/**
 * Premium SEO Template - Mega Menu CSS
 * 超大菜单样式，支持25+分类的美观布局
 */

/* ========== 超大菜单容器 ========== */
.mega-menu-item {
  position: relative;
}

.mega-menu-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* ========== 超大菜单面板 ========== */
.mega-menu-panel {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: var(--transition);
  z-index: 1001;
  min-width: 100vw;
  margin-left: calc(-50vw + 50%);
}

.mega-menu-item:hover .mega-menu-panel {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* ========== 超大菜单容器 ========== */
.mega-menu-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px 15px;
}

/* ========== 超大菜单网格 ========== */
.mega-menu-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 15px;
}

/* ========== 超大菜单列 ========== */
.mega-menu-column {
  padding: 10px 0;
}

.mega-menu-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--primary-color);
  margin: 0 0 12px 0;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--highlight-color);
}

.mega-menu-title a {
  color: var(--primary-color);
  text-decoration: none;
  transition: var(--transition);
  display: block;
}

.mega-menu-title a:hover {
  color: var(--highlight-color);
}

/* ========== 超大菜单列表 ========== */
.mega-menu-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.mega-menu-list li {
  margin: 0;
  padding: 0;
  line-height: 1.8;
}

.mega-menu-list a {
  color: var(--text-light);
  text-decoration: none;
  font-size: 13px;
  transition: var(--transition);
  display: block;
  padding: 4px 0;
}

.mega-menu-list a:hover {
  color: var(--highlight-color);
  padding-left: 5px;
}

/* ========== 超大菜单底部 ========== */
.mega-menu-footer {
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
  text-align: center;
}

.mega-menu-link-all {
  display: inline-block;
  color: var(--accent-color);
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
}

.mega-menu-link-all:hover {
  color: var(--highlight-color);
  text-decoration: underline;
}

/* ========== 响应式设计 ========== */

/* 平板设备 (768px - 1024px) */
@media (max-width: 1024px) {
  .mega-menu-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
  }

  .mega-menu-panel {
    min-width: 90vw;
    margin-left: calc(-45vw + 50%);
  }

  .mega-menu-container {
    padding: 15px 10px;
  }
}

/* 大手机 (480px - 768px) */
@media (max-width: 768px) {
  .mega-menu-panel {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    background: rgba(0, 0, 0, 0.05);
    border: none;
    box-shadow: none;
    border-radius: 0;
    margin-left: 0;
    min-width: auto;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }

  .mega-menu-item:hover .mega-menu-panel,
  .mega-menu-item.active .mega-menu-panel {
    max-height: 600px;
  }

  .mega-menu-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

  .mega-menu-container {
    padding: 10px 0;
  }

  .mega-menu-column {
    padding: 8px 0;
  }

  .mega-menu-title {
    font-size: 13px;
    margin: 0 0 10px 0;
  }

  .mega-menu-list a {
    font-size: 12px;
    padding: 3px 0;
  }
}

/* 小手机 (360px - 480px) */
@media (max-width: 480px) {
  .mega-menu-grid {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .mega-menu-title {
    font-size: 12px;
    margin: 0 0 8px 0;
  }

  .mega-menu-list a {
    font-size: 11px;
  }

  .mega-menu-footer {
    padding-top: 8px;
  }

  .mega-menu-link-all {
    font-size: 12px;
  }
}

/* ========== 动画效果 ========== */
.mega-menu-panel {
  animation: slideInDown 0.3s ease-out;
  animation-fill-mode: both;
}

.mega-menu-item:hover .mega-menu-panel {
  animation-play-state: running;
}

.mega-menu-column {
  animation: fadeIn 0.3s ease-out;
  animation-fill-mode: both;
}

.mega-menu-column:nth-child(1) { animation-delay: 0.05s; }
.mega-menu-column:nth-child(2) { animation-delay: 0.1s; }
.mega-menu-column:nth-child(3) { animation-delay: 0.15s; }
.mega-menu-column:nth-child(4) { animation-delay: 0.2s; }

/* ========== 键盘导航 ========== */
.mega-menu-toggle:focus {
  outline: 2px solid var(--highlight-color);
  outline-offset: 2px;
}

.mega-menu-list a:focus {
  outline: 2px solid var(--highlight-color);
  outline-offset: 2px;
}

/* ========== 暗黑模式 ========== */
@media (prefers-color-scheme: dark) {
  .mega-menu-panel {
    background: var(--bg-white);
  }

  .mega-menu-title {
    color: var(--text-dark);
  }

  .mega-menu-list a {
    color: var(--text-light);
  }
}

/* ========== 打印样式 ========== */
@media print {
  .mega-menu-panel {
    display: none;
  }
}