/* ============================================
   Challenge cards — 4-up small white cards with icon + short
   text. Used on the Industrial IoT page (§3) to enumerate the
   pressures manufacturers face.

   Smaller and lighter than .gs-wgs-feature cards — no card-level
   hover, no h3, just an icon-on-top + one-line descriptor. The
   bg-shift to muted is doing the section framing; cards should
   feel quiet.
   ============================================ */

.gs-uc-challenges {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  max-width: var(--content-frame);
  margin: 0 auto;
}

.gs-uc-challenge {
  /* Same card chrome as .gs-wgs-pillar (coral static border + coral-
     tinted soft shadow, no hover) — keeps the coral-card language
     consistent across pages. */
  background: var(--color-bg);
  border: 2px solid var(--color-brand-accent);
  border-radius: 24px;
  padding: 2rem 1.5rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  box-shadow: 0 18px 40px rgba(246, 89, 84, 0.1);
}

/* Icon — same recipe as .gs-wgs-pillar__icon (44×44 rounded
   square, light-coral bg, vivid coral icon). */
.gs-uc-challenge__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: #ffe9e7;
  border-radius: 10px;
  color: var(--color-brand-accent);
}

.gs-uc-challenge__icon svg {
  width: 20px;
  height: 20px;
  stroke-width: 2;
}

/* On a dark section, the challenge cards switch to a glass-effect
   chrome (translucent white bg + blur). Icon container picks up
   the same translucent-white language at slightly higher opacity
   (sits "deeper" than the card's bg). Icon glyph turns pure white.
   Description text flips to muted-white for legibility on dark. */
.gs-wgs-section--dark .gs-uc-challenge {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.2);
}

.gs-wgs-section--dark .gs-uc-challenge__icon {
  background: rgba(255, 255, 255, 0.12);  /* 2× the card bg — reads as one tone deeper */
  color: #fff;
}

.gs-wgs-section--dark .gs-uc-challenge__desc {
  color: rgba(255, 255, 255, 0.85);
}

.gs-uc-challenge__desc {
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--color-fg-body);
  margin: 0;
  text-wrap: pretty;
}

@media (max-width: 900px) {
  /* Tablet: 2x2 grid. */
  .gs-uc-challenges {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
  }
}

@media (max-width: 480px) {
  /* Phone: single column stack. */
  .gs-uc-challenges {
    grid-template-columns: 1fr;
  }
}