/* ==========================================================================
   STICKY STACKING CARDS (Services Section)
   ========================================================================== */

.stack-section {
  padding: var(--space-3xl) var(--space-md);
  position: relative;
}

.stack-container {
  display: flex;
  flex-direction: column;
  gap: 4vh;
  margin-bottom: var(--space-3xl);
}

.stack-card {
  position: sticky;
  top: calc(var(--navbar-height) + 2rem);
  background-color: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-3xl);
  min-height: 400px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  transition: all var(--transition-base);
}

.stack-card:nth-child(2) {
  top: calc(var(--navbar-height) + 3rem);
  background-color: var(--color-surface-higher);
}

.stack-card:nth-child(3) {
  top: calc(var(--navbar-height) + 4rem);
}

.stack-card:nth-child(4) {
  top: calc(var(--navbar-height) + 5rem);
  background-color: var(--color-surface-higher);
}

.stack-card:nth-child(5) {
  top: calc(var(--navbar-height) + 6rem);
}

.stack-card:nth-child(6) {
  top: calc(var(--navbar-height) + 7rem);
  background-color: var(--color-surface-higher);
}

.stack-card:nth-child(7) {
  top: calc(var(--navbar-height) + 8rem);
}

.stack-card:hover {
  border-color: var(--color-border-hover);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.card-left {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.step-num {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-accent-text);
  margin-bottom: var(--space-sm);
  font-weight: 700;
}

.card-left h3 {
  font-size: 2.5rem;
  margin-bottom: var(--space-md);
}

.card-left p {
  color: var(--color-text-secondary);
  font-size: 1.1rem;
}

.card-right {
  background: rgba(0, 0, 0, 0.03);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: var(--font-heading);
  color: rgba(var(--color-brand-green-rgb), 0.4);
  font-size: 5rem;
  font-weight: 700;
}

.dark-band .card-right {
  background: rgba(255, 255, 255, 0.03);
  color: rgba(var(--color-brand-green-rgb), 0.5);
}

/* Mobile: sticky stacking gets disorienting on short viewports - disable it
   and let cards flow normally (matches the responsive rules in main.css) */
@media (max-width: 900px) {
  .stack-card {
    position: static;
  }
}