:root {
    /* Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --success-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);

    /* Background Colors */
    --bg-primary: #0f0f1e;
    --bg-secondary: #1a1a2e;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-input: rgba(255, 255, 255, 0.08);

    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #b4b4c8;
    --text-muted: #828292;

    /* Border & Shadow */
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --glow: 0 0 20px rgba(102, 126, 234, 0.3);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    background-image:
        radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(118, 75, 162, 0.15) 0%, transparent 50%);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    padding: var(--spacing-lg) var(--spacing-sm);
}

.container {
    max-width: 900px;
    margin: 0 auto;
}

.checkout-wrapper {
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Header */
.checkout-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    animation: fadeIn 0.8s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.checkout-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
}

.checkout-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Checkout Content */
.checkout-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
}

@media (min-width: 768px) {
    .checkout-content {
        grid-template-columns: 1fr 1fr;
    }
}

/* Section Cards */
.product-section,
.payment-section {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.product-section:hover,
.payment-section:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg), var(--glow);
}

.product-section h2,
.payment-section h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-lg);
}

/* Form Elements */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.label-text {
    display: flex;
    align-items: center;
}

.label-icon {
    font-size: 1.2rem;
}

.form-input,
.form-textarea {
    width: 100%;
    padding: var(--spacing-sm);
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: var(--font-family);
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: #667eea;
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--text-muted);
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
}

/* Stripe Element */
.stripe-element {
    padding: var(--spacing-sm);
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
}

.stripe-element.StripeElement--focus {
    border-color: #667eea;
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

/* Order Summary */
.order-summary {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: rgba(102, 126, 234, 0.1);
    border: 1px solid rgba(102, 126, 234, 0.3);
    border-radius: var(--radius-md);
    animation: slideIn 0.4s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.summary-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
}

.summary-row:last-child {
    margin-bottom: 0;
}

.summary-total {
    margin-top: var(--spacing-sm);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.summary-value {
    font-weight: 500;
}

.summary-value-total {
    background: var(--success-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

/* Pay Button */
.pay-button {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--primary-gradient);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
    margin-top: var(--spacing-md);
}

.pay-button:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 30px rgba(102, 126, 234, 0.4);
}

.pay-button:active:not(:disabled) {
    transform: translateY(0);
}

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

.button-icon {
    font-size: 1.2rem;
}

/* Payment Info */
.payment-info {
    text-align: center;
    margin-top: var(--spacing-md);
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* Error Messages */
.error-message {
    color: #ff6b6b;
    font-size: 0.85rem;
    margin-top: var(--spacing-xs);
    min-height: 20px;
}

/* Payment Status */
.payment-status {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: rgba(67, 233, 123, 0.1);
    border: 2px solid rgba(67, 233, 123, 0.3);
    border-radius: var(--radius-md);
    text-align: center;
    animation: successPulse 0.6s ease-out;
}

@keyframes successPulse {
    0% {
        opacity: 0;
        transform: scale(0.9);
    }

    50% {
        transform: scale(1.02);
    }

    100% {
        opacity: 1;
        transform: scale(1);
    }
}

.payment-status.hidden {
    display: none;
}

.status-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: var(--spacing-sm);
}

.status-content h3 {
    color: #43e97b;
    margin-bottom: var(--spacing-xs);
}

.status-content p {
    color: var(--text-secondary);
}

/* Test Notice */
.test-notice {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: rgba(245, 87, 108, 0.1);
    border: 1px solid rgba(245, 87, 108, 0.3);
    border-radius: var(--radius-md);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.test-notice code {
    background: rgba(255, 255, 255, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: var(--text-primary);
}

/* Responsive Design */
@media (max-width: 767px) {
    .checkout-header h1 {
        font-size: 2rem;
    }

    .checkout-content {
        gap: var(--spacing-md);
    }

    .product-section,
    .payment-section {
        padding: var(--spacing-md);
    }

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

/* Loading Animation */
@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.pay-button.loading::after {
    content: '';
    width: 16px;
    height: 16px;
    margin-left: 10px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}