/* =============================================
   Qisheng Precision · qisheng.eu  
   Shared stylesheet – clean, no external deps
   ============================================= */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: "Helvetica Neue", "Arial", sans-serif;
  color: #333;
  font-size: 14px;
  line-height: 1.6;
  background: #fff;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img, svg { max-width: 100%; display: block; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* ── HEADER ── */
header.main-header {
  background: #fff;
  border-bottom: 1px solid #e5e5e5;
  position: sticky; top: 0; z-index: 999;
  box-shadow: 0 2px 8px rgba(0,0,0,.06);
}
.header-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 20px;
  display: flex; align-items: center; justify-content: space-between;
  height: 78px; gap: 24px;
}
.logo-link { display: flex; align-items: center; height: 100%; }
.logo-link img { height: 46px; width: auto; border-radius: 3px; box-shadow: 0 1px 3px rgba(0,0,0,.08); }
.logo-link svg { height: 46px; width: auto; }

/* ── NAV ── */
nav.main-nav { display: flex; align-items: center; }
nav.main-nav > ul { display: flex; gap: 0; }
nav.main-nav > ul > li { position: relative; }
nav.main-nav > ul > li > a {
  display: flex; align-items: center; height: 78px;
  padding: 0 18px;
  font-size: 13px; font-weight: 600; color: #222;
  border-bottom: 3px solid transparent;
  transition: color .2s, border-color .2s;
  white-space: nowrap;
  letter-spacing: .03em;
}
nav.main-nav > ul > li > a:hover,
nav.main-nav > ul > li.active > a { color: #c00; border-bottom-color: #c00; }
.dropdown {
  display: none; position: absolute; top: 100%; left: 0;
  background: #fff; border-top: 3px solid #c00;
  min-width: 220px; box-shadow: 0 6px 20px rgba(0,0,0,.12);
  z-index: 1000;
}
nav.main-nav > ul > li:hover .dropdown { display: block; }
.dropdown li a {
  display: block; padding: 10px 18px;
  font-size: 13px; color: #333;
  border-bottom: 1px solid #f0f0f0;
  transition: background .15s, color .15s;
}
.dropdown li a:hover { background: #c00; color: #fff; }

.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; background: none; border: none; padding: 8px; }
.hamburger span { display: block; width: 24px; height: 2px; background: #222; }

/* ── BREADCRUMB ── */
.breadcrumb-bar {
  background: #f5f5f5; border-bottom: 1px solid #e8e8e8;
  padding: 10px 0;
}
.breadcrumb-bar .inner {
  max-width: 1200px; margin: 0 auto; padding: 0 20px;
  font-size: 12px; color: #888;
  display: flex; align-items: center; gap: 6px; flex-wrap: wrap;
}
.breadcrumb-bar .inner a { color: #888; }
.breadcrumb-bar .inner a:hover { color: #c00; }
.breadcrumb-bar .inner span { color: #bbb; }

/* ── PAGE BANNER ── */
.page-banner {
  width: 100%; position: relative;
  height: 240px;
  background: #0d2140 url('images/banner-bg.svg') center/cover no-repeat;
  display: flex; align-items: center; justify-content: center;
}
.page-banner .banner-title { text-align: center; color: #fff; padding: 0 20px; }
.page-banner .banner-title h1 {
  font-size: 30px; font-weight: 700; letter-spacing: .04em;
  text-shadow: 0 2px 8px rgba(0,0,0,.4);
}
.page-banner .banner-title p {
  font-size: 13px; margin-top: 8px;
  color: rgba(255,255,255,.75); letter-spacing: .15em;
}

/* ── SECTION TITLE ── */
.section-title { text-align: center; margin-bottom: 36px; padding-top: 56px; }
.section-title h2 {
  font-size: 26px; font-weight: 700; color: #1a3a6b;
  position: relative; display: inline-block; padding-bottom: 14px;
}
.section-title h2::after {
  content: '';
  position: absolute; bottom: 0; left: 50%; transform: translateX(-50%);
  width: 48px; height: 3px; background: #c00; border-radius: 2px;
}
.section-title p { font-size: 14px; color: #777; margin-top: 12px; }

/* ── BUTTONS ── */
.btn-primary, .btn-outline, .btn-light {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 26px; font-size: 13px; font-weight: 600;
  letter-spacing: .06em; text-transform: uppercase;
  border-radius: 3px; transition: all .2s; text-decoration: none;
  border: 0; cursor: pointer; font-family: inherit;
}
.btn-primary { background: #c00; color: #fff; }
.btn-primary:hover { background: #1a3a6b; }
.btn-outline { background: transparent; color: #1a3a6b; border: 2px solid #1a3a6b; padding: 10px 24px; }
.btn-outline:hover { background: #1a3a6b; color: #fff; }
.btn-light { background: rgba(255,255,255,.1); color: #fff; border: 1px solid rgba(255,255,255,.3); }
.btn-light:hover { background: #fff; color: #1a3a6b; }

/* ── FOOTER ── */
footer.main-footer { background: #1a2538; color: #aaa; padding: 50px 0 0; margin-top: 80px; }
.footer-grid {
  max-width: 1200px; margin: 0 auto; padding: 0 20px;
  display: grid; grid-template-columns: 2fr 1.2fr 1.2fr 1.6fr;
  gap: 40px; padding-bottom: 36px;
}
.footer-col h4 {
  font-size: 14px; font-weight: 700; color: #fff;
  margin-bottom: 16px; padding-bottom: 10px;
  border-bottom: 1px solid #3a4660;
}
.footer-col p, .footer-col li { font-size: 13px; color: #aab; margin-bottom: 8px; line-height: 1.7; }
.footer-col li a { color: #aab; transition: color .2s; }
.footer-col li a:hover { color: #fff; }
.footer-col .contact-item { display: flex; gap: 8px; align-items: flex-start; margin-bottom: 10px; }
.footer-col .contact-item .icon { color: #c00; flex-shrink: 0; margin-top: 1px; font-style: normal; }
.footer-bottom {
  border-top: 1px solid #2a3548;
  padding: 16px 20px; text-align: center;
  font-size: 12px; color: #788;
  max-width: 1200px; margin: 0 auto;
}
.footer-bottom a { color: #aab; }
.footer-bottom a:hover { color: #fff; }
.footer-logo { display: flex; align-items: center; margin-bottom: 14px; }
.footer-logo svg { height: 44px; width: auto; filter: brightness(0) invert(1); opacity: .9; }

/* ── BACK TO TOP ── */
#backTop {
  position: fixed; right: 24px; bottom: 80px;
  width: 44px; height: 44px;
  background: #c00; color: #fff;
  border-radius: 4px; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; opacity: 0;
  transition: opacity .3s, background .2s;
  z-index: 999;
}
#backTop.show { opacity: 1; }
#backTop:hover { background: #1a3a6b; }

/* ── MOBILE ── */
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  nav.main-nav { display: none; }
  nav.main-nav.open {
    display: flex; position: absolute; top: 78px; left: 0; right: 0;
    background: #fff; box-shadow: 0 4px 12px rgba(0,0,0,.1);
    padding: 12px 20px;
  }
  nav.main-nav.open ul { flex-direction: column; width: 100%; }
  nav.main-nav.open ul li a { height: auto; padding: 12px 0; border-bottom: 1px solid #eee; }
  .hamburger { display: flex; }
  .header-inner { gap: 12px; }
}