* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: #f5f5f5;
  color: #333;
  line-height: 1.6;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem;
}

/* Header */
header {
  background: #007bff;
  color: white;
  padding: 1rem 0;
  margin-bottom: 2rem;
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}

header h1 {
  font-size: 1.5rem;
}

header nav a {
  color: white;
  text-decoration: none;
  margin-left: 1rem;
}

header nav a:hover {
  text-decoration: underline;
}

/* Cards */
.card {
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  padding: 2rem;
  margin-bottom: 1.5rem;
}

.card h2 {
  margin-bottom: 1rem;
  color: #333;
}

/* Forms */
.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: #555;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 1rem;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: #007bff;
  box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}

.form-row {
  display: flex;
  gap: 1rem;
}

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

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  cursor: pointer;
  text-decoration: none;
  text-align: center;
}

.btn-primary {
  background: #007bff;
  color: white;
}

.btn-primary:hover {
  background: #0056b3;
}

.btn-danger {
  background: #dc3545;
  color: white;
}

.btn-danger:hover {
  background: #c82333;
}

.btn-secondary {
  background: #6c757d;
  color: white;
}

.btn-secondary:hover {
  background: #545b62;
}

.btn-small {
  padding: 0.4rem 0.8rem;
  font-size: 0.875rem;
}

/* Expense List */
.expense-list {
  list-style: none;
}

.expense-item {
  display: flex;
  align-items: center;
  padding: 1rem;
  border-bottom: 1px solid #eee;
}

.expense-item:last-child {
  border-bottom: none;
}

.expense-info {
  flex: 1;
}

.expense-amount {
  font-size: 1.25rem;
  font-weight: 600;
  color: #dc3545;
}

.expense-description {
  color: #333;
}

.expense-date {
  color: #888;
  font-size: 0.875rem;
}

.expense-actions {
  display: flex;
  gap: 0.5rem;
}

/* Summary */
.summary {
  display: flex;
  gap: 2rem;
  margin-bottom: 1rem;
}

.summary-item {
  text-align: center;
}

.summary-value {
  font-size: 1.5rem;
  font-weight: 600;
  color: #007bff;
}

.summary-label {
  color: #888;
  font-size: 0.875rem;
}

/* Messages */
.message {
  padding: 1rem;
  border-radius: 4px;
  margin-bottom: 1rem;
}

.message-error {
  background: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
}

.message-success {
  background: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
}

/* Auth pages */
.auth-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.auth-card {
  width: 100%;
  max-width: 400px;
}

.auth-card h1 {
  text-align: center;
  margin-bottom: 1.5rem;
  color: #007bff;
}

.auth-footer {
  text-align: center;
  margin-top: 1rem;
  color: #666;
}

.auth-footer a {
  color: #007bff;
}

/* Loading */
.loading {
  text-align: center;
  padding: 2rem;
  color: #888;
}

/* Empty state */
.empty-state {
  text-align: center;
  padding: 3rem;
  color: #888;
}

.empty-state p {
  margin-bottom: 1rem;
}

/* Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal {
  background: white;
  border-radius: 8px;
  padding: 2rem;
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal h2 {
  margin-bottom: 1rem;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 1rem;
  margin-top: 1.5rem;
}

.hidden {
  display: none !important;
}