.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.app-header h1 {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 600;
}

.header-actions {
  display: flex;
  gap: 0.5rem;
}

.app-main {
  max-width: 760px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

.screen {
  display: block;
}

@media (max-width: 540px) {
  .app-header { padding: 0.75rem 1rem; }
  .app-header h1 { font-size: 1rem; }
  .app-main { padding: 1rem 0.75rem 2rem; }
}