/* ========================================
   移动端 Footer 优化
   ======================================== */
@media (max-width: 767px) {
  .footer-links,
  .footer-contact p:not(:first-child),
  .footer-bottom p:last-child {
    display: none;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--space-4);
    text-align: center;
  }
  
  .footer-about,
  .footer-contact {
    padding: var(--space-4) 0;
  }
  
  .footer-bottom {
    padding: var(--space-3) 0;
  }
}

/* ========================================
   Footer 页脚样式
   专业 B2B 设计 - 信任感 + 清晰层次
   ======================================== */

/* ========================================
   页脚主容器
   ======================================== */
.site-footer {
  background: linear-gradient(to bottom, var(--color-bg-secondary), var(--color-bg-tertiary));
  border-top: 1px solid var(--color-border-light);
  margin-top: var(--space-20);
}

/* ========================================
   页脚主内容区
   ======================================== */
.footer-main {
  padding: var(--space-16) 0 var(--space-12);
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}

@media (min-width: 640px) {
  .footer-content {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .footer-content {
    grid-template-columns: 2fr 1fr 1.5fr 1fr;
    gap: var(--space-12);
  }
}

/* ========================================
   页脚列
   ======================================== */
.footer-col {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.footer-title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-2);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
  width: fit-content;
}

/* ========================================
   关于我们区域
   ======================================== */
.footer-about {
  max-width: 400px;
}

.footer-logo {
  margin-bottom: var(--space-4);
}

.footer-logo img {
  height: 48px;
  width: auto;
}

.footer-desc {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  line-height: 1.6;
  margin-bottom: var(--space-6);
}

/* 社交媒体按钮 */
.footer-social {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.social-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background-color: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  color: var(--color-text-secondary);
  font-size: var(--text-xl);
  transition: all var(--transition-base) ease;
  cursor: pointer;
}

.social-btn:hover {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-inverse);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.social-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ========================================
   快速导航
   ======================================== */
.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-links li {
  display: flex;
  align-items: center;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  transition: all var(--transition-base) ease;
  padding: var(--space-2) 0;
  min-height: 32px;
}

.footer-links a:hover {
  color: var(--color-primary);
  transform: translateX(4px);
}

.footer-links a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.footer-links .fa {
  color: var(--color-primary);
  font-size: var(--text-xs);
}

/* ========================================
   联系我们
   ======================================== */
.contact-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.contact-list li {
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
}

.contact-list .fa {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  font-size: var(--text-base);
  margin-top: 2px;
}

.contact-text {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.contact-label {
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.contact-text a,
.contact-text span {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  transition: color var(--transition-base) ease;
}

.contact-text a:hover {
  color: var(--color-primary);
}

.contact-text a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ========================================
   微信二维码
   ======================================== */
.footer-qrcode {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.qrcode-box {
  background-color: var(--color-bg-primary);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-xl);
  padding: var(--space-4);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base) ease;
}

.qrcode-box:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.qrcode-image {
  width: 120px;
  height: 120px;
  border-radius: var(--radius-md);
}

.qrcode-tip {
  margin-top: var(--space-3);
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

/* ========================================
   友情链接
   ======================================== */
.footer-links-section {
  background-color: var(--color-bg-tertiary);
  border-top: 1px solid var(--color-border-light);
  padding: var(--space-8) 0;
}

.links-title {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
}

.links-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4) var(--space-6);
  align-items: center;
}

.links-list a {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  transition: color var(--transition-base) ease;
  padding: var(--space-2);
  border-radius: var(--radius-sm);
}

.links-list a:hover {
  color: var(--color-primary);
}

.links-list a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ========================================
   版权信息
   ======================================== */
.footer-bottom {
  background-color: var(--color-bg-primary);
  border-top: 1px solid var(--color-border-light);
  padding: var(--space-6) 0;
}

.copyright-text {
  text-align: center;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

.copyright-text p {
  margin-bottom: var(--space-2);
}

.copyright-text p:last-child {
  margin-bottom: 0;
}

.beian-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: var(--space-2) var(--space-4);
}

.beian-links a {
  color: var(--color-text-tertiary);
  transition: color var(--transition-base) ease;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}

.beian-links a:hover {
  color: var(--color-primary);
}

.beian-links a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.separator {
  color: var(--color-border-medium);
}

/* ========================================
   回到顶部按钮
   ======================================== */
.back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 48px;
  height: 48px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
  border: none;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base) ease;
  z-index: var(--z-fixed);
}

.back-to-top.show,
.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background-color: var(--color-primary-dark);
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.back-to-top:active {
  transform: translateY(-2px);
}

.back-to-top:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 4px;
}

.back-to-top .fa {
  font-size: var(--text-lg);
}

.back-text {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.05em;
}

/* ========================================
   二维码弹窗
   ======================================== */
.qrcode-popup {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: var(--z-modal);
  display: none;
  align-items: center;
  justify-content: center;
}

.qrcode-popup.active {
  display: flex;
}

.popup-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.popup-content {
  position: relative;
  background-color: var(--color-bg-primary);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
  max-width: 400px;
  width: 90%;
  padding: var(--space-8);
  animation: fadeIn var(--transition-slow) ease;
  z-index: 1;
}

.popup-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: transparent;
  border: none;
  border-radius: var(--radius-lg);
  color: var(--color-text-secondary);
  font-size: var(--text-xl);
  cursor: pointer;
  transition: all var(--transition-base) ease;
}

.popup-close:hover {
  background-color: rgba(239, 68, 68, 0.1);
  color: var(--color-error);
}

.popup-close:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.popup-body {
  text-align: center;
}

.popup-title {
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--space-6);
}

.popup-qrcode {
  display: flex;
  justify-content: center;
  margin-bottom: var(--space-4);
}

.popup-qrcode img {
  width: 200px;
  height: 200px;
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-border-light);
}

.popup-desc {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

/* ========================================
   响应式优化
   ======================================== */
@media (max-width: 639px) {
  .footer-main {
    padding: var(--space-12) 0 var(--space-8);
  }
  
  .footer-about {
    max-width: 100%;
  }
  
  .back-to-top {
    bottom: var(--space-4);
    right: var(--space-4);
    width: 44px;
    height: 44px;
  }
  
  .back-text {
    display: none;
  }
}

@media (min-width: 640px) and (max-width: 1023px) {
  .footer-qrcode {
    grid-column: span 2;
    align-items: flex-start;
  }
}

/* ========================================
   无障碍增强
   ======================================== */
@media (prefers-reduced-motion: reduce) {
  .back-to-top {
    transition: opacity var(--transition-base) ease;
    transform: none !important;
  }
  
  .popup-content {
    animation: none;
  }
}

/* ========================================
   打印样式
   ======================================== */
@media print {
  .footer-social,
  .back-to-top,
  .qrcode-popup {
    display: none !important;
  }
  
  .site-footer {
    background: white;
    border-top: 2px solid #000;
  }
  
  .footer-main {
    padding: var(--space-8) 0;
  }
  
  .footer-links a,
  .contact-text a {
    text-decoration: underline;
  }
}