/* === Base Reset & Typography === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-deep: #060b18;
  --bg: #0a1128;
  --bg-card: rgba(15, 25, 55, 0.7);
  --bg-card-highlight: rgba(40, 20, 30, 0.6);
  --bg-card-green: rgba(15, 40, 30, 0.6);
  --blue: #00bfff;
  --blue-dim: #1a7aad;
  --blue-glow: rgba(0, 191, 255, 0.15);
  --blue-glow-strong: rgba(0, 191, 255, 0.3);
  --cyan: #00e5ff;
  --purple: #a855f7;
  --accent: #ff4466;
  --accent-glow: rgba(255, 68, 102, 0.15);
  --green: #22d3ee;
  --green-glow: rgba(34, 211, 238, 0.15);
  --text: #c8d6e5;
  --text-bright: #edf2f7;
  --text-dim: #7f8c9b;
  --border: rgba(0, 191, 255, 0.12);
  --border-glow: rgba(0, 191, 255, 0.25);
  --glass: rgba(255, 255, 255, 0.03);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  line-height: 1.8;
  color: var(--text);
  background-color: var(--bg-deep);
  background-image:
    radial-gradient(ellipse at 20% 0%, rgba(0, 100, 255, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 100%, rgba(100, 0, 255, 0.06) 0%, transparent 50%);
  background-attachment: fixed;
  min-height: 100vh;
}

/* === Navigation === */
nav {
  background: rgba(6, 11, 24, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 0;
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
  box-shadow: 0 0 30px rgba(0, 100, 255, 0.08);
}

nav .nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
}

nav .site-title {
  color: var(--blue);
  font-size: 1rem;
  font-weight: 700;
  padding: 0.75rem 1.25rem;
  text-decoration: none;
  letter-spacing: 1px;
  text-transform: uppercase;
  text-shadow: 0 0 20px var(--blue-glow-strong);
}

nav a {
  color: var(--text-dim);
  text-decoration: none;
  padding: 0.65rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  letter-spacing: 0.3px;
  transition: color 0.3s, text-shadow 0.3s;
}

nav a:hover {
  color: var(--blue);
  text-shadow: 0 0 12px var(--blue-glow-strong);
}

nav a.active {
  color: var(--cyan);
  text-shadow: 0 0 15px rgba(0, 229, 255, 0.4);
}

/* === Layout === */
.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

/* === Hero === */
.hero {
  background: linear-gradient(135deg, var(--bg-deep) 0%, #0d1f4a 50%, #0a1128 100%);
  color: #fff;
  padding: 5rem 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 40%, rgba(0, 191, 255, 0.1) 0%, transparent 40%),
              radial-gradient(circle at 70% 60%, rgba(168, 85, 247, 0.08) 0%, transparent 40%);
  animation: heroGlow 8s ease-in-out infinite alternate;
}

@keyframes heroGlow {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-2%, 2%) scale(1.05); }
}

.hero h1 {
  font-size: 2.8rem;
  margin-bottom: 0.75rem;
  letter-spacing: -0.5px;
  color: #fff;
  text-shadow: 0 0 40px rgba(0, 191, 255, 0.3);
  position: relative;
  z-index: 1;
}

.hero .subtitle {
  font-size: 1.15rem;
  opacity: 0.8;
  font-style: italic;
  max-width: 600px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
  color: var(--text);
}

/* === Headings === */
h1, h2, h3 {
  color: var(--text-bright);
  line-height: 1.3;
}

h1 {
  font-size: 2rem;
  margin-bottom: 1rem;
  text-shadow: 0 0 30px var(--blue-glow);
}

h2 {
  font-size: 1.4rem;
  margin: 3rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
  color: var(--blue);
  text-shadow: 0 0 20px var(--blue-glow);
}

h3 {
  font-size: 1.15rem;
  margin: 1.5rem 0 0.75rem;
  color: var(--cyan);
}

/* === Body Text === */
p {
  margin-bottom: 1.25rem;
}

strong {
  color: var(--text-bright);
}

em {
  color: var(--text-bright);
}

/* === Cards (Glassmorphism) === */
.card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: 12px;
  padding: 1.75rem;
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
  box-shadow: 0 0 20px rgba(0, 100, 255, 0.05), inset 0 1px 0 var(--glass);
  transition: border-color 0.3s, box-shadow 0.3s, transform 0.3s;
}

.card:hover {
  border-color: var(--border-glow);
  box-shadow: 0 0 35px rgba(0, 191, 255, 0.1), inset 0 1px 0 var(--glass);
  transform: translateY(-2px);
}

.card h3 {
  margin-top: 0;
}

.card.highlight {
  border-color: rgba(255, 68, 102, 0.2);
  background: var(--bg-card-highlight);
  box-shadow: 0 0 20px var(--accent-glow), inset 0 1px 0 var(--glass);
}

.card.highlight:hover {
  border-color: rgba(255, 68, 102, 0.35);
  box-shadow: 0 0 35px rgba(255, 68, 102, 0.15), inset 0 1px 0 var(--glass);
}

.card.green {
  border-color: rgba(34, 211, 238, 0.2);
  background: var(--bg-card-green);
  box-shadow: 0 0 20px var(--green-glow), inset 0 1px 0 var(--glass);
}

.card.green:hover {
  border-color: rgba(34, 211, 238, 0.35);
  box-shadow: 0 0 35px rgba(34, 211, 238, 0.15), inset 0 1px 0 var(--glass);
}

/* === Lists === */
ul, ol {
  margin: 0.75rem 0 1.25rem 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

li::marker {
  color: var(--blue-dim);
}

/* === Blockquote === */
blockquote {
  border-left: 3px solid var(--blue);
  margin: 1.5rem 0;
  padding: 1rem 1.5rem;
  background: rgba(0, 191, 255, 0.05);
  border-radius: 0 8px 8px 0;
  font-style: italic;
  color: var(--text-bright);
  box-shadow: -3px 0 20px var(--blue-glow);
}

blockquote cite {
  display: block;
  margin-top: 0.5rem;
  font-style: normal;
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* === Figure / Key Stats === */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.stat-box {
  text-align: center;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  padding: 1.5rem 1rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: 0 0 15px rgba(0, 100, 255, 0.05);
  transition: border-color 0.3s, box-shadow 0.3s;
}

.stat-box:hover {
  border-color: var(--border-glow);
  box-shadow: 0 0 25px var(--blue-glow);
}

.stat-box .number {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--blue);
  display: block;
  text-shadow: 0 0 20px var(--blue-glow-strong);
}

.stat-box .label {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 0.25rem;
}

/* === Timeline === */
.timeline {
  position: relative;
  padding-left: 2rem;
  margin: 1.5rem 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--blue), var(--purple));
  border-radius: 3px;
  box-shadow: 0 0 10px var(--blue-glow);
}

.timeline-item {
  position: relative;
  margin-bottom: 1.5rem;
  padding-left: 1rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2.35rem;
  top: 0.5rem;
  width: 12px;
  height: 12px;
  background: var(--blue);
  border: 2px solid var(--bg);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--blue-glow-strong);
}

.timeline-item .year {
  font-weight: 700;
  color: var(--blue);
  font-size: 0.9rem;
  text-shadow: 0 0 10px var(--blue-glow);
}

/* === Tables === */
table {
  color: var(--text);
}

th {
  color: var(--text-bright);
}

td {
  border-color: rgba(255,255,255,0.05);
}

/* === Sources / References === */
.sources {
  background: rgba(15, 25, 55, 0.5);
  border: 1px solid var(--border);
  padding: 1.5rem;
  border-radius: 10px;
  margin-top: 2rem;
  font-size: 0.85rem;
}

.sources h3 {
  margin-top: 0;
  font-size: 0.95rem;
  color: var(--cyan);
}

.sources ol {
  margin-left: 1.25rem;
}

.sources li {
  margin-bottom: 0.4rem;
  color: var(--text-dim);
}

/* === Footer === */
footer {
  margin-top: 3rem;
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-dim);
  text-align: center;
}

footer a {
  color: var(--blue);
}

.license-box {
  background: rgba(0, 191, 255, 0.05);
  border: 1px solid var(--border);
  padding: 0.75rem 1rem;
  border-radius: 8px;
  display: inline-block;
  margin-bottom: 0.75rem;
}

/* === Links === */
a {
  color: var(--blue);
  text-decoration: none;
  transition: color 0.2s, text-shadow 0.2s;
}

a:hover {
  color: var(--cyan);
  text-shadow: 0 0 10px var(--blue-glow);
}

/* === Page Nav (prev/next) === */
.page-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
}

.page-nav a {
  font-weight: 600;
  color: var(--blue);
  transition: color 0.2s, text-shadow 0.2s;
}

.page-nav a:hover {
  color: var(--cyan);
  text-shadow: 0 0 15px var(--blue-glow);
}

/* === Responsive === */
@media (max-width: 700px) {
  .hero h1 { font-size: 1.75rem; }
  .hero .subtitle { font-size: 0.95rem; }
  .stat-grid { grid-template-columns: 1fr; }
  nav .nav-inner { flex-direction: column; align-items: flex-start; }
  nav a { padding: 0.5rem 1.25rem; font-size: 0.78rem; }
  .container { padding: 1.5rem 1rem 3rem; }
}

/* === Ambient Floating Particles (applied to body) === */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  background-image:
    radial-gradient(1px 1px at 10% 20%, rgba(0, 191, 255, 0.3), transparent),
    radial-gradient(1px 1px at 30% 65%, rgba(168, 85, 247, 0.2), transparent),
    radial-gradient(1px 1px at 55% 15%, rgba(0, 229, 255, 0.25), transparent),
    radial-gradient(1px 1px at 70% 80%, rgba(0, 191, 255, 0.2), transparent),
    radial-gradient(1px 1px at 85% 35%, rgba(168, 85, 247, 0.15), transparent),
    radial-gradient(1px 1px at 20% 90%, rgba(0, 229, 255, 0.2), transparent),
    radial-gradient(1px 1px at 45% 45%, rgba(0, 191, 255, 0.15), transparent),
    radial-gradient(1px 1px at 90% 55%, rgba(0, 229, 255, 0.2), transparent);
  animation: starfield 20s linear infinite alternate;
}

@keyframes starfield {
  0% { opacity: 0.6; transform: translateY(0); }
  100% { opacity: 1; transform: translateY(-10px); }
}

/* === Glow pulse on card borders === */
@keyframes glowPulse {
  0%, 100% { box-shadow: 0 0 15px rgba(0, 191, 255, 0.05); }
  50% { box-shadow: 0 0 25px rgba(0, 191, 255, 0.12); }
}

.card {
  animation: glowPulse 6s ease-in-out infinite;
}

.card:hover {
  animation: none;
}