body {
  font-family: system-ui, sans-serif;
  margin: 0;
  background: #f9fafb;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #1f2937;
  color: white;
  padding: 1rem 2rem;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.navbar .left h1 {
  margin: 0;
  font-size: 1.5rem;
}

.navbar .right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.nav-btn {
  padding: 0.5rem 1rem;
  background: #2f5050;
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 0.9rem;
  cursor: pointer;
}

.nav-btn:hover {
  background: #1d3232;
}

.nav-btn.secondary {
  background-color: #6b7280;
}

.nav-btn.secondary:hover {
  background-color: #4b5563;
}

#user-info {
  font-size: 0.95rem;
  color: #f3f4f6;
}

.hidden {
  display: none !important;
}

main {
  max-width: 700px;
  margin: 2rem auto;
  background: white;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

/* Spinner container */
.spinner {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 2rem;
  color: #6b7280;
  font-size: 0.95rem;
}

/* The spinning circle itself */
.loader {
  border: 4px solid #e5e7eb;
  border-top: 4px solid #2f5050;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  animation: spin 1s linear infinite;
  margin-bottom: 0.5rem;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Form layout */
form {
  background-color: #f9fafb;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.05);
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Group labels and inputs */
form label {
  font-weight: 600;
  margin-bottom: 0.3rem;
  display: block;
  color: #374151;
}

/* All inputs */
form input[type="text"],
form input[type="number"],
form textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  transition: border-color 0.2s ease;
  background-color: white;
  color: #111827;
}

form input:focus,
form textarea:focus {
  border-color: #3b82f6;
  outline: none;
}

/* Number input arrows: Chrome, Safari, Edge */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
  -webkit-appearance: inner-spin-button !important;
  height: 24px;
  width: 24px;
}

/* Number input arrows: Firefox */
input[type=number] {
  -moz-appearance: textfield;
}

.number-fields {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

/* Submit button */
form button[type="submit"] {
  align-self: flex-start;
  background-color: #2f5050;
  color: white;
  font-weight: 600;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

form button[type="submit"]:hover {
  background-color: #1d3232;
}

/* Message */
.message {
  font-size: 0.95rem;
  font-weight: 500;
  color: #10b981;
}

/* Responsive tweaks */
@media (max-width: 600px) {
  .number-fields {
    grid-template-columns: 1fr;
  }
}