/* Basic page reset and typography */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

/* Center card vertically and horizontally on a light gray background */
body {
  background-color: #f4f6f9;
  color: #333333;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 20px;
}

/* Container to constrain width */
.container {
  width: 100%;
  max-width: 520px;
}

/* White card with subtle border and shadow */
.card {
  background-color: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  padding: 32px 28px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
}

/* Header typography */
.title {
  font-size: 1.5rem;
  font-weight: 700;
  color: #1e293b;
  text-align: center;
  margin-bottom: 8px;
}

.subtitle {
  font-size: 0.9rem;
  color: #64748b;
  text-align: center;
  margin-bottom: 24px;
  line-height: 1.4;
}

/* Form group layout */
.form-group {
  margin-bottom: 16px;
  display: flex;
  flex-direction: column;
}

/* Two-column layout for paired fields */
.form-row {
  display: flex;
  gap: 16px;
}

.form-row .form-group {
  flex: 1;
}

/* Labels */
label {
  font-size: 0.85rem;
  font-weight: 600;
  color: #475569;
  margin-bottom: 6px;
}

/* Inputs and Select Dropdown */
input[type="number"],
select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
  font-size: 0.95rem;
  color: #1e293b;
  background-color: #ffffff;
  transition: border-color 0.15s ease;
}

input[type="number"]:focus,
select:focus {
  outline: none;
  border-color: #2563eb;
}

/* Submit Button */
button[type="submit"] {
  width: 100%;
  background-color: #2563eb;
  color: #ffffff;
  border: none;
  border-radius: 6px;
  padding: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  margin-top: 8px;
  transition: background-color 0.15s ease;
}

button[type="submit"]:hover {
  background-color: #1d4ed8;
}

button[type="submit"]:disabled {
  background-color: #94a3b8;
  cursor: not-allowed;
}

/* Result Box */
.result-box {
  margin-top: 20px;
  padding: 14px 16px;
  border-radius: 6px;
  text-align: center;
  font-size: 1rem;
  font-weight: 600;
}

/* State-specific result styles */
.result-box.checking {
  background-color: #eff6ff;
  color: #1d4ed8;
  border: 1px solid #bfdbfe;
}

.result-box.legitimate {
  background-color: #f0fdf4;
  color: #15803d;
  border: 1px solid #bbf7d0;
}

.result-box.fraudulent {
  background-color: #fef2f2;
  color: #b91c1c;
  border: 1px solid #fecaca;
}

.result-box.error {
  background-color: #fffbeb;
  color: #b45309;
  border: 1px solid #fde68a;
}

.hidden {
  display: none;
}

/* Mobile responsiveness */
@media (max-width: 480px) {
  .card {
    padding: 24px 18px;
  }

  .form-row {
    flex-direction: column;
    gap: 0;
  }
}