.sidebar {
  width: 240px;
  background-color: #f8fafd;
  border-right: 1px solid #e9eff6;
  display: flex;
  flex-direction: column;
  padding: 40px 0 20px;
  z-index: 10;
}

.sidebar-header {
  padding: 0 28px 36px;
}

.brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.3px;
}

.sidebar-nav {
  flex: 1;
}

.nav-item,
.nav-item-header {
  padding: 12px 20px;
  margin: 4px 12px;
  display: flex;
  align-items: center;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  color: #4a5568;
  font-size: 14px;
  font-weight: 500;
  border-radius: 12px;
}

.nav-item:hover,
.nav-item-header:hover {
  background-color: #edf2f7;
  color: #2d3748;
}

.nav-item.active {
  background-color: #ebf4ff;
  color: #04448a;
  font-weight: 600;
}

.icon {
  margin-right: 12px;
  font-size: 18px;
  width: 24px;
  text-align: center;
}

.arrow {
  margin-left: auto;
  transition: transform 0.3s;
  font-size: 10px;
  color: #a0aec0;
}

.arrow.open {
  transform: rotate(180deg);
  color: #4a5568;
}

.nav-sub-items {
  margin-bottom: 8px;
}

.nav-sub-item {
  padding: 10px 20px 10px 52px;
  margin: 2px 12px;
  cursor: pointer;
  font-size: 13px;
  color: #718096;
  transition: all 0.2s;
  border-radius: 10px;
}

.nav-sub-item:hover {
  background-color: #edf2f7;
  color: #2d3748;
}

.nav-sub-item.active {
  color: #007aff;
  font-weight: 600;
  background-color: #ebf4ff;
}

.sidebar-footer {
  padding: 0 20px;
  text-align: center;
}

.version {
  font-size: 12px;
  color: #cbd5e0;
  font-weight: 500;
  letter-spacing: 0.2px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

.content {
  flex: 1;
  padding: 40px 60px;
  overflow-y: auto;
  height: 100%;
  scrollbar-gutter: stable;
}

.content:has(.page-container.full-width) {
  overflow-y: hidden;
  padding-bottom: 24px;
}

.page-container {
  max-width: 800px;
  margin: 0 auto;
  padding-bottom: 0;
  transition: max-width 0.4s ease;
}

.page-container.full-width {
  max-width: 1400px;
  height: calc(100vh - 64px);
  display: flex;
  flex-direction: column;
}

.page-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
  flex-shrink: 0;
}

.header-info {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-header h1 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 0;
  color: var(--text-main);
  line-height: 1.2;
}

.page-header p {
  color: var(--text-sec);
  font-size: 13px;
  margin-bottom: 0;
  line-height: 1.2;
}

.header-actions {
  display: flex;
  align-items: center;
}

.placeholder-page {
  padding-top: 120px;
  text-align: center;
  color: var(--text-sec);
}

.empty-icon {
  font-size: 64px;
  display: block;
  margin-bottom: 24px;
  opacity: 0.5;
}