/* ===== 全局配色 ===== */
:root {
  --navy:     #010737;
  --deepblue: #0A2847;
  --teal:     #2EB5C9;
  --lightblue: #E8F4F8;
}

/* ===== 基础 ===== */
body { scroll-behavior: smooth; }

/* ===== 导航高亮 ===== */
.nav-link.active { color: var(--teal) !important; }
.nav-link.active .nav-underline { width: 100% !important; }

/* ===== 页面容器 ===== */
#pages { position: relative; }

/* ===== 页面切换 ===== */
.page-section { display: none; }
.page-section.active { display: block; }

/* ===== Hero 背景图 ===== */
.hero-bg {
  background-image: url('../images/hero-bg.jpg');
  background-size: cover;
  background-position: center;
}

/* ===== 产品中心图片 ===== */
.product-img-1 { background-image: url('../images/frozen-seafood.jpg'); background-size: cover; background-position: center; }
.product-img-2 { background-image: url('../images/shrimp-farm.jpg');   background-size: cover; background-position: center; }
.product-img-3 { background-image: url('../images/gift-box.jpg');       background-size: cover; background-position: center; }

/* ===== 滚动入场动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 1.2s cubic-bezier(0.22, 1, 0.36, 1),
              transform 1.2s cubic-bezier(0.22, 1, 0.36, 1);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 原地淡入（用于 Hero 头部） */
.reveal-fade {
  opacity: 0;
  transition: opacity 1.5s cubic-bezier(0.22, 1, 0.36, 1);
}
.reveal-fade.visible { opacity: 1; }

/* 子元素依次入场 */
.reveal-group > * {
  opacity: 0;
  transform: translateY(36px);
  transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1),
              transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
}
.reveal-group.visible > * {
  opacity: 1;
  transform: none;
}
.reveal-group.visible > *:nth-child(1) { transition-delay: 0s; }
.reveal-group.visible > *:nth-child(2) { transition-delay: 0.1s; }
.reveal-group.visible > *:nth-child(3) { transition-delay: 0.2s; }
.reveal-group.visible > *:nth-child(4) { transition-delay: 0.3s; }
.reveal-group.visible > *:nth-child(5) { transition-delay: 0.4s; }
.reveal-group.visible > *:nth-child(n+6) { transition-delay: 0.5s; }

/* ===== 卡片悬浮 ===== */
.card-hover {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card-hover:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 28px rgba(0,0,0,0.12);
}

/* ===== 按钮渐变 ===== */
.btn-primary {
  background: linear-gradient(135deg, var(--deepblue), var(--teal));
  transition: opacity 0.25s ease, transform 0.25s ease;
}
.btn-primary:hover {
  opacity: 0.92;
  transform: translateY(-1px);
}

/* ===== 导航栏背景 ===== */
.nav-scrolled {
  background: rgba(1,7,55,0.92) !important;
  backdrop-filter: blur(8px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.15);
}

/* ===== 导航下划线 ===== */
.nav-underline { transition: width 0.25s ease; }

/* ===== 移动端菜单 ===== */
#mobile-menu { transition: max-height 0.3s ease, opacity 0.3s ease; }