/* CSS Reset & Variables */
:root {
  --color-black: #0a0a0a;
  --color-white: #ffffff;
  --color-gray-50: #fafafa;
  --color-gray-100: #f5f5f5;
  --color-gray-200: #e5e5e5;
  --color-gray-300: #d4d4d4;
  --color-gray-400: #a3a3a3;
  --color-gray-500: #737373;
  --color-gray-600: #525252;
  --color-gray-700: #404040;
  --color-gray-800: #262626;
  --color-gray-900: #171717;
  
  --color-accent: #0a0a0a;
  --color-success: #16a34a;
  --color-error: #dc2626;
  --color-info: #2563eb;
  
  --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', Consolas, monospace;
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  
  --transition: 150ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-gray-50);
  color: var(--color-black);
  line-height: 1.6;
  min-height: 100vh;
}

/* Typography */

h1, h2, h3, h4, h5, h6 {
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: -0.02em;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }

p {
  color: var(--color-gray-600);
}

.text-sm { font-size: 0.875rem; }
.text-xs { font-size: 0.75rem; }
.text-mono { font-family: var(--font-mono); }

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
}

.page-wrapper {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.logo {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-black);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: var(--color-black);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
  font-weight: 700;
  font-size: 0.875rem;
}

.nav-badge {
  font-size: 0.75rem;
  padding: 0.25rem 0.75rem;
  background: var(--color-gray-100);
  border-radius: 100px;
  color: var(--color-gray-600);
  font-weight: 500;
}

/* Main Content */
.main {
  flex: 1;
  padding: 3rem 0;
}

/* Cards & Sections */
.card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.section-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-gray-500);
  margin-bottom: 1rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 500;
  font-family: inherit;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  border: none;
}

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

.btn-primary:hover {
  background: var(--color-gray-800);
}

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

.btn-secondary {
  background: var(--color-white);
  color: var(--color-black);
  border: 1px solid var(--color-gray-300);
}

.btn-secondary:hover {
  background: var(--color-gray-50);
  border-color: var(--color-gray-400);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1rem;
}

.btn-block {
  width: 100%;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ============================================
   Form Elements
   ============================================ */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--color-gray-700);
}

.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  background: var(--color-white);
  transition: all var(--transition);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-black);
  box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.form-input::placeholder {
  color: var(--color-gray-400);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* Hosted Fields Container */
.hosted-field-container {
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  height: 48px;
  background: var(--color-white);
  transition: all var(--transition);
  overflow: hidden;
}

.hosted-field-container:focus-within {
  border-color: var(--color-black);
  box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.hosted-field-container iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* Express Checkout Container */
.express-checkout-container {
  min-height: 500px;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.express-checkout-container iframe {
  min-height: 500px;
  width: 100%;
  height: 100%;
  border: none;
}

/* Status Messages */
.status-message {
  padding: 1rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  margin-top: 1rem;
  display: none;
}

.status-message.visible {
  display: block;
}

.status-message.success {
  background: #f0fdf4;
  border: 1px solid #bbf7d0;
  color: #166534;
}

.status-message.error {
  background: #fef2f2;
  border: 1px solid #fecaca;
  color: #991b1b;
}

.status-message.info {
  background: var(--color-gray-100);
  border: 1px solid var(--color-gray-200);
  color: var(--color-gray-700);
}

/* Back Link */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--color-gray-600);
  text-decoration: none;
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
  transition: color var(--transition);
}

.back-link:hover {
  color: var(--color-black);
}

.back-link svg {
  width: 16px;
  height: 16px;
}

/* Footer */
.footer {
  padding: 2rem 0;
  border-top: 1px solid var(--color-gray-200);
  margin-top: auto;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  color: var(--color-gray-500);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--color-gray-500);
  text-decoration: none;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--color-black);
}

/* Loading States */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 2rem;
  color: var(--color-gray-500);
}

.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-gray-200);
  border-top-color: var(--color-black);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.btn-spinner {
  display: inline-flex;
  align-items: center;
  margin-right: 0.5rem;
}

.btn-spinner .spinner {
  width: 16px;
  height: 16px;
  border-width: 2px;
  border-color: rgba(255, 255, 255, 0.3);
  border-top-color: white;
}

.btn-spinner.hidden {
  display: none;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Security Badge */
.security-badge {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--color-gray-500);
  margin-top: 1rem;
}

.security-badge svg {
  width: 14px;
  height: 14px;
}

/* Test Card Info */
.test-info {
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  padding: 1rem;
  font-size: 0.8125rem;
}

.test-info-title {
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-gray-700);
}

.test-info code {
  font-family: var(--font-mono);
  background: var(--color-white);
  padding: 0.125rem 0.375rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
}

/* Landing Page - SDK Selector */
.landing-content {
  max-width: 700px;
  margin: 0 auto;
}

.landing-header {
  text-align: center;
  margin-bottom: 2rem;
}

.landing-header h1 {
  margin-bottom: 0.5rem;
}

.landing-header p {
  font-size: 1.125rem;
}

.sdk-selector {
  margin-bottom: 2rem;
}

.sdk-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.sdk-option {
  cursor: pointer;
}

.sdk-option input[type="radio"] {
  display: none;
}

.sdk-option-content {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  border: 2px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  transition: all var(--transition);
}

.sdk-option:hover .sdk-option-content {
  border-color: var(--color-gray-400);
}

.sdk-option input:checked + .sdk-option-content {
  border-color: var(--color-black);
  background: var(--color-gray-50);
}

.sdk-option-icon {
  width: 48px;
  height: 48px;
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.sdk-option-icon svg {
  width: 24px;
  height: 24px;
  color: var(--color-gray-700);
}

.sdk-option-text {
  display: flex;
  flex-direction: column;
}

.sdk-option-title {
  font-weight: 500;
  color: var(--color-black);
}

.sdk-option-desc {
  font-size: 0.8125rem;
  color: var(--color-gray-500);
}

/* Landing Page - Flow Cards */
.flow-options {
  margin-bottom: 2rem;
}

.flow-cards {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.flow-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem;
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition);
}

.flow-card:hover {
  border-color: var(--color-gray-400);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.flow-card-icon {
  width: 48px;
  height: 48px;
  background: var(--color-gray-100);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.flow-card-icon svg {
  width: 24px;
  height: 24px;
  color: var(--color-gray-700);
}

.flow-card-content {
  flex: 1;
}

.flow-card-content h3 {
  font-size: 1rem;
  margin-bottom: 0.25rem;
}

.flow-card-content p {
  font-size: 0.875rem;
  color: var(--color-gray-500);
  margin: 0;
}

.flow-badge {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.25rem 0.5rem;
  background: var(--color-black);
  color: var(--color-white);
  border-radius: 100px;
  margin-top: 0.375rem;
}

.flow-card-arrow {
  color: var(--color-gray-400);
  transition: transform var(--transition);
}

.flow-card-arrow svg {
  width: 20px;
  height: 20px;
}

.flow-card:hover .flow-card-arrow {
  transform: translateX(4px);
  color: var(--color-gray-600);
}

/* Tokenize Page Layout */
.tokenize-layout {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 3rem;
  align-items: start;
}

@media (max-width: 900px) {
  .tokenize-layout {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .sdk-options {
    grid-template-columns: 1fr;
  }
}

/* Result Display */
.result-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-top: 1.5rem;
}

.result-card.success {
  border-color: #bbf7d0;
  background: #f0fdf4;
}

.result-card.error {
  border-color: #fecaca;
  background: #fef2f2;
}

.result-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.result-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.result-icon.success {
  background: #dcfce7;
  color: #166534;
}

.result-icon.error {
  background: #fee2e2;
  color: #991b1b;
}

.result-icon svg {
  width: 24px;
  height: 24px;
}

.result-title {
  font-size: 1.125rem;
  font-weight: 500;
}

.result-details {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  overflow-x: auto;
}

.result-row {
  display: flex;
  justify-content: space-between;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--color-gray-100);
}

.result-row:last-child {
  border-bottom: none;
}

.result-label {
  color: var(--color-gray-500);
}

.result-value {
  font-weight: 500;
  color: var(--color-black);
  word-break: break-all;
  text-align: right;
  max-width: 60%;
}

/* Config Panel (Right Side) */
.config-panel {
  position: sticky;
  top: 5rem;
}

.config-section {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1rem;
}

.config-section-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-gray-500);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.config-section-title svg {
  width: 16px;
  height: 16px;
}

.config-option {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.625rem 0;
  border-bottom: 1px solid var(--color-gray-100);
}

.config-option:last-child {
  border-bottom: none;
}

.config-checkbox {
  width: 18px;
  height: 18px;
  margin-top: 2px;
  cursor: pointer;
  accent-color: var(--color-black);
  flex-shrink: 0;
}

.config-option-content {
  flex: 1;
}

.config-option-label {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-black);
  cursor: pointer;
  display: block;
}

.config-option-desc {
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  margin-top: 0.125rem;
}

/* ============================================
   Utilities
   ============================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }

.hidden { display: none !important; }

/* Display Mode Options (Express Checkout) */
.display-mode-options {
  display: flex;
  gap: 0.75rem;
}

.display-mode-option {
  cursor: pointer;
  flex: 1;
}

.display-mode-option input[type="radio"] {
  display: none;
}

.display-mode-label {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-gray-600);
  transition: all var(--transition);
}

.display-mode-option:hover .display-mode-label {
  border-color: var(--color-gray-400);
}

.display-mode-option input:checked + .display-mode-label {
  border-color: var(--color-black);
  background: var(--color-gray-50);
  color: var(--color-black);
}

/* Express Checkout Dialog Overlay */
.express-dialog-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 1;
  transition: opacity var(--transition);
}

.express-dialog-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.express-dialog-content {
  width: 550px;
  height: 550px;
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.express-dialog-content #express-checkout-container {
  width: 100%;
  height: 100%;
}

.express-dialog-content #express-checkout-container iframe {
  width: 100%;
  height: 100%;
  border: none;
}

.express-dialog-content #express-checkout-dialog-container {
  width: 100%;
  height: 100%;
}

.express-dialog-content #express-checkout-dialog-container iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* 3DS Challenge Modal */
.threeds-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1100;
  opacity: 1;
  transition: opacity var(--transition);
}

.threeds-modal.hidden {
  opacity: 0;
  pointer-events: none;
}

.threeds-modal-content {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 1rem;
  max-width: 640px;
  width: 95%;
  max-height: 90vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.challenge-iframe {
  width: 100%;
  height: 600px;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
}