.app-header {
  background: linear-gradient(135deg, var(--primary, #1976d2) 0%, var(--primary-dark, #115293) 100%);
  color: #fff;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
}

:root {
  --app-navbar-height: 68px;
}

.app-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("/res/vitech2.svg");
  opacity: 0.1;
  pointer-events: none;
  background-repeat: repeat;
  background-size: 100px 100px;
  background-position: left top;
}

.app-navbar {
  background: transparent;
  min-height: var(--app-navbar-height);
}

.app-navbar .container-fluid {
  min-height: var(--app-navbar-height);
  align-items: center;
}

.app-navbar .navbar-brand {
  color: #fff;
}

.app-navbar .app-logo {
  width: 28px;
  height: 28px;
  display: inline-block;
  flex-shrink: 0;
}

.app-navbar .navbar-brand:hover {
  color: #fff;
  opacity: 0.92;
}

.app-navbar .navbar-toggler {
  border-color: rgba(255, 255, 255, 0.4);
}

.app-navbar .navbar-toggler:focus {
  box-shadow: 0 0 0 0.15rem rgba(255, 255, 255, 0.2);
}

.app-navbar .navbar-toggler-icon {
  filter: invert(1);
}

.app-navbar .nav-link {
  color: rgba(255, 255, 255, 0.88);
  font-weight: 600;
  border-radius: 8px;
  padding: 0.4rem 0.75rem;
}

.app-navbar .nav-link:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
}

.app-navbar .nav-link.active {
  color: #fff;
  background: rgba(255, 255, 255, 0.18);
}

.app-navbar .navbar-text,
.app-navbar .navbar-brand,
.app-navbar .nav-link {
  line-height: 1.2;
}

.app-navbar .app-timestamp,
.app-navbar .page-context {
  color: #fff;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50px;
  padding: 0.35rem 0.8rem;
  font-size: 0.88rem;
  backdrop-filter: blur(4px);
}

.app-navbar .app-user-status {
  color: #fff;
  background: rgba(25, 135, 84, 0.4);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 50px;
  padding: 0.35rem 0.8rem;
  font-size: 0.88rem;
  white-space: nowrap;
  backdrop-filter: blur(4px);
}

@media (max-width: 991.98px) {
  .app-navbar .navbar-collapse {
    background: rgba(0, 0, 0, 0.12);
    border-radius: 10px;
    margin-top: 0.6rem;
    padding: 0.4rem;
  }

  .app-navbar .app-timestamp,
  .app-navbar .page-context {
    display: none;
  }
}