.app-header {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 36px;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.75rem;
  margin: 0 0 10px;
  color: var(--accent);
  font-weight: 600;
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(2rem, 3vw, 3rem);
}

.subtitle {
  margin: 0;
  color: var(--muted);
}

.header-actions {
  display: flex;
  gap: 12px;
}

.materials-section {
  background: rgba(255, 255, 255, 0.7);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  border: 3px solid var(--outline);
}

.section-header {
  margin-bottom: 18px;
}

.section-header h2 {
  margin: 0;
  font-size: 1.5rem;
}

.section-header p {
  margin: 6px 0 0;
  color: var(--muted);
}

.materials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
}

.material-card {
  background: var(--card);
  border-radius: 16px;
  padding: 20px;
  box-shadow: var(--outline-shadow);
  border: 3px solid var(--outline);
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.material-card:hover {
  transform: translateY(-2px);
  box-shadow: 10px 10px 0 rgba(18, 18, 18, 0.24);
}

.material-card h3 {
  margin: 0 0 4px;
}

.material-meta {
  display: grid;
  gap: 6px;
  font-size: 0.9rem;
  color: var(--muted);
}

.material-actions {
  display: flex;
  gap: 8px;
}

@media (max-width: 640px) {
  #app {
    padding: 24px;
  }

  .app-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .header-actions {
    width: 100%;
    flex-direction: column;
  }
}