/* Basic layout */
html, body, #_dash-app-content {
  height: 100%;
}
.sidebar {
  position: fixed;
  top: 0;
  bottom: 0;
  width: 260px;
  background: #f8f9fa;
  border-right: 1px solid #e9ecef;
  display: flex;
  flex-direction: column;
  z-index: 1000;
}
#main-content {
  min-height: 100vh;
  background: #ffffff;
}
.sidebar-link {
  margin: 2px 8px;
  border-radius: 8px;
}
.sidebar .navbar-brand { font-weight: 600; }
.login-card {
  background: #fff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 2px 20px rgba(0,0,0,0.06);
}