this media query. */
@media (prefers-reduced-motion: no-preference) {
  @keyframes al-404-01-up {
    from {
      opacity: 0;
      transform: translateY(14px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .notfound01__badge,
  .notfound01__heading,
  .notfound01__copy,
  .notfound01__cta-wrap,
  .notfound01__secondary {
    animation: al-404-01-up 640ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  .notfound01__badge {
    animation-delay: 60ms;
  }
  .notfound01__heading {
    animation-delay: 140ms;
  }
  .notfound01__copy {
    animation-delay: 220ms;
  }
  .notfound01__cta-wrap {
    animation-delay: 300ms;
  }
  .notfound01__secondary {
    animation-delay: 360ms;
  }
}

@media (prefers-reduced-motion: reduce) {
  .notfound01__cta-arrow,
  .notfound01__cta:hover .notfound01__cta-arrow,
  .notfound01__cta:focus-visible .notfound01__cta-arrow {
    transition: none !important;
    transform: none !important;
  }
}
404 01

Requirements

Dependencies

Usage
