.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
}

[data-mantine-color-scheme="light"] .header {
  border-bottom: 1px solid var(--mantine-color-gray-3);
}

[data-mantine-color-scheme="dark"] .header {
  border-bottom: 1px solid var(--mantine-color-dark-5);
}