/* ================= AI 智能制造自动化 aismart.html 专用样式 ================= */
:root {
  --ai-bg: #f5f8fc;
  --ai-card: #ffffff;
  --ai-line: #e3ecff;
  --ai-blue: #2563eb;
  --ai-cyan: #06b6d4;
  --ai-grad: linear-gradient(135deg, #2563eb, #06b6d4);
  --ai-text: #1f2937;
  --ai-sub: #64748b;
  --radius: 18px;
}
body {
  background: var(--ai-bg);
  color: var(--ai-text);
}

/*---------- 首屏轮播文字 ----------*/
#hero .swiper-item::after {
  content: "";
  position: absolute;
  top: 0; right: 0; bottom: 0; left: 0;
  background: linear-gradient(to top, rgba(2, 10, 40, .62), rgba(2, 10, 40, .18) 55%, rgba(2,10,40,.25));
  pointer-events: none;
}
#hero .swiper-text { z-index: 2; }
#hero .swiper-text h1 {
  color: #fff;
  text-shadow: 0 2px 18px rgba(0,0,0,.5), 0 0 30px rgba(37,99,235,.45);
  letter-spacing: 3px;
}
#hero .swiper-text p { color: rgba(255,255,255,.95); text-shadow: 0 1px 10px rgba(0,0,0,.45); }

/*---------- 智能导航条 ----------*/
.ai-nav-wrap {
  padding: 0 0 84px;
  position: relative;
  z-index: 3;
}
.ai-nav {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin-top: -64px;           /* 上浮压在 hero 上沿，形成层次 */
  position: relative;
}
@media (min-width: 768px) { .ai-nav { grid-template-columns: repeat(3, 1fr); } }
.ai-nav-card {
  background: var(--ai-card);
  border: 1px solid var(--ai-line);
  border-radius: 16px;
  padding: 22px 24px;
  text-decoration: none;
  color: var(--ai-text);
  box-shadow: 0 12px 34px rgba(15, 23, 42, .10);
  display: flex;
  flex-direction: column;
  gap: 6px;
  position: relative;
  overflow: hidden;
  transition: transform .25s ease, box-shadow .25s ease;
}
.ai-nav-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--ai-grad);
  opacity: 0;
  transition: opacity .25s ease;
}
.ai-nav-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 40px rgba(37, 99, 235, .16);
}
.ai-nav-card:hover::before { opacity: 1; }
.ai-nav-num {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 2px;
  background: var(--ai-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.ai-nav-t { font-size: 18px; font-weight: 700; letter-spacing: 1px; }
.ai-nav-d { font-size: 13px; color: var(--ai-sub); }

/*---------- 板块通用 ----------*/
.ai-board { padding: 84px 0 96px; }
.ai-board.alt { background: var(--ai-card); border-top: 1px solid var(--ai-line); }
.board-head { text-align: center; margin-bottom: 52px; }
.board-tag {
  display: inline-block;
  padding: 4px 16px;
  border-radius: 999px;
  background: rgba(37, 99, 235, .08);
  color: var(--ai-blue);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 2px;
  margin-bottom: 14px;
}
.board-head h2 {
  font-size: 34px;
  font-weight: 800;
  letter-spacing: 2px;
  color: var(--ai-text);
}
@media (min-width: 768px) { .board-head h2 { font-size: 40px; } }
.board-head h2 em {
  font-style: normal;
  background: var(--ai-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.board-head > p {
  margin-top: 14px;
  color: var(--ai-sub);
  font-size: 15px;
  letter-spacing: 1px;
  max-width: 720px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.8;
}

/*---------- 板块主体：图 + 文案 ----------*/
.board-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  align-items: center;
}
@media (min-width: 960px) {
  .board-body { grid-template-columns: 46% 1fr; gap: 52px; }
  .ai-board.reverse .board-body { grid-template-columns: 1fr 46%; }
  .ai-board.reverse .board-media { order: 2; }
}
.board-media {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid #d6e4ff;
  box-shadow: 0 18px 44px rgba(37, 99, 235, .16);
}
.board-media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  display: block;
  transition: transform .5s ease;
}
.ai-board:hover .board-media img { transform: scale(1.03); }
.board-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(2, 10, 40, .28), transparent 55%);
  pointer-events: none;
}

/*---------- 文案与优势 ----------*/
.board-content h3 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--ai-text);
  position: relative;
  padding-bottom: 14px;
}
.board-content h3::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 52px;
  height: 3px;
  border-radius: 3px;
  background: var(--ai-grad);
}
.board-content > p {
  margin-top: 18px;
  color: var(--ai-sub);
  font-size: 15px;
  line-height: 1.9;
  letter-spacing: .5px;
}
.board-adv {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}
@media (min-width: 600px) { .board-adv { grid-template-columns: 1fr 1fr; } }
.adv-item {
  background: #f6f9ff;
  border: 1px solid #e3ecff;
  border-radius: 14px;
  padding: 16px 16px 14px;
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s;
}
.adv-item:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 26px rgba(37, 99, 235, .12);
  border-color: #bcd0ff;
}
.adv-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--ai-grad);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 10px;
  box-shadow: 0 6px 14px rgba(37, 99, 235, .28);
}
.adv-icon svg { width: 20px; height: 20px; }
.adv-item h4 {
  font-size: 15px;
  font-weight: 700;
  color: var(--ai-text);
  letter-spacing: .5px;
}
.adv-item p {
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ai-sub);
}

/*---------- 板块底部标签条 ----------*/
.board-tags {
  margin-top: 40px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.board-tags span {
  padding: 6px 16px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid #d6e4ff;
  color: #2563eb;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 1px;
}

/*---------- 板块视频：懒加载 + 鼠标悬浮播放 ----------*/
.board-media {
  position: relative;
  overflow: hidden;
}
.board-poster {
  position: relative;
  z-index: 1;
  transition: opacity .45s ease;
}
.board-video {
  position: absolute;
  inset: 0;
  z-index: 2;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  visibility: hidden;
  transition: opacity .45s ease, visibility .45s ease;
  background: #0b1b3d;
}
/* 悬浮播放状态：视频淡入盖住封面图 */
.board-media.video-playing .board-video {
  opacity: 1;
  visibility: visible;
}
.board-media.video-playing .board-poster {
  opacity: 0;
}