/* 基础样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}


/* 导航方框样式 */
.content-container {
  margin-top: 120px; /* 留出导航栏高度 */
  padding: 20px 5%;
}

.nav-boxes {
  display: flex;
  justify-content: space-between;
  margin: 30px 0;
}

.nav-box {
  flex: 1;
  min-width: 28%;
  margin: 0 1%;
  padding: 20px;
  text-align: center;
  background: #f0f0f0;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.nav-box:hover {
  background: #2196F3;
  color: white;
  transform: translateY(-5px);
}


/* 图片 */
.cover-image {
  width: 100%;
  height: 500px;
  display: block;
  object-fit: cover;
}

.banner-title {
  position: absolute;
  top: calc(50% - 200px);
  left: 15%;
  transform: translateY(-50%);
  z-index: 2;
  color: white;
  font-size: 3em;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
  text-align: left;
  padding-left: 20px;
}

/* 热门解决方案标题样式 */
.section-title {
  font-size: 2.2rem;
  color: #2c3e50;
  margin: 40px 0 30px;
  padding-bottom: 12px;
  border-bottom: 2px solid #3498db;
  display: inline-block;
}

/* 解决方案项样式 */
.solution-item {
  display: flex;
  margin-bottom: 60px;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 6px 18px rgba(0,0,0,0.08);
  overflow: hidden;
  transition: transform 0.3s ease;
}

.solution-item:hover {
  transform: translateY(-5px);
}

/* 解决方案标题样式 */
.solution-title {
  font-size: 1.8rem;
  color: #2c3e50;
  margin: 0 0 25px 0;
  padding-bottom: 12px;
  border-bottom: 2px solid #3498db;
  font-weight: 600;
}

.solution-image {
  flex: 0 0 38%;
  padding: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #f8f9fa;
}

.solution-image img {
  width: 100%;
  height: 280px;
  border-radius: 8px;
  object-fit: cover;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.solution-description {
  flex: 1;
  padding: 45px;
  display: flex;
  align-items: flex-start;
  flex-direction: column;
}

.solution-description p {
  font-size: 1.15rem;
  line-height: 1.85;
  color: #4a5568;
  margin: 0 0 22px 0;
  text-align: justify;
  letter-spacing: 0.3px;
}

.solution-points {
  width: 100%;
}

.solution-points ul {
  margin: 0;
  padding-left: 24px;
}

.solution-points li {
  font-size: 1.15rem;
  line-height: 1.85;
  color: #4a5568;
  margin-bottom: 16px;
  list-style-type: disc;
  text-align: justify;
  letter-spacing: 0.3px;
}

/* 交替排列的解决方案项 */
.solution-item:nth-child(even) {
  flex-direction: row-reverse;
}

.solution-item:nth-child(even) .solution-description {
  text-align: right;
}

.solution-item:nth-child(even) .solution-points ul {
  padding-left: 0;
  padding-right: 24px;
  direction: rtl;
}

.solution-item:nth-child(even) .solution-points li {
  direction: ltr;
}

/* 下拉菜单样式 */
.dropdown-content {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: rgba(255,255,255,0.9);
  width: 100%;
  padding: 20px 5%;
  box-shadow: 0 8px 16px rgba(0,0,0,0.1);
  z-index: 1000;
}

.dropdown:hover .dropdown-content {
  display: flex;
  justify-content: space-between;
}

.submenu {
  flex: 1;
  padding: 0 20px;
}

.submenu h4 {
  color: #2c3e50;
  margin-bottom: 12px;
  font-size: 16px;
}

.submenu ul {
  list-style: none;
  padding: 0;
}

/* 响应式设计 */
@media (max-width: 1200px) {
  .nav-boxes {
    flex-direction: column;
    align-items: center;
  }
  
  .nav-box {
    min-width: 80%;
    margin: 10px 0;
  }
  
  .solution-item {
    flex-direction: column !important;
  }
  
  .solution-item:nth-child(even) {
    flex-direction: column !important;
  }
  
  .solution-item:nth-child(even) .solution-description {
    text-align: left;
  }
  
  .solution-item:nth-child(even) .solution-points ul {
    padding-left: 24px;
    padding-right: 0;
    direction: ltr;
  }
  
  .solution-image {
    flex: none;
    padding: 20px;
  }
  
  .solution-description {
    padding: 30px;
  }
}

@media (max-width: 768px) {
  .content-container {
    margin-top: 80px;
    padding: 15px 3%;
  }
  
  .cover-image {
    height: 350px;
  }
  
  .banner-title {
    font-size: 2rem;
    left: 8%;
    top: calc(50% - 150px);
  }
  
  .section-title {
    font-size: 1.8rem;
    margin: 30px 0 20px;
  }
  
  .solution-title {
    font-size: 1.5rem;
  }
  
  .solution-image img {
    height: 200px;
  }
  
  .solution-description {
    padding: 20px;
  }
  
  .solution-description p,
  .solution-points li {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .content-container {
    padding: 10px 2%;
  }
  
  .cover-image {
    height: 250px;
  }
  
  .banner-title {
    font-size: 1.6rem;
    left: 5%;
    top: calc(50% - 120px);
    padding-left: 15px;
  }
  
  .section-title {
    font-size: 1.5rem;
  }
  
  .nav-box {
    min-width: 95%;
    padding: 15px;
  }
  
  .solution-image {
    padding: 15px;
  }
  
  .solution-description {
    padding: 15px;
  }
  
  .solution-description p,
  .solution-points li {
    font-size: 0.95rem;
  }
}

.submenu li {
  margin: 8px 0;
}

.submenu a {
  color: #4a5568;
  font-size: 14px;
  transition: color 0.3s;
}

.submenu a:hover {
  color: #2196F3;
}

.divider {
  height: 1px;
  background: rgba(255,255,255,0.1);
  margin: 30px 0;
}

.dropdown-content {
  opacity: 0;
  transform: translateY(-10px);
  transition: opacity 0.3s ease-out, transform 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.dropdown-content.active {
  opacity: 1;
  transform: translateY(0);
}

.submenu {
  animation: submenuAppear 0.4s 0.2s both;
}

@keyframes submenuAppear {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}