/* ===== 方案一：红白企业风 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #D40000;
  --primary-dark: #A80000;
  --accent: #1A1A1A;
  --text: #1e293b;
  --text-light: #64748b;
  --bg: #ffffff;
  --bg-alt: #F7F7F7;
  --bg-dark: #1A1A1A;
  --border: #e8e8e8;
  --header-h: 70px;
  --transition: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: 0 2px 20px rgba(0,0,0,0.08);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  line-height: 0;
}

.logo img {
  height: 44px;
  width: auto;
  display: block;
}

.nav-desktop {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-desktop a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  position: relative;
  padding: 4px 0;
  transition: color var(--transition);
}

.nav-desktop a::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 0;
  width: 0; height: 2px;
  background: var(--primary);
  transition: width var(--transition);
}

.nav-desktop a:hover,
.nav-desktop a.active {
  color: var(--primary);
}

.nav-desktop a:hover::after,
.nav-desktop a.active::after {
  width: 100%;
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: 16px;
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 4px;
  background: var(--bg-alt);
}

.lang-switch button {
  border: none;
  background: transparent;
  padding: 4px 12px;
  border-radius: 16px;
  font-size: 0.85rem;
  cursor: pointer;
  color: var(--text-light);
  transition: all var(--transition);
}

.lang-switch button.active {
  background: var(--primary);
  color: #fff;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  transition: all var(--transition);
}

.menu-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.nav-mobile {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0; right: 0;
  background: #fff;
  border-bottom: 1px solid var(--border);
  padding: 20px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
  z-index: 999;
  transform: translateY(-10px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--transition), transform var(--transition), visibility var(--transition);
}

.nav-mobile.open {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.nav-mobile a {
  display: block;
  padding: 12px 0;
  font-size: 1rem;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}

.nav-mobile a.active { color: var(--primary); font-weight: 600; }

.nav-mobile .lang-switch {
  margin: 16px 0 0;
  justify-content: center;
}

.site-footer {
  background: var(--bg-dark);
  color: #b0b0b0;
  padding: 48px 0 24px;
}

.footer-nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 32px;
  margin-bottom: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-nav a {
  color: #e0e0e0;
  font-size: 0.95rem;
  transition: color var(--transition);
}

.footer-nav a:hover { color: var(--primary); }

.footer-info {
  text-align: center;
  font-size: 0.85rem;
  line-height: 2;
  color: #888;
}

.footer-info a { color: #888; }
.footer-info a:hover { color: var(--primary); }

.anim-section {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.anim-section.anim-in { opacity: 1; transform: translateY(0); }
.anim-section.anim-out { opacity: 0; transform: translateY(-30px); }

.anim-fade { opacity: 0; transition: opacity 0.8s ease; }
.anim-fade.anim-in { opacity: 1; }
.anim-fade.anim-out { opacity: 0; }

.anim-slide-left {
  opacity: 0;
  transform: translateX(-60px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.anim-slide-left.anim-in { opacity: 1; transform: translateX(0); }

.anim-slide-right {
  opacity: 0;
  transform: translateX(60px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.anim-slide-right.anim-in { opacity: 1; transform: translateX(0); }

.anim-scale {
  opacity: 0;
  transform: scale(0.9);
  transition: opacity 0.8s ease, transform 0.8s ease;
}
.anim-scale.anim-in { opacity: 1; transform: scale(1); }

.page-main {
  padding-top: var(--header-h);
  min-height: calc(100vh - 200px);
}

.page-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 24px;
  position: relative;
  display: inline-block;
}

.page-title::after {
  content: '';
  position: absolute;
  bottom: -8px; left: 0;
  width: 60px; height: 4px;
  background: linear-gradient(90deg, var(--primary), #FF9900);
  border-radius: 2px;
}

.section-block { padding: 80px 0; }
.section-block:nth-child(even) { background: var(--bg-alt); }

@media (max-width: 768px) {
  :root { --header-h: 60px; }
  .nav-desktop { display: none; }
  .menu-toggle { display: flex; }
  .nav-mobile { display: block; }
  .page-title { font-size: 1.8rem; }
  .section-block { padding: 48px 0; }
  .footer-nav { gap: 16px 24px; }
  .logo img { height: 36px; }
}