.page-header {
  max-width: 900px;
  margin: 0 auto;
  padding: 3.5rem 1rem 2rem;
  text-align: center;
}

.page-title {
  margin: 0;
  color: var(--color-accent-blue);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 650;
  letter-spacing: -0.035em;
}

.happy-leader-container {
  max-width: 900px;
  margin: 0 auto;
  color: var(--color-text-high-contrast);
  background: transparent;
  border: 0;
  border-radius: 0;
}

.book-title {
  margin-bottom: 2rem;
  color: #163d52;
  font-size: clamp(1.45rem, 2.5vw, 2rem);
  text-align: center;
}

.book-image {
  width: min(100%, 380px);
  margin: 0 auto 2.5rem;
  display: block;
  aspect-ratio: 3 / 4;
  object-fit: contain;
  background: #f1f4f5;
  border: 1px solid #dce6ea;
  border-radius: 10px;
}

.chinese_blue_passage,
.English_blue_passage {
  color: #31404a;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 450;
  line-height: 1.75;
}

.chinese_blue_passage {
  max-width: 720px;
  margin: 0 auto;
  text-align: left;
}

.center-link {
  margin: 1.5rem 0;
  text-align: center;
}

.center-link a {
  color: #006a9d;
  font-weight: 600;
  text-underline-offset: 3px;
}

.download-section {
  margin: 2.5rem 0 0;
  text-align: center;
}

.button1 {
  min-height: 44px;
  padding: 0.75rem 1.25rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  background: var(--color-accent-blue);
  border: 1px solid var(--color-accent-blue);
  border-radius: 8px;
  font: 650 0.9rem/1.2 var(--font-sans);
  letter-spacing: 0;
  text-decoration: none;
}

.button1:hover,
.button1:focus-visible {
  color: #fff;
  background: #006a9d;
  border-color: #006a9d;
}

.preview-section,
.gallery-section {
  margin: 0;
}

.preview-section .English_blue_passage,
.gallery-title {
  margin-bottom: 1rem;
  color: #163d52;
  font-size: 1.2rem;
  font-weight: 650;
  text-align: left;
}

.preview-iframe {
  width: 100%;
  height: min(68vh, 620px);
  border: 1px solid #cddbe1;
  border-radius: 10px;
  background: #f1f4f5;
}

.photo-grid {
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.photo-item,
.photo-item:hover {
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: #eef3f5;
  border: 1px solid #dce6ea;
  border-radius: 10px;
  box-shadow: none;
  transform: none;
}

.photo-item img,
.photo-item:hover img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  transform: none;
}

@media (max-width: 700px) {
  .page-header {
    padding-top: 2.5rem;
  }

  .photo-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 420px) {
  .photo-grid {
    grid-template-columns: 1fr;
  }
}