/* ===================================================================
   site.css — AI智站（企业官网重建 / 海外独立站重建 / 站点诊断）
   1) 顶部 Banner 排版（铺满结构在 base.css）
   2) 引擎屏通用：网格、文字、链接
   3) 服务卡片（2 列 / 3 列，浅底与深底两种样式）
   4) 底部联系条
   5) 响应式
   依赖 base.css 的设计变量与通用全屏 Banner
   =================================================================== */

/* ===================================================================
   1. 顶部 Banner 排版
   =================================================================== */
/* 结构（100svh 铺满、居中、页头偏移）由 base.css 提供，这里只写本页背景与文字 */
/* Hero 照片已移到 HTML 的 <picture>（横版 Pexels 12903116 / 竖版 site-hero-m.jpg），
   裁切与焦点样式统一在 base.css 的 .page-hero-img */

/* 左实右透的斜向白色渐变：压白保证文字可读，右侧留出画面 */
.page-hero-mask {
  background:
    linear-gradient(100deg,
      rgba(255,255,255,.94) 0%,
      rgba(255,255,255,.80) 30%,
      rgba(255,255,255,.34) 62%,
      rgba(255,255,255,.10) 100%);
}

.page-hero-title {
  font-size: clamp(32px, 4vw, 54px);
  font-weight: 800;
  line-height: 1.24;
  letter-spacing: -.6px;
  color: var(--c-ink);
  text-shadow: 0 1px 0 rgba(255,255,255,.7);
}
.page-hero-sub {
  margin-top: 20px;
  max-width: 640px;
  font-size: 16.5px;
  line-height: 1.95;
  color: var(--c-ink-soft);
}
.page-hero-actions {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

/* ===================================================================
   2. 引擎屏通用
   =================================================================== */
.engine { position: relative; scroll-margin-top: calc(var(--header-h) + 16px); }

.engine-grid {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 72px;
  align-items: center;
  padding: 118px 0;
}
.engine-grid--reverse .engine-copy   { order: 2; }
.engine-grid--reverse .engine-visual { order: 1; }

.engine-title {
  font-size: clamp(28px, 3vw, 42px);
  font-weight: 800;
  letter-spacing: -.6px;
  color: var(--c-ink);
}
.engine-title::after {
  content: "";
  display: block;
  width: 48px; height: 3px;
  margin-top: 18px;
  border-radius: 3px;
  background: var(--c-accent);
}
.engine-lead {
  margin-top: 20px;
  font-size: 20px;
  font-weight: 600;
  line-height: 1.7;
  color: var(--c-accent-dk);
}
.engine-text {
  margin-top: 16px;
  font-size: 16.5px;
  line-height: 2;
  color: var(--c-text);
}
.engine-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 28px;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--c-accent-dk);
  transition: gap var(--tr), color var(--tr);
}
.engine-link svg { width: 18px; height: 18px; }
.engine-link:hover { gap: 14px; color: var(--c-accent); }

/* 配图统一 16:10 */
.engine-visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: var(--radius-lg);
  background: var(--c-bg-tint);
  box-shadow: var(--sh-md);
}

/* 三屏底色：白 → 深墨绿 → 浅青灰 */
.engine--wall { background: #fff; }
.engine--loop { background: var(--c-bg-alt); }

.engine--funnel {
  background:
    radial-gradient(80% 130% at 78% 22%, rgba(18,165,148,.28) 0%, transparent 62%),
    linear-gradient(100deg, #0F2C26 0%, var(--c-ink) 100%);
}
.engine--funnel .engine-title { color: #fff; }
.engine--funnel .engine-lead  { color: #7FE3D4; }
.engine--funnel .engine-text  { color: rgba(255,255,255,.82); }
.engine--funnel .engine-link  { color: #7FE3D4; }
.engine--funnel .engine-link:hover { color: #fff; }
.engine--funnel .funnel { margin: 0; }
.engine--funnel .funnel img {
  box-shadow: 0 24px 60px rgba(0,0,0,.32);
  border: 1px solid rgba(255,255,255,.10);
}

/* ===================================================================
   3. 服务卡片
   =================================================================== */
.svc-grid {
  display: grid;
  gap: 24px;
  padding-bottom: 132px;      /* 用 padding 而非 margin：避免外边距塌陷截断深色背景 */
}
.svc-grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.svc-grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.svc-card {
  padding: 30px 28px 32px;
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--sh-sm);
  transition: transform var(--tr), box-shadow var(--tr), border-color var(--tr);
}
.svc-card:hover {
  transform: translateY(-5px);
  border-color: transparent;
  box-shadow: var(--sh-md);
}
/* 左侧一道主题色短竖线，和页脚/流程区的视觉语言一致 */
.svc-card::before {
  content: "";
  display: block;
  width: 34px; height: 3px;
  border-radius: 3px;
  background: var(--c-accent);
}
.svc-title { margin-top: 20px; font-size: 18.5px; color: var(--c-ink); }
.svc-text {
  margin-top: 11px;
  font-size: 15px;
  line-height: 1.95;
  color: var(--c-text-mute);
}

/* 深色屏上的卡片 */
.engine--funnel .svc-card {
  background: rgba(255,255,255,.06);
  border-color: rgba(255,255,255,.14);
  box-shadow: none;
}
.engine--funnel .svc-card:hover {
  background: rgba(255,255,255,.10);
  border-color: rgba(127,227,212,.45);
}
.engine--funnel .svc-card::before { background: #7FE3D4; }
.engine--funnel .svc-title { color: #fff; }
.engine--funnel .svc-text  { color: rgba(255,255,255,.72); }

/* ===================================================================
   4. 站点诊断：关键动作（编号卡三栏 + AI 实测强调行）
   =================================================================== */
.diag { padding-bottom: 34px; }
.diag-title {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -.2px;
  color: var(--c-ink);
}
.diag-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}
.diag-item {
  padding: 22px 22px 24px;
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--sh-sm);
  transition: transform var(--tr), box-shadow var(--tr), border-color var(--tr);
}
.diag-item:hover {
  transform: translateY(-4px);
  border-color: transparent;
  box-shadow: var(--sh-md);
}

.diag-num {
  display: inline-block;
  font-size: 14px;
  font-weight: 800;
  letter-spacing: .5px;
  color: var(--c-accent);
  font-variant-numeric: tabular-nums;
}
.diag-num::after {
  content: "";
  display: block;
  width: 22px; height: 2px;
  margin-top: 6px;
  border-radius: 2px;
  background: var(--c-accent);
  opacity: .45;
}
.diag-item-title {
  margin-top: 12px;
  font-size: 17px;
  font-weight: 700;
  color: var(--c-ink);
}
.diag-text {
  margin-top: 8px;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--c-text-mute);
}

/* 第 07 条：AI 实测是压轴动作，单独占满一行并做浅色强调 */
.diag-item--wide {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 26px;
  align-items: start;
  background: linear-gradient(100deg, #E9F6F3 0%, #F7FBFA 72%);
  border-color: transparent;
}
.diag-item--wide .diag-item-title { margin-top: 15px; }
.diag-item--wide .diag-text { margin-top: 6px; }
.diag-notes { padding-top: 22px; }

/* ===================================================================
   5. 底部联系条
   =================================================================== */
.band {
  padding: 72px 0;
  background:
    radial-gradient(90% 140% at 12% 20%, rgba(18,165,148,.26) 0%, transparent 62%),
    linear-gradient(100deg, #0F2C26 0%, var(--c-ink) 100%);
}
.band-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  flex-wrap: wrap;
}
.band-text h2 { font-size: 28px; color: #fff; }
.band-text p {
  margin-top: 12px;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(255,255,255,.72);
}
.band-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* ===================================================================
   6. 响应式
   =================================================================== */
@media (max-width: 1080px) {
  .engine-grid { grid-template-columns: 1fr; gap: 40px; padding: 92px 0; }
  .engine-grid--reverse .engine-copy   { order: 0; }
  .engine-grid--reverse .engine-visual { order: 0; }
  .svc-grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .svc-grid { padding-bottom: 92px; }
  .diag { padding-bottom: 26px; }
  .diag-list { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
}

@media (max-width: 900px) {
  .page-hero-sub { font-size: 15.5px; }
  .engine-grid { padding: 72px 0; }
  .engine-lead { font-size: 18px; }
  .engine-text { font-size: 15.5px; line-height: 1.95; }
  .svc-grid { padding-bottom: 72px; gap: 20px; }
  .diag { padding-bottom: 20px; }
  .diag-title { font-size: 20px; }
  .diag-item { padding: 18px 18px 20px; }
  .diag-item-title { font-size: 16px; }
  .band-text h2 { font-size: 24px; }
}

@media (max-width: 640px) {
  .svc-grid--2,
  .svc-grid--3 { grid-template-columns: 1fr; gap: 16px; }
  .diag-list { grid-template-columns: 1fr; gap: 14px; }
  .diag-item { padding: 16px 16px 18px; }
  .diag-text { font-size: 14px; }
  .svc-card { padding: 24px 20px 26px; }
  .svc-title { font-size: 17px; }
  .band { padding: 56px 0; }
  .band-actions .btn { width: 100%; }
}

@media (max-width: 520px) {
  .engine-title { font-size: 26px; }
  .engine-lead { font-size: 17px; }
}