/**
 * styles/main.css
 * Core Design System, CSS Custom Properties, Cyber Palette Tokens,
 * Responsive Layout, Fluid Typography & Zero-CLS Foundations.
 * Author: Andrew Strachan Electronic Career Portfolio
 */

:root {
  /* ==========================================================================
     Cyber Design System - Color Palette Tokens (WCAG AAA Compliant)
     ========================================================================== */
  --color-midnight-base: #060b13;       /* Deep canvas background (18.4:1 vs white) */
  --color-midnight-surface: #0b1220;    /* Card & section elevation background */
  --color-midnight-elevated: #111a2e;   /* Floating controls, popovers, drawers */
  --color-circuit-gold: #d4af37;        /* Radiant PCB gold traces & accent borders */
  --color-gold-glow: rgba(212, 175, 55, 0.35);
  --color-gold-subtle: #e9d8a6;
  --color-cyber-cyan: #00e5ff;          /* Electric cyan accent & active highlights */
  --color-cyan-glow: rgba(0, 229, 255, 0.4);
  --color-cyber-teal: #0a9396;          /* Secondary cyber accent */
  --color-alert-crimson: #ef4444;       /* Timer warning threshold */
  --color-alert-glow: rgba(239, 68, 68, 0.5);

  /* Typography Colors */
  --color-text-primary: #f8fafc;        /* High-contrast crisp white */
  --color-text-secondary: #cbd5e1;      /* Slate-300 secondary copy */
  --color-text-muted: #94a3b8;          /* Slate-400 metadata */
  --color-text-accent: #00e5ff;

  /* Glassmorphism & Borders */
  --glass-bg: rgba(11, 18, 32, 0.85);
  --glass-border: rgba(0, 229, 255, 0.18);
  --glass-border-gold: rgba(212, 175, 55, 0.3);
  --glass-backdrop-blur: blur(12px);

  /* Geometry, Spacing & Layout */
  --header-height: 4.5rem;
  --max-content-width: 1440px;
  --border-radius-sm: 0.375rem;
  --border-radius-md: 0.75rem;
  --border-radius-lg: 1.25rem;
  --border-radius-full: 9999px;

  /* Shadows */
  --shadow-elevation: 0 10px 30px -10px rgba(0, 0, 0, 0.7);
  --shadow-cyan-glow: 0 0 20px rgba(0, 229, 255, 0.25);
  --shadow-gold-glow: 0 0 20px rgba(212, 175, 55, 0.25);

  /* Motion & Transitions */
  --transition-fast: 0.15s ease-out;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ==========================================================================
   CSS Reset & Zero-CLS Architecture
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-midnight-base);
  scroll-behavior: smooth;
  scrollbar-gutter: stable; /* Eliminates CLS when scrollbars toggle */
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  min-height: 100dvh;
  background: radial-gradient(circle at 50% 0%, #0d1b2a 0%, var(--color-midnight-base) 75%);
  background-attachment: fixed;
  color: var(--color-text-primary);
  overflow-x: clip; /* Prevent mobile horizontal scroll blowout */
  position: relative;
}

/* Accessibility: Skip Navigation Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--color-circuit-gold);
  color: var(--color-midnight-base);
  padding: 0.75rem 1.5rem;
  font-weight: 700;
  z-index: 9999;
  border-radius: var(--border-radius-sm);
  text-decoration: none;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 1rem;
  outline: 3px solid var(--color-cyber-cyan);
}

/* Accessibility: Visually Hidden ARIA Live Announcer */
.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;
}

/* ==========================================================================
   Typography Foundations
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-text-primary);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2rem, 4vw + 1rem, 3.5rem);
}

h2 {
  font-size: clamp(1.75rem, 3vw + 0.5rem, 2.5rem);
  margin-bottom: 1.25rem;
  position: relative;
  display: inline-block;
}

h2.section-header::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -0.5rem;
  width: 3.5rem;
  height: 3px;
  background: linear-gradient(90deg, var(--color-cyber-cyan), var(--color-circuit-gold));
  border-radius: var(--border-radius-full);
}

h3 {
  font-size: clamp(1.25rem, 2vw + 0.25rem, 1.75rem);
}

p {
  color: var(--color-text-secondary);
  margin-bottom: 1rem;
}

a {
  color: var(--color-cyber-cyan);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover, a:focus-visible {
  color: var(--color-circuit-gold);
}

:focus-visible {
  outline: 2px solid var(--color-cyber-cyan);
  outline-offset: 3px;
}

/* ==========================================================================
   Structural Layout Containers
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--max-content-width);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

section.portfolio-section {
  padding-block: 5rem;
  scroll-margin-top: var(--header-height);
  position: relative;
}

section.portfolio-section:nth-child(even) {
  background: rgba(11, 18, 32, 0.4);
}

.section-intro {
  max-width: 48rem;
  margin-bottom: 3rem;
  font-size: 1.125rem;
  color: var(--color-text-secondary);
}

/* ==========================================================================
   Sticky Navigation Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-backdrop-blur);
  -webkit-backdrop-filter: var(--glass-backdrop-blur);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  align-items: center;
  transition: border-color var(--transition-normal);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 0.875rem;
  text-decoration: none;
  color: var(--color-text-primary);
  flex-shrink: 0;
}

.brand-logo-img {
  width: 2.75rem;
  height: 2.75rem;
  aspect-ratio: 1 / 1;
  border-radius: var(--border-radius-sm);
  border: 1px solid var(--color-circuit-gold);
  box-shadow: 0 0 10px rgba(212, 175, 55, 0.3);
  object-fit: cover;
}

.brand-identity {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--color-text-primary);
}

.brand-subtitle {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-circuit-gold);
}

/* Nav Menu Links */
.site-nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-links-list {
  display: flex;
  list-style: none;
  gap: 0.5rem;
  align-items: center;
}

.nav-link {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
  padding: 0.5rem 0.75rem;
  border-radius: var(--border-radius-sm);
  transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--color-cyber-cyan);
  background: rgba(0, 229, 255, 0.08);
}

/* Nav Action Controls (Presenter Mode & PDF Download) */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-nav-action {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-presenter {
  background: rgba(0, 229, 255, 0.12);
  color: var(--color-cyber-cyan);
  border-color: rgba(0, 229, 255, 0.4);
}

.btn-presenter:hover {
  background: rgba(0, 229, 255, 0.22);
  box-shadow: var(--shadow-cyan-glow);
}

.btn-pdf {
  background: rgba(212, 175, 55, 0.12);
  color: var(--color-circuit-gold);
  border-color: rgba(212, 175, 55, 0.4);
}

.btn-pdf:hover {
  background: rgba(212, 175, 55, 0.22);
  box-shadow: var(--shadow-gold-glow);
}

/* Mobile Nav Toggle Button */
.nav-toggle-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--glass-border);
  color: var(--color-text-primary);
  padding: 0.5rem;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
}

/* ==========================================================================
   Hero Section Layout
   ========================================================================== */
.hero-section {
  padding-block: 6rem 4rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.85fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  padding: 0.375rem 1rem;
  background: rgba(212, 175, 55, 0.1);
  border: 1px solid rgba(212, 175, 55, 0.35);
  border-radius: var(--border-radius-full);
  color: var(--color-circuit-gold);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.hero-headline {
  margin-bottom: 1.25rem;
}

.hero-headline span.highlight-cyan {
  color: var(--color-cyber-cyan);
  text-shadow: 0 0 15px rgba(0, 229, 255, 0.3);
}

.hero-subhead {
  font-size: 1.25rem;
  color: var(--color-circuit-gold);
  font-weight: 500;
  margin-bottom: 1.5rem;
}

.hero-description {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin-bottom: 2rem;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.btn-primary-cyan {
  background: rgba(255, 255, 255, 0.15);
  color: var(--color-midnight-base);
  font-weight: 700;
  padding: 0.875rem 1.75rem;
  border-radius: var(--border-radius-sm);
  border: none;
  cursor: pointer;
  box-shadow: 0 0 20px rgba(0, 229, 255, 0.4);
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary-cyan:hover {
  background: #33ebff;
  transform: translateY(-2px);
  box-shadow: 0 0 25px rgba(0, 229, 255, 0.6);
  color: var(--color-midnight-base);
}

.btn-secondary-outline {
  background: transparent;
  color: var(--color-text-primary);
  font-weight: 600;
  padding: 0.875rem 1.75rem;
  border-radius: var(--border-radius-sm);
  border: 1px solid var(--glass-border);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-secondary-outline:hover {
  border-color: var(--color-circuit-gold);
  color: var(--color-circuit-gold);
  background: rgba(212, 175, 55, 0.05);
}

/* Hero Visual Diamond Emblem */
.hero-visual-card {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-crest-frame {
  position: relative;
  width: 100%;
  max-width: 380px;
  aspect-ratio: 1 / 1;
  border-radius: var(--border-radius-lg);
  padding: 0.75rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border-gold);
  box-shadow: var(--shadow-elevation), var(--shadow-gold-glow);
}

.hero-crest-img {
  width: 100%;
  height: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: var(--border-radius-md);
  border: 1px solid var(--color-cyber-cyan);
}

/* ==========================================================================
   Footer Layout
   ========================================================================== */
.site-footer {
  background: var(--color-midnight-surface);
  border-top: 1px solid var(--glass-border);
  padding-block: 4rem 2rem;
  position: relative;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-meta-block p {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

.footer-col-title {
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-circuit-gold);
  margin-bottom: 1.25rem;
}

.footer-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.footer-links-list a {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
}

.footer-links-list a:hover {
  color: var(--color-cyber-cyan);
}

.footer-bottom-bar {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* ==========================================================================
   Responsive Media Queries (375px Mobile & 768px Tablet)
   ========================================================================== */

/* Tablet Viewport (768px) */
@media (max-width: 768px) {
  :root {
    --header-height: 4rem;
  }

  .site-header .container {
    position: relative;
  }

  .nav-toggle-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    width: 100%;
    background: var(--color-midnight-surface);
    border-bottom: 2px solid var(--color-circuit-gold);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1rem;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.9);
  }

  .site-nav.open {
    display: flex;
  }

  .nav-links-list {
    flex-direction: column;
    width: 100%;
    gap: 0.25rem;
  }

  .nav-link {
    width: 100%;
    display: block;
    padding: 0.75rem 1rem;
  }

  .nav-actions {
    width: 100%;
    flex-direction: column;
  }

  .btn-nav-action {
    width: 100%;
    justify-content: center;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
    text-align: center;
  }

  .hero-badge-pill {
    margin-inline: auto;
  }

  .hero-cta-group {
    justify-content: center;
  }

  .hero-crest-frame {
    max-width: 280px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-bottom-bar {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

/* Mobile Viewport (375px) */
@media (max-width: 375px) {
  .container {
    padding-inline: 1rem;
  }

  h1 {
    font-size: 1.75rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  .brand-title {
    font-size: 0.95rem;
  }

  .hero-description {
    font-size: 1rem;
  }

  .btn-primary-cyan, .btn-secondary-outline {
    width: 100%;
    justify-content: center;
  }

  .hero-crest-frame {
    max-width: 220px;
  }
}

/* Desktop Expansion (1440px) */
@media (min-width: 1440px) {
  .container {
    padding-inline: 2rem;
  }
}

/* ==========================================================================
   Scroll-Driven Animations & Mobile Responsiveness
   ========================================================================== */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1), transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
  will-change: opacity, transform;
}

.animate-on-scroll.animated,
.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.animate-fade-in {
  opacity: 0;
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}
.animate-fade-in.animated,
.animate-fade-in.is-visible {
  opacity: 1;
}

.animate-slide-left {
  opacity: 0;
  transform: translateX(-24px);
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1), transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
  will-change: opacity, transform;
}
.animate-slide-left.animated,
.animate-slide-left.is-visible {
  opacity: 1;
  transform: translateX(0);
}

/* Stagger delay classes */
.delay-100 { transition-delay: 0.1s; }
.delay-200 { transition-delay: 0.2s; }
.delay-300 { transition-delay: 0.3s; }
.delay-400 { transition-delay: 0.4s; }

/* Mobile Viewport Optimization (<768px, 375px) */
@media (max-width: 768px) {
  .animate-on-scroll {
    transform: translateY(16px);
    transition-duration: 0.45s;
  }
  .animate-on-scroll.animated,
  .animate-on-scroll.is-visible {
    opacity: 1 !important;
    transform: translateY(0) !important;
  }
}

/* Accessibility: Prefers Reduced Motion */
@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;
  }
  .animate-on-scroll,
  .animate-fade-in,
  .animate-slide-left {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* Revamp Blueprint Specifications */
.accordion { border: 1px solid var(--glass-border); margin-bottom: 1rem; border-radius: var(--border-radius-md); overflow: hidden; }
.accordion.active { border-color: var(--color-circuit-gold); }
.accordion-header { cursor: pointer; padding: 1rem 1.25rem; display: flex; justify-content: space-between; align-items: center; user-select: none; }
.accordion-content { display: none; padding: 1.25rem; }
.accordion.active .accordion-content { display: block; }
.carousel-container { display: flex; overflow-x: auto; scroll-snap-type: x mandatory; white-space: nowrap; gap: 1rem; padding-bottom: 1rem; }
.carousel-container > * { scroll-snap-align: start; flex: 0 0 auto; white-space: normal; }

/* Sticky Window Canvas Pipeline */
.sticky-canvas-wrapper { height: 400dvh; position: relative; }
.sticky-canvas-inner { position: sticky; top: 0; height: 100dvh; z-index: 1; pointer-events: none; margin-bottom: -100dvh; }
.interactive-card { pointer-events: auto; position: relative; z-index: 2; }

/* Touch Navigation vs Desktop Arrow Cues */
.nav-cues { display: none !important; }
@media (hover: hover) and (pointer: fine) {
  .nav-cues { display: flex !important; }
}
.mobile-swipe-cues { display: flex !important; }
@media (hover: hover) and (pointer: fine) {
  .mobile-swipe-cues { display: none !important; }
}

/* Modal Close Button & Ellipsis Truncation */
.modal-close-btn, #btn-modal-close {
  z-index: 9999 !important;
  pointer-events: auto !important;
  position: relative;
}
.modal-title, .modal-header-fix {
  flex: 1;
  min-width: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  padding-right: 16px;
}

/* Pro-Dev Layout Fix */
#development { width: 100%; box-sizing: border-box; }

/* Custom Internal Scroller */
.scrolling-internal-container {
  max-height: 60vh;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding-right: 0.5rem;
  scrollbar-width: thin;
  scrollbar-color: var(--color-cyber-cyan) rgba(255,255,255,0.05);
}
.scrolling-internal-container::-webkit-scrollbar {
  width: 6px;
}
.scrolling-internal-container::-webkit-scrollbar-track {
  background: rgba(255,255,255,0.05);
  border-radius: 4px;
}
.scrolling-internal-container::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 4px;
}