/*
  Features 21 — standalone HTML/CSS/JS implementation.
  No build step, no framework, no external dependency: copy these three
  files into any project and open index.html as-is.
*/

*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --white: #ffffff;
  --slate-50: #f8fafc;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-900: #0f172a;
  --blue-600: #2563eb;
  --violet-600: #7c3aed;
  --emerald-600: #059669;
  --amber-500: #f59e0b;
  --font-sans:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji",
    "Segoe UI Emoji";
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--slate-900);
  background-color: var(--white);
  line-height: 1.5;
}

.features {
  padding: clamp(4rem, 3.5rem + 2vw, 6rem) clamp(1rem, 0.3rem + 3vw, 2rem);
}

.features__inner {
  width: 100%;
  max-width: 72rem;
  margin: 0 auto;
}

.intro {
  max-width: 34rem;
  margin: 0 auto;
  text-align: center;
}

.kicker {
  margin: 0;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--slate-500);
}

.heading {
  margin: 0.75rem 0 0;
  font-weight: 600;
  font-size: clamp(1.875rem, 1.5rem + 1.9vw, 2.5rem);
  line-height: 1.15;
  letter-spacing: -0.01em;
}

.grid {
  margin-top: 3rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.card {
  border-radius: 1rem;
  border: 1px solid var(--slate-200);
  padding: 1.5rem;
}

.card--wide {
  background-color: var(--slate-50);
}

.swatch-row {
  display: flex;
  gap: 0.375rem;
}

.dot {
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 999px;
}

.dot--blue {
  background-color: var(--blue-600);
}

.dot--violet {
  background-color: var(--violet-600);
}

.dot--emerald {
  background-color: var(--emerald-600);
}

.dot--amber {
  background-color: var(--amber-500);
}

.type-sample {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.type-sample__lg {
  font-size: 1.125rem;
  line-height: 1;
  font-weight: 700;
}

.type-sample__md {
  font-size: 0.875rem;
  line-height: 1;
  font-weight: 600;
  color: var(--slate-500);
}

.type-sample__sm {
  font-size: 0.75rem;
  line-height: 1;
  color: var(--slate-400);
}

.spacing-sample {
  display: flex;
  align-items: flex-end;
  gap: 0.375rem;
  height: 1.25rem;
}

.spacing-sample__bar {
  border-radius: 0.125rem;
  background-color: var(--slate-900);
  transform-origin: bottom;
}

.spacing-sample__bar--1 {
  width: 0.5rem;
  height: 0.5rem;
}

.spacing-sample__bar--2 {
  width: 0.75rem;
  height: 0.75rem;
}

.spacing-sample__bar--3 {
  width: 1rem;
  height: 1rem;
}

.spacing-sample__bar--4 {
  width: 1.25rem;
  height: 1.25rem;
}

.radius-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.radius-swatch {
  width: 2rem;
  height: 2rem;
  border: 2px solid var(--slate-900);
}

.radius-swatch--sharp {
  border-radius: 0;
}

.radius-swatch--md {
  border-radius: 0.375rem;
}

.radius-swatch--full {
  border-radius: 999px;
}

.card__title {
  margin: 1rem 0 0;
  font-size: 0.875rem;
  font-weight: 600;
}

.card__text {
  margin: 0.375rem 0 0;
  font-size: 0.75rem;
  line-height: 1.6;
  color: var(--slate-600);
}

.card__text--wide {
  max-width: 24rem;
}

.preview {
  margin-top: 1.25rem;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.75rem;
  border-radius: 0.75rem;
  border: 1px solid var(--slate-200);
  background-color: var(--white);
  padding: 1rem;
}

.preview__label {
  display: block;
  width: 6rem;
  height: 0.625rem;
  border-radius: 999px;
  background-color: var(--slate-200);
}

.preview__input {
  display: block;
  width: 100%;
  max-width: 13rem;
  height: 2.25rem;
  border-radius: 0.5rem;
  border: 1px solid var(--slate-300);
  background-color: var(--white);
}

.preview__button {
  border-radius: 0.5rem;
  background-color: var(--slate-900);
  padding: 0.5rem 1.25rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--white);
}

@media (min-width: 640px) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .card--wide {
    grid-column: span 2;
  }

  .preview {
    flex-direction: row;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .card--wide {
    grid-column: span 4;
  }
}

/* Motion — disabled entirely under reduced motion; every module and its
   contents already render at their final, fully visible state outside
   this media query. */
@media (prefers-reduced-motion: no-preference) {
  @keyframes al-features21-card {
    from {
      opacity: 0;
      transform: translateY(24px) scale(0.9);
      box-shadow: 0 0 0 0 rgba(15, 23, 42, 0);
    }
    to {
      opacity: 1;
      transform: translateY(0) scale(1);
      box-shadow: 0 20px 40px -28px rgba(15, 23, 42, 0.25);
    }
  }

  @keyframes al-features21-swatch {
    from {
      opacity: 0;
      transform: scale(0.4);
    }
    to {
      opacity: 1;
      transform: scale(1);
    }
  }

  @keyframes al-features21-type-line {
    from {
      opacity: 0;
      transform: translateX(-8px);
    }
    to {
      opacity: 1;
      transform: translateX(0);
    }
  }

  @keyframes al-features21-bar-grow {
    from {
      transform: scaleY(0);
    }
    to {
      transform: scaleY(1);
    }
  }

  @keyframes al-features21-piece {
    from {
      opacity: 0;
      transform: translateY(6px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .card {
    animation: al-features21-card 650ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  .dot,
  .radius-swatch {
    animation: al-features21-swatch 350ms cubic-bezier(0.34, 1.35, 0.64, 1) both;
  }

  .type-sample__lg,
  .type-sample__md,
  .type-sample__sm {
    animation: al-features21-type-line 400ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  .spacing-sample__bar {
    animation: al-features21-bar-grow 400ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }

  .preview__label,
  .preview__input,
  .preview__button {
    animation: al-features21-piece 400ms cubic-bezier(0.16, 1, 0.3, 1) both;
  }
}
Features 21

Requirements

Dependencies

Usage
