/* 纵向导航整体容器 */
.left-nav {
  width: 220px;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.06);
  padding: 1.5rem 0.5rem;
  font-family: 'Microsoft YaHei', Arial, sans-serif;
}

.left-nav-title {
  font-size: 1.15rem;
  font-weight: bold;
  color: #fff;
  background: linear-gradient(90deg, #1677ff 0%, #005ecb 100%);
  border-radius: 8px 8px 0 0;
  padding: 1.1rem 0 1.1rem 0;
  text-align: center;
  margin-bottom: 0.5rem;
  letter-spacing: 1px;
  box-shadow: 0 2px 8px rgba(22,119,255,0.08);
}

.left-nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.left-nav-item {
  margin: 0.1rem 0;
}
.left-nav-link {
  display: block;
  padding: 0.7rem 1.2rem;
  color: #222;
  font-size: 1rem;
  border-radius: 6px;
  text-decoration: none;
  transition: background 0.2s, color 0.2s, font-weight 0.2s;
  position: relative;
}
.left-nav-link.active,
.left-nav-link:hover {
  background: linear-gradient(90deg, #eaf3ff 0%, #f7fbff 100%);
  color: #1677ff;
  font-weight: bold;
}
.left-nav-link.active::before {
  content: '';
  display: inline-block;
  position: absolute;
  left: 0.7rem;
  top: 50%;
  transform: translateY(-50%);
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #1677ff;
}