/**
 * Responsive Design Utilities
 * 
 * Production-ready responsive CSS utilities for the Wetail e-commerce platform.
 * Follows mobile-first approach with common breakpoints.
 * 
 * Breakpoints:
 * - xs: < 576px (mobile)
 * - sm: ≥ 576px (mobile landscape)
 * - md: ≥ 768px (tablet)
 * - lg: ≥ 992px (desktop)
 * - xl: ≥ 1200px (large desktop)
 * - xxl: ≥ 1400px (extra large desktop)
 */

/* ===== CSS Custom Properties for Theming ===== */
:root {
    /* Spacing Scale */
    --spacing-xs: 0.25rem;  /* 4px */
    --spacing-sm: 0.5rem;   /* 8px */
    --spacing-md: 1rem;     /* 16px */
    --spacing-lg: 1.5rem;   /* 24px */
    --spacing-xl: 2rem;     /* 32px */
    --spacing-xxl: 3rem;    /* 48px */
    
    /* Typography Scale */
    --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 */
    
    /* Responsive Container Widths */
    --container-sm: 540px;
    --container-md: 720px;
    --container-lg: 960px;
    --container-xl: 1140px;
    --container-xxl: 1320px;
    
    /* Z-Index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* ===== Container Utilities ===== */
/* .container-fluid spans full width with padding */
.container-fluid {
    width: 100%;
    padding-right: var(--spacing-md);
    padding-left: var(--spacing-md);
    margin-right: auto;
    margin-left: auto;
}

/* .container has max-width constraints at different breakpoints (set below) */
.container {
    width: 100%;
    padding-right: var(--spacing-md);
    padding-left: var(--spacing-md);
    margin-right: auto;
    margin-left: auto;
}

/* ===== Responsive Visibility Utilities ===== */
.d-none { display: none !important; }
.d-inline { display: inline !important; }
.d-inline-block { display: inline-block !important; }
.d-block { display: block !important; }
.d-flex { display: flex !important; }
.d-inline-flex { display: inline-flex !important; }
.d-grid { display: grid !important; }

/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {
    .container { max-width: var(--container-sm); }
    
    .d-sm-none { display: none !important; }
    .d-sm-inline { display: inline !important; }
    .d-sm-inline-block { display: inline-block !important; }
    .d-sm-block { display: block !important; }
    .d-sm-flex { display: flex !important; }
    .d-sm-inline-flex { display: inline-flex !important; }
    .d-sm-grid { display: grid !important; }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 768px) {
    .container { max-width: var(--container-md); }
    
    .d-md-none { display: none !important; }
    .d-md-inline { display: inline !important; }
    .d-md-inline-block { display: inline-block !important; }
    .d-md-block { display: block !important; }
    .d-md-flex { display: flex !important; }
    .d-md-inline-flex { display: inline-flex !important; }
    .d-md-grid { display: grid !important; }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
    .container { max-width: var(--container-lg); }
    
    .d-lg-none { display: none !important; }
    .d-lg-inline { display: inline !important; }
    .d-lg-inline-block { display: inline-block !important; }
    .d-lg-block { display: block !important; }
    .d-lg-flex { display: flex !important; }
    .d-lg-inline-flex { display: inline-flex !important; }
    .d-lg-grid { display: grid !important; }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
    .container { max-width: var(--container-xl); }
    
    .d-xl-none { display: none !important; }
    .d-xl-inline { display: inline !important; }
    .d-xl-inline-block { display: inline-block !important; }
    .d-xl-block { display: block !important; }
    .d-xl-flex { display: flex !important; }
    .d-xl-inline-flex { display: inline-flex !important; }
    .d-xl-grid { display: grid !important; }
}

/* ===== Flexbox Utilities ===== */
.flex-row { flex-direction: row !important; }
.flex-column { flex-direction: column !important; }
.flex-wrap { flex-wrap: wrap !important; }
.flex-nowrap { flex-wrap: nowrap !important; }

.justify-content-start { justify-content: flex-start !important; }
.justify-content-end { justify-content: flex-end !important; }
.justify-content-center { justify-content: center !important; }
.justify-content-between { justify-content: space-between !important; }
.justify-content-around { justify-content: space-around !important; }

.align-items-start { align-items: flex-start !important; }
.align-items-end { align-items: flex-end !important; }
.align-items-center { align-items: center !important; }
.align-items-baseline { align-items: baseline !important; }
.align-items-stretch { align-items: stretch !important; }

/* ===== Spacing Utilities ===== */
.m-0 { margin: 0 !important; }
.m-1 { margin: var(--spacing-xs) !important; }
.m-2 { margin: var(--spacing-sm) !important; }
.m-3 { margin: var(--spacing-md) !important; }
.m-4 { margin: var(--spacing-lg) !important; }
.m-5 { margin: var(--spacing-xl) !important; }

.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: var(--spacing-xs) !important; }
.mt-2 { margin-top: var(--spacing-sm) !important; }
.mt-3 { margin-top: var(--spacing-md) !important; }
.mt-4 { margin-top: var(--spacing-lg) !important; }
.mt-5 { margin-top: var(--spacing-xl) !important; }

.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: var(--spacing-xs) !important; }
.mb-2 { margin-bottom: var(--spacing-sm) !important; }
.mb-3 { margin-bottom: var(--spacing-md) !important; }
.mb-4 { margin-bottom: var(--spacing-lg) !important; }
.mb-5 { margin-bottom: var(--spacing-xl) !important; }

.p-0 { padding: 0 !important; }
.p-1 { padding: var(--spacing-xs) !important; }
.p-2 { padding: var(--spacing-sm) !important; }
.p-3 { padding: var(--spacing-md) !important; }
.p-4 { padding: var(--spacing-lg) !important; }
.p-5 { padding: var(--spacing-xl) !important; }

/* ===== Typography Utilities ===== */
.text-left { text-align: left !important; }
.text-right { text-align: right !important; }
.text-center { text-align: center !important; }
.text-justify { text-align: justify !important; }

.text-xs { font-size: var(--font-size-xs) !important; }
.text-sm { font-size: var(--font-size-sm) !important; }
.text-base { font-size: var(--font-size-base) !important; }
.text-lg { font-size: var(--font-size-lg) !important; }
.text-xl { font-size: var(--font-size-xl) !important; }
.text-2xl { font-size: var(--font-size-2xl) !important; }
.text-3xl { font-size: var(--font-size-3xl) !important; }

.font-weight-light { font-weight: 300 !important; }
.font-weight-normal { font-weight: 400 !important; }
.font-weight-medium { font-weight: 500 !important; }
.font-weight-semibold { font-weight: 600 !important; }
.font-weight-bold { font-weight: 700 !important; }

/* ===== Image Utilities ===== */
.img-fluid {
    max-width: 100%;
    height: auto;
}

.img-responsive {
    display: block;
    max-width: 100%;
    height: auto;
}

/* ===== Responsive Images with Lazy Loading ===== */
img[loading="lazy"] {
    opacity: 0;
    transition: opacity 0.3s ease-in;
}

img[loading="lazy"].loaded {
    opacity: 1;
}

/* Image placeholder while loading */
img[data-src] {
    background-color: #f0f0f0;
    min-height: 200px;
}

/* ===== Responsive Tables ===== */
.table-responsive {
    display: block;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

@media (max-width: 767px) {
    .table-responsive table {
        border: 0;
    }
    
    .table-responsive thead {
        display: none;
    }
    
    .table-responsive tr {
        display: block;
        margin-bottom: 1rem;
        border: 1px solid #ddd;
    }
    
    .table-responsive td {
        display: block;
        text-align: right;
        border-bottom: 1px solid #ddd;
    }
    
    .table-responsive td::before {
        content: attr(data-label);
        float: left;
        font-weight: bold;
    }
}

/* ===== Responsive Grid System ===== */
.row {
    display: flex;
    flex-wrap: wrap;
    margin-right: calc(var(--spacing-md) * -0.5);
    margin-left: calc(var(--spacing-md) * -0.5);
}

[class*="col-"] {
    position: relative;
    width: 100%;
    padding-right: calc(var(--spacing-md) * 0.5);
    padding-left: calc(var(--spacing-md) * 0.5);
}

.col-12 { flex: 0 0 100%; max-width: 100%; }
.col-11 { flex: 0 0 91.666667%; max-width: 91.666667%; }
.col-10 { flex: 0 0 83.333333%; max-width: 83.333333%; }
.col-9 { flex: 0 0 75%; max-width: 75%; }
.col-8 { flex: 0 0 66.666667%; max-width: 66.666667%; }
.col-7 { flex: 0 0 58.333333%; max-width: 58.333333%; }
.col-6 { flex: 0 0 50%; max-width: 50%; }
.col-5 { flex: 0 0 41.666667%; max-width: 41.666667%; }
.col-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
.col-3 { flex: 0 0 25%; max-width: 25%; }
.col-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
.col-1 { flex: 0 0 8.333333%; max-width: 8.333333%; }

@media (min-width: 768px) {
    .col-md-12 { flex: 0 0 100%; max-width: 100%; }
    .col-md-6 { flex: 0 0 50%; max-width: 50%; }
    .col-md-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
    .col-md-3 { flex: 0 0 25%; max-width: 25%; }
    .col-md-2 { flex: 0 0 16.666667%; max-width: 16.666667%; }
}

@media (min-width: 992px) {
    .col-lg-12 { flex: 0 0 100%; max-width: 100%; }
    .col-lg-6 { flex: 0 0 50%; max-width: 50%; }
    .col-lg-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
    .col-lg-3 { flex: 0 0 25%; max-width: 25%; }
}

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

.sr-only-focusable:active,
.sr-only-focusable:focus {
    position: static;
    width: auto;
    height: auto;
    overflow: visible;
    clip: auto;
    white-space: normal;
}

/* Focus visible for keyboard navigation */
:focus-visible {
    outline: 2px solid #0066cc;
    outline-offset: 2px;
}

/* ===== Reduced Motion Support ===== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ===== High Contrast Mode Support ===== */
@media (prefers-contrast: high) {
    * {
        border-width: 2px !important;
    }
    
    a {
        text-decoration: underline !important;
    }
}

/* ===== Print Styles ===== */
@media print {
    .no-print {
        display: none !important;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.5;
    }
    
    a[href]::after {
        content: " (" attr(href) ")";
    }
    
    img {
        max-width: 100% !important;
    }
}

/* ===== Performance Utilities ===== */
.will-change-transform {
    will-change: transform;
}

.will-change-opacity {
    will-change: opacity;
}

/* GPU acceleration for smoother animations */
.gpu-accelerated {
    transform: translateZ(0);
    backface-visibility: hidden;
    perspective: 1000px;
}

/* ===== Loading States ===== */
.skeleton {
    background: linear-gradient(
        90deg,
        #f0f0f0 25%,
        #e0e0e0 50%,
        #f0f0f0 75%
    );
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s ease-in-out infinite;
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ===== Utility Mixins (as CSS classes) ===== */
.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.line-clamp-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.line-clamp-3 {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ===== Aspect Ratio Utilities ===== */
.aspect-ratio-16-9 {
    aspect-ratio: 16 / 9;
}

.aspect-ratio-4-3 {
    aspect-ratio: 4 / 3;
}

.aspect-ratio-1-1 {
    aspect-ratio: 1 / 1;
}

/* Fallback for browsers without aspect-ratio support */
@supports not (aspect-ratio: 1 / 1) {
    .aspect-ratio-16-9 {
        padding-bottom: 56.25%; /* 9/16 = 0.5625 */
    }
    
    .aspect-ratio-4-3 {
        padding-bottom: 75%; /* 3/4 = 0.75 */
    }
    
    .aspect-ratio-1-1 {
        padding-bottom: 100%;
    }
}