/* UUCC 风格导航栏 - 大气版 */
.uucc-navbar {
  background: #ffffff;
  border-bottom: 1px solid #e5e7eb;
  position: sticky;
  top: 0;
  z-index: 1030;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  backdrop-filter: blur(20px);
}

.nav-wrapper {
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  max-width: 1400px;
  margin: 0 auto;
}

.nav-brand .brand-link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: #111827;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.5rem;
  letter-spacing: -0.02em;
}

.nav-brand .brand-link:hover {
  color: #4f46e5;
  text-decoration: none;
  transform: scale(1.02);
}

.nav-menu {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex: 1;
  margin: 0 3rem;
}

.nav-tab {
  display: inline-flex;
  align-items: center;
  padding: 16px 28px;
  color: #6b7280;
  text-decoration: none;
  font-weight: 500;
  font-size: 1rem;
  border-radius: 12px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  letter-spacing: 0.01em;
}

.nav-tab::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #4f46e5, #7c3aed);
  border-radius: 1px;
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

.nav-tab:hover {
  color: #111827;
  background: linear-gradient(135deg, #f8fafc, #f1f5f9);
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.nav-tab:hover::before {
  width: 60%;
}

.nav-tab.active {
  color: #4f46e5;
  background: linear-gradient(135deg, #eef2ff, #e0e7ff);
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(79, 70, 229, 0.2);
}

.nav-tab.active::before {
  width: 80%;
}

/* 移动端菜单按钮 - 大气版 */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 12px;
  border-radius: 10px;
  transition: all 0.3s ease;
  background: linear-gradient(135deg, #f8fafc, #f1f5f9);
  border: 1px solid #e2e8f0;
}

.mobile-menu-btn:hover {
  background: linear-gradient(135deg, #e2e8f0, #cbd5e1);
  transform: scale(1.05);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.mobile-menu-btn span {
  width: 24px;
  height: 3px;
  background: linear-gradient(90deg, #4f46e5, #7c3aed);
  display: block;
  border-radius: 2px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
}

@media (max-width: 992px) {
  .nav-wrapper {
    height: 70px;
    padding: 0 1.5rem;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, #ffffff, #f8fafc);
    flex-direction: column;
    gap: 0;
    display: none;
    box-shadow: 0 20px 40px rgba(0,0,0,.15);
    border-top: 1px solid #e2e8f0;
    margin: 0;
    padding: 2rem 0;
    backdrop-filter: blur(20px);
  }

  .nav-menu.active {
    display: flex;
    animation: slideDown 0.3s ease-out;
  }

  @keyframes slideDown {
    from {
      opacity: 0;
      transform: translateY(-20px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .nav-menu .nav-tab {
    width: 90%;
    justify-content: center;
    border-bottom: 1px solid #f1f5f9;
    border-radius: 12px;
    padding: 1.25rem 2rem;
    margin: 0.25rem auto;
    font-size: 1.1rem;
    font-weight: 500;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
  }

  .nav-menu .nav-tab:hover {
    background: linear-gradient(135deg, #eef2ff, #e0e7ff);
    transform: translateX(8px);
    box-shadow: 0 4px 16px rgba(79, 70, 229, 0.2);
  }

  .nav-menu .nav-tab:last-child {
    border-bottom: none;
  }

  .nav-menu .nav-tab::before {
    display: none;
  }

  .mobile-menu-btn {
    display: inline-flex;
  }

  .nav-brand .brand-link {
    font-size: 1.3rem;
  }
}

/* 隐藏旧的 Bootstrap 导航残留，避免排版错乱 */
.main-navbar, .navbar, .navbar-nav, .collapse.navbar-collapse { display: none !important; }