.main {
  padding: 1.4rem 0;
  background: #fff;
  min-height: 50vh;
}
.problem-list {
  width: 100%;
}
.problem-list .problem-item {
  margin-bottom: 0.2rem;
  background: #fff;
  overflow: hidden;
}
.problem-list .problem-item .problem-header {
  background: #fff;
  padding: 0.3rem 0.4rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: background-color 0.3s, color 0.3s;
  border: 1px solid #E6E6E6;
}
.problem-list .problem-item .problem-header:hover {
  background: #f5f5f5;
}
.problem-list .problem-item .problem-header .problem-title {
  color: #333;
  font-size: 0.2rem;
  font-weight: 500;
  flex: 1;
  transition: color 0.3s;
}
.problem-list .problem-item .problem-header .problem-toggle {
  width: 0.4rem;
  height: 0.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-left: 0.2rem;
}
.problem-list .problem-item .problem-header .problem-toggle .toggle-icon {
  width: 0.4rem;
  height: 0.4rem;
  border-radius: 50%;
  border: 1px solid #004B9B;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: all 0.3s;
}
.problem-list .problem-item .problem-header .problem-toggle .toggle-icon::before,
.problem-list .problem-item .problem-header .problem-toggle .toggle-icon::after {
  content: '';
  position: absolute;
  background: #004B9B;
  transition: all 0.3s;
  border-radius: 0.01rem;
}
.problem-list .problem-item .problem-header .problem-toggle .toggle-icon-plus::before {
  width: 0.16rem;
  height: 0.02rem;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}
.problem-list .problem-item .problem-header .problem-toggle .toggle-icon-plus::after {
  width: 0.01rem;
  height: 0.16rem;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}
.problem-list .problem-item .problem-header .problem-toggle .toggle-icon-minus::before {
  width: 0.16rem;
  height: 0.01rem;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}
.problem-list .problem-item .problem-header .problem-toggle .toggle-icon-minus::after {
  display: none;
}
.problem-list .problem-item.expanded .problem-header {
  background: #004B9B;
  border-color: #004B9B;
}
.problem-list .problem-item.expanded .problem-header:hover {
  background: #0069D9;
  border-color: #0069D9;
}
.problem-list .problem-item.expanded .problem-header .problem-title {
  color: #fff;
}
.problem-list .problem-item.expanded .problem-header .problem-toggle {
  border-color: #fff;
}
.problem-list .problem-item.expanded .problem-header .problem-toggle .toggle-icon {
  border-color: #fff;
}
.problem-list .problem-item.expanded .problem-header .problem-toggle .toggle-icon::before,
.problem-list .problem-item.expanded .problem-header .problem-toggle .toggle-icon::after {
  background: #fff;
}
.problem-list .problem-item .problem-content {
  padding: 0.4rem;
  background: #fff;
  border: 1px solid #E6E6E6;
}
.problem-list .problem-item .problem-content .problem-list-content {
  margin: 0;
  padding-left: 0.3rem;
}
.problem-list .problem-item .problem-content .problem-list-content li {
  color: #333;
  font-size: 0.18rem;
  line-height: 0.36rem;
  margin-bottom: 0.15rem;
}
.problem-list .problem-item .problem-content .problem-list-content li:last-child {
  margin-bottom: 0;
}
@media (max-width: 1024px) {
  .main {
    padding: 1rem 0 ;
  }
  .problem-list .problem-item .problem-header {
    padding: 0.25rem 0.3rem;
  }
  .problem-list .problem-item .problem-header .problem-title {
    font-size: 0.3rem;
  }
  .problem-list .problem-item .problem-header .problem-toggle {
    width: 0.48rem;
    height: 0.48rem;
  }
  .problem-list .problem-item .problem-header .problem-toggle .toggle-icon {
    width: 0.48rem;
    height: 0.48rem;
  }
  .problem-list .problem-item .problem-header .problem-toggle .toggle-icon-plus::before {
    width: 0.32rem;
  }
  .problem-list .problem-item .problem-header .problem-toggle .toggle-icon-plus::after {
    height: 0.32rem;
  }
  .problem-list .problem-item .problem-header .problem-toggle .toggle-icon-minus::before {
    width: 0.24rem;
  }
  .problem-list .problem-item .problem-content {
    padding: 0.4rem 0.27rem 0.55rem;
  }
  .problem-list .problem-item .problem-content .problem-list-content {
    padding-left: 0;
  }
  .problem-list .problem-item .problem-content .problem-list-content li {
    font-size: 0.28rem;
    line-height: 0.55rem;
  }
}