/* ============================================================
   广汽集团 · 网络安全宣传周 — 共享品牌样式
   引用：所有子页面（topic / news / games）在 <link> 引入
   ============================================================ */
:root {
  --gac-red: #C7000B;
  --gac-red-bright: #E60012;
  --gac-red-deep: #8E0008;
  --space-gray: #1A1A1A;
  --space-gray-2: #242424;
  --space-gray-3: #2F2F2F;
  --pearl: #F5F5F5;
  --pearl-warm: #FAFAF7;
  --ink: #222222;
  --ink-soft: #555555;
  --ink-mute: #8A8A8A;
  --line-light: rgba(0, 0, 0, 0.08);
  --line-dark: rgba(255, 255, 255, 0.14);
  --red-glow: 0 0 34px rgba(199, 0, 11, 0.45);
  --font-cn: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", "Helvetica Neue", sans-serif;
  --font-en: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.06);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

body {
  font-family: var(--font-cn);
  color: var(--ink);
  background: var(--pearl);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ---------- 共享顶栏 ---------- */
.gac-topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 68px;
  z-index: 200;
  display: flex;
  align-items: center;
  background: rgba(245, 245, 245, 0.9);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line-light);
  transition: background 0.35s var(--ease), box-shadow 0.35s var(--ease);
}
.gac-topbar-inner {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.gac-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  min-width: 0;
  flex-shrink: 1;
  flex-basis: auto;
}
.gac-brand-logo { height: 32px; width: auto; max-width: 140px; object-fit: contain; flex-shrink: 0; }
.gac-brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
  min-width: 0;
  overflow: hidden;
}
.gac-brand-cn {
  font-family: var(--font-en), var(--font-cn);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--space-gray);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.gac-brand-en {
  font-family: var(--font-en);
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--gac-red);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.gac-nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}
.gac-nav-links a {
  position: relative;
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  font-weight: 500;
  color: #333;
  text-decoration: none;
  transition: color 0.25s;
  white-space: nowrap;
}
.gac-nav-links a::after {
  content: '';
  position: absolute;
  left: 15px; right: 15px;
  bottom: 2px;
  height: 2px;
  background: var(--gac-red);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.28s var(--ease);
}
.gac-nav-links a:hover,
.gac-nav-links a.active { color: var(--gac-red); }
.gac-nav-links a:hover::after,
.gac-nav-links a.active::after { transform: scaleX(1); }
.gac-nav-cta {
  display: inline-block;
  margin-left: 10px;
  padding: 8px 20px;
  background: var(--gac-red);
  color: #fff !important;
  border-radius: 6px;
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: 1px;
  transition: background 0.25s, box-shadow 0.25s, transform 0.25s;
}
.gac-nav-cta::after { display: none; }
.gac-nav-cta:hover {
  background: var(--gac-red-bright);
  box-shadow: 0 6px 18px rgba(199, 0, 11, 0.35);
  transform: translateY(-1px);
}
.gac-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: none;
  border: none;
  cursor: pointer;
  border-radius: 6px;
  flex-shrink: 0;
}
.gac-hamburger span {
  display: block;
  width: 100%;
  height: 3px;
  background: var(--space-gray);
  border-radius: 3px;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}
.gac-hamburger[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.gac-hamburger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.gac-hamburger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.gac-mobile-menu {
  position: fixed;
  top: 68px; left: 0; right: 0;
  z-index: 199;
  background: rgba(255, 255, 255, 0.99);
  border-bottom: 1px solid var(--line-light);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.12);
  padding: 10px 24px 22px;
  display: none;
}
.gac-mobile-menu.open {
  display: block;
  animation: gacMenuDrop 0.32s var(--ease);
}
@keyframes gacMenuDrop {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}
.gac-mobile-menu a {
  display: block;
  padding: 14px 6px;
  font-size: 16px;
  font-weight: 500;
  color: var(--space-gray);
  text-decoration: none;
  border-bottom: 1px solid var(--line-light);
}
.gac-mobile-menu a:last-of-type { border-bottom: none; }
.gac-mobile-menu a:active { color: var(--gac-red); }
.gac-mobile-menu .gac-nav-cta { margin: 14px 0 0; text-align: center; }

/* ---------- 共享页脚 ---------- */
.gac-footer {
  background: #111;
  color: rgba(255, 255, 255, 0.55);
  padding: 36px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 13px;
  margin-top: auto;
}
.gac-footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 28px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  text-align: center;
}
.gac-footer-org { color: rgba(255, 255, 255, 0.72); letter-spacing: 0.5px; }
.gac-footer-copy { letter-spacing: 0.5px; }
.gac-footer-links a {
  color: rgba(255, 255, 255, 0.45);
  text-decoration: none;
  margin: 0 10px;
  transition: color 0.2s;
}
.gac-footer-links a:hover { color: #fff; }
.gac-footer-visit {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  margin-top: 6px;
  padding: 6px 18px;
  border-radius: 100px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.55);
  letter-spacing: 1px;
}
.gac-footer-visit .fv-num {
  font-family: var(--font-en);
  font-size: 18px;
  font-weight: 800;
  color: var(--gac-red-bright);
  font-variant-numeric: tabular-nums;
  min-width: 2.5ch;
  text-align: right;
}
.gac-footer-visit .fv-txt b { color: #fff; font-weight: 600; }

/* ---------- 通用组件 ---------- */
.gac-wrap { max-width: 1280px; margin: 0 auto; padding: 0 28px; }
.gac-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 38px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 3px;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  font-family: var(--font-cn);
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s;
}
.gac-btn-primary {
  background: var(--gac-red);
  color: #fff;
  box-shadow: 0 10px 30px rgba(199, 0, 11, 0.35);
}
.gac-btn-primary:hover {
  background: var(--gac-red-bright);
  transform: translateY(-2px);
  box-shadow: 0 16px 40px rgba(199, 0, 11, 0.5);
}
.gac-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-en);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--gac-red);
  margin-bottom: 14px;
}
.gac-eyebrow::before,
.gac-eyebrow::after {
  content: '';
  width: 26px;
  height: 1px;
  background: currentColor;
  opacity: 0.5;
}
.gac-section-title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  letter-spacing: 2px;
  color: var(--space-gray);
  line-height: 1.25;
}
.gac-section-title .red { color: var(--gac-red); }

/* 面包屑 */
.gac-breadcrumb {
  font-size: 13.5px;
  color: var(--ink-mute);
  margin-bottom: 18px;
}
.gac-breadcrumb a {
  color: var(--gac-red);
  text-decoration: none;
}
.gac-breadcrumb a:hover { text-decoration: underline; }

/* 回到顶部 */
.gac-backtop {
  position: fixed;
  right: 26px;
  bottom: 30px;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: var(--space-gray);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.3s, visibility 0.3s, transform 0.3s, background 0.25s;
  z-index: 150;
}
.gac-backtop.show { opacity: 1; visibility: visible; transform: translateY(0); }
.gac-backtop:hover { background: var(--gac-red); }

/* 视口动画 */
.gac-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
  transition-delay: var(--d, 0s);
}
.gac-reveal.in { opacity: 1; transform: translateY(0); }

@media (max-width: 1440px) {
  .gac-nav-links { display: none; }
  .gac-hamburger { display: flex; }
  .gac-topbar { height: 60px; }
  .gac-mobile-menu { top: 60px; }
}
@media (max-width: 640px) {
  .gac-topbar-inner { padding: 0 16px; }
  .gac-brand-logo { height: 25px; }
  .gac-brand-cn { font-size: 15px; letter-spacing: 1px; }
  .gac-brand-en { font-size: 8px; letter-spacing: 2.5px; }
  .gac-wrap { padding: 0 20px; }
}

@media (prefers-reduced-motion: reduce) {
  .gac-reveal { opacity: 1; transform: none; transition: none; }
}