/* SAL — Thư Báo Đậu Đại Học Trung Quốc */

.sal-header {
  background: linear-gradient(135deg, #c41230 0%, #8b0000 100%);
  color: #fff;
  text-align: center;
  padding: 40px 16px 32px;
}
.sal-header h1 {
  font-size: 26px;
  margin: 0 0 8px;
  font-weight: 700;
}
.sal-header p {
  font-size: 15px;
  opacity: 0.9;
  margin: 0;
  max-width: 600px;
  margin: 0 auto;
}

/* Tabs */
.sal-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 16px 40px;
}
.sal-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 24px;
}
.sal-tab {
  padding: 8px 20px;
  border: 2px solid #c41230;
  background: #fff;
  color: #c41230;
  font-size: 15px;
  font-weight: 600;
  border-radius: 24px;
  cursor: pointer;
  transition: all .2s;
}
.sal-tab:hover {
  background: #fdf0f2;
}
.sal-tab-active {
  background: #c41230;
  color: #fff;
}
.sal-tab-active:hover {
  background: #a50f28;
}

/* Grid */
.sal-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}
.sal-img-wrap {
  position: relative;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  cursor: pointer;
  transition: transform .2s, box-shadow .2s;
  background: #f5f5f5;
}
.sal-img-wrap:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}
.sal-img-wrap img {
  display: block;
  width: 100%;
  height: auto;
}
/* CSS watermark overlay (layer 2) */
.sal-img-wrap::after {
  content: 'ISL Education x SCG';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) rotate(-25deg);
  font-size: 18px;
  font-weight: 700;
  color: rgba(196, 18, 48, 0.06);
  letter-spacing: 4px;
  white-space: nowrap;
  pointer-events: none;
  z-index: 2;
}

/* Lightbox */
.sal-lightbox {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.85);
  z-index: 10000;
  align-items: center;
  justify-content: center;
}
.sal-lb-open {
  display: flex;
}
.sal-lightbox img {
  max-width: 90vw;
  max-height: 90vh;
  object-fit: contain;
  border-radius: 4px;
}
.sal-lb-close,
.sal-lb-prev,
.sal-lb-next {
  position: absolute;
  background: none;
  border: none;
  color: #fff;
  cursor: pointer;
  font-size: 40px;
  padding: 10px;
  opacity: 0.7;
  transition: opacity .2s;
  z-index: 10001;
}
.sal-lb-close:hover,
.sal-lb-prev:hover,
.sal-lb-next:hover {
  opacity: 1;
}
.sal-lb-close {
  top: 16px;
  right: 20px;
  font-size: 48px;
}
.sal-lb-prev {
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 56px;
}
.sal-lb-next {
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 56px;
}

/* CTA */
.sal-cta {
  text-align: center;
  padding: 40px 16px;
  background: #fdf0f2;
  margin-top: 10px;
}
.sal-cta h3 {
  font-size: 22px;
  color: #1a1a1a;
  margin: 0 0 8px;
}
.sal-cta p {
  color: #666;
  margin: 0 0 16px;
}
.sal-cta-btn {
  display: inline-block;
  background: #c41230;
  color: #fff;
  padding: 12px 32px;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
  transition: background .2s;
}
.sal-cta-btn:hover {
  background: #a50f28;
  color: #fff;
}

/* Mobile */
@media (max-width: 600px) {
  .sal-header { padding: 28px 12px 24px; }
  .sal-header h1 { font-size: 20px; }
  .sal-grid { grid-template-columns: 1fr; gap: 12px; }
  .sal-tab { padding: 6px 14px; font-size: 13px; }
  .sal-lb-prev, .sal-lb-next { font-size: 36px; }
  .sal-cta h3 { font-size: 18px; }
}