/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Arial', sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f4f4f4;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header Styles */
header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 1rem 0;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: bold;
}

.nav-links {
  display: flex;
  gap: 20px;
}

.nav-links a {
  color: white;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  transition: background-color 0.3s;
}

.nav-links a:hover {
  background-color: rgba(255,255,255,0.2);
}

/* Main Content */
main {
  padding: 2rem 0;
  min-height: calc(100vh - 120px);
}

/* Card Styles */
.card {
  background: white;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  padding: 2rem;
  margin-bottom: 2rem;
}

.card h2 {
  color: #667eea;
  margin-bottom: 1rem;
}

/* Form Styles */
.form-group {
  margin-bottom: 1.5rem;
}

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

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border: 2px solid #ddd;
  border-radius: 5px;
  font-size: 1rem;
  transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: #667eea;
}

/* Button Styles */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  font-size: 1rem;
  text-decoration: none;
  display: inline-block;
  transition: all 0.3s;
  text-align: center;
}

.btn-primary {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

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

.btn-success {
  background: #28a745;
  color: white;
}

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

.btn-small {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

/* Login/Register Form */
.auth-container {
  max-width: 400px;
  margin: 2rem auto;
}

.auth-tabs {
  display: flex;
  margin-bottom: 2rem;
}

.auth-tab {
  flex: 1;
  padding: 1rem;
  background: #ddd;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  transition: background-color 0.3s;
}

.auth-tab.active {
  background: #667eea;
  color: white;
}

.auth-form {
  display: none;
}

.auth-form.active {
  display: block;
}

/* Dashboard Styles */
.dashboard-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: white;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  text-align: center;
}

.stat-card h3 {
  color: #667eea;
  margin-bottom: 1rem;
}

.stat-value {
  font-size: 2rem;
  font-weight: bold;
  color: #333;
}

/* Expense List */
.expense-list {
  background: white;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.expense-header {
  background: #667eea;
  color: white;
  padding: 1rem;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 1rem;
  font-weight: bold;
}

.expense-item {
  padding: 1rem;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 1rem;
  border-bottom: 1px solid #eee;
  align-items: center;
}

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

.expense-item:hover {
  background: #f8f9fa;
}

.expense-amount {
  font-weight: bold;
  color: #dc3545;
}

.expense-category {
  background: #e9ecef;
  padding: 0.25rem 0.5rem;
  border-radius: 15px;
  font-size: 0.875rem;
  text-align: center;
}

.expense-date {
  color: #6c757d;
  font-size: 0.875rem;
}

/* Category Colors */
.category-food { background: #ffeaa7; }
.category-transport { background: #74b9ff; }
.category-entertainment { background: #fd79a8; }
.category-utilities { background: #fdcb6e; }
.category-healthcare { background: #e17055; }
.category-shopping { background: #a29bfe; }
.category-other { background: #ddd; }

/* Error/Success Messages */
.error {
  background: #f8d7da;
  color: #721c24;
  padding: 1rem;
  border-radius: 5px;
  margin-bottom: 1rem;
  border: 1px solid #f5c6cb;
}

.success {
  background: #d4edda;
  color: #155724;
  padding: 1rem;
  border-radius: 5px;
  margin-bottom: 1rem;
  border: 1px solid #c3e6cb;
}

/* Responsive Design */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: 1rem;
  }
  
  .nav-links {
    flex-direction: column;
    text-align: center;
  }
  
  .dashboard-stats {
    grid-template-columns: 1fr;
  }
  
  .expense-header,
  .expense-item {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .expense-header {
    display: none;
  }
  
  .expense-item {
    padding: 1rem;
    border: 1px solid #ddd;
    margin-bottom: 1rem;
    border-radius: 5px;
  }
}