/**
 * main.css - Core styles for Al Paso Billar POS
 * 
 * Phase 3 Frontend CSS - Mobile-first foundation
 * Requirements: 9.1, 9.4
 * 
 * Structure:
 * 1. CSS Custom Properties (Design Tokens)
 * 2. CSS Reset
 * 3. Base Styles
 * 4. Typography
 * 5. Layout Utilities
 */

/* ============================================
   1. CSS CUSTOM PROPERTIES (Design Tokens)
   ============================================ */

:root {
  /* --- Color Palette --- */
  /* Primary - Deep navy blue */
  --color-primary: #1a1a2e;
  --color-primary-light: #2d2d4a;
  --color-primary-dark: #0f0f1a;
  
  /* Secondary - Teal accent */
  --color-secondary: #0f3460;
  --color-secondary-light: #1a4a7a;
  
  /* Accent - Coral/Orange for actions */
  --color-accent: #e94560;
  --color-accent-light: #ff6b6b;
  --color-accent-dark: #c73e54;
  
  /* Success - Green for positive actions */
  --color-success: #16a34a;
  --color-success-light: #22c55e;
  --color-success-dark: #15803d;
  
  /* Warning - Yellow/Orange */
  --color-warning: #f59e0b;
  --color-warning-light: #fbbf24;
  --color-warning-dark: #d97706;
  
  /* Error - Red */
  --color-error: #dc2626;
  --color-error-light: #ef4444;
  --color-error-dark: #b91c1c;
  
  /* Neutral - Grays */
  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2937;
  --color-gray-900: #111827;
  
  /* Semantic colors */
  --color-background: var(--color-primary);
  --color-surface: var(--color-primary-light);
  --color-surface-elevated: var(--color-secondary);
  --color-text-primary: #ffffff;
  --color-text-secondary: var(--color-gray-300);
  --color-text-muted: var(--color-gray-400);
  --color-border: var(--color-gray-700);
  --color-divider: rgba(255, 255, 255, 0.1);
  
  /* --- Typography --- */
  /* Font families */
  --font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 
    Oxygen, Ubuntu, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', 
    sans-serif;
  --font-family-mono: 'SF Mono', 'Fira Code', 'Fira Mono', Menlo, Monaco, 
    Consolas, 'Liberation Mono', 'Courier New', monospace;
  
  /* Font sizes - Mobile-first 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 */
  
  /* Font weights */
  --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;
  
  /* --- Spacing Scale --- */
  --space-0: 0;
  --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 */
  --space-24: 6rem;     /* 96px */
  
  /* --- Border Radius --- */
  --radius-none: 0;
  --radius-sm: 0.25rem;   /* 4px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 0.75rem;   /* 12px */
  --radius-xl: 1rem;      /* 16px */
  --radius-2xl: 1.5rem;   /* 24px */
  --radius-full: 9999px;
  
  /* --- Shadows --- */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 
               0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 
               0 4px 6px -4px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 
               0 8px 10px -6px rgba(0, 0, 0, 0.3);
  
  /* --- Z-Index Scale --- */
  --z-base: 0;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-popover: 600;
  --z-tooltip: 700;
  --z-toast: 800;
  
  /* --- Transitions --- */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;
  
  /* --- Touch Targets (WCAG 2.1) --- */
  --touch-target-min: 44px;  /* Minimum touch target size */
  
  /* --- Layout --- */
  --navbar-height: 56px;
  --container-max-width: 1920px;
  --container-padding: var(--space-4);
}


/* ============================================
   2. CSS RESET
   ============================================ */

/* Box sizing rules */
*,
*::before,
*::after {
  box-sizing: border-box;
}

/* Remove default margin and padding */
* {
  margin: 0;
  padding: 0;
}

/* Prevent font size inflation */
html {
  -moz-text-size-adjust: none;
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
}

/* Set core root defaults */
html {
  font-size: 100%; /* Respects user's browser settings */
  scroll-behavior: smooth;
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* Set core body defaults */
body {
  min-height: 100vh;
  min-height: 100dvh; /* Dynamic viewport height for mobile */
  line-height: var(--line-height-normal);
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  color: var(--color-text-primary);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* Remove list styles on ul, ol elements with list role */
ul[role='list'],
ol[role='list'] {
  list-style: none;
}

/* Set shorter line heights on headings and interactive elements */
h1, h2, h3, h4, h5, h6 {
  line-height: var(--line-height-tight);
  text-wrap: balance;
  overflow-wrap: break-word;
}

button,
input,
label {
  line-height: var(--line-height-normal);
}

/* A elements that don't have a class get default styles */
a:not([class]) {
  text-decoration-skip-ink: auto;
  color: currentColor;
}

/* Make images easier to work with */
img,
picture,
video,
canvas,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

/* Inherit fonts for inputs and buttons */
input,
button,
textarea,
select {
  font: inherit;
  color: inherit;
}

/* Remove default button styles */
button {
  background: none;
  border: none;
  cursor: pointer;
}

/* Remove default fieldset styles */
fieldset {
  border: none;
}

/* Make sure textareas without a rows attribute are not tiny */
textarea:not([rows]) {
  min-height: 10em;
}

/* Anything that has been anchored to should have extra scroll margin */
:target {
  scroll-margin-block: 5ex;
}

/* Remove all animations and transitions for people that prefer not to see them */
@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;
  }
}

/* Hidden attribute support */
[hidden] {
  display: none !important;
}

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

/* Remove focus outline for mouse users */
:focus:not(:focus-visible) {
  outline: none;
}


/* ============================================
   3. BASE STYLES
   ============================================ */

/* Root container */
#app {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

/* Selection styling */
::selection {
  background-color: var(--color-accent);
  color: var(--color-text-primary);
}

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

a:hover {
  color: var(--color-accent);
}

/* Horizontal rule */
hr {
  border: none;
  border-top: 1px solid var(--color-divider);
  margin: var(--space-4) 0;
}

/* Disabled state */
[disabled],
.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* Visually hidden but accessible */
.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;
}


/* ============================================
   4. TYPOGRAPHY
   ============================================ */

/* Headings */
h1 {
  font-size: var(--font-size-3xl);
  font-weight: var(--font-weight-bold);
  letter-spacing: -0.025em;
}

h2 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-semibold);
  letter-spacing: -0.025em;
}

h3 {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
}

h4 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-medium);
}

h5 {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
}

h6 {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
}

/* Paragraphs */
p {
  margin-bottom: var(--space-4);
}

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

/* Small text */
small,
.text-small {
  font-size: var(--font-size-sm);
}

/* Muted text */
.text-muted {
  color: var(--color-text-muted);
}

/* Secondary text */
.text-secondary {
  color: var(--color-text-secondary);
}

/* Monospace text */
code,
kbd,
pre,
samp,
.font-mono {
  font-family: var(--font-family-mono);
  font-size: 0.9em;
}

/* Code blocks */
code {
  background-color: var(--color-surface);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}

pre {
  background-color: var(--color-surface);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  overflow-x: auto;
}

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

/* Text alignment utilities */
.text-left { text-align: left; }
.text-center { text-align: center; }
.text-right { text-align: right; }

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

/* Font weight utilities */
.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); }


/* ============================================
   5. LAYOUT UTILITIES
   ============================================ */

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

/* --- Display utilities --- */
.block { display: block; }
.inline-block { display: inline-block; }
.inline { display: inline; }
.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }
.hidden { display: none; }

/* --- Flexbox utilities --- */
.flex-row { flex-direction: row; }
.flex-col { flex-direction: column; }
.flex-row-reverse { flex-direction: row-reverse; }
.flex-col-reverse { flex-direction: column-reverse; }

.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }

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

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

.flex-1 { flex: 1 1 0%; }
.flex-auto { flex: 1 1 auto; }
.flex-initial { flex: 0 1 auto; }
.flex-none { flex: none; }

.flex-grow { flex-grow: 1; }
.flex-grow-0 { flex-grow: 0; }
.flex-shrink { flex-shrink: 1; }
.flex-shrink-0 { flex-shrink: 0; }

/* --- Grid utilities --- */
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.col-span-1 { grid-column: span 1 / span 1; }
.col-span-2 { grid-column: span 2 / span 2; }
.col-span-3 { grid-column: span 3 / span 3; }
.col-span-full { grid-column: 1 / -1; }

/* --- Gap utilities --- */
.gap-0 { gap: 0; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-5 { gap: var(--space-5); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* --- Spacing utilities --- */
/* Margin */
.m-0 { margin: 0; }
.m-1 { margin: var(--space-1); }
.m-2 { margin: var(--space-2); }
.m-3 { margin: var(--space-3); }
.m-4 { margin: var(--space-4); }
.m-auto { margin: auto; }

.mx-auto { margin-left: auto; margin-right: auto; }
.my-auto { margin-top: auto; margin-bottom: auto; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.ml-0 { margin-left: 0; }
.ml-1 { margin-left: var(--space-1); }
.ml-2 { margin-left: var(--space-2); }
.ml-auto { margin-left: auto; }

.mr-0 { margin-right: 0; }
.mr-1 { margin-right: var(--space-1); }
.mr-2 { margin-right: var(--space-2); }
.mr-auto { margin-right: auto; }

/* Padding */
.p-0 { padding: 0; }
.p-1 { padding: var(--space-1); }
.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-5 { padding: var(--space-5); }
.p-6 { padding: var(--space-6); }

.px-0 { padding-left: 0; padding-right: 0; }
.px-1 { padding-left: var(--space-1); padding-right: var(--space-1); }
.px-2 { padding-left: var(--space-2); padding-right: var(--space-2); }
.px-3 { padding-left: var(--space-3); padding-right: var(--space-3); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }

.py-0 { padding-top: 0; padding-bottom: 0; }
.py-1 { padding-top: var(--space-1); padding-bottom: var(--space-1); }
.py-2 { padding-top: var(--space-2); padding-bottom: var(--space-2); }
.py-3 { padding-top: var(--space-3); padding-bottom: var(--space-3); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }

/* --- Width and Height utilities --- */
.w-full { width: 100%; }
.w-auto { width: auto; }
.w-screen { width: 100vw; }
.max-w-full { max-width: 100%; }

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

/* --- Position utilities --- */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

.inset-0 { top: 0; right: 0; bottom: 0; left: 0; }
.top-0 { top: 0; }
.right-0 { right: 0; }
.bottom-0 { bottom: 0; }
.left-0 { left: 0; }

/* --- Overflow utilities --- */
.overflow-auto { overflow: auto; }
.overflow-hidden { overflow: hidden; }
.overflow-scroll { overflow: scroll; }
.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }
.overflow-x-hidden { overflow-x: hidden; }
.overflow-y-hidden { overflow-y: hidden; }

/* --- Border utilities --- */
.border { border: 1px solid var(--color-border); }
.border-0 { border: none; }
.border-t { border-top: 1px solid var(--color-border); }
.border-b { border-bottom: 1px solid var(--color-border); }
.border-l { border-left: 1px solid var(--color-border); }
.border-r { border-right: 1px solid var(--color-border); }

.rounded-none { border-radius: var(--radius-none); }
.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); }

/* --- Shadow utilities --- */
.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); }

/* --- Cursor utilities --- */
.cursor-pointer { cursor: pointer; }
.cursor-not-allowed { cursor: not-allowed; }

/* --- User select --- */
.select-none { user-select: none; }
.select-text { user-select: text; }
.select-all { user-select: all; }

/* --- Pointer events --- */
.pointer-events-none { pointer-events: none; }
.pointer-events-auto { pointer-events: auto; }

/* --- Opacity --- */
.opacity-0 { opacity: 0; }
.opacity-25 { opacity: 0.25; }
.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }
.opacity-100 { opacity: 1; }

/* --- Transition utilities --- */
.transition { transition-property: all; transition-duration: var(--transition-normal); }
.transition-colors { transition-property: color, background-color, border-color; transition-duration: var(--transition-fast); }
.transition-opacity { transition-property: opacity; transition-duration: var(--transition-fast); }
.transition-transform { transition-property: transform; transition-duration: var(--transition-normal); }

/* --- Transform utilities --- */
.scale-95 { transform: scale(0.95); }
.scale-100 { transform: scale(1); }
.scale-105 { transform: scale(1.05); }
.translate-y-0 { transform: translateY(0); }
.translate-y-full { transform: translateY(100%); }
.-translate-y-full { transform: translateY(-100%); }


/* ============================================
   RESPONSIVE BREAKPOINTS
   Mobile-first: Base styles are for mobile (320px+)
   Breakpoints defined for larger screens
   ============================================ */

/* Small devices (landscape phones, 576px and up) */
@media (min-width: 576px) {
  :root {
    --container-padding: var(--space-5);
  }
  
  .sm\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sm\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .sm\:flex-row { flex-direction: row; }
}

/* Medium devices (tablets, 768px and up) */
@media (min-width: 768px) {
  :root {
    --container-padding: var(--space-6);
    --navbar-height: 64px;
  }
  
  h1 { font-size: var(--font-size-4xl); }
  
  .md\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .md\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .md\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .md\:flex-row { flex-direction: row; }
}

/* Large devices (desktops, 992px and up) */
@media (min-width: 992px) {
  :root {
    --container-padding: var(--space-8);
  }
  
  .lg\:grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .lg\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .lg\:flex-row { flex-direction: row; }
}

/* Extra large devices (large desktops, 1200px and up) */
@media (min-width: 1200px) {
  .xl\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .xl\:grid-cols-5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .xl\:flex-row { flex-direction: row; }
}

/* 2XL devices (1920px and up) */
@media (min-width: 1920px) {
  :root {
    --container-padding: var(--space-12);
  }
}