/* ============================================================
   布局样式 - 导航栏 / 页脚 / 网格
   ============================================================ */

/* ============ 主导航栏 ============ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow-nav);
  z-index: 1000;
  transition: box-shadow var(--transition);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo-img {
  height: 40px;
  width: auto;
  object-fit: contain;
}

.header .logo-img {
  height: 36px;
}

.footer-brand .logo-img {
  height: 36px;
}

.logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -1px;
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.logo-text .zh {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 1px;
}

.logo-text .en {
  font-size: 0.6875rem;
  color: var(--color-primary);
  letter-spacing: 2px;
  font-weight: 600;
}

/* 主菜单 */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 8px 16px;
  color: var(--color-text);
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: var(--radius-btn);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.nav-link:hover,
.nav-item:hover > .nav-link {
  color: var(--color-primary);
  background: rgba(21, 101, 192, 0.06);
}

.nav-link svg {
  width: 12px;
  height: 12px;
  transition: transform var(--transition-fast);
}

.nav-item:hover .nav-link svg {
  transform: rotate(180deg);
}

/* 当前页高亮 */
.nav-link.is-active {
  color: var(--color-primary);
  font-weight: 600;
}

.nav-link.is-active::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: -4px;
  height: 3px;
  border-radius: 2px;
  background: var(--gradient-primary);
}

/* 下拉子菜单 */
.dropdown {
  position: absolute;
  top: calc(100% + 12px);
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  min-width: 240px;
  background: #fff;
  border-radius: var(--radius-card);
  box-shadow: 0 12px 32px rgba(13, 71, 161, 0.14);
  padding: 10px;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
}

.nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.dropdown::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 50%;
  transform: translateX(-50%) rotate(45deg);
  width: 14px;
  height: 14px;
  background: #fff;
}

.dropdown a {
  display: flex;
  flex-direction: column;
  padding: 10px 14px;
  border-radius: var(--radius-btn);
  color: var(--color-text);
  transition: background var(--transition-fast), color var(--transition-fast);
}

.dropdown a:hover {
  background: var(--color-bg-gray);
  color: var(--color-primary);
}

.dropdown a .sub-title {
  font-size: 0.9375rem;
  font-weight: 600;
}

.dropdown a .sub-desc {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-top: 2px;
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-btn);
}

.nav-toggle svg {
  width: 26px;
  height: 26px;
  color: var(--color-text);
}

/* 移动端遮罩 */
.nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  z-index: 999;
  opacity: 0;
  transition: opacity var(--transition);
}

.nav-overlay.is-open {
  display: block;
  opacity: 1;
}

/* ============ 移动端抽屉导航 ============ */
@media (max-width: 1024px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 0;
    right: -320px;
    width: 300px;
    height: 100vh;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: #fff;
    padding: 80px 0 24px;
    overflow-y: auto;
    transition: right var(--transition);
    z-index: 1000;
    box-shadow: -8px 0 24px rgba(0, 0, 0, 0.12);
  }

  .nav-menu.is-open {
    right: 0;
  }

  .nav-item {
    width: 100%;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-link {
    width: 100%;
    justify-content: space-between;
    padding: 16px 24px;
    border-radius: 0;
  }

  .nav-link.is-active::after {
    display: none;
  }

  .nav-item:hover > .nav-link {
    background: transparent;
  }

  .dropdown {
    position: static;
    transform: none;
    opacity: 1;
    visibility: visible;
    min-width: 0;
    box-shadow: none;
    padding: 0 24px 8px;
    background: var(--color-bg-soft);
    border-radius: 0;
    display: none;
  }

  .dropdown::before {
    display: none;
  }

  .nav-item.is-expanded .dropdown {
    display: block;
  }

  .nav-item:hover .dropdown {
    transform: none;
  }
}

/* ============ 页脚 ============ */
.footer {
  background: #0B1B33;
  color: rgba(255, 255, 255, 0.7);
  padding-top: 64px;
}

.footer .container {
  display: grid;
  grid-template-columns: 1.5fr 0.8fr 1.2fr 1fr;
  gap: 40px;
  padding-bottom: 48px;
}

.footer-col h4 {
  color: #fff;
  font-size: 1.0625rem;
  margin-bottom: 20px;
  font-weight: 600;
}

.footer-brand .logo-text .zh {
  color: #fff;
}

.footer-brand p {
  font-size: var(--fs-small);
  line-height: 1.8;
  margin-top: 16px;
  color: rgba(255, 255, 255, 0.6);
}

.footer-links li {
  margin-bottom: 12px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  font-size: var(--fs-small);
}

.footer-links a:hover {
  color: #fff;
}

.footer-contact li {
  font-size: var(--fs-small);
  margin-bottom: 14px;
  display: flex;
  gap: 10px;
  align-items: flex-start;
  color: rgba(255, 255, 255, 0.7);
}

.footer-contact svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  margin-top: 3px;
  color: var(--color-accent);
}

.footer-qr {
  display: flex;
  flex-direction: row;
  gap: 16px;
}

.footer-qr .qr-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.footer-qr .qr-box {
  width: 110px;
  height: 110px;
  background: #fff;
  border-radius: var(--radius-btn);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.footer-qr .qr-item span {
  font-size: var(--fs-small);
  color: rgba(255, 255, 255, 0.6);
  text-align: center;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 20px 0;
}

.footer-bottom .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  grid-template-columns: none;
  padding-bottom: 0;
}

.footer-bottom p {
  font-size: var(--fs-xs);
  color: rgba(255, 255, 255, 0.5);
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.5);
  font-size: var(--fs-xs);
}

.footer-bottom a:hover {
  color: #fff;
}

/* ============ 通用网格 ============ */
.grid {
  display: grid;
  gap: var(--space-block);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-5 { grid-template-columns: repeat(5, 1fr); }

@media (max-width: 1024px) {
  .grid-5 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .footer .container {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4,
  .grid-5 {
    grid-template-columns: 1fr;
  }
  .footer {
    padding-top: 48px;
  }
  .footer .container {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-qr {
    flex-direction: column;
    align-items: flex-start;
  }
  .footer-bottom .container {
    flex-direction: column;
    text-align: center;
  }
}