/* Improved UI Styling for Better User Experience */
/* Focus on clean typography, better spacing, and reduced cognitive load */

/* Import Google Fonts for better typography */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

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

/* Root Variables for Consistent Design System */
:root {
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;    /* 12px */
    --font-size-sm: 0.875rem;   /* 14px */
    --font-size-base: 1rem;     /* 16px */
    --font-size-lg: 1.125rem;   /* 18px */
    --font-size-xl: 1.25rem;    /* 20px */
    --font-size-2xl: 1.5rem;    /* 24px */
    --font-size-3xl: 1.875rem;  /* 30px */
    --font-size-4xl: 2.25rem;   /* 36px */
    
    /* Font Weights */
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Line Heights */
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* Colors - Improved for better readability */
    --color-primary: #2563eb;      /* Blue 600 - more accessible */
    --color-primary-hover: #1d4ed8; /* Blue 700 */
    --color-primary-light: #dbeafe; /* Blue 100 */
    --color-secondary: #64748b;     /* Slate 500 */
    --color-success: #059669;       /* Emerald 600 */
    --color-warning: #d97706;       /* Amber 600 */
    --color-error: #dc2626;         /* Red 600 */
    
    /* Neutral Colors */
    --color-gray-50: #f8fafc;
    --color-gray-100: #f1f5f9;
    --color-gray-200: #e2e8f0;
    --color-gray-300: #cbd5e1;
    --color-gray-400: #94a3b8;
    --color-gray-500: #64748b;
    --color-gray-600: #475569;
    --color-gray-700: #334155;
    --color-gray-800: #1e293b;
    --color-gray-900: #0f172a;
    
    /* Spacing */
    --space-1: 0.25rem;   /* 4px */
    --space-2: 0.5rem;    /* 8px */
    --space-3: 0.75rem;   /* 12px */
    --space-4: 1rem;      /* 16px */
    --space-5: 1.25rem;   /* 20px */
    --space-6: 1.5rem;    /* 24px */
    --space-8: 2rem;      /* 32px */
    --space-10: 2.5rem;   /* 40px */
    --space-12: 3rem;     /* 48px */
    --space-16: 4rem;     /* 64px */
    --space-20: 5rem;     /* 80px */
    
    /* Border Radius */
    --radius-sm: 0.375rem;  /* 6px */
    --radius-md: 0.5rem;    /* 8px */
    --radius-lg: 0.75rem;   /* 12px */
    --radius-xl: 1rem;      /* 16px */
    --radius-2xl: 1.5rem;   /* 24px */
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* Base Typography */
body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--color-gray-800);
    background-color: var(--color-gray-50);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Improved Headings */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-semibold);
    line-height: var(--line-height-tight);
    color: var(--color-gray-900);
    margin-bottom: var(--space-4);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

/* Paragraphs */
p {
    margin-bottom: var(--space-4);
    color: var(--color-gray-600);
    line-height: var(--line-height-relaxed);
}

/* Links */
a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-hover);
    text-decoration: underline;
}

/* Buttons - Improved Design System */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    line-height: 1;
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
    user-select: none;
}

.btn:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

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

/* Button Variants */
.btn-primary {
    background-color: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
    color: white;
    text-decoration: none;
}

.btn-secondary {
    background-color: white;
    color: var(--color-gray-700);
    border-color: var(--color-gray-300);
}

.btn-secondary:hover:not(:disabled) {
    background-color: var(--color-gray-50);
    border-color: var(--color-gray-400);
    color: var(--color-gray-800);
    text-decoration: none;
}

.btn-outline {
    background-color: transparent;
    color: var(--color-primary);
    border-color: var(--color-primary);
}

.btn-outline:hover:not(:disabled) {
    background-color: var(--color-primary);
    color: white;
    text-decoration: none;
}

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

.btn-success:hover:not(:disabled) {
    background-color: #047857;
    border-color: #047857;
    color: white;
    text-decoration: none;
}

/* Button Sizes */
.btn-sm {
    padding: var(--space-2) var(--space-4);
    font-size: var(--font-size-xs);
}

.btn-lg {
    padding: var(--space-4) var(--space-8);
    font-size: var(--font-size-lg);
}

/* Form Elements - Improved Design */
.form-group {
    margin-bottom: var(--space-6);
}

label {
    display: block;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: var(--color-gray-700);
    margin-bottom: var(--space-2);
}

input[type="text"],
input[type="email"],
input[type="tel"],
input[type="number"],
input[type="password"],
select,
textarea {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--color-gray-800);
    background-color: white;
    border: 1px solid var(--color-gray-300);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

input::placeholder,
textarea::placeholder {
    color: var(--color-gray-400);
}

/* Cards - Improved Design */
.card {
    background: white;
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-lg);
    padding: var(--space-8);
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition-normal);
}

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

/* Pricing Specific Improvements */
.pricing-hero {
    padding: var(--space-20) 0 var(--space-12);
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.pricing-hero .subtitle {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-gray-900);
    margin-bottom: var(--space-4);
}

.pricing-hero .desc {
    font-size: var(--font-size-lg);
    color: var(--color-gray-600);
    max-width: 600px;
    margin: 0 auto;
}

/* Currency Toggle - Improved */
.currency-toggle {
    display: inline-flex;
    gap: var(--space-1);
    padding: var(--space-1);
    background: var(--color-gray-100);
    border-radius: var(--radius-2xl);
    border: 1px solid var(--color-gray-200);
}

.currency-btn {
    padding: var(--space-2) var(--space-4);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: var(--color-gray-600);
    background: transparent;
    border: none;
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.currency-btn:hover {
    color: var(--color-gray-800);
    background: var(--color-gray-200);
}

.currency-btn.active {
    background: var(--color-primary);
    color: white;
    box-shadow: var(--shadow-sm);
}

/* Pricing Cards - Improved */
.pricing-card {
    background: white;
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    text-align: center;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.pricing-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.pricing-card.featured {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-xl);
    transform: scale(1.05);
}

.pricing-card .price {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-gray-900);
    margin: var(--space-4) 0;
}

.pricing-card .price-period {
    font-size: var(--font-size-base);
    color: var(--color-gray-500);
    font-weight: var(--font-weight-normal);
}

/* Checkout Page Improvements */
.checkout-container {
    max-width: 1000px;
    margin: var(--space-8) auto;
    padding: 0 var(--space-6);
}

.checkout-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-8);
    padding-bottom: var(--space-6);
    border-bottom: 1px solid var(--color-gray-200);
}

.checkout-header h1 {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-gray-900);
    margin: 0;
}

.checkout-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: var(--space-8);
}

.checkout-form {
    background: white;
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-sm);
}

.checkout-summary {
    background: white;
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: var(--space-8);
}

.summary-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-3) 0;
    border-bottom: 1px solid var(--color-gray-100);
}

.summary-item:last-child {
    border-bottom: none;
    font-weight: var(--font-weight-semibold);
    font-size: var(--font-size-lg);
}

.summary-total {
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-gray-900);
}

/* Error and Success Messages */
.alert {
    padding: var(--space-4);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-4);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
}

.alert-error {
    background-color: #fef2f2;
    border: 1px solid #fecaca;
    color: var(--color-error);
}

.alert-success {
    background-color: #f0fdf4;
    border: 1px solid #bbf7d0;
    color: var(--color-success);
}

.alert-warning {
    background-color: #fffbeb;
    border: 1px solid #fed7aa;
    color: var(--color-warning);
}

/* Loading States */
.loading {
    position: relative;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid var(--color-gray-300);
    border-top: 2px solid var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .checkout-grid {
        grid-template-columns: 1fr;
        gap: var(--space-6);
    }
    
    .checkout-container {
        padding: 0 var(--space-4);
        margin: var(--space-4) auto;
    }
    
    .pricing-hero .subtitle {
        font-size: var(--font-size-3xl);
    }
    
    .pricing-card.featured {
        transform: none;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .pricing-hero {
        padding: var(--space-16) 0 var(--space-8);
    }
    
    .pricing-hero .subtitle {
        font-size: var(--font-size-2xl);
    }
    
    .checkout-header {
        flex-direction: column;
        gap: var(--space-4);
        text-align: center;
    }
}

/* Accessibility Improvements */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus indicators for keyboard navigation */
*:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --color-gray-300: #000000;
        --color-gray-600: #000000;
        --color-gray-800: #000000;
    }
}