/* ============================================================
   Uitdagingen (h2g/usps) — 3-koloms grid met randen + hoverlijn
   ============================================================ */

.challenges { background: var(--nile-900); }

.ch-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 0;
  border-top: 1px solid rgba(255,255,255,.10);
  counter-reset: ch;
}
.ch-item {
  padding: 42px 30px 50px;
  border-bottom: 1px solid rgba(255,255,255,.10);
  border-right: 1px solid rgba(255,255,255,.10);
  position: relative;
  transition: background .4s ease;
  counter-increment: ch;
}
.ch-item:nth-child(3n) { border-right: none; }
.ch-item::after {
  content: ""; position: absolute; left: 0; bottom: -1px; height: 2px; width: 0;
  background: var(--teal-300); transition: width .5s cubic-bezier(.2,.7,.3,1);
}
.ch-item:hover { background: rgba(47,158,141,.05); }
.ch-item:hover::after { width: 100%; }

.ch-tag {
  font-family: var(--font-h); font-size: 12px; font-weight: 700;
  letter-spacing: .16em; text-transform: uppercase; color: var(--teal-300);
  margin: 0;
}
.ch-item h3 { font-size: 22px; margin: 20px 0 14px; line-height: 1.18; }
.ch-item p  { color: var(--nile-300); font-size: 15.5px; font-weight: 300; margin: 0; }

.ch-idx {
  font-family: var(--font-h); font-weight: 800; color: rgba(255,255,255,.07);
  font-size: 54px; position: absolute; top: 24px; right: 26px; line-height: 1;
}
.ch-idx::before { content: counter(ch, decimal-leading-zero); }

@media (max-width: 820px) {
  .ch-grid { grid-template-columns: 1fr; }
  .ch-item { border-right: none; }
}
@media (max-width: 640px) {
  .ch-item { padding: 34px 2px 40px; }
  .ch-idx { font-size: 44px; top: 20px; right: 2px; }
}