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

:root {
  --primary-color: #3498db;
  --secondary-color: #2ecc71;
  --danger-color: #e74c3c;
  --warning-color: #f39c12;
  --dark-color: #2c3e50;
  --light-color: #ecf0f1;
  --bg-color: #f5f5f5;
  --text-color: #333;
  --border-radius: 12px;
  --shadow: 0 2px 10px rgba(0,0,0,0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  padding: 0;
  margin: 0;
  -webkit-font-smoothing: antialiased;
  max-width: 100%;
  overflow-x: hidden;
}

/* Contenedor principal */
.container {
  max-width: 480px;
  margin: 0 auto;
  padding: 15px;
  min-height: 100vh;
}

/* Header */
.header {
  background: linear-gradient(135deg, var(--primary-color), #2980b9);
  color: white;
  padding: 20px 15px;
  margin: -15px -15px 20px -15px;
  box-shadow: var(--shadow);
}

.header h1 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 5px;
}

.header p {
  font-size: 14px;
  opacity: 0.9;
}

/* Tarjetas */
.card {
  background: white;
  border-radius: var(--border-radius);
  padding: 20px;
  margin-bottom: 15px;
  box-shadow: var(--shadow);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
  padding-bottom: 15px;
  border-bottom: 1px solid var(--light-color);
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--dark-color);
}

/* Formularios */
.form-group {
  margin-bottom: 15px;
}

.form-label {
  display: block;
  margin-bottom: 5px;
  font-weight: 500;
  font-size: 14px;
  color: var(--dark-color);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 12px;
  border: 2px solid var(--light-color);
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.3s;
  font-family: inherit;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--primary-color);
}

.form-textarea {
  min-height: 80px;
  resize: vertical;
}

/* Botones */
.btn {
  display: inline-block;
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  text-align: center;
  transition: all 0.3s;
  text-decoration: none;
  width: 100%;
  margin-bottom: 10px;
}

.btn-primary {
  background-color: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background-color: #2980b9;
}

.btn-success {
  background-color: var(--secondary-color);
  color: white;
}

.btn-success:hover {
  background-color: #27ae60;
}

.btn-danger {
  background-color: var(--danger-color);
  color: white;
}

.btn-danger:hover {
  background-color: #c0392b;
}

.btn-secondary {
  background-color: #95a5a6;
  color: white;
}

.btn-secondary:hover {
  background-color: #7f8c8d;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Estadísticas */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-bottom: 15px;
}

.stat-card {
  background: white;
  padding: 15px;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  text-align: center;
}

.stat-label {
  font-size: 12px;
  color: #7f8c8d;
  text-transform: uppercase;
  margin-bottom: 5px;
}

.stat-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--dark-color);
}

.stat-positive {
  color: var(--secondary-color);
}

.stat-negative {
  color: var(--danger-color);
}

/* Lista de items */
.item-list {
  list-style: none;
}

.item {
  background: white;
  border-radius: 8px;
  padding: 15px;
  margin-bottom: 10px;
  box-shadow: 0 1px 5px rgba(0,0,0,0.08);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.item-info {
  flex: 1;
}

.item-title {
  font-weight: 600;
  font-size: 16px;
  margin-bottom: 4px;
}

.item-subtitle {
  font-size: 14px;
  color: #7f8c8d;
}

.item-amount {
  font-size: 18px;
  font-weight: 700;
}

.item-amount.expense {
  color: var(--danger-color);
}

.item-amount.income {
  color: var(--secondary-color);
}

/* Tabs de navegación */
.tabs {
  display: flex;
  background: white;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

.tab {
  flex: 1;
  padding: 15px;
  text-align: center;
  background: white;
  border: none;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  color: #7f8c8d;
  transition: all 0.3s;
  border-bottom: 3px solid transparent;
}

.tab.active {
  color: var(--primary-color);
  border-bottom-color: var(--primary-color);
}

/* Bottom navigation */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: white;
  display: flex;
  justify-content: space-around;
  padding: 10px 0;
  padding-bottom: calc(10px + env(safe-area-inset-bottom));
  box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
  z-index: 1000;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-decoration: none;
  color: #7f8c8d;
  font-size: 12px;
  padding: 5px 15px;
  transition: color 0.3s;
}

.nav-item.active {
  color: var(--primary-color);
}

.nav-icon {
  font-size: 24px;
  margin-bottom: 4px;
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
  z-index: 2000;
  padding: 20px;
  overflow-y: auto;
}

.modal.active {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background: white;
  border-radius: var(--border-radius);
  padding: 25px;
  max-width: 480px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.modal-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--dark-color);
}

.modal-close {
  background: none;
  border: none;
  font-size: 28px;
  color: #7f8c8d;
  cursor: pointer;
  padding: 0;
  width: 30px;
  height: 30px;
  line-height: 1;
}

/* Alertas */
.alert {
  padding: 12px 15px;
  border-radius: 8px;
  margin-bottom: 15px;
  font-size: 14px;
}

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

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

.alert-info {
  background-color: #d1ecf1;
  color: #0c5460;
  border: 1px solid #bee5eb;
}

/* Loading spinner */
.spinner {
  border: 3px solid var(--light-color);
  border-top: 3px solid var(--primary-color);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  animation: spin 1s linear infinite;
  margin: 20px auto;
}

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

/* Ocultar elementos */
.hidden {
  display: none !important;
}

/* Progress bar */
.progress-bar {
  width: 100%;
  height: 8px;
  background-color: var(--light-color);
  border-radius: 4px;
  overflow: hidden;
  margin: 10px 0;
}

.progress-fill {
  height: 100%;
  background-color: var(--primary-color);
  transition: width 0.3s;
}

/* Fotografías preview */
.photo-preview {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.photo-item {
  position: relative;
  width: 80px;
  height: 80px;
  border-radius: 8px;
  overflow: hidden;
}

.photo-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.photo-remove {
  position: absolute;
  top: 5px;
  right: 5px;
  background: var(--danger-color);
  color: white;
  border: none;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  font-size: 16px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Espaciado para bottom nav */
.content-with-nav {
  padding-bottom: 160px !important;
  min-height: 100vh;
}

@supports (padding: max(0px)) {
  .content-with-nav {
    padding-bottom: max(160px, env(safe-area-inset-bottom)) !important;
  }
}

/* Checkbox personalizado */
.checkbox-container {
  display: flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
  margin-bottom: 10px;
}

.checkbox-container input[type="checkbox"] {
  width: 18px;
  height: 18px;
  margin-right: 10px;
  cursor: pointer;
  accent-color: var(--primary-color);
}

.checkbox-label {
  font-size: 14px;
  font-weight: 500;
  color: var(--dark-color);
  cursor: pointer;
}

.checkbox-container:hover .checkbox-label {
  color: var(--primary-color);
}

/* Responsive ajustes */
@media (max-width: 480px) {
  .container {
    padding: 10px;
  }

  .header {
    margin: -10px -10px 15px -10px;
  }
}