/* ================================================================
   CSS Variables & Reset
================================================================ */
:root {
  --blue: #1a5ee8;
  --blue-d: #0d38c0;
  --blue-deep: #0c2a9e;
  --text-dark: #0c1830;
  --text-gray: #666;
  --text-lt: #999;
  --bg-gray: #f4f6fb;
  --bg-white: #fff;
  --max-w: 1200px;
  --nav-h: 64px;
}
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  font-family: 'Microsoft YaHei', '微软雅黑', 'PingFang SC', Arial, sans-serif;
  color: #333;
  overflow-x: hidden;
  line-height: 1;
}
a {
  text-decoration: none;
  color: inherit;
}
img {
  display: block;
  max-width: 100%;
}
ul {
  list-style: none;
}

/* ================================================================
   Scroll-reveal  (NGC-style: fade + translateY)
================================================================ */
[data-sr] {
  opacity: 0;
  transform: translateY(44px);
  transition:
    opacity 0.85s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.85s cubic-bezier(0.16, 1, 0.3, 1);
}
[data-sr].sr-visible {
  opacity: 1;
  transform: translateY(0);
}
[data-sr-d='1'] {
  transition-delay: 0.1s;
}
[data-sr-d='2'] {
  transition-delay: 0.2s;
}
[data-sr-d='3'] {
  transition-delay: 0.3s;
}
[data-sr-d='4'] {
  transition-delay: 0.4s;
}
[data-sr-d='5'] {
  transition-delay: 0.5s;
}
.f14 {
  font-size: 14px;
}
.f16 {
  font-size: 16px;
}

/* ================================================================
   Navigation
================================================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 800;
  height: var(--nav-h);
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(12px);
  box-shadow:
    0 1px 0 rgba(0, 0, 0, 0.07),
    0 4px 24px rgba(0, 0, 0, 0.04);
  display: flex;
  align-items: center;
  transition:
    background 0.35s,
    box-shadow 0.35s,
    backdrop-filter 0.35s;
}
.nav.nav-transparent {
  background: transparent;
  backdrop-filter: none;
  box-shadow: none;
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  width: 100%;
  padding: 0 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
}
.nav-logo img {
  height: 34px;
  width: auto;
}

.nav-menu {
  display: flex;
  gap: 40px;
  align-items: center;
}
.nav-item {
  position: relative;
}
.nav-item > a {
  font-size: 14px;
  color: #444;
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 22px 0 20px;
  position: relative;
  transition: color 0.22s;
  white-space: nowrap;
}
.nav-item > a::after {
  content: '';
  position: absolute;
  bottom: 14px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--blue);
  border-radius: 1px;
  transform: scaleX(0);
  transition: transform 0.22s;
}
.nav-item > a.active,
.nav-item:hover > a {
  color: var(--blue);
}
.nav-item > a.active::after,
.nav-item:hover > a::after {
  transform: scaleX(1);
}

.nav-arrow {
  display: inline-block;
  width: 0;
  height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 5px solid currentColor;
  transition: transform 0.22s;
  margin-top: 1px;
}
.nav-item:hover .nav-arrow {
  transform: rotate(180deg);
}

/* dropdown */
.dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(-6px);
  background: #fff;
  border-radius: 8px;
  min-width: 148px;
  padding: 8px 0;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.12);
  opacity: 0;
  visibility: hidden;
  transition:
    opacity 0.2s,
    transform 0.2s,
    visibility 0.2s;
  z-index: 900;
}
.nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}
.dropdown::before {
  content: '';
  position: absolute;
  top: -6px;
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top: 0;
  border-bottom-color: #fff;
}
.dropdown a {
  display: block;
  padding: 10px 20px;
  font-size: 13px;
  color: #555;
  transition:
    background 0.15s,
    color 0.15s;
  white-space: nowrap;
}
.dropdown a:hover {
  background: #f0f5ff;
  color: var(--blue);
}

/* ================================================================
   共用 Footer
================================================================ */
.footer {
  background: #0e1928;
  color: rgba(255, 255, 255, 0.5);
  padding: 44px 0 28px;
  text-align: center;
}
.footer p {
  margin-bottom: 10px;
}
.footer-phone-label {
  font-family:
    PingFang SC,
    PingFang SC;
  font-weight: 400;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 22px;
  text-align: center;
  font-style: normal;
  text-transform: none;
}
.footer-phone {
  font-family:
    PingFang SC,
    PingFang SC;
  font-weight: 400;
  font-size: 16px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 22px;
  text-align: center;
  font-style: normal;
  text-transform: none;
}
.footer-addr-label {
  font-family:
    PingFang SC,
    PingFang SC;
  font-weight: 400;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 22px;
  text-align: center;
  font-style: normal;
  text-transform: none;
}
.footer-addr {
  font-family:
    PingFang SC,
    PingFang SC;
  font-weight: 400;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 22px;
  text-align: center;
  font-style: normal;
  text-transform: none;
}
.footer-copy {
  font-family:
    PingFang SC,
    PingFang SC;
  font-weight: 400;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 22px;
  text-align: center;
  font-style: normal;
  text-transform: none;
}

/* ================================================================
   面包屑
================================================================ */
.breadcrumb {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 14px 48px;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: #888;
}
.breadcrumb a {
  color: #888;
  transition: color 0.2s;
}
.breadcrumb a:hover {
  color: var(--blue);
}
.breadcrumb span {
  color: #bbb;
}
.breadcrumb-home {
  font-size: 16px;
}

/* ================================================================
   页面顶部 Banner（非首页）
================================================================ */
.page-banner {
  height: 300px;
  background: linear-gradient(135deg, #e8eeff 0%, #d4e4ff 100%);
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  margin-top: var(--nav-h);
}
.page-banner img.banner-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.18;
}
.page-banner-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 48px;
  position: relative;
  z-index: 2;
  width: 100%;
}
.page-banner h1 {
  font-size: 40px;
  font-weight: 800;
  color: var(--text-dark);
  margin-bottom: 10px;
}
.page-banner p {
  font-size: 15px;
  color: var(--text-gray);
}

/* ================================================================
   Section 公用
================================================================ */
.sec {
  padding: 88px 0;
}
.sec-bg {
  background: var(--bg-gray);
}
.sec-dark {
  background: #0d1a30;
}
.sec-center {
  text-align: center;
}
.sec-wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 48px;
}

.sec-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 8px;
}
.sec-dark .sec-title {
  color: #fff;
}
.sec-en {
  font-size: 12px;
  color: #c0c8d8;
  text-transform: uppercase;
  margin-bottom: 52px;
}
.sec-dark .sec-en {
  color: rgba(255, 255, 255, 0.3);
}

/* head row（标题左 + 链接右）*/
.sec-head-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 44px;
}
.sec-head-row .sec-title {
  margin-bottom: 6px;
}
.sec-more {
  font-size: 13px;
  color: var(--blue);
  display: flex;
  align-items: center;
  gap: 6px;
  transition: gap 0.2s;
}
.sec-more:hover {
  gap: 12px;
}

/* 通用按钮（跨页使用） */
.biz-item-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--blue);
  color: #fff;
  padding: 10px 22px;
  border-radius: 4px;
  font-size: 13px;
  transition:
    background 0.2s,
    gap 0.2s;
  margin-bottom: 16px;
}
.biz-item-btn:hover {
  background: var(--blue-d);
  gap: 14px;
}

/* ================================================================
   PC 专用：右下角回到顶部（按钮仅在大屏由 JS 插入，样式亦仅在此断点生效）
================================================================ */
@media (min-width: 992px) {
  .back-to-top {
    display: flex;
    align-items: center;
    justify-content: center;
    position: fixed;
    right: 28px;
    bottom: 40px;
    z-index: 950;
    width: 44px;
    height: 44px;
    padding: 0;
    border: none;
    border-radius: 50%;
    background: var(--blue);
    color: #fff;
    cursor: pointer;
    box-shadow: 0 4px 14px rgba(26, 94, 232, 0.35);
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
    transition:
      opacity 0.25s ease,
      visibility 0.25s ease,
      transform 0.25s ease,
      background 0.2s;
  }
  .back-to-top.is-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
  .back-to-top:hover {
    background: var(--blue-d);
    box-shadow: 0 6px 18px rgba(26, 94, 232, 0.45);
  }
  .back-to-top:focus-visible {
    outline: 2px solid var(--blue);
    outline-offset: 3px;
  }
  .back-to-top svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
  }
}