/**
 * =============================================
 * Core Base CSS - Foundation Styles
 * /core/assets/css/base.css
 * =============================================
 * 
 * Core styles for public-facing sites:
 * - CSS Variables (site-customisable colours)
 * - Reset & normalisation
 * - Typography
 * - Layout containers
 * - Utility classes
 */

/* ==============================================
   CSS VARIABLES - CUSTOMISE PER SITE
   ============================================== */
:root {
    /* Primary Colours - Blue/Teal Theme */
    --primary-color: #0ea5e9;
    --primary-dark: #0284c7;
    --primary-light: #38bdf8;
    
    /* Secondary Colours */
    --secondary-color: #14b8a6;
    --secondary-dark: #0d9488;
    --secondary-light: #2dd4bf;
    
    /* Accent Colours */
    --accent-color: #8b5cf6;
    --accent-dark: #7c3aed;
    --accent-light: #a78bfa;
    
    /* Status Colours */
    --success-color: #10b981;
    --success-bg: #d1fae5;
    --success-border: #6ee7b7;
    
    --error-color: #ef4444;
    --error-bg: #fee2e2;
    --error-border: #fca5a5;
    
    --warning-color: #f59e0b;
    --warning-bg: #fef3c7;
    --warning-border: #fcd34d;
    
    --info-color: #3b82f6;
    --info-bg: #dbeafe;
    --info-border: #93c5fd;
    
    /* Neutral Colours */
    --white: #ffffff;
    --black: #000000;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    
    --border-color: #e5e7eb;
    --border-light: #f3f4f6;
    --border-dark: #d1d5db;
    
    /* 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);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
    --radius-full: 9999px;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 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 */
    
    /* Line Heights */
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* Font Weights */
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 200ms ease-in-out;
    --transition-slow: 300ms ease-in-out;
    
    /* Z-index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* ==============================================
   RESET & BOX SIZING
   ============================================== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
* { position: relative; }

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

/* ==============================================
   BODY & LAYOUT
   ============================================== */
body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Main content wrapper */
main {
    flex: 1;
    width: 100%;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.container-sm {
    max-width: 640px;
}

.container-md {
    max-width: 768px;
}

.container-lg {
    max-width: 1024px;
}

.container-xl {
    max-width: 1280px;
}

.container-full {
    max-width: 100%;
    padding: 0;
}

/* Section spacing */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-sm {
    padding: var(--spacing-xl) 0;
}

.section-lg {
    padding: 64px 0;
}

/* ==============================================
   TYPOGRAPHY
   ============================================== */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: var(--font-weight-bold);
    line-height: var(--line-height-tight);
    margin-bottom: 0.5em;
}

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);
}

p {
    margin-bottom: 1em;
    line-height: var(--line-height-relaxed);
}

p:last-child {
    margin-bottom: 0;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-base);
}

a:hover {
    color: var(--primary-dark);
}

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

strong, b {
    font-weight: var(--font-weight-bold);
}

em, i {
    font-style: italic;
}

small {
    font-size: var(--font-size-sm);
}

/* Lists */
ul, ol {
    margin-bottom: 1em;
    padding-left: 1.5em;
}

ul ul, ol ol, ul ol, ol ul {
    margin-bottom: 0;
    margin-top: 0.5em;
}

li {
    margin-bottom: 0.5em;
}

/* Horizontal rule */
hr {
    border: 0;
    border-top: 1px solid var(--border-color);
    margin: var(--spacing-xl) 0;
}

/* Blockquote */
blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    font-style: italic;
    color: var(--text-secondary);
}

/* Code */
code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9em;
    padding: 2px 6px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    color: var(--accent-color);
}

pre {
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin-bottom: 1em;
}

pre code {
    padding: 0;
    background: transparent;
}

/* ==============================================
   UTILITY CLASSES - SPACING
   ============================================== */
/* Margin */
.m-0 { margin: 0; }
.m-xs { margin: var(--spacing-xs); }
.m-sm { margin: var(--spacing-sm); }
.m-md { margin: var(--spacing-md); }
.m-lg { margin: var(--spacing-lg); }
.m-xl { margin: var(--spacing-xl); }
.m-auto { margin: auto; }

/* Margin Top */
.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

/* Margin Bottom */
.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

/* Margin Left/Right */
.ml-0 { margin-left: 0; }
.ml-sm { margin-left: var(--spacing-sm); }
.ml-md { margin-left: var(--spacing-md); }
.ml-lg { margin-left: var(--spacing-lg); }
.ml-auto { margin-left: auto; }

.mr-0 { margin-right: 0; }
.mr-sm { margin-right: var(--spacing-sm); }
.mr-md { margin-right: var(--spacing-md); }
.mr-lg { margin-right: var(--spacing-lg); }
.mr-auto { margin-right: auto; }

/* Padding */
.p-0 { padding: 0; }
.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

/* Padding Top/Bottom */
.pt-0 { padding-top: 0; }
.pt-sm { padding-top: var(--spacing-sm); }
.pt-md { padding-top: var(--spacing-md); }
.pt-lg { padding-top: var(--spacing-lg); }
.pt-xl { padding-top: var(--spacing-xl); }

.pb-0 { padding-bottom: 0; }
.pb-sm { padding-bottom: var(--spacing-sm); }
.pb-md { padding-bottom: var(--spacing-md); }
.pb-lg { padding-bottom: var(--spacing-lg); }
.pb-xl { padding-bottom: var(--spacing-xl); }

/* Padding Left/Right */
.pl-0 { padding-left: 0; }
.pl-sm { padding-left: var(--spacing-sm); }
.pl-md { padding-left: var(--spacing-md); }
.pl-lg { padding-left: var(--spacing-lg); }

.pr-0 { padding-right: 0; }
.pr-sm { padding-right: var(--spacing-sm); }
.pr-md { padding-right: var(--spacing-md); }
.pr-lg { padding-right: var(--spacing-lg); }

/* ==============================================
   UTILITY CLASSES - TEXT
   ============================================== */
/* Text alignment */
.text-left { text-align: left; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-justify { text-align: justify; }

/* Text colours */
.text-primary { color: var(--primary-color); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-success { color: var(--success-color); }
.text-error { color: var(--error-color); }
.text-warning { color: var(--warning-color); }
.text-info { color: var(--info-color); }
.text-white { color: var(--white); }
.text-black { color: var(--black); }

/* Text sizes */
.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-base { font-size: var(--font-size-base); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-2xl { font-size: var(--font-size-2xl); }
.text-3xl { font-size: var(--font-size-3xl); }

/* Text weights */
.font-normal { font-weight: var(--font-weight-normal); }
.font-medium { font-weight: var(--font-weight-medium); }
.font-semibold { font-weight: var(--font-weight-semibold); }
.font-bold { font-weight: var(--font-weight-bold); }

/* Text transform */
.uppercase { text-transform: uppercase; }
.lowercase { text-transform: lowercase; }
.capitalize { text-transform: capitalize; }

/* Text decoration */
.underline { text-decoration: underline; }
.no-underline { text-decoration: none; }

/* Line height */
.leading-tight { line-height: var(--line-height-tight); }
.leading-normal { line-height: var(--line-height-normal); }
.leading-relaxed { line-height: var(--line-height-relaxed); }

/* ==============================================
   UTILITY CLASSES - DISPLAY
   ============================================== */
.d-none { display: none; }
.d-block { display: block; }
.d-inline { display: inline; }
.d-inline-block { display: inline-block; }
.d-flex { display: flex; }
.d-inline-flex { display: inline-flex; }
.d-grid { display: grid; }

/* Visibility */
.invisible { visibility: hidden; }
.visible { visibility: visible; }

/* ==============================================
   UTILITY CLASSES - FLEXBOX
   ============================================== */
.flex-row { flex-direction: row; }
.flex-column { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }

/* Justify content */
.justify-start { justify-content: flex-start; }
.justify-end { justify-content: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }
.justify-evenly { justify-content: space-evenly; }

/* Align items */
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.items-center { align-items: center; }
.items-baseline { align-items: baseline; }
.items-stretch { align-items: stretch; }

/* Gap */
.gap-xs { gap: var(--spacing-xs); }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* ==============================================
   UTILITY CLASSES - GRID
   ============================================== */
.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
.grid-cols-6 { grid-template-columns: repeat(6, 1fr); }
.grid-cols-12 { grid-template-columns: repeat(12, 1fr); }

/* Auto-fit responsive grid */
.grid-auto-fit {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.grid-auto-fill {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

/* ==============================================
   UTILITY CLASSES - BORDERS
   ============================================== */
.border { border: 1px solid var(--border-color); }
.border-t { border-top: 1px solid var(--border-color); }
.border-r { border-right: 1px solid var(--border-color); }
.border-b { border-bottom: 1px solid var(--border-color); }
.border-l { border-left: 1px solid var(--border-color); }
.border-0 { border: 0; }

/* Border radius */
.rounded-none { border-radius: 0; }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

/* ==============================================
   UTILITY CLASSES - SHADOWS
   ============================================== */
.shadow-none { box-shadow: none; }
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

/* ==============================================
   UTILITY CLASSES - BACKGROUNDS
   ============================================== */
.bg-white { background-color: var(--white); }
.bg-primary { background-color: var(--bg-primary); }
.bg-secondary { background-color: var(--bg-secondary); }
.bg-tertiary { background-color: var(--bg-tertiary); }
.bg-transparent { background-color: transparent; }

/* ==============================================
   UTILITY CLASSES - WIDTH & HEIGHT
   ============================================== */
.w-full { width: 100%; }
.w-auto { width: auto; }
.w-screen { width: 100vw; }

.h-full { height: 100%; }
.h-auto { height: auto; }
.h-screen { height: 100vh; }

.min-h-screen { min-height: 100vh; }

/* ==============================================
   UTILITY CLASSES - POSITION
   ============================================== */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

/* ==============================================
   UTILITY CLASSES - OVERFLOW
   ============================================== */
.overflow-auto { overflow: auto; }
.overflow-hidden { overflow: hidden; }
.overflow-visible { overflow: visible; }
.overflow-scroll { overflow: scroll; }

.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }

/* ==============================================
   UTILITY CLASSES - CURSOR
   ============================================== */
.cursor-pointer { cursor: pointer; }
.cursor-default { cursor: default; }
.cursor-not-allowed { cursor: not-allowed; }

/* ==============================================
   UTILITY CLASSES - POINTER EVENTS
   ============================================== */
.pointer-events-none { pointer-events: none; }
.pointer-events-auto { pointer-events: auto; }

/* ==============================================
   LOADING STATE
   ============================================== */
.loading {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-muted);
}

.loading::after {
    content: '...';
    animation: loading 1.5s infinite;
}

@keyframes loading {
    0%, 20% { content: '.'; }
    40% { content: '..'; }
    60%, 100% { content: '...'; }
}

/* Spinner */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(0, 0, 0, 0.1);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.spinner-lg {
    width: 40px;
    height: 40px;
    border-width: 4px;
}

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

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

/* ==============================================
   RESPONSIVE BREAKPOINTS
   ============================================== */
@media (max-width: 1024px) {
    .container {
        padding: 0 var(--spacing-md);
    }
}

@media (max-width: 768px) {
    html {
        font-size: 15px;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .section {
        padding: var(--spacing-xl) 0;
    }
    
    h1 { font-size: var(--font-size-3xl); }
    h2 { font-size: var(--font-size-2xl); }
    h3 { font-size: var(--font-size-xl); }
}

@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .section {
        padding: var(--spacing-lg) 0;
    }
}

/* Hide on specific breakpoints */
@media (max-width: 768px) {
    .hidden-mobile { display: none !important; }
}

@media (min-width: 769px) {
    .hidden-desktop { display: none !important; }
}