body {
  background-color: #F0F2F5;
  color: #000;
  transition: background-color 0.5s, color 0.5s;
}

.dark-mode {
  background-color: #1A1D23;
  color: #fff;
}

.navbar {
  transition: background-color 0.5s;
}

.dark-mode .navbar {
  background-color: #2A2F33;
}

.btn-primary {
  background-color: #007bff;
  border-color: #007bff;
  transition: background-color 0.5s, border-color 0.5s;
}

.dark-mode .btn-primary {
  background-color: #3A3F43;
  border-color: #3A3F43;
}

.nav-link {
  color: #000;
  transition: color 0.5s;
}

.dark-mode .nav-link {
  color: #fff;
}
#messages {
      height: calc(100vh - 60px);
      overflow-y: auto;
    }