.page-news {
  --page-news-timeline-width: 4px;
  --page-news-dot-size: 18px;
  --page-news-filter-gap: 0.75rem;
  --page-news-index-gap: 1.5rem;
  --page-news-card-shadow: 6px 6px 0 rgba(10,31,68,0.08);
}

/* === Hero 区域 === */
.page-news__hero {
  position: relative;
  background: var(--color-primary-deep-blue, #0A1F44);
  padding: 3rem 1rem;
  margin-bottom: 2rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  overflow: hidden;
}

.page-news__hero-inner {
  flex: 1;
  position: relative;
  z-index: 2;
}

.page-news__hero-label {
  color: var(--color-primary-gold, #D4A84B);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  display: inline-block;
  margin-bottom: 0.5rem;
}

.page-news__hero-title {
  margin: 0 0 0.75rem;
  font-size: clamp(2.2rem, 6vw, 4rem);
  line-height: 1.1;
}

.page-news__hero-sub {
  color: var(--color-neutral-white, #FFFFFF);
  font-size: 1.05rem;
  line-height: 1.7;
  max-width: 520px;
  opacity: 0.85;
}

.page-news__hero-bg {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 100px;
  height: 800px;
  object-fit: cover;
  opacity: 0.15;
  pointer-events: none;
}

/* === 筛选标签 === */
.page-news__filter {
  display: flex;
  flex-wrap: wrap;
  gap: var(--page-news-filter-gap);
  padding: 0 1rem;
  max-width: var(--content-max-width, 1200px);
  margin: 0 auto 2.5rem;
}

.page-news__filter-btn {
  background: transparent;
  border: 2px solid var(--color-primary-deep-blue, #0A1F44);
  color: var(--color-primary-deep-blue, #0A1F44);
  padding: 0.5rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1)),
              color var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1)),
              box-shadow var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1));
}

.page-news__filter-btn--active,
.page-news__filter-btn:hover,
.page-news__filter-btn:focus-visible {
  background: var(--color-primary-deep-blue, #0A1F44);
  color: var(--color-primary-gold, #D4A84B);
  box-shadow: var(--shadow-strong, 8px 8px 0 rgba(0,0,0,0.12));
  outline: none;
}

/* === 公共section容器 === */
.page-news .section {
  padding: 0 1rem 3rem;
  max-width: var(--content-max-width, 1200px);
  margin: 0 auto;
}

.page-news__section-title {
  font-size: clamp(1.6rem, 4vw, 2.8rem);
  font-weight: 800;
  color: var(--color-primary-deep-blue, #0A1F44);
  margin: 0 0 0.5rem;
  position: relative;
  display: inline-block;
}

.page-news__section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--color-primary-gold, #D4A84B);
  margin-top: 0.35rem;
}

.page-news__section-desc {
  color: var(--color-secondary-dark-ink, #1C1E21);
  font-size: 1rem;
  line-height: 1.7;
  max-width: 600px;
  margin-bottom: 2rem;
}

/* === 时间轴 === */
.page-news__timeline {
  padding-bottom: 4rem;
}

.page-news__timeline-list {
  position: relative;
  padding-left: 2rem;
}

/* 时间轴竖线（金色） */
.page-news__timeline-list::before {
  content: '';
  position: absolute;
  left: 9px;
  top: 0;
  bottom: 0;
  width: var(--page-news-timeline-width);
  background: var(--color-primary-gold, #D4A84B);
  border-radius: 2px;
}

.page-news__timeline-item {
  position: relative;
  padding-bottom: 2.5rem;
  display: flex;
  gap: 1rem;
}

.page-news__timeline-item:last-child {
  padding-bottom: 0;
}

.page-news__timeline-dot {
  flex-shrink: 0;
  width: var(--page-news-dot-size);
  height: var(--page-news-dot-size);
  background: var(--color-primary-deep-blue, #0A1F44);
  border: 3px solid var(--color-primary-gold, #D4A84B);
  border-radius: 50%;
  position: relative;
  z-index: 2;
  margin-top: 0.35rem;
}

.page-news__timeline-content {
  flex: 1;
  background: var(--color-secondary-warm-paper, #F5F0E6);
  border: 4px solid var(--color-primary-deep-blue, #0A1F44);
  padding: 1.25rem 1.5rem;
  box-shadow: var(--page-news-card-shadow);
  transition: box-shadow var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1)),
              transform var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1));
}

.page-news__timeline-content:hover {
  box-shadow: var(--shadow-stronger, 12px 12px 0 rgba(0,0,0,0.08));
  transform: translate(-2px, -2px);
}

.page-news__timeline-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
}

.page-news__timeline-icon {
  width: 40px;
  height: 40px;
  object-fit: contain;
  flex-shrink: 0;
}

.page-news__timeline-date {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-accent-cyan, #00B4D8);
  text-transform: uppercase;
}

.page-news__timeline-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  background: var(--color-primary-gold, #D4A84B);
  color: var(--color-primary-deep-blue, #0A1F44);
  padding: 0.2em 0.6em;
  border: 1px solid var(--color-primary-deep-blue, #0A1F44);
}

.page-news__timeline-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--color-primary-deep-blue, #0A1F44);
  margin: 0 0 0.3rem;
}

.page-news__timeline-desc {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-secondary-dark-ink, #1C1E21);
  margin-bottom: 0.5rem;
}

.page-news__timeline-detail {
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--color-secondary-dark-ink, #1C1E21);
  border-top: 2px solid var(--color-neutral-light-gray, #E0DDD5);
  padding-top: 0.75rem;
  margin-top: 0.5rem;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.35s ease-out, opacity 0.35s ease-out, padding 0.35s ease-out;
}

.page-news__timeline-item[data-expanded] .page-news__timeline-detail {
  max-height: 400px;
  opacity: 1;
  padding-top: 0.75rem;
  margin-top: 0.5rem;
}

.page-news__timeline-toggle {
  margin-top: 0.5rem;
}

.page-news__timeline-detail a {
  color: var(--color-primary-gold, #D4A84B);
  text-decoration: underline;
  text-underline-offset: 2px;
  font-weight: 600;
}

.page-news__timeline-detail a:hover {
  color: var(--color-accent-cyan, #00B4D8);
}

/* === 优化日志区域 === */
.page-news__optimize {
  background: var(--color-primary-deep-blue, #0A1F44);
  padding: 3rem 1rem;
  margin: 0 0 3rem;
}

.page-news__optimize .page-news__section-title {
  color: var(--color-primary-gold, #D4A84B);
}

.page-news__optimize .page-news__section-title::after {
  background: var(--color-neutral-white, #FFFFFF);
}

.page-news__optimize .page-news__section-desc {
  color: var(--color-neutral-white, #FFFFFF);
  opacity: 0.85;
}

.page-news__optimize-inner {
  max-width: var(--content-max-width, 1200px);
  margin: 0 auto;
}

.page-news__optimize-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.page-news__optimize-card {
  background: var(--color-secondary-warm-paper, #F5F0E6);
  border: 4px solid var(--color-primary-gold, #D4A84B);
  padding: 1.5rem;
  box-shadow: var(--shadow-strong, 8px 8px 0 rgba(0,0,0,0.12));
  transition: box-shadow var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1)),
              transform var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1));
}

.page-news__optimize-card:hover {
  box-shadow: var(--shadow-stronger, 12px 12px 0 rgba(0,0,0,0.08));
  transform: translate(-3px, -3px);
}

.page-news__optimize-card-num {
  font-size: 2rem;
  font-weight: 900;
  color: var(--color-primary-gold, #D4A84B);
  margin-bottom: 0.5rem;
  line-height: 1;
}

.page-news__optimize-card-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--color-primary-deep-blue, #0A1F44);
  margin: 0 0 0.3rem;
}

.page-news__optimize-card-desc {
  font-size: 0.92rem;
  line-height: 1.6;
  color: var(--color-secondary-dark-ink, #1C1E21);
}

.page-news__optimize-visual {
  margin-top: 1.5rem;
  text-align: center;
}

.page-news__optimize-img {
  max-width: 100%;
  height: auto;
  border: 4px solid var(--color-primary-gold, #D4A84B);
  box-shadow: var(--shadow-strong, 8px 8px 0 rgba(0,0,0,0.12));
  object-fit: cover;
}

/* === 内容目录索引 === */
.page-news__index-layout {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.page-news__index-tree {
  flex-shrink: 0;
}

.page-news__index-img {
  max-width: 100%;
  height: auto;
  border: 4px solid var(--color-primary-deep-blue, #0A1F44);
  box-shadow: var(--shadow-strong, 8px 8px 0 rgba(0,0,0,0.12));
  object-fit: contain;
}

.page-news__index-list {
  display: flex;
  flex-direction: column;
  gap: var(--page-news-index-gap);
}

.page-news__index-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem;
  background: var(--color-secondary-warm-paper, #F5F0E6);
  border: 4px solid var(--color-primary-deep-blue, #0A1F44);
  box-shadow: var(--page-news-card-shadow);
  transition: box-shadow var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1)),
              transform var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1));
}

.page-news__index-item:hover {
  box-shadow: var(--shadow-stronger, 12px 12px 0 rgba(0,0,0,0.08));
  transform: translate(-2px, -2px);
}

.page-news__index-num {
  flex-shrink: 0;
  width: 2.2rem;
  height: 2.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-gold, #D4A84B);
  color: var(--color-primary-deep-blue, #0A1F44);
  font-size: 1.1rem;
  font-weight: 900;
  border: 2px solid var(--color-primary-deep-blue, #0A1F44);
}

.page-news__index-item div {
  flex: 1;
}

.page-news__index-name {
  font-size: 1.05rem;
  display: block;
  margin-bottom: 0.2rem;
}

.page-news__index-name a {
  color: var(--color-primary-deep-blue, #0A1F44);
  text-decoration: none;
  font-weight: 800;
  transition: color var(--transition-base, 0.25s cubic-bezier(0.4,0,0.2,1));
}

.page-news__index-name a:hover {
  color: var(--color-primary-gold, #D4A84B);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-news__index-desc {
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--color-secondary-dark-ink, #1C1E21);
  opacity: 0.8;
}

/* === 桌面断点（768px 及以上） === */
@media (min-width: 768px) {
  .page-news__hero {
    padding: 4rem 2rem;
  }

  .page-news__filter {
    padding: 0 2rem;
  }

  .page-news .section {
    padding-left: 2rem;
    padding-right: 2rem;
  }

  .page-news__timeline-list {
    padding-left: 3rem;
  }

  .page-news__timeline-list::before {
    left: 15px;
  }

  .page-news__timeline-item {
    gap: 1.5rem;
  }

  .page-news__timeline-dot {
    width: 22px;
    height: 22px;
    margin-top: 0.5rem;
  }

  .page-news__timeline-content {
    padding: 1.5rem 2rem;
  }

  .page-news__optimize {
    padding: 4rem 2rem;
  }

  .page-news__optimize-grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-news__index-layout {
    flex-direction: row;
    align-items: flex-start;
  }

  .page-news__index-tree {
    flex: 1;
    max-width: 50%;
  }

  .page-news__index-list {
    flex: 1;
  }

  .page-news__index-item {
    padding: 1.25rem 1.5rem;
  }

  .page-news__optimize-visual {
    text-align: left;
  }
}

/* === 大桌面断点（1200px 及以上） === */
@media (min-width: 1200px) {
  .page-news__optimize-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-news__index-layout {
    gap: 3rem;
  }
}