body {
  font-family: Lato, 'Helvetica Neue', Arial, Helvetica, sans-serif;
  margin: 0;
  padding: 0;
}

.container {
  display: flex;
  min-height: 100vh;
}

.left-nav {
  width: 220px;
  background: #1f2937;
  color: #fff;
  padding: 20px;
}

.left-nav .brand {
  font-weight: 700;
  font-size: 18px;
  margin-bottom: 12px;
}

.left-nav .nav-list {
  list-style: none;
  padding: 0;
}

.left-nav .nav-list li {
  margin: 8px 0;
}

.left-nav a {
  color: #cbd5e1;
  text-decoration: none;
}

.main-content {
  flex: 1;
  padding: 24px;
  background: #f8fafc;
}

.login-container {
  width: 320px;
  margin: 80px auto;
  background: #fff;
  padding: 20px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, .1);
}

.login-container input {
  width: 100%;
  padding: 8px;
  margin: 8px 0;
}

.error {
  color: red;
  margin-bottom: 8px;
  display: block;
}

.logout-btn {
  margin-top: 12px;
  background: #e53e3e;
  color: white;
  border: none;
  padding: 8px 10px;
  cursor: pointer;
  border-radius: 5px;
}