/* ============================================
   STACK / TOOLKIT — Cyber Dark Terminal
   Accented cards with cyan corner brackets
   Hover reveals tech and blurs others
   ============================================ */

.stack {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--bg-alt); /* Alternating section background */
  position: relative;
  overflow: hidden;
  padding: 100px var(--section-pad);
}

.stack__header {
  text-align: center;
  margin-bottom: 60px;
  position: relative;
  z-index: 2;
}

.stack__label {
  font-family: var(--font-heading);
  font-size: 0.8rem;
  color: var(--accent-cyan);
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.stack__title {
  font-family: var(--font-hero);
  font-size: clamp(3.5rem, 8vw, 5.5rem);
  color: var(--text-primary);
}

/* ── Stack Grid (Breathable & Handles hover states) ── */
.stack__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
  max-width: 1100px;
  width: 100%;
  position: relative;
  z-index: 2;
}

/* When the grid is hovered, blur and fade out the cards that are NOT hovered */
.stack__grid:hover .stack-card:not(:hover) {
  filter: blur(4px);
  opacity: 0.3;
  transform: scale(0.95);
}

/* ── Stack Card ── */
.stack-card {
  background: var(--bg-card);
  border-radius: var(--card-radius);
  padding: 40px 36px;
  border: 1px solid var(--divider);
  transition: border-color var(--transition-med), transform var(--transition-med), box-shadow var(--transition-med), filter var(--transition-med), opacity var(--transition-med);
  position: relative;
  overflow: visible;
  z-index: 5;
}

/* Cyan Corner Brackets on Hover */
.stack-card::before {
  content: '';
  position: absolute;
  top: -2px;
  left: -2px;
  width: 16px;
  height: 16px;
  border-top: 2px solid var(--accent-cyan);
  border-left: 2px solid var(--accent-cyan);
  opacity: 0;
  transform: scale(1.4);
  transition: opacity var(--transition-med), transform var(--transition-med);
  pointer-events: none;
  z-index: 10;
}

.stack-card::after {
  content: '';
  position: absolute;
  bottom: -2px;
  right: -2px;
  width: 16px;
  height: 16px;
  border-bottom: 2px solid var(--accent-cyan);
  border-right: 2px solid var(--accent-cyan);
  opacity: 0;
  transform: scale(1.4);
  transition: opacity var(--transition-med), transform var(--transition-med);
  pointer-events: none;
  z-index: 10;
}

/* Hovered Card: scale up, front layer, highlight border, add glow */
.stack-card:hover {
  transform: scale(1.08) translateY(-5px);
  z-index: 15; /* Bring to front */
  box-shadow: 0 0 35px rgba(0, 68, 255, 0.25);
}

.stack-card:hover::before,
.stack-card:hover::after {
  opacity: 1;
  transform: scale(1);
}

/* Hover border colors mapped to blue or cyan accents */
.stack-card--ai:hover { border-color: var(--accent-blue); }
.stack-card--web:hover { border-color: var(--accent-cyan); }
.stack-card--rpa:hover { border-color: var(--accent-cyan); }
.stack-card--dev:hover { border-color: var(--accent-blue); }

/* Radar / sonar circle SVG — decorative */
.stack-card__radar {
  position: absolute;
  bottom: 16px;
  right: 16px;
  width: 64px;
  height: 64px;
  opacity: 0.25;
  pointer-events: none;
}

.stack-card__radar svg {
  width: 100%;
  height: 100%;
}

.stack-card__name {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  letter-spacing: 1.5px;
  margin-bottom: 0px; /* Reset margin since tech list is collapsed by default */
  text-transform: uppercase;
  transition: margin var(--transition-med);
}

/* Adjust title margin on hover when tech collapses open */
.stack-card:hover .stack-card__name {
  margin-bottom: 20px;
}

/* Category header colors alternating blue and cyan */
.stack-card--ai .stack-card__name { color: var(--accent-blue); }
.stack-card--web .stack-card__name { color: var(--accent-cyan); }
.stack-card--rpa .stack-card__name { color: var(--accent-cyan); }
.stack-card--dev .stack-card__name { color: var(--accent-blue); }

/* ── Technologies List (Collapsed by default, reveals on hover) ── */
.stack-card__techs {
  font-family: var(--font-body);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text-secondary);
  line-height: 1.8;
  letter-spacing: 0.5px;
  
  /* Collapsed properties */
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  margin-top: 0;
  transition: opacity 0.3s ease, max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1), margin-top 0.3s ease;
}

/* Hover reveals tech specs */
.stack-card:hover .stack-card__techs {
  max-height: 150px; /* Large enough to reveal details */
  opacity: 1;
  margin-top: 16px;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .stack__grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  /* For mobile, keep techs visible since hover is less common */
  .stack-card__techs {
    max-height: none;
    opacity: 1;
    margin-top: 16px;
  }
  .stack-card__name {
    margin-bottom: 20px;
  }
  .stack-card {
    padding: 32px 24px;
  }
  .stack__grid:hover .stack-card:not(:hover) {
    filter: none;
    opacity: 1;
    transform: none;
  }
}