.about-section {
    background-image: none;
}
.masthead {
    height: auto;
    min-height: 100vh;
}

#sponsor .sponsor-card {
  display: flex !important;
  flex-direction: column;
  justify-content: center;   /* căn dọc */
  align-items: center;       /* căn ngang */
  padding: 1rem;
  background: #fff;
  border-radius: 0.5rem;
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease !important;
}

#sponsor .sponsor-card:hover {
  transform: translateY(-8px) scale(1.05) !important;
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.18) !important;
}

#sponsor .sponsor-logo {
  /* cho logo rộng tối đa 80% chiều ngang của card */
  max-width: 95% !important;     
  /* cho phép cao tối đa 150px (hoặc chỉnh tuỳ ý) */
  max-height: 95% !important;  
  width: auto !important;
  height: auto !important;
  transition: transform 0.3s ease, filter 0.3s ease !important;
}

#sponsor .sponsor-card:hover .sponsor-logo {
  transform: scale(1.1) !important;
  filter: brightness(1.3) !important;
}