/* ==========================================================================
   千匠 · 汽车汽配解决方案页  AI 模块（新增 / 替换）
   --------------------------------------------------------------------------
   1. 依赖站点公共变量：--color(#277fff) --gray(#f6f6f6) --big-title --big-desc
      --small-title --small-desc（来自 ../../css/20260411/public.css）
   2. 全部类名以 ai- 前缀，避免与站内既有样式冲突
   3. 断点与站内保持一致：1200 / 1000 / 768
   4. 深色区块使用 .ai-stack-title / .ai-stack-desc 而非 .section-title /
      .section-desc —— 因为 public.css 对后者写了 color:#000 !important
   ========================================================================== */

/* ============ 通用 ============ */
.ai-sec .container,
.ai-stack .container {
  text-align: left;
}
.ai-sec .section-title,
.ai-sec .section-desc {
  text-align: center;
}

/* ============ 模块一：AI 赋能 · 双链路场景（浅灰底） ============ */
.ai-lanes {
  margin-top: 52px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.ai-lane {
  background: #fff;
  border: 1px solid rgba(39, 127, 255, 0.1);
  border-radius: 16px;
  padding: 30px 30px 24px;
  box-shadow: 0 10px 34px -22px rgba(15, 45, 90, 0.28);
  display: flex;
  flex-direction: column;
}

.ai-lane-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding-bottom: 18px;
  margin-bottom: 8px;
  border-bottom: 1px dashed rgba(0, 0, 0, 0.09);
}

.ai-lane-tag {
  flex: none;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: #fff;
  background: var(--color);
  border-radius: 999px;
  padding: 4px 12px;
}
.ai-lane:nth-child(2) .ai-lane-tag {
  background: #0f172a;
}

.ai-lane-head h3 {
  font-size: 22px;
  font-weight: 700;
  color: #0f172a;
  margin: 0;
  letter-spacing: 0.2px;
}

.ai-lane-head span.ai-lane-for {
  font-size: 14px;
  color: #333;
  opacity: 0.55;
}

.ai-cards {
  display: flex;
  flex-direction: column;
}

.ai-card {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 14px;
  align-items: start;
  padding: 16px 0;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}
.ai-card:last-child {
  border-bottom: 0;
  padding-bottom: 4px;
}

.ai-card-icon {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  background: linear-gradient(140deg, #eef4ff 0%, #e2ecff 100%);
  color: var(--color);
}
.ai-card-icon svg {
  width: 22px;
  height: 22px;
  display: block;
}

.ai-card h4 {
  margin: 0 0 5px;
  font-size: 18px;
  font-weight: 600;
  color: #0f172a;
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px;
}

.ai-card-out {
  flex: none;
  font-size: 12px;
  font-weight: 500;
  color: var(--color);
  background: rgba(39, 127, 255, 0.09);
  border-radius: 5px;
  padding: 3px 8px;
  letter-spacing: 0.2px;
}

.ai-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: #333;
  opacity: 0.78;
}


/* ============ 模块二：技术底座 星云 + 智元 + 星枢（深色） ============ */
.section.ai-stack {
  position: relative;
  overflow: hidden;
  padding: 88px 0;
  text-align: center;
  color: #fff;
  background: #0b1220;
  background-image:
    radial-gradient(
      900px 420px at 18% -8%,
      rgba(39, 127, 255, 0.28),
      transparent 62%
    ),
    radial-gradient(
      760px 400px at 88% 108%,
      rgba(39, 127, 255, 0.16),
      transparent 60%
    ),
    linear-gradient(180deg, #0b1220 0%, #101a2e 52%, #0b1220 100%);
}
/* 细网格纹理，避免大面积纯色 */
.section.ai-stack::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(
      rgba(255, 255, 255, 0.035) 1px,
      transparent 1px
    ),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(
    72% 62% at 50% 42%,
    #000 0%,
    transparent 100%
  );
  mask-image: radial-gradient(72% 62% at 50% 42%, #000 0%, transparent 100%);
  pointer-events: none;
}
.section.ai-stack > .container {
  position: relative;
  z-index: 1;
  text-align: left;
}

.ai-eyebrow {
  display: block;
  width: -moz-fit-content;
  width: fit-content;
  margin: 0 auto 20px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 3px;
  color: #7fb2ff;
  border: 1px solid rgba(127, 178, 255, 0.32);
  border-radius: 999px;
  padding: 5px 16px;
  margin-bottom: 20px;
}

.ai-stack-title {
  margin: 0 auto 20px;
  font-size: var(--big-title);
  line-height: 1.42;
  font-weight: 700;
  letter-spacing: 0.2px;
  color: #fff;
  text-align: center;
}
.ai-stack-title em {
  font-style: normal;
  color: #6ba6ff;
}

.ai-stack-desc {
  width: 1200px;
  max-width: 100%;
  margin: 0 auto;
  text-align: center;
  font-size: var(--big-desc);
  line-height: 1.9;
  color: rgba(255, 255, 255, 0.68);
}

/* --- 五层架构栈 --- */
.ai-stack-diagram {
  margin: 50px auto 0;
  max-width: 1080px;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.ai-layer {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
  padding: 17px 26px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.11);
  background: rgba(255, 255, 255, 0.045);
  backdrop-filter: blur(2px);
}
.ai-layer-meta {
  display: flex;
  align-items: baseline;
  gap: 14px;
  flex-wrap: wrap;
  min-width: 260px;
}
.ai-layer-meta span {
  font-size: 13px;
  letter-spacing: 1px;
  color: rgba(255, 255, 255, 0.5);
}
.ai-layer-meta b {
  font-size: 19px;
  font-weight: 700;
  color: #fff;
}
.ai-layer-tags {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.6);
  text-align: right;
  flex: 1;
  min-width: 220px;
}

.ai-layer--scene {
  border-color: rgba(107, 166, 255, 0.4);
  background: linear-gradient(
    100deg,
    rgba(39, 127, 255, 0.22) 0%,
    rgba(39, 127, 255, 0.06) 100%
  );
}
.ai-layer--agent {
  border-color: rgba(107, 166, 255, 0.3);
  background: rgba(39, 127, 255, 0.1);
}
.ai-layer--base {
  border-color: rgba(107, 166, 255, 0.24);
  background: rgba(39, 127, 255, 0.06);
}
.ai-layer--model {
  background: rgba(255, 255, 255, 0.035);
}
.ai-layer--exist {
  border-style: dashed;
  border-color: rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.02);
}
.ai-layer--exist .ai-layer-meta b {
  color: rgba(255, 255, 255, 0.58);
  font-weight: 600;
}

.ai-flow {
  align-self: center;
  width: 1px;
  height: 18px;
  background: linear-gradient(
    180deg,
    rgba(107, 166, 255, 0.6),
    rgba(107, 166, 255, 0.15)
  );
  position: relative;
}
.ai-flow::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -1px;
  transform: translateX(-50%);
  width: 0;
  height: 0;
  border-left: 3.5px solid transparent;
  border-right: 3.5px solid transparent;
  border-top: 5px solid rgba(107, 166, 255, 0.55);
}

/* ============ 响应式 ============ */
@media screen and (max-width: 1200px) {
  .ai-lanes {
    gap: 22px;
  }
  .ai-lane {
    padding: 26px 22px 20px;
  }
  .ai-layer-tags {
    text-align: left;
    flex-basis: 100%;
  }
}

@media screen and (max-width: 1000px) {
  .ai-lanes {
    grid-template-columns: 1fr;
  }
  .ai-stack-diagram {
    margin-top: 38px;
  }
}

@media screen and (max-width: 768px) {
  .section.ai-stack {
    padding: 60px 0;
  }
  .ai-lane-head h3 {
    font-size: 19px;
  }
  .ai-card {
    grid-template-columns: 40px 1fr;
    gap: 12px;
  }
  .ai-card-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
  }
  .ai-card-icon svg {
    width: 19px;
    height: 19px;
  }
  .ai-card h4 {
    font-size: 16.5px;
  }
  .ai-card p {
    font-size: 14px;
  }
  .ai-layer {
    padding: 15px 18px;
  }
  .ai-layer-meta {
    min-width: 0;
  }
  .ai-layer-meta b {
    font-size: 17px;
  }
  .ai-layer-tags {
    font-size: 13px;
  }
}