main {
  margin: 3rem 3rem;
}

main section {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1.5rem;
}

.card {
  background: #18191c;
  border-radius: 14px;
  border: 1px solid #232323;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  padding: 2.2rem 1rem 1.2rem 1rem;
  transition: box-shadow 0.18s, transform 0.18s;
  color: #fff;
  font-size: 1.08rem;
  font-weight: 500;
  gap: 0.7rem;
  text-align: center;
}

.card-content {
  display: flex;
  flex-direction: column;
  align-items: center; /* This centers all children horizontally */
  text-align: center;
}

.card:hover {
  box-shadow: 0 2px 12px 0 rgba(79, 172, 254, 0.25),
    0 2px 24px 0 rgba(0, 242, 254, 0.18);
  transform: translateY(-4px) scale(1.02);
}

.card img {
  width: 50px;
  height: 50px;
  border-radius: 50px;
  margin-bottom: 0.5rem;
  object-fit: contain;
  filter: drop-shadow(0 2px 8px rgba(76, 175, 80, 0.07));
  background: #232323;
  padding: 0.5rem;
}

h4 {
  font-weight: 100;
}

.stack-progress {
  width: 100%;
  background: white;
  border-radius: 8px;
  height: 8px;
  margin: 0.7rem 0 0.3rem 0;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  border-radius: 8px;
  transition: width 0.4s;
}

.progress-bar.basic {
  background: linear-gradient(90deg, #ff9800 60%, #ffb74d 100%);
}
.progress-bar.intermediate {
  background: linear-gradient(90deg, #2196f3 60%, #64b5f6 100%);
}
.progress-bar.advanced {
  background: linear-gradient(90deg, #4caf50 60%, #81c784 100%);
}
.progress-bar.expert {
  background: linear-gradient(90deg, #ffd700 60%, #fff176 100%);
}

.level-badge {
  background: #232323;
  font-weight: 600;
  padding: 0.15em 0.7em;
  border-radius: 12px;
  letter-spacing: 0.5px;
  display: inline-block;
}

.level-badge.basic,
.progress-bar.basic {
  color: #ff9800;
}
.level-badge.intermediate,
.progress-bar.intermediate {
  color: #2196f3;
}
.level-badge.advanced,
.progress-bar.advanced {
  color: #4caf50;
}
.level-badge.expert,
.progress-bar.expert {
  color: #ffd700;
}

/* 4K responsive design */
@media (min-width: 1968px) { 
  .card {
    height: 350px;
    font-size: 1.35rem;
  }
  .card img {
    width: 80px;
    height: 80px;
    border-radius: 80px;
    padding: 0.7rem;
  }
  .level-badge {
    font-size: 1.15rem;
    padding: 0.22em 1em;
    border-radius: 16px;
  }
}