/* ============================================================
   about-main.css — Global styles, CSS variables, reset
   Tech Cartographer About Page
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=DM+Serif+Display&family=JetBrains+Mono:wght@300;400;700&display=swap');

/* ── CSS Custom Properties ────────────────────────────────── */
:root {
  /* TC Navy Palette */
  --color-bg-deep:     hsl(220, 25%, 6%);
  --color-bg-surface:  hsl(220, 22%, 10%);
  --color-bg-elevated: hsl(218, 20%, 16%);
  --color-bg-card:     hsl(222, 24%, 8%);

  /* Single accent — TC ice-blue */
  --color-accent-cyan:       hsl(200, 80%, 60%);
  --color-accent-cyan-dark:  hsl(200, 80%, 45%);
  --color-accent-cyan-light: hsl(200, 80%, 72%);

  /* Text */
  --color-text-primary: #e8f4f8;
  --color-text-muted:   #7da0b8;
  --color-text-dim:     hsl(220, 18%, 22%);

  /* Borders */
  --color-border:        rgba(255, 255, 255, 0.08);
  --color-border-bright: rgba(255, 255, 255, 0.16);

  /* Glows */
  --color-glow-cyan:    hsla(200, 80%, 60%, 0.15);
  --color-glow-cyan-md: hsla(200, 80%, 60%, 0.28);

  /* Shadows */
  --shadow-card:        0 4px 24px rgba(0, 0, 0, 0.5);
  --shadow-card-hover:  0 8px 40px rgba(0, 0, 0, 0.7);
  --glow-border-cyan:   0 0 0 1px var(--color-accent-cyan), 0 0 20px var(--color-glow-cyan);

  /* Typography */
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body:    'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono:    'JetBrains Mono', 'Fira Code', monospace;

  /* Font sizes — fluid with clamp() */
  --fs-hero:   clamp(2rem, 5.5vw, 4.4rem);
  --fs-h1:     clamp(1.4rem, 3vw, 2rem);
  --fs-h2:     clamp(1.1rem, 2vw, 1.4rem);
  --fs-h3:     clamp(0.95rem, 1.5vw, 1.1rem);
  --fs-body:   clamp(0.875rem, 1.2vw, 1rem);
  --fs-small:  clamp(0.75rem, 1vw, 0.875rem);
  --fs-mono:   clamp(0.7rem, 1vw, 0.825rem);
  --fs-tag:    clamp(0.65rem, 0.9vw, 0.75rem);

  /* Spacing */
  --space-xs:  0.25rem;
  --space-sm:  0.5rem;
  --space-md:  1rem;
  --space-lg:  1.5rem;
  --space-xl:  2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Borders & Radius */
  --border-width: 1px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  --transition-slow: 500ms ease;

  /* Layout */
  --max-width:  1280px;
  --nav-height: 56px;
}

/* ── Reset ────────────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--color-bg-deep);
  color: var(--color-text-primary);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

a:hover { color: #fff; }

ul { list-style: none; }

img, svg { display: block; max-width: 100%; }

button {
  cursor: pointer;
  font-family: var(--font-mono);
  border: none;
  background: none;
}

/* ── Typography Utilities ─────────────────────────────────── */
.font-display { font-family: var(--font-display); }
.font-mono    { font-family: var(--font-mono); }
.text-cyan    { color: var(--color-accent-cyan); }
.text-muted   { color: var(--color-text-muted); }
.text-small   { font-size: var(--fs-small); }
.text-upper   { text-transform: uppercase; letter-spacing: 0.12em; }

/* ── Layout Utilities ─────────────────────────────────────── */
.container {
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-xl);
  padding-right: var(--space-xl);
}

@media (max-width: 600px) {
  .container {
    padding-left: var(--space-md);
    padding-right: var(--space-md);
  }
}

.flex-center  { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }

/* ── Top Navigation Bar ───────────────────────────────────── */
.top-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: hsla(220, 25%, 6%, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-xl);
  z-index: 100;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.top-nav--hidden {
  transform: translateY(-100%);
  opacity: 0;
  pointer-events: none;
}

.btn-back {
  font-family: var(--font-mono);
  font-size: var(--fs-mono);
  color: var(--color-accent-cyan);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.btn-back:hover {
  border-color: var(--color-accent-cyan);
  background: var(--color-glow-cyan);
  box-shadow: var(--glow-border-cyan);
}

.nav-breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--fs-mono);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.15em;
}

.nav-site-link {
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.nav-site-link:hover {
  color: var(--color-accent-cyan);
  border-color: var(--color-accent-cyan);
  background: var(--color-glow-cyan);
}

/* ── Section Container ────────────────────────────────────── */
.section-container {
  min-height: 100vh;
  padding-top: calc(var(--nav-height) + var(--space-2xl));
  padding-bottom: var(--space-3xl);
  transition: opacity var(--transition-base), transform var(--transition-base);
}

.section-container--hidden { display: none; }

/* ── View Transitions ─────────────────────────────────────── */
.view--enter { animation: viewEnter 0.4s ease forwards; }

@keyframes viewEnter {
  from { opacity: 0; transform: translateX(50px); }
  to   { opacity: 1; transform: translateX(0); }
}

/* ── Section Headers ──────────────────────────────────────── */
.section-header { margin-bottom: var(--space-xl); }

.section-eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-mono);
  color: var(--color-accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.2em;
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.section-eyebrow::before {
  content: '>';
  color: var(--color-accent-cyan);
  opacity: 0.5;
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: 400;
  color: var(--color-text-primary);
  position: relative;
  display: inline-block;
  line-height: 1.2;
}

.section-title::after {
  content: '';
  display: block;
  height: 2px;
  background: linear-gradient(90deg, var(--color-accent-cyan), transparent);
  margin-top: var(--space-sm);
  animation: expandLine 0.8s ease forwards;
}

@keyframes expandLine {
  from { width: 0; }
  to   { width: 100%; }
}

/* ── Shared Section Components ────────────────────────────── */
.section-opening {
  font-size: clamp(1rem, 1.8vw, 1.15rem);
  color: var(--color-text-muted);
  line-height: 1.8;
  margin-bottom: var(--space-2xl);
  max-width: 800px;
  border-left: 3px solid var(--color-accent-cyan);
  padding-left: var(--space-lg);
}

.section-pullquote {
  background: var(--color-bg-surface);
  border-left: 3px solid var(--color-accent-cyan);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: var(--space-lg) var(--space-2xl);
  font-style: italic;
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--color-text-primary);
  line-height: 1.75;
  margin-top: var(--space-2xl);
  position: relative;
}

.section-pullquote::before {
  content: '\201C';
  position: absolute;
  top: -10px;
  left: var(--space-lg);
  font-size: 4rem;
  color: var(--color-accent-cyan);
  opacity: 0.2;
  font-family: var(--font-display);
  line-height: 1;
}

/* ── Tag / Badge ──────────────────────────────────────────── */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 2px var(--space-sm);
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  background: var(--color-bg-surface);
  white-space: nowrap;
}

.tag--cyan {
  color: var(--color-accent-cyan);
  border-color: hsla(200, 80%, 60%, 0.3);
  background: hsla(200, 80%, 60%, 0.05);
}

/* ── Stat Card ────────────────────────────────────────────── */
.stat-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg) var(--space-xl);
  text-align: center;
  transition: all var(--transition-base);
}

.stat-card:hover {
  border-color: var(--color-accent-cyan);
  box-shadow: var(--glow-border-cyan);
}

.stat-value {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 400;
  color: var(--color-accent-cyan);
  line-height: 1;
  margin-bottom: var(--space-xs);
}

.stat-label {
  font-family: var(--font-mono);
  font-size: var(--fs-tag);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

/* ── Scrollbar ────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--color-bg-deep); }
::-webkit-scrollbar-thumb { background: var(--color-border-bright); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--color-accent-cyan); }

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

/* ── Tooltip ──────────────────────────────────────────────── */
.tooltip {
  position: fixed;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-accent-cyan);
  border-radius: var(--radius-md);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-body);
  font-size: var(--fs-small);
  color: var(--color-text-primary);
  max-width: 280px;
  text-align: center;
  z-index: 99999;
  box-shadow: 0 4px 20px rgba(0,0,0,0.6), var(--glow-border-cyan);
  pointer-events: none;
  animation: tooltipFade 0.15s ease forwards;
}

@keyframes tooltipFade {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}