html {
  scroll-behavior: smooth;
}

.a-page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 60px;
}

/* ──  返回 ── */
.a-label {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: #999;
  text-transform: uppercase;
  margin-bottom: 20px;
  display: block;
}

.back {
  position: fixed;
  top: 100px;
  left: 40px;
  z-index: 999;

  padding: 6px 14px;
  border-radius: 999px;

  font-size: 13px;
  color: #333;
  background: rgba(255, 255, 255, 0.77);

  cursor: pointer;
  transition: all 0.25s ease;
}

.back:hover {
  background: #111;
  color: #fff;
   transform: translateX(-4px);
}

/* 右侧悬浮目录卡片 - 永久固定版 */
.side-toc-right {
  position: fixed;
  top: 100px;          /* 距离顶部高度，避开 header */
  right: 20px;         /* 稍微往右边靠一点（从40px改到20px），放大时更不容易挡住正文 */
  z-index: 999;

  /* 默认隐藏，滚动到第一个目录区块才显示 */
  opacity: 0;
  pointer-events: none;
  transform: translateX(16px);
  transition: opacity 0.4s ease, transform 0.4s ease;
  
  width: 160px;        /* 稍微收窄一点点，提高兼容性 */
  padding: 16px;
  
  /* 现代高级感：白色半透明毛玻璃背景 */
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  
  /* 柔和阴影与圆角 */
  border-radius: 12px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  
  display: flex;
  flex-direction: column;
  gap: 12px;           /* 每一项的间距 */
}

/* 目录出现状态（滚动到第一个区块后触发） */
.side-toc-right.toc-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateX(0);
}

/* 目录标题 */
.toc-title {
  font-size: 13px;     
  font-weight: 700;
  color: #888;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  padding-bottom: 6px;
}

/* 目录的每一个链接 */
.toc-item {
  font-size: 14px;     /* 稍微微调到 14px，让整体更精致 */
  color: #444;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.25s ease;
  display: block;
}

/* 鼠标悬浮时的效果 */
.toc-item:hover {
  color: #1a56db;      /* 悬浮时变蓝色 */
  font-weight: 600;
  transform: translateX(4px); /* 轻轻往右挪一点点 */
}

.toc-item.active {
  color: #1a56db !important;       /* 强行变成行知主品牌蓝 */
  font-weight: 700 !important;     /* 字体加粗，更有重点 */
  transform: translateX(4px);      /* 保持微微向右突出的活跃感 */
  position: relative;
}

.toc-item.active::before {
  content: "•";
  color: #1a56db;
  font-size: 16px;
  position: absolute;
  left: -10px;
  top: -1px;
}

/* ── ① HERO ── */
.a-hero {
  position: relative;
  height: 65vh;
  min-height: 350px;
  overflow: hidden;
  
}

.a-hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.a-hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(0,0,0,0.15) 0%,
    rgba(0,0,0,0.55) 60%,
    rgba(0,0,0,0.75) 100%
  );
}

.a-hero-content {
  position: absolute;
  top: 150px;
  bottom: 80px;
  left: 0;
  right: 0;
  padding: 0 80px;
  z-index: 2;
}

.a-hero-eyebrow {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: rgba(255,255,255,0.65);
  text-transform: uppercase;
  margin-bottom: 16px;
}

.a-hero-title {
  font-size: 64px;
  font-weight: 700;
  color: #fff;
  line-height: 1.1;
  margin-bottom: 20px;
}

.a-hero-sub {
  font-size: 15px;
  color: rgba(255,255,255,0.8);
  max-width: 480px;
  line-height: 1.8;
}

/* ── ② 大字引言 ── */
.a-quote-section {
  padding: 50px 0;
  background: #fafafa;
  border-top: 0.5px solid #e5e5e5;
  border-bottom: 0.5px solid #e5e5e5;
}

.a-big-quote {
  font-size: 60px;
  font-weight: 700;
  color: #111;
  line-height: 1.25;
  margin-bottom: 20px;
  letter-spacing: 0.15em;
  opacity: 0;
  transform: translateY(-40px);
  transition: all 0.8s cubic-bezier(0.25, 1, 0.5, 1);
}

.a-big-quote.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.a-quote-sub {
  font-size: 15px;
  color: #888;
  line-height: 1.8;
  max-width: 500px;
}

/* 深色版引言 */
.a-quote-dark {
  background: #111;
  border-color: #222;
}

.a-big-quote-white { color: #fff; }
.a-quote-sub-white { color: rgba(255,255,255,0.55); }

/* ── ③ 三栏 ── */
.a-intro {
  padding: 100px 0;
  border-bottom: 0.5px solid #e5e5e5;
}

.a-three-col {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
  margin-top: 40px;
}

.a-col-num {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: #bbb;
  display: block;
  margin-bottom: 14px;
}

.a-col-item h3 {
  font-size: 17px;
  font-weight: 600;
  color: #111;
  margin-bottom: 12px;
}

.a-col-item p {
  font-size: 14px;
  color: #666;
  line-height: 1.85;
}

/* ── ④ 数据亮点 ── */
.a-stats {
  padding: 50px 0;
  background: #1e1e6e;
}

.a-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}

.a-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 40px 20px;
  overflow: hidden;
}

.a-stat:last-child { border-right: none; }

.a-stat-num,.a-stat-label {
  opacity: 0;
  transform: translateY(-40px);
  transition: all 0.8s cubic-bezier(0.25, 1, 0.5, 1); /* 平滑的缓动效果 */
}

.a-stat-num {
  font-size: 52px;
  font-weight: 700;
  color: #fff;
  line-height: 1;
  margin-bottom: 10px;
}

.a-stat-label {
  font-size: 13px;
  color: rgba(255,255,255,0.5);
  text-align: center;
  letter-spacing: 0.04em;
}

.a-stat.is-visible .a-stat-num, .a-stat.is-visible .a-stat-label {
  opacity: 1;
  transform: translateY(0);
}

.a-stat:nth-child(1) .a-stat-num, .a-stat:nth-child(1) .a-stat-label { transition-delay: 0.1s; }
.a-stat:nth-child(2) .a-stat-num, .a-stat:nth-child(2) .a-stat-label { transition-delay: 0.25s; }
.a-stat:nth-child(3) .a-stat-num, .a-stat:nth-child(3) .a-stat-label { transition-delay: 0.4s; }
.a-stat:nth-child(4) .a-stat-num, .a-stat:nth-child(4) .a-stat-label { transition-delay: 0.55s; }

/* ── ⑤ 故事 ── */
.a-story {
  padding: 100px 0;
  border-bottom: 0.5px solid #e5e5e5;
}

.a-story-title {
  font-size: 42px;
  font-weight: 700;
  color: #111;
  margin-bottom: 56px;
  line-height: 1.2;
}

/* ── 标题的初始隐藏状态 ── */
.a-story-title,
.a-sec-title {
  opacity: 0;
  transform: translateY(30px); /* 初始位置向下潜 30px */
  transition: opacity 2.4s cubic-bezier(0.16, 1, 0.3, 1), 
              transform 1.6s cubic-bezier(0.16, 1, 0.3, 1);
  will-change: transform, opacity;
}

/* ── 标题被 JS 发现并加上 is-visible 后的浮现状态 ── */
.a-story-title.is-visible,
.a-sec-title.is-visible {
  opacity: 1;
  transform: translateY(0); /* 完美平滑归位 */
}

.a-story-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: start;
}

.a-story-left p {
  font-size: 15px;
  color: #555;
  line-height: 1.9;
  margin-bottom: 20px;
}

.a-service-card {
  padding: 24px 0;
  border-bottom: 0.5px solid #e5e5e5;
}

.a-service-card:first-child { border-top: 0.5px solid #e5e5e5; }

.a-service-card h4 {
  font-size: 15px;
  font-weight: 600;
  color: #111;
  margin-bottom: 8px;
}

.a-service-card p {
  font-size: 13px;
  color: #777;
  line-height: 1.75;
}

 /* ── Section wrapper ── */
    .a-section {
      padding: 80px 7%;
    }
    .a-section--alt {
      background: var(--leam-soft);
    }
    .a-section--dark {
      background: var(--leam-navy);
      color: white;
    }
    .a-section--blue {
      background: var(--leam-blue);
      color: white;
    }

    .a-section-label {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.18em;
      text-transform: uppercase;
      color: var(--leam-blue);
      margin-bottom: 14px;
    }
    .a-section-label::before {
      content: '';
      display: block;
      width: 24px;
      height: 2px;
      background: var(--leam-blue);
      border-radius: 2px;
    }
    .a-section--dark .a-section-label,
    .a-section--blue .a-section-label {
      color: #93c5fd;
    }
    .a-section--dark .a-section-label::before,
    .a-section--blue .a-section-label::before {
      background: #93c5fd;
    }

    .a-section-title {
      font-size: clamp(28px, 4vw, 46px);
      font-weight: 800;
      color: var(--text-main);
      line-height: 1.15;
      letter-spacing: -0.02em;
      margin-bottom: 16px;
    }
    .a-section--dark .a-section-title,
    .a-section--blue .a-section-title { color: white; }

    .a-section-desc {
      font-size: 16px;
      color: var(--text-sub);
      line-height: 1.8;
      max-width: 640px;
    }
    .a-section--dark .a-section-desc { color: rgba(255,255,255,0.7); }
    .a-section--blue .a-section-desc { color: rgba(255,255,255,0.85); }

    /* ── Connect 4-col cards ── */
    .a-connect-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-top: 48px;
    }
    .a-connect-card {
      background: white;
      border: 1px solid var(--leam-line);
      border-radius: 20px;
      padding: 28px 24px;
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }
    .a-connect-card:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 50px rgba(26,86,219,0.12);
    }
    .a-connect-icon {
      width: 52px;
      height: 52px;
      border-radius: 14px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 22px;
      margin-bottom: 18px;
    }
    .a-connect-card h4 {
      font-size: 17px;
      font-weight: 700;
      margin-bottom: 10px;
      transition: color 0.25s ease;
    }
    .card-blue h4 {
  color: #1a56db; /* 亮蓝色 */
}
.card-green h4 {
  color: #16a34a; /* 翠绿色 */
}
.card-orange h4 {
  color: #ea580c; /* 活力橙色 */
}
.card-purple h4 {
  color: #9333ea; /* 优雅紫色 */
}

/* ── ✨ 附加高级动效：鼠标悬浮时，标题颜色加深 ── */
.card-blue:hover h4 { color: #1e429f; }
.card-green:hover h4 { color: #15803d; }
.card-orange:hover h4 { color: #c2410c; }
.card-purple:hover h4 { color: #7e22ce; }

    .a-connect-card p {
      font-size: 14px;
      color: var(--text-sub);
      line-height: 1.7;
    }

/* ── ⑦ 创办人 ── */
.a-founder {
  padding: 100px 0;
  border-bottom: 0.5px solid #e5e5e5;
}

.a-founder-grid {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 72px;
  align-items: start;
  margin-top: 40px;
}

.a-founder-photo-wrap {
  position: sticky;
  top: 100px;
}

.a-founder-photo {
  width: 100%;
  aspect-ratio: 3/4;
  object-fit: cover;
  border-radius: 16px;
  display: block;
  background: #e5e5e5;
}

.a-founder-namecard {
  margin-top: 16px;
}

.a-founder-namecard h2 {
  font-size: 25px;
  font-weight: 600;
  color: #111;
  margin-bottom: 4px;
}

.a-founder-namecard p {
  font-size: 15px;
  color: #999;
}

/* 时间轴 */
.a-founder-timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  padding-top: 8px;
}

.a-tl-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 0.5px solid #e5e5e5;
  align-items: start;
}

.a-tl-item:first-child { border-top: 0.5px solid #e5e5e5; }

.a-tl-year {
  font-size: 13px;
  font-weight: 600;
  color: #111;
  letter-spacing: 0.04em;
  padding-top: 3px;
}

.a-tl-body p {
  font-size: 14px;
  color: #555;
  line-height: 1.85;
}

/* ── ⑧ 校长 ── */
/* ── 书本场景 ── */
.a-principals { padding: 100px 0; }

.a-section-title {
  font-size: 36px;
  font-weight: 600;
  color: #111;
  margin-bottom: 56px;
}

.a-book-scene {
  perspective: 1200px;
  display: flex;
  justify-content: center;
}

.a-book {
  display: flex;
  width: 100%;
  max-width: 860px;
  min-height: 440px;
  transform: rotateX(3deg);
  transform-style: preserve-3d;
  border-radius: 3px 20px 20px 3px;
  box-shadow:
    -10px 16px 48px rgba(0,0,0,0.22),
    9px 5px 0 #4d589a;
}

/* 左页 */
.a-book-left {
  flex: 0 0 42%;
  background: #ebf2f5;
  border-radius: 3px 0 0 3px;
  padding: 48px 36px 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  border-right: 3px solid #c8bfb0;
  position: relative;
  overflow: hidden;
}

/* 书脊阴影 */
.a-book-left::after {
  content: '';
  position: absolute;
  right: 0; top: 0; bottom: 0;
  width: 20px;
  background: linear-gradient(to right, rgba(0,0,0,0.09), transparent);
}

.a-book-left img {
  width: 100%;
  max-width: 200px;
  aspect-ratio: 3/4;
  object-fit: cover;
  object-position: top;
  border-radius: 10px;
  display: block;
  background: #cccccc;
}

.a-book-namecard h3 {
  font-size: 18px;
  font-weight: 600;
  color: #2c2820;
  margin-bottom: 5px;
  text-align: center;
}

.a-book-namecard p {
  font-size: 13px;
  color: #7a7060;
  text-align: center;
}

/* 右页 */
.a-book-right {
  flex: 0 0 58%;
  background: #eef8fb;
  border-radius: 0 20px 20px 0;
  padding: 52px 48px 44px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.a-book-tag {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: #b0a898;
  text-transform: uppercase;
  margin-bottom: 18px;
}

.a-book-desc {
  font-size: 15px;
  color: #3a3530;
  line-height: 1.95;
  border-left: 2px solid #d8d0c4;
  padding-left: 20px;
  font-style: italic;
}

/* 翻页导航 */
.a-book-nav {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 32px;
}

.a-book-nav-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 0.5px solid #ccc;
  background: #fff;
  cursor: pointer;
  font-size: 16px;
  color: #555;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  flex: 0 0 auto;
}

.a-book-nav-btn:hover { background: #f0ece3; }
.a-book-nav-btn:disabled { opacity: 0.3; cursor: default; }

.a-book-nav-count {
  font-size: 14px;
  color: #7a7060;
  flex: 1;
  text-align: center;
  font-weight: 500;
}

.a-book-pagenum {
  font-size: 11px;
  color: #c8bfb0;
  text-align: center;
  margin-top: 10px;
  letter-spacing: 0.06em;
}

/* 翻页动画 */
.a-flip-left {
  animation: aFlipL 0.4s cubic-bezier(0.4, 0, 0.2, 1) both;
}
.a-flip-right {
  animation: aFlipR 0.4s cubic-bezier(0.4, 0, 0.2, 1) both;
}

@keyframes aFlipL {
  from { opacity: 0; transform: rotateY(-25deg); }
  to   { opacity: 1; transform: none; }
}
@keyframes aFlipR {
  from { opacity: 0; transform: rotateY(25deg); }
  to   { opacity: 1; transform: none; }
}

@media (max-width: 700px) {
  .a-book { flex-direction: column; border-radius: 16px; transform: none; }
  .a-book-left { border-radius: 16px 16px 0 0; border-right: none; border-bottom: 3px solid #c8bfb0; }
  .a-book-left::after { display: none; }
  .a-book-right { border-radius: 0 0 16px 16px; }
}
/* ── RESPONSIVE ── */
@media (max-width: 768px) {
  .nav {display: none; /* ❌ 隐藏原菜单 */}
  .menu-btn { display: block; /* ✅ 显示 ☰ */}
  .a-hero-title { font-size: 40px; }
  .a-hero-content { padding: 0 32px; bottom: 48px; }
  .a-page { padding: 0 24px; }
  .a-big-quote { font-size: 32px; }
  .a-three-col { grid-template-columns: 1fr; gap: 32px; }
  .a-stats-grid { grid-template-columns: repeat(2, 1fr); }
  .a-story-grid { grid-template-columns: 1fr; gap: 48px; }
  .a-founder-grid { grid-template-columns: 1fr; }
  .a-founder-photo-wrap { position: static; }
  .a-principals-grid { grid-template-columns: 1fr; }
}

/* ── 书本 responsive ── */
@media (max-width: 900px) {
  .a-book {
    flex-direction: column;
    max-width: 480px;
    min-height: auto;
    border-radius: 20px;
    transform: none;
    box-shadow: 0 12px 40px rgba(0,0,0,0.18);
  }

  .a-book-left {
    flex: none;
    width: 100%;
    border-radius: 20px 20px 0 0;
    border-right: none;
    border-bottom: 3px solid #c8bfb0;
    padding: 32px 28px 24px;
    flex-direction: row;
    align-items: center;
    gap: 20px;
  }

  .a-book-left::after { display: none; }

  .a-book-left img {
    max-width: 100px;
    flex: 0 0 100px;
  }

  .a-book-namecard {
    text-align: left;
  }

  .a-book-namecard h3 { text-align: left; }
  .a-book-namecard p  { text-align: left; }

  .a-book-right {
    flex: none;
    width: 100%;
    border-radius: 0 0 20px 20px;
    padding: 28px 28px 32px;
  }

  .a-book-nav {
    margin-top: 20px;
  }
}

@media (max-width: 600px) {
  .a-book-scene {
    perspective: none;
  }

  .a-book {
    max-width: 100%;
  }

  .a-book-left {
    flex-direction: column;
    align-items: center;
    gap: 14px;
  }

  .a-book-left img {
    max-width: 140px;
    flex: none;
  }

  .a-book-namecard {
    text-align: center;
  }

  .a-book-namecard h3 { text-align: center; }
  .a-book-namecard p  { text-align: center; }

  .a-book-desc {
    font-size: 14px;
  }
}


/* ── a-intro：我们的故事 两栏布局 ── */
.a-intro-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  align-items: center;
}

.a-intro-photo {
  border-radius: 16px;
  overflow: hidden;
  aspect-ratio: 6 / 4;
}

.a-intro-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
  display: block;
  transition: transform 0.5s ease;
}

.a-intro-photo:hover img {
  transform: scale(1.03);
}

.a-intro-grid .a-col-item h3 {
  font-size: 42px;
  font-weight: 700;
  color: #111;
  margin-bottom: 24px;
}

@media (max-width: 768px) {
  .a-intro-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
  .a-intro-photo {
    aspect-ratio: 16 / 9;
  }
}
/* ── 愿景与使命 ── */
.a-vm-section {
  padding: 80px 0;
  background: var(--leam-blue);
  border-bottom: 0.5px solid #e5e5e5;
}

.a-vm-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

/* 左侧 */
.a-vm-title {
  font-size: clamp(28px, 3.5vw, 42px);
  font-weight: 700;
  color: #111;
  margin-bottom: 36px;
  line-height: 1.2;
}

.a-vm-items {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.a-vm-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.a-vm-icon {
  flex: 0 0 52px;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: #c4d1e8;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  overflow: hidden;
}

.a-vm-icon img {
  width: 28px;
  height: 28px;
  object-fit: contain;
}

.a-vm-text h3 {
  font-size: 17px;
  font-weight: 700;
  color: #111;
  margin-bottom: 8px;
}

.a-vm-text p {
  font-size: 14px;
  color: #555;
  line-height: 1.85;
}

/* 右侧照片 */
.a-vm-right {
  border-radius: 16px;
  overflow: hidden;
  aspect-ratio: 4 / 3;
}

.a-vm-right img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.5s ease;
}

.a-vm-right:hover img {
  transform: scale(1.03);
}

@media (max-width: 768px) {
  .a-vm-layout {
    grid-template-columns: 1fr;
    gap: 36px;
  }
  .a-vm-right {
    aspect-ratio: 16 / 9;
  }
}

/* ── Advantages 2x2 ── */
    .a-adv-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 20px;
      margin-top: 48px;
    }
    .a-adv-card {
      background: white;
      border: 1px solid var(--leam-line);
      border-radius: 20px;
      overflow: hidden;
      display: grid;
      grid-template-columns: 1fr 1fr;
      min-height: 220px;
    }
    .a-adv-text {
      padding: 32px 28px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }
    .a-adv-num {
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 0.14em;
      color: var(--leam-blue);
      margin-bottom: 10px;
    }
    .a-adv-text h4 {
      font-size: 19px;
      font-weight: 700;
      color: var(--text-main);
      margin-bottom: 10px;
      line-height: 1.3;
    }
    .a-adv-text p {
      font-size: 13px;
      color: var(--text-sub);
      line-height: 1.75;
    }
    .a-adv-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 6px;
      margin-top: 14px;
    }
    .a-adv-tag {
      font-size: 11px;
      padding: 4px 10px;
      border-radius: 999px;
      background: var(--leam-blue-light);
      color: var(--leam-blue);
      font-weight: 500;
    }
    .a-adv-img {
      overflow: hidden;
    }
    .a-adv-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
/* ── 我们的优势（文字上 + 照片下） ── */
.a-adv-section {
  padding: 80px 0;
  background: var(--leam-blue);
  border-bottom: 0.5px solid #e5e5e5;
}

.a-adv-main-title {
  font-size: clamp(26px, 3.5vw, 40px);
  font-weight: 700;
  color: #111;
  text-align: center;
  margin-bottom: 48px;
}

.a-adv-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: start;
}

/* 每栏：文字在上，照片在下 */
.a-adv-col {
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid #ebebeb;
  border-radius: 16px;
  overflow: hidden;
  background: #fff;
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.a-adv-col:hover {
  box-shadow: 0 12px 36px rgba(0,0,0,0.09);
  transform: translateY(-4px);
}

.a-adv-text {
  padding: 28px 24px 20px;
  flex: 1;
}

.a-adv-num {
  display: block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: #aaa;
  margin-bottom: 10px;
}

.a-adv-text h4 {
  font-size: 18px;
  font-weight: 700;
  color: #111;
  margin-bottom: 12px;
  line-height: 1.3;
}

.a-adv-text > p {
  font-size: 13px;
  color: #555;
  line-height: 1.85;
  margin-bottom: 16px;
}

/* 关键词列表 */
.a-adv-tags {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-bottom: 4px;
}

.a-adv-tags li {
  font-size: 13px;
  color: #1a56db;
  font-weight: 500;
  padding-left: 12px;
  position: relative;
}

.a-adv-tags li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: #1a56db;
}

/* 照片固定在底部 */
.a-adv-photo {
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  flex-shrink: 0;
}

.a-adv-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.5s ease;
}

.a-adv-col:hover .a-adv-photo img {
  transform: scale(1.05);
}

@media (max-width: 900px) {
  .a-adv-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 500px) {
  .a-adv-grid { grid-template-columns: 1fr; }
}

/* ── 按钮组 ── */
.program-button {
  margin-top: 30px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 12px 24px;
  border: 1px solid #111;
  border-radius: 999px;
  background: #111;
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  box-shadow: 0 12px 28px rgba(17, 17, 17, 0.12);
  transition: all 0.3s ease; 
  cursor: pointer;
}

.program-button.secondary {
  background: rgba(255, 255, 255, 0.85); 
  color: #111;
  border-color: rgba(17, 17, 17, 0.12);
  box-shadow: none;
}

/* ── 🌌 携手共创未来：高级渐变蒙层 + HTML 清晰照片版 ── */
.program-b2b {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 40px;
  align-items: center;
  padding: 50px 60px; 
  
  /* ⚠️ 核心修改：删除了原本的 background: url(...) 代码 */
  background-color: #0a142f; /* 设置一个深蓝底色作为加载兜底 */
  
  color: #fff;
  border-radius: 20px;
  overflow: hidden; /* 锁死圆角边界，严防图片溢出 */
  box-shadow: 0 15px 35px rgba(10, 20, 50, 0.12);
  z-index: 1;
}

/* 📸 ✨ 新增：控制 HTML 中背景图片的绝对定位与完美拉伸 */
.b2b-bg-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover; /* 保证图片比例完美，不拉伸变形 */
  object-position: center center;
  z-index: -2; /* 关键：将其塞到最底层，比蒙层还要低 */
}

/* ✨ 局部渐变蒙层：夹在图片与文字中间，完美保护文字 */
.program-b2b::before {
  content: "";
  position: absolute;
  inset: 0;
  
  /* 左侧深邃暗蓝遮罩保护文字，右侧完全透明漏出100%清晰的 HTML 照片 */
  background: linear-gradient(90deg, 
    rgba(14, 24, 55, 0.92) 0%,    
    rgba(14, 24, 55, 0.75) 45%,   
    rgba(14, 24, 55, 0) 100%      
  );
  
  z-index: -1; /* 关键：夹在图片 (-2) 和文字内容 (0) 之间 */
}

/* 标题样式 */
.program-b2b h2 {
  font-size: 26px;
  font-weight: 700;
  color: #ffffff;
  margin: 0;
  letter-spacing: -0.01em;
}

/* 描述文字 */
.program-b2b p {
  margin: 12px 0 0 !important;
  color: rgba(255, 255, 255, 0.85) !important;
  font-size: 15px;
  line-height: 1.75;
}

/* ── 📱 完美移动端响应式适配 ── */
@media (max-width: 768px) {
  .program-b2b {
    grid-template-columns: 1fr !important; 
    text-align: center;
    padding: 40px 24px !important;
    gap: 24px !important;
  }
  
  .b2b-text-content {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  /* 手机端由于文字在上方，蒙层改为“上深下透明” */
  .program-b2b::before {
    background: linear-gradient(180deg, 
      rgba(14, 24, 55, 0.90) 0%, 
      rgba(14, 24, 55, 0.70) 60%, 
      rgba(14, 24, 55, 0) 100%
    ) !important;
  }
}

.btn-icon {
  width: 18px;   
  height: auto;
  margin-left: 10px;
  transition: transform 0.3s ease, filter 0.3s ease;
}

.program-button.secondary:hover, 
.program-button.secondary:active {
  background: #111 !important;
  color: #fff !important;
  border-color: #111;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.program-button.secondary:hover .btn-icon,
.program-button.secondary:active .btn-icon {
  filter: invert(1) brightness(2);
  transform: translateX(3px); 
}