:root {
  /* Mercado Livre Theme */
  --color-primary: #FFF159;
  --color-primary-dark: #F5E236;
  --color-secondary: #2D3277;
  --color-secondary-light: #3D44A1;
  --color-background: #EBEBEB;
  --color-surface: #FFFFFF;
  --color-text-primary: #333333;
  --color-text-secondary: #666666;
  --color-text-muted: #999999;
  --color-error: #E53935;
  --color-success: #00A650;
  
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  
  --border-radius: 6px;
  --border-radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--color-background);
  color: var(--color-text-primary);
  line-height: 1.5;
}

#app {
  max-width: 600px; /* Mobile first, but centered on larger screens */
  margin: 0 auto;
  min-height: 100vh;
  background-color: var(--color-surface);
  position: relative;
  display: flex;
  flex-direction: column;
}

/* Header */
.app-header {
  background-color: var(--color-primary);
  padding: 0 var(--spacing-md);
  height: 70px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: var(--shadow-sm);
}

.app-header h1 {
  font-size: 1.25rem;
  color: var(--color-secondary);
  font-weight: 700;
  flex: 1;
  text-align: center;
}

/* Content Area */
.app-content {
  flex: 1;
  padding: var(--spacing-md);
  overflow-y: auto;
  padding-bottom: 80px; /* Space for sticky footer button */
}

/* Typography */
h2 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

/* Cards */
.card {
  background: var(--color-surface);
  border: 1px solid #E0E0E0;
  border-radius: var(--border-radius);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  display: flex;
  flex-direction: column;
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  box-shadow: var(--shadow-md);
}

/* Product Card */
.product-card {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: var(--spacing-md);
}

.product-image {
  width: 70px;
  height: 70px;
  background-color: var(--color-background);
  border-radius: var(--border-radius);
  object-fit: cover;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.product-info {
  flex: 1;
}

.product-name {
  font-weight: 500;
  font-size: 1rem;
  margin-bottom: var(--spacing-xs);
}

.product-price {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text-primary);
}

.product-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.btn-qty {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1px solid var(--color-secondary);
  background: transparent;
  color: var(--color-secondary);
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.2s;
}

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

.qty-display {
  font-weight: 600;
  min-width: 20px;
  text-align: center;
}

/* Forms */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}

.form-input {
  width: 100%;
  padding: 12px;
  border: 1px solid #CCC;
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-family: inherit;
  transition: border-color 0.2s;
}

.form-input:focus {
  outline: none;
  border-color: var(--color-secondary);
}

.form-error {
  color: var(--color-error);
  font-size: 0.75rem;
  margin-top: var(--spacing-xs);
  display: none;
}

.form-group.has-error .form-input {
  border-color: var(--color-error);
}

.form-group.has-error .form-error {
  display: block;
}

/* Buttons */
.btn {
  display: block;
  width: 100%;
  padding: 14px;
  border: none;
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

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

.btn-secondary {
  background-color: transparent;
  color: var(--color-secondary);
  border: 1px solid var(--color-secondary);
}

/* Sticky Footer Button Container */
.sticky-footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  max-width: 600px;
  margin: 0 auto;
  padding: var(--spacing-md);
  background: white;
  box-shadow: 0 -2px 10px rgba(0,0,0,0.05);
  z-index: 10;
}

/* Summary Row */
.summary-row {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--spacing-sm);
  font-size: 0.875rem;
}

.summary-row.total {
  font-size: 1.125rem;
  font-weight: 700;
  margin-top: var(--spacing-md);
  padding-top: var(--spacing-sm);
  border-top: 1px solid #EEE;
}

/* Error/Empty State Alerts */
.alert {
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  background-color: #FFF3CD;
  color: #856404;
  margin-bottom: var(--spacing-md);
  font-size: 0.875rem;
}

.alert-error {
  background-color: #F8D7DA;
  color: #721C24;
}

.alert-success {
  background-color: #D4EDDA;
  color: #155724;
}

/* Pix Container */
.pix-container {
  text-align: center;
  padding: var(--spacing-lg) 0;
}

.pix-key-box {
  background: var(--color-background);
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  font-family: monospace;
  font-size: 0.875rem;
  word-break: break-all;
  margin: var(--spacing-md) 0;
  border: 1px dashed var(--color-text-muted);
}

/* Bank Grid */
.bank-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.btn-bank {
  background: white;
  border: 1px solid #DDD;
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-bank:hover {
  background: #F5F5F5;
}

/* Modal for Fallback */
.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: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-content {
  background: white;
  padding: var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  width: 90%;
  max-width: 400px;
  text-align: center;
}

.modal-content p {
  margin-bottom: var(--spacing-lg);
  font-size: 1rem;
}

.modal-content .btn {
  margin-bottom: var(--spacing-sm);
}