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

html,
body {
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #000;
  max-width: 100%;
  overflow-x: hidden;
}

.site-header {
  background-color: #ffffff;
  border-bottom: 3px solid #e40000;
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  padding: 15px 0 10px;
}

.logo img {
  display: block;
  height: 60px;
}

.main-nav {
  display: flex;
  align-items: center;
  margin-left: 80px;
  flex-grow: 1;
  gap: 60px;
}

.nav-item {
  text-decoration: none;
  font-size: 16px;
  color: #000000;
  white-space: nowrap;
  transition: color 0.3s ease;
}

.nav-item.active,
.nav-item:hover {
  color: #e40000;
}

.language-switcher {
  display: flex;
  align-items: center;
  font-size: 14px;
  color: #e40000;
}

.language-switcher .triangle {
  margin-left: 4px;
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 6px solid #999999;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 14px;
}

.nav-action-item {
  text-decoration: none;
  color: #000000;
  font-weight: 600;
  white-space: nowrap;
  transition: color 0.3s ease;
}

.nav-action-item:hover {
  color: #e40000;
}

.nav-action-item.active {
  color: #e40000;
}

.nav-actions .nav-action-item:first-child {
  margin-left: 60px;
}

.banner-slider {
  position: relative;
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
  overflow: hidden;
}

.slides {
  position: relative;
  width: 100%;
  padding-top: 36.46%; /* 700 / 1920，保持原始比例 */
}

.slide {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 1s ease;
}

.slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.slide.active {
  opacity: 1;
}

.bottom-bar {
  margin-top: 0;
}

.about-main {
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
}

.about-block img {
  width: 100%;
  height: auto;
  display: block;
}

.programs-main {
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
}

.program-block img {
  width: 100%;
  height: auto;
  display: block;
}

.artists-main {
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
}

.artists-block img {
  width: 100%;
  height: auto;
  display: block;
}

.education-main {
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
}

.education-block img {
  width: 100%;
  height: auto;
  display: block;
}

.donor-main {
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
}

.donor-block img {
  width: 100%;
  height: auto;
  display: block;
}

.join-main,
.donate-main,
.login-main {
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
}

.join-block img,
.donate-block img,
.login-block img {
  width: 100%;
  height: auto;
  display: block;
}

.bottom-bar-bg {
  width: 100%;
  max-width: 1920px;
  margin: 0 auto;
  padding-top: 21.875%; /* 420 / 1920，保持原始比例 */
  background-image: url("底bar.jpg");
  background-size: cover;
  background-position: center;
}

.about-intro {
  width: 100%;
  max-width: 1920px;
  margin: 32px auto;
  padding: 24px 24px;
  text-align: center;
}

.about-intro-title {
  font-size: clamp(20px, 3vw, 28px);
  font-weight: 600;
  letter-spacing: 0.05em;
  color: #e40000;
}

.fade-in {
  opacity: 0;
  transform: translateY(10px);
}

.fade-in.in-view {
  animation: fadeInUp 0.8s ease-out forwards;
}

.fade-in.delay-1 { animation-delay: 0.1s; }
.fade-in.delay-2 { animation-delay: 0.2s; }
.fade-in.delay-3 { animation-delay: 0.3s; }
.fade-in.delay-4 { animation-delay: 0.4s; }
.fade-in.delay-5 { animation-delay: 0.5s; }
.fade-in.delay-6 { animation-delay: 0.6s; }
.fade-in.delay-7 { animation-delay: 0.7s; }

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 768px) {
  .nav-inner {
    flex-wrap: wrap;
    justify-content: space-between;
    padding: 10px 16px;
  }

  .logo img {
    height: 40px;
  }

  .main-nav {
    flex-wrap: wrap;
    margin-left: 0;
    gap: 16px;
    margin-top: 8px;
  }

  .nav-item {
    font-size: 12px;
  }

  .language-switcher {
    font-size: 12px;
  }

  .nav-actions {
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 8px;
  }

  .nav-actions .nav-action-item:first-child {
    margin-left: 24px;
  }
}