/* ========================================
   主色调：红色 #d7271b | 蓝色：#00a3e4 
   ======================================== */

/* Reset */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: "Microsoft YaHei", "微软雅黑", Arial, sans-serif; color: #333; line-height: 1.6; overflow-x: hidden; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }
img { max-width: 100%; display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

.container { width: 100%; max-width: 1600px; margin: 0 auto; padding: 0 7.8125%; }
.container--narrow { max-width: 1400px; }

/* ========================================
   Header
   ======================================== */
.header { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; background: #fff; transition: transform 0.3s, box-shadow 0.3s; }
.header.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.06); }
.header.hidden { transform: translateY(-100%); }

.header__content { display: flex; align-items: center; height: 100px; max-width: 1600px; margin: 0 auto; padding: 0 7.8125%; position: relative; }

.header__logo { flex-shrink: 0; }
.header__logo img { height: 74px; }

.header__nav { flex: 1; display: flex; justify-content: flex-start; align-items: center; margin-right: 20px; }
.nav__list { display: flex; align-items: center; }
.nav__item { position: relative; min-width: 100px; height: 100px; line-height: 100px; text-align: center; }
.nav__item > a { display: block; font-size: 16px; color: #da251c; transition: color 0.3s; font-family: "Microsoft YaHei", "微软雅黑", sans-serif; }
.nav__item > a:hover{ color: rgba(0, 163, 228, 1); }
.nav__item.active > a { color: #da251c; }

.nav__item--dropdown { position: relative; }
.nav__item--dropdown > a::after { content: ''; display: inline-block; width: 10px; height: 6px; margin-left: 4px; background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 10 6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%23212121'/%3E%3C/svg%3E") no-repeat center; background-size: contain; vertical-align: middle; transition: transform 0.3s; }
.nav__item--dropdown:hover > a::after { transform: rotate(180deg); }

.dropdown { position: absolute; top: 100%; left: 50%; transform: translateX(-50%); min-width: 130px; background: #fff; box-shadow: 0 6px 24px rgba(0,0,0,0.12); border-radius: 0 0 6px 6px; opacity: 0; visibility: hidden; transition: opacity 0.3s, visibility 0.3s; z-index: 100; padding: 8px 0; }
.nav__item--dropdown:hover .dropdown { opacity: 1; visibility: visible; }
.dropdown__item { }
.dropdown__item a { display: block; padding: 10px 24px; font-size: 14px; color: #555; white-space: nowrap; line-height: 1.4; transition: color 0.3s, background 0.3s; }
.dropdown__item a:hover { color: rgba(82, 90, 158, 1); background: #f5f6fa; }
.dropdown__item--sub { position: relative; }
.dropdown__item--sub > a::after { content: '›'; margin-left: 6px; font-size: 16px; }
.dropdown__sub { position: absolute; left: 100%; top: 0; min-width: 130px; background: #fff; box-shadow: 0 6px 24px rgba(0,0,0,0.12); border-radius: 6px; opacity: 0; visibility: hidden; transition: opacity 0.3s, visibility 0.3s; padding: 8px 0; }
.dropdown__item--sub:hover .dropdown__sub { opacity: 1; visibility: visible; }

.header__actions { display: flex; align-items: center; gap: 20px; flex-shrink: 0; }
.header__search { width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; }
.header__search svg { width: 22px; height: 22px; fill: #555; transition: fill 0.3s; }
.header__search:hover svg { fill: rgba(82, 90, 158, 1); }

.header__phone { display: flex; align-items: center; }
.header__phone img { height: 40px; }

/* Hamburger menu (mobile) */
.hamburger { display: none; flex-direction: column; justify-content: center; width: 30px; height: 30px; cursor: pointer; z-index: 1001; }
.hamburger span { display: block; width: 30px; height: 3px; background: #333; margin: 3px 0; transition: all 0.3s; border-radius: 2px; }
.hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(6px, 6px); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(6px, -6px); }

/* Mobile nav - desktop hidden */
.mobile-nav,
.mobile-nav-overlay {
  display: none;
}

/* ========================================
   顶部轮播图
   ======================================== */
.banner { position: relative; width: 100%; height: calc(100vh - 100px); margin-top: 100px; overflow: hidden; }
.banner__slides { display: flex; height: 100%; transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1); }
.banner__slide { min-width: 100%; height: 100%; background-size:cover; background-position: center; position: relative; }
.banner__slide:nth-child(1) { background-image: url('../images/banner1.jpg'); }
.banner__slide:nth-child(2) { background-image: url('../images/banner2.jpg'); }
.banner__slide:nth-child(3) { background-image: url('../images/banner3.jpg'); }
.banner__slide:nth-child(4) { background-image: url('../images/banner4.jpg'); }

.banner__arrows { }
.banner__arrow { position: absolute; top: 50%; transform: translateY(-50%); width: 50px; height: 50px; background: rgba(255,255,255,0.2); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; font-size: 24px; backdrop-filter: blur(4px); transition: background 0.3s; z-index: 10; }
.banner__arrow:hover { background: rgba(30, 80, 174, 0.6); }
.banner__arrow--prev { left: 30px; }
.banner__arrow--next { right: 30px; }

.banner__dots { position: absolute; bottom: 30px; left: 50%; transform: translateX(-50%); display: flex; gap: 10px; z-index: 10; }
.banner__dot { width: 12px; height: 12px; border-radius: 50%; background: rgba(255,255,255,0.4); cursor: pointer; transition: background 0.3s, transform 0.3s; }
.banner__dot.active { background: #fff; transform: scale(1.2); }

/* ========================================
   四个快速方框
   ======================================== */
.quick-entry { padding: 0; background: #fff; margin-top:15px;}
.quick-entry__grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; max-width: 100%; }
.quick-entry__card { position: relative; overflow: hidden; cursor: pointer; aspect-ratio: 386 / 231; margin:10px;border-radius: 8px;}
.quick-entry__card img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.quick-entry__card:hover img { transform: scale(1.15); }
.quick-entry__card::after { content: ''; position: absolute; inset: 0; background: linear-gradient(to top, rgba(0,0,0,0.45), transparent 60%); }

/* ========================================
   关于我们
   ======================================== */
.about { padding: 50px 0; background: #fff; }
.about__row { display: flex; gap: 10px; align-items: flex-start; }
.about__video { flex: 0 0 55%; position: relative; border-radius: 8px; overflow: hidden; box-shadow: 0 8px 40px rgba(0,0,0,0.1); }
.about__video video { width: 100%; display: block; border-radius: 8px; }
.about__video-poster { position: relative; cursor: pointer; }
.about__video-poster img { width: 100%; display: block; }
.about__video-play { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 70px; height: 70px; background: rgba(255,255,255,0.85); border-radius: 50%; display: flex; align-items: center; justify-content: center; transition: background 0.3s; }
.about__video-play::before { content: ''; display: block; width: 0; height: 0; border-left: 22px solid rgba(82, 90, 158, 1); border-top: 13px solid transparent; border-bottom: 13px solid transparent; margin-left: 4px; }
.about__video-poster:hover .about__video-play { background: rgba(30, 80, 174, 0.9); }
.about__video-poster:hover .about__video-play::before { border-left-color: #fff; }

.about__info { flex: 1; padding-top: 0px; padding-left:50px;}
.about__title { font-size: 36px; font-weight: bold; color: #1f2981; margin-bottom: 12px; }
.about__divider { width: 75px; height: 7px; margin-bottom: 24px; }
.about__divider img { width: 100%; }
.about__text { font-size: 14px; color: #0c0f30; line-height: 2; margin-bottom: 36px; }
.about__btn { display: inline-block; padding: 16px 52px; background: rgba(82, 90, 158, 1); color: #fff; font-size: 14px; border-radius: 29px; transition: background 0.3s, transform 0.3s; font-family: "Microsoft YaHei", sans-serif; }
.about__btn:hover { background: #1e50ae; transform: translateY(-2px); }

/* ========================================
   正和项目
   ======================================== */
.projects { padding-top:80px;background: #fff; }
.projects__header { text-align: center; margin-bottom: 36px; }
.projects__title { font-size: 36px; font-weight: bold; color: #d7271b; letter-spacing: 0.2em;}
.projects__subtitle { font-size: 16px; color: #999; margin-top: 4px; letter-spacing: 2px; }

.projects__tabs { display: flex; justify-content: center; gap: 0; margin-bottom: 24px; }
.projects__tab { padding: 12px 36px; font-size: 14px; border: 1px solid #dedede; cursor: pointer; transition: all 0.3s; font-family: "Microsoft YaHei", sans-serif; background: #fff; color: #333; }
.projects__tab:first-child { border-radius: 4px 0 0 4px; }
.projects__tab:last-child { border-radius: 0 4px 4px 0; }
.projects__tab.active { background: rgba(82, 90, 158, 1); color: #fff; border-color: rgba(82, 90, 149, 1); }
.projects__tab:hover:not(.active) { color: rgba(82, 90, 158, 1); }

.projects__content { }
.projects__panel { display: none; }
.projects__panel.active { display: flex; gap: 40px; align-items: flex-start;}
.projects__panel-image { flex: 0 0 50%; border-radius: 8px; overflow: hidden; }
.projects__panel-image img { width: 100%; display: block; transition: transform 0.5s; }
.projects__panel-image:hover img { transform: scale(1.10); }
.projects__panel-info { flex: 1; }
.projects__panel-name { font-size: 24px; font-weight: bold; color: #00a3e4; margin-bottom: 4px; }
.projects__panel-eng { font-size: 14px; color: #999; margin-bottom: 20px; }
.projects__panel-desc { font-size: 16px; color: #333; line-height: 1.9; margin-bottom: 28px; }
.projects__panel-link { color: #303183; font-size: 14px; font-weight: bold; transition: color 0.3s; }
.projects__panel-link:hover { color: #1e50ae; }

/* ========================================
   新闻动态
   ======================================== */
.news { padding: 100px 0 80px; background: #f7f7f7; }
.news__header { text-align: center; margin-bottom: 36px; }
.news__title { font-size: 36px; font-weight: bold; color: #d7271b; letter-spacing: 0.2em;}
.news__subtitle { font-size: 16px; color: rgba(48, 49, 131, 0.5); margin-top: 4px; letter-spacing: 3px; }

.news__grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.news__card { background: #fff; border-radius: 6px; overflow: hidden; transition: transform 0.3s, box-shadow 0.3s; }
.news__card:hover { transform: translateY(-6px); box-shadow: 0 12px 36px rgba(0,0,0,0.1); }
.news__card-img { aspect-ratio: 16 / 10; overflow: hidden; }
.news__card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s; }
.news__card:hover .news__card-img img { transform: scale(1.05); }
.news__card-body { padding: 20px; }
.news__card-title { font-size: 16px; font-weight: bold; color: #00a3e4; line-height: 1.5; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; margin-bottom: 10px; transition: color 0.3s; }
.news__card-title:hover { color: #d7271b; }
.news__card-summary { font-size: 13px; color: #888; line-height: 1.7; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; margin-bottom: 14px; }
.news__card-meta { display: flex; justify-content: space-between; align-items: center; }
.news__card-tag { font-size: 12px; color: rgba(82, 90, 158, 1); background: rgba(82, 90, 158, 0.08); padding: 3px 10px; border-radius: 3px; }
.news__card-date { font-size: 12px; color: #bbb; }

/* ========================================
   Footer
   ======================================== */
.footer { background: #fff; padding: 24px 0; text-align: center; border-top: 1px solid #f0f0f0; }
.footer__copyright { font-size: 13px; color: #999; }
.footer__links { font-size: 13px; color: #999; margin-top: 6px; }
.footer__links a { color: #999; transition: color 0.3s; }
.footer__links a:hover { color: rgba(82, 90, 158, 1); }
.footer__links span { margin: 0 6px; }

/* ========================================
   Search Overlay
   ======================================== */
.search-overlay { position: fixed; inset: 0; z-index: 2000; display: flex; align-items: flex-start; justify-content: center; opacity: 0; visibility: hidden; transition: opacity 0.3s, visibility 0.3s; }
.search-overlay.open { opacity: 1; visibility: visible; }
.search-overlay__bg { position: absolute; inset: 0; background: rgba(0,0,0,0.6); }
.search-overlay__content { position: relative; z-index: 1; width: 800px; max-width: 90vw; background: #fff; margin-top: 100px; padding: 40px; border-radius: 8px; }
.search-overlay__input { width: 100%; padding: 14px 20px; font-size: 18px; border: 2px solid #eee; border-radius: 6px; outline: none; transition: border-color 0.3s; }
.search-overlay__input:focus { border-color: rgba(82, 90, 158, 1); }
.search-overlay__btn { margin-top: 16px; padding: 12px 40px; background: rgba(82, 90, 158, 1); color: #fff; border-radius: 6px; font-size: 14px; transition: background 0.3s; }
.search-overlay__btn:hover { background: #1e50ae; }
.search-overlay__close { position: absolute; top: 16px; right: 16px; width: 32px; height: 32px; display: flex; align-items: center; justify-content: center; font-size: 24px; color: #999; cursor: pointer; transition: color 0.3s; }
.search-overlay__close:hover { color: #333; }

/* ========================================
   Sidebar tools
   ======================================== */
.sidebar-tools { position: fixed; right: 20px; bottom: 80px; z-index: 999; display: flex; flex-direction: column; gap: 8px; }
.sidebar-tools__item { width: 46px; height: 46px; background: #fff; border-radius: 8px; display: flex; align-items: center; justify-content: center; box-shadow: 0 2px 12px rgba(0,0,0,0.1); cursor: pointer; transition: background 0.3s, transform 0.3s; }
.sidebar-tools__item:hover { background: rgba(82, 90, 158, 1); transform: translateY(-2px); }
.sidebar-tools__item:hover svg { fill: #fff; }
.sidebar-tools__item svg { width: 22px; height: 22px; fill: #555; transition: fill 0.3s; }

/* ========================================
   Animations
   ======================================== */
.animate-on-scroll { opacity: 0; transform: translateY(30px); transition: opacity 0.6s ease-out, transform 0.6s ease-out; }
.animate-on-scroll.visible { opacity: 1; transform: translateY(0); }

/* ========================================
   Responsive - Tablet
   ======================================== */
@media (max-width: 1024px) {
  .header__nav { display: none; }
  .hamburger { display: flex; }
  .header__content { height: 70px; }
  .header__logo img { height: 50px; }
  .header__actions { margin-left: auto; }
  .banner { height: 50vw; margin-top: 70px; min-height: 300px; }
  .banner__arrow { width: 36px; height: 36px; font-size: 18px; }
  .banner__arrow--prev { left: 12px; }
  .banner__arrow--next { right: 12px; }
  .banner__dot { width: 8px; height: 8px; }
  .banner__dots { bottom: 16px; gap: 6px; }

  .quick-entry__grid { grid-template-columns: repeat(2, 1fr); }

  .about { padding: 60px 0; }
  .about__row { flex-direction: column; gap: 30px; }
  .about__video { flex: none; }
  .about__info { padding-top: 0; }
  .about__title { font-size: 28px; }

  .projects { padding: 60px 0; }
  .projects__title { font-size: 28px; }
  .projects__panel.active { flex-direction: column; gap: 20px; }
  .projects__panel-image { flex: none; }

  .news { padding: 60px 0 40px; }
  .news__title { font-size: 28px; }
  .news__grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }

  .container { padding: 0 4%; }
  .header__content { padding: 0 4%; }

  /* Mobile nav - visible on tablet/mobile */
  .mobile-nav-overlay { display: block; position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 1499; opacity: 0; visibility: hidden; transition: opacity 0.3s, visibility 0.3s; }
  .mobile-nav-overlay.open { opacity: 1; visibility: visible; }
  .mobile-nav { display: block; position: fixed; top: 0; right: -100%; width: 280px; height: 100vh; background: #fff; z-index: 1500; padding: 80px 30px 30px; overflow-y: auto; transition: right 0.4s ease; box-shadow: -4px 0 20px rgba(0,0,0,0.1); }
  .mobile-nav.open { right: 0; }
  .mobile-nav__item { border-bottom: 1px solid #f0f0f0; }
  .mobile-nav__item > a { display: block; padding: 14px 0; font-size: 16px; color: #333; }
  .mobile-nav__item > a:hover { color: rgba(82, 90, 158, 1); }
  .mobile-nav__sub { padding-left: 16px; display: none; }
  .mobile-nav__sub.open { display: block; }
  .mobile-nav__sub a { display: block; padding: 10px 0; font-size: 14px; color: #666; }
  .mobile-nav__sub a:hover { color: rgba(82, 90, 158, 1); }
  .mobile-nav__toggle { float: right; width: 24px; height: 24px; display: flex; align-items: center; justify-content: center; font-size: 18px; color: #999; cursor: pointer; transition: transform 0.3s; }
  .mobile-nav__toggle.open { transform: rotate(45deg); }
}

/* ========================================
   Responsive - Mobile
   ======================================== */
@media (max-width: 768px) {
  .header__content { height: 60px; }
  .header__logo img { height: 40px; }
  .header__search { width: 32px; height: 32px; }
  .header__search svg { width: 18px; height: 18px; }
  .header__phone img { height: 30px; }
  .header__actions { gap: 12px; }
  .banner { margin-top: 60px; height: 56vw; min-height: 200px; }

  .quick-entry__grid { grid-template-columns: repeat(2, 1fr); }

  .about__title { font-size: 24px; }
  .about__btn { padding: 12px 32px; font-size: 13px; }

  .projects__title,
  .news__title { font-size: 24px; }
  .projects__tab { padding: 10px 20px; font-size: 13px; }
  .news__grid { grid-template-columns: 1fr; gap: 14px; }

  .sidebar-tools { right: 10px; bottom: 40px; }
  .sidebar-tools__item { width: 38px; height: 38px; }

  .search-overlay__content { margin-top: 60px; padding: 24px; }
  .search-overlay__input { font-size: 16px; padding: 10px 14px; }
}