/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  background: transparent;
  z-index: var(--z-nav);
  transition: var(--transition);
}

.navbar.scrolled {
  background: var(--glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: var(--shadow-sm);
  height: 4.5rem;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: var(--weight-bold);
  color: var(--primary-dark);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  z-index: 1001;
}

.nav-logo img {
  height: 3rem;
  width: auto;
  border-radius: 4px;
  display: block;
}

.navbar.scrolled .nav-logo img {
  height: 2.5rem;
}

.nav-links {
  display: flex;
  gap: var(--space-12);
}

.nav-link {
  font-size: 1.1rem;
  font-weight: var(--weight-medium);
  color: var(--text-main);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width 0.3s ease;
  border-radius: 1px;
}

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

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

/* Mobile Menu Toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  cursor: pointer;
  z-index: 1001;
  padding: 5px;
}

.menu-toggle span {
  width: 28px;
  height: 2px;
  background: var(--text-main);
  border-radius: 2px;
  transition: var(--transition);
}

.navbar.scrolled .menu-toggle span {
  background: var(--text-main);
}

.navbar:not(.scrolled) .menu-toggle span {
  background: var(--text-main); /* 默认透明背景时也显示为暗色 */
}

/* 菜单打开时的动画 */
.menu-toggle.active span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

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

.menu-toggle.active span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

@media (max-width: 991px) {
  .menu-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    height: 100vh;
    background: white;
    display: flex; /* 确保在移动端是显示的 */
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--space-8);
    padding: var(--space-20) var(--space-6);
    transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -10px 0 30px rgba(0,0,0,0.1);
    z-index: 1000;
  }

  .nav-links.active {
    right: 0;
  }

  .nav-link {
    font-size: 1.3rem;
    color: var(--text-main) !important;
  }

  .cert-grid {
    grid-template-columns: 1fr !important;
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 2rem;
  font-weight: var(--weight-semibold);
  border-radius: var(--radius-full);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--primary);
  color: var(--bg-white);
  box-shadow: var(--shadow);
}

.btn-primary::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s ease;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  background: var(--primary-dark);
}

.btn-primary:hover::before {
  left: 100%;
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 2px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: var(--bg-white);
  transform: translateY(-2px);
}

/* Cards */
.card {
  background: var(--bg-white);
  padding: var(--space-10);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid rgba(0, 0, 0, 0.04);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--primary-gradient);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

.card:hover::before {
  opacity: 1;
}

.card-icon {
  width: 3.5rem;
  height: 3.5rem;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(13, 148, 136, 0.15));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  margin-bottom: var(--space-6);
  transition: var(--transition);
}

.card:hover .card-icon {
  background: var(--primary-gradient);
  color: white;
  transform: scale(1.1);
}

/* Cert Grid */
.cert-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1.6fr;
  gap: var(--space-8);
  margin-bottom: var(--space-16);
}

.cert-card {
  background: var(--bg-light);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  text-align: center;
}

.cert-img {
  height: 200px;
  width: 100%;
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
  object-fit: contain;
  background: white;
  border: 1px solid var(--border-color);
}

.cert-card h4 {
  font-size: 0.95rem;
  color: var(--text-main);
  margin-top: 0.5rem;
}

/* Footer */
.footer {
  background: linear-gradient(135deg, var(--primary-dark) 0%, #064e3b 100%);
  color: white;
  padding: var(--space-20) 0 var(--space-8);
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary-light), var(--accent), var(--primary-light));
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}

.footer-logo {
  font-size: 1.5rem;
  font-weight: var(--weight-bold);
  margin-bottom: var(--space-4);
}

.footer-title {
  font-weight: var(--weight-bold);
  margin-bottom: var(--space-4);
  color: white;
}

.footer-links li {
  margin-bottom: var(--space-2);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
}

.footer-links a:hover {
  color: var(--accent-light);
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-6);
  text-align: center;
  font-size: var(--text-sm);
  color: #ffffff;
}

.footer-bottom p,
.footer-bottom a {
  color: #ffffff !important;
}

@media (max-width: 991px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}