/* Ảnh chính */
#main-image {
  max-height: 450px;
  object-fit: cover;
  transition: all 0.3s ease;
}

/* Ảnh phụ (thumbnail) */
.thumb-img {
  width: 21%;
  height: 80px;
  object-fit: cover;
  margin: 5px;
  border: 2px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.2s, border-color 0.3s;
}

.thumb-img:hover,
.thumb-img.active {
  /* -webkit-transform: scale3d(1, 1, 1);
  transform: scale3d(1, 1, 1);
  -webkit-filter: brightness(0.95);
  filter: brightness(0.95); */
  border-color: #2d3338;
  transform: scale(1.05);
}

.image-frame::before,
.image-frame::after,
.image-frame span::before,
.image-frame span::after {
  content: '';
  position: absolute;
  background: #3498db;
  transition: all 0.5s;
}

.image-frame::before {
  /* top */
  height: 2px;
  width: 0;
  top: 0;
  left: 0;
}
.image-frame::after {
  /* right */
  width: 2px;
  height: 0;
  top: 0;
  right: 0;
}
.image-frame span::before {
  /* bottom */
  height: 2px;
  width: 0;
  bottom: 0;
  right: 0;
}
.image-frame span::after {
  /* left */
  width: 2px;
  height: 0;
  bottom: 0;
  left: 0;
}
/* Hover effect */
.image-frame:hover::before,
.image-frame:hover span::before {
  width: 100%;
  box-shadow: 0 0 10px #3498db, 0 0 20px #3498db;
}

.image-frame:hover::before,
.image-frame:hover span::before {
  width: 100%;
}
.image-frame:hover::after,
.image-frame:hover span::after {
  height: 100%;
}