/* ==========================================================================
   CROWNATE CONSTRUCTION PROFESSIONAL SERVICES LIMITED (CCPSL)
   Core Design System - European Minimalist Engineering Architecture
   EN 301 549 & WCAG AA Compliant Monochrome Palette
   ========================================================================== */

/* 1. CSS Custom Properties / Tokens */
:root {
  /* Color Palette - Strict Monochrome System */
  --ccpsl-black: #0a0a0a;
  --ccpsl-true-black: #000000;
  --ccpsl-offwhite: #f9f9f8;
  --ccpsl-white: #ffffff;
  --ccpsl-light-grey: #f0f0ee;
  --ccpsl-mid-grey: #e2e2df;
  --ccpsl-dark-grey: #1f1f1f;
  --ccpsl-subtle-grey: #666666;
  --ccpsl-border-light: #d6d6d2;
  --ccpsl-border-dark: #333333;

  /* Text Colors & High-Contrast Guarantees */
  --color-bg-primary: var(--ccpsl-offwhite);
  --color-text-primary: var(--ccpsl-black);
  --color-text-muted: var(--ccpsl-subtle-grey);
  
  --color-bg-dark: var(--ccpsl-black);
  --color-text-on-dark: var(--ccpsl-white);

  --color-bg-light-surface: var(--ccpsl-light-grey);
  --color-text-on-light-surface: var(--ccpsl-black);

  --color-bg-white-surface: var(--ccpsl-white);
  --color-text-on-white-surface: var(--ccpsl-black);

  /* Status Colors (Strictly for system feedback only) */
  --color-error-bg: #1a0000;
  --color-error-text: #ff6b6b;
  --color-error-border: #990000;

  --color-success-bg: #001a0a;
  --color-success-text: #51cf66;
  --color-success-border: #0b7285;

  /* Typography Stack */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', Courier, monospace;

  /* Type Scale */
  --text-xs: 0.75rem;     /* 12px */
  --text-sm: 0.875rem;    /* 14px */
  --text-base: 1rem;      /* 16px */
  --text-lg: 1.125rem;    /* 18px */
  --text-xl: 1.25rem;     /* 20px */
  --text-2xl: 1.5rem;     /* 24px */
  --text-3xl: 2rem;       /* 32px */
  --text-4xl: 2.75rem;    /* 44px */
  --text-5xl: 3.75rem;    /* 60px */
  --text-hero: 4.5rem;    /* 72px */

  /* Line Heights */
  --lh-tight: 1.15;
  --lh-heading: 1.25;
  --lh-base: 1.6;

  /* Spacing Scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Max Layout Widths */
  --container-max: 1440px;
  --container-narrow: 960px;
  --container-text: 760px;

  /* Z-Index Hierarchy */
  --z-base: 1;
  --z-sticky: 100;
  --z-header: 1000;
  --z-drawer-backdrop: 2000;
  --z-drawer: 2010;
  --z-modal: 3000;
  --z-cookie: 4000;
  --z-toast: 5000;
  --z-skip-link: 9999;

  /* Touch Targets & Minimum Dimensions (WCAG 2.2 AA) */
  --touch-target-min: 44px;
  --touch-target-comfortable: 48px;

  /* Accessibility & Transitions */
  --focus-ring: 2px solid var(--ccpsl-black);
  --focus-ring-on-dark: 2px solid var(--ccpsl-white);
  /* Header & Fixed Layout Metrics */
  --header-height: 80px;

  --transition-fast: 0.2s ease-in-out;
  --transition-smooth: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 2. Global Reset & Box Sizing */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-sans);
  font-size: 100%;
  line-height: var(--lh-base);
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  overflow-x: clip;
  padding-top: var(--header-height, 80px);
}

/* Smooth anchor targeting with fixed header clearance */
[id] {
  scroll-margin-top: calc(var(--header-height, 80px) + 24px);
}

body.ccpsl-scroll-locked {
  overflow: hidden !important;
  touch-action: none;
}

/* 3. Accessibility Focus States & Screen Reader Classes */
:focus-visible {
  outline: var(--focus-ring);
  outline-offset: 3px;
}

body.dark-theme :focus-visible,
.section-dark :focus-visible {
  outline: var(--focus-ring-on-dark);
  outline-offset: 3px;
}

.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;
}

/* Skip to Content Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--ccpsl-black);
  color: var(--ccpsl-white);
  padding: 0.75rem 1.25rem;
  z-index: 9999;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--ccpsl-white);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 1rem;
}

/* 4. Typography Base Styles */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: var(--lh-heading);
  letter-spacing: -0.02em;
  color: inherit;
}

h1 { font-size: clamp(2.25rem, 5vw, var(--text-5xl)); font-weight: 800; }
h2 { font-size: clamp(1.75rem, 3.5vw, var(--text-3xl)); font-weight: 700; }
h3 { font-size: clamp(1.25rem, 2.5vw, var(--text-2xl)); font-weight: 600; }
h4 { font-size: var(--text-xl); font-weight: 600; }
h5 { font-size: var(--text-lg); font-weight: 600; }
h6 { font-size: var(--text-base); font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; }

p {
  margin-bottom: var(--space-4);
  color: inherit;
}

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

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

a:hover {
  text-decoration-thickness: 2px;
}

code, pre, .mono {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

/* Technical Label Tag */
.tech-tag {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.25rem 0.6rem;
  background-color: var(--ccpsl-light-grey);
  color: var(--ccpsl-black);
  border: 1px solid var(--ccpsl-border-light);
  display: inline-block;
}

.section-dark .tech-tag {
  background-color: var(--ccpsl-dark-grey);
  color: var(--ccpsl-white);
  border-color: var(--ccpsl-border-dark);
}

/* 5. Container & Grid Utilities */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-6);
  padding-right: var(--space-6);
}

.container-narrow {
  max-width: var(--container-narrow);
}

.container-text {
  max-width: var(--container-text);
}

/* Architectural Grid System */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-8);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-6);
}

@media (max-width: 1024px) {
  .grid-3, .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  .container {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
  }
}

/* 6. Surface Color Themes */
.section-offwhite {
  background-color: var(--ccpsl-offwhite);
  color: var(--ccpsl-black);
}

.section-white {
  background-color: var(--ccpsl-white);
  color: var(--ccpsl-black);
}

.section-light-grey {
  background-color: var(--ccpsl-light-grey);
  color: var(--ccpsl-black);
}

.section-dark {
  background-color: var(--ccpsl-black);
  color: var(--ccpsl-white);
}

.section-dark-grey {
  background-color: var(--ccpsl-dark-grey);
  color: var(--ccpsl-white);
}

.padding-space {
  padding-top: var(--space-16);
  padding-bottom: var(--space-16);
}

.padding-space-large {
  padding-top: var(--space-24);
  padding-bottom: var(--space-24);
}

/* Border Dividers */
.border-top {
  border-top: 1px solid var(--ccpsl-border-light);
}
.section-dark .border-top {
  border-top-color: var(--ccpsl-border-dark);
}

.border-bottom {
  border-bottom: 1px solid var(--ccpsl-border-light);
}
.section-dark .border-bottom {
  border-bottom-color: var(--ccpsl-border-dark);
}

/* 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;
  }
}