/* ===========================================
   EduTech — Aurora theme (dark)
   Inspired by CustomWare presentation OAPV_2026
   =========================================== */

:root {
  --bg: #0a0f1c;
  --surface-1: hsl(220 40% 14%);
  --surface-2: hsl(223 45% 10%);
  --surface-3: hsl(220 30% 18%);
  --magenta: #ff3ee6;
  --magenta-dim: rgba(255, 62, 230, 0.18);
  --cyan: #2cb6ff;
  --cyan-dim: rgba(44, 182, 255, 0.18);
  --mint: #34d399;
  --text: #fafafa;
  --text-soft: hsl(222 18% 80%);
  --muted: hsl(222 18% 60%);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.35);
  --shadow-glow-magenta: 0 0 60px -10px rgba(255, 62, 230, 0.45);
  --shadow-glow-cyan: 0 0 60px -10px rgba(44, 182, 255, 0.45);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
  overflow-x: hidden;
}

/* Aurora background blobs */
body::before, body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}
body::before {
  background:
    radial-gradient(60vw 60vh at 15% 12%, var(--magenta-dim), transparent 60%),
    radial-gradient(50vw 50vh at 85% 28%, var(--cyan-dim), transparent 60%),
    radial-gradient(70vw 50vh at 50% 92%, rgba(255, 62, 230, 0.10), transparent 60%);
  filter: blur(40px);
  animation: aurora-drift 60s ease-in-out infinite;
}
body::after {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/></filter><rect width='100%25' height='100%25' filter='url(%23n)' opacity='0.35'/></svg>");
  opacity: 0.04;
  mix-blend-mode: overlay;
}

@keyframes aurora-drift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(3vw, -2vh) scale(1.05); }
  66% { transform: translate(-2vw, 3vh) scale(0.98); }
}

img { max-width: 100%; height: auto; }

a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .15s, color .15s;
}
a:hover { color: var(--magenta); border-bottom-color: currentColor; }

/* ====== Hero ====== */
.hero {
  position: relative;
  padding: 88px 24px 72px;
  z-index: 1;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(40vw 40vh at 20% 20%, rgba(255, 62, 230, 0.18), transparent 60%),
    radial-gradient(45vw 45vh at 80% 30%, rgba(44, 182, 255, 0.18), transparent 60%);
  pointer-events: none;
}
.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}
.hero-eyebrow {
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 18px;
  font-weight: 600;
}
.hero h1 {
  font-size: clamp(32px, 5.2vw, 60px);
  line-height: 1.08;
  margin: 0 0 18px;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.gradient-text {
  background: linear-gradient(135deg, #ff3ee6 0%, #2cb6ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  background-size: 200% 200%;
  animation: gradient-shift 10s ease-in-out infinite;
}
@keyframes gradient-shift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}
.hero-subtitle {
  font-size: clamp(16px, 1.8vw, 20px);
  color: var(--text-soft);
  margin: 0 0 32px;
  max-width: 760px;
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 8px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .14s, box-shadow .14s, background .15s;
  white-space: nowrap;
}
.btn:hover {
  transform: translateY(-1px);
  border-bottom-color: transparent;
}
.btn-primary {
  background: linear-gradient(135deg, #ff3ee6 0%, #2cb6ff 100%);
  color: #fff;
  box-shadow: var(--shadow-glow-magenta);
}
.btn-primary:hover {
  box-shadow: 0 0 80px -10px rgba(255, 62, 230, 0.7);
  color: #fff;
}
.btn-outline {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  border-color: var(--border-strong);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}
.btn-outline:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.32);
  color: #fff;
}

/* ====== Stats strip ====== */
.stats {
  position: relative;
  z-index: 1;
  padding: 24px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}
.stats-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 20px;
}
.stat {
  text-align: center;
  padding: 8px 4px;
}
.stat-num {
  font-size: clamp(22px, 2.4vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  display: block;
  margin-bottom: 6px;
  background: linear-gradient(135deg, #ff3ee6 0%, #2cb6ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.stat-label {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

/* ====== Layout ====== */
.layout {
  max-width: 1100px;
  margin: 0 auto;
  padding: 48px 24px 96px;
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 56px;
  position: relative;
  z-index: 1;
}
@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; gap: 32px; padding: 32px 20px 64px; }
  .toc { position: static !important; max-height: none !important; }
  .hero { padding: 56px 20px 48px; }
}

/* ====== TOC ====== */
.toc {
  position: sticky;
  top: 24px;
  align-self: start;
  max-height: calc(100vh - 48px);
  overflow-y: auto;
  font-size: 13.5px;
  padding: 20px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid var(--border);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}
.toc-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--magenta);
  margin: 0 0 14px;
}
.toc ul { list-style: none; padding: 0; margin: 0; }
.toc li { margin: 4px 0; }
.toc a {
  color: var(--text-soft);
  border-bottom: none;
  display: block;
  padding: 6px 10px;
  border-radius: 6px;
  line-height: 1.4;
  transition: background .15s, color .15s;
}
.toc a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.05);
}

/* ====== Content ====== */
.content { min-width: 0; }

.content h1 {
  font-size: clamp(28px, 3.6vw, 38px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 16px;
  background: linear-gradient(135deg, #ff3ee6 0%, #2cb6ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.content h2 {
  font-size: clamp(22px, 2.6vw, 30px);
  margin: 64px 0 22px;
  padding-bottom: 14px;
  position: relative;
  color: #fff;
  font-weight: 700;
  letter-spacing: -0.01em;
  scroll-margin-top: 24px;
}
.content h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 64px;
  height: 3px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--magenta), var(--cyan));
}
.content h2:first-child { margin-top: 0; }
.content h3 {
  font-size: 20px;
  margin: 36px 0 12px;
  color: var(--cyan);
  font-weight: 600;
}
.content h4 {
  font-size: 17px;
  margin: 24px 0 10px;
  color: #fff;
  font-weight: 600;
}
.content p {
  margin: 0 0 16px;
  color: var(--text-soft);
}
.content ul, .content ol {
  margin: 0 0 16px;
  padding-left: 22px;
  color: var(--text-soft);
}
.content li { margin: 6px 0; }
.content li::marker { color: var(--magenta); }
.content strong { color: #fff; font-weight: 600; }
.content em { color: var(--text); font-style: italic; }
.content code {
  background: rgba(44, 182, 255, 0.12);
  color: var(--cyan);
  padding: 2px 7px;
  border-radius: 4px;
  font-size: 0.92em;
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
}

/* Tables */
.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 22px 0 28px;
  font-size: 14.5px;
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}
.content th, .content td {
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
  color: var(--text-soft);
}
.content th {
  background: rgba(255, 62, 230, 0.08);
  color: #fff;
  font-weight: 600;
  font-size: 13.5px;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}
.content tr:last-child td { border-bottom: none; }
.content tr:hover td { background: rgba(255, 255, 255, 0.03); }
.content table td:last-child {
  color: var(--mint);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}
.content table td[align="right"], .content table th[align="right"] {
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.content table td[align="center"], .content table th[align="center"] {
  text-align: center;
}

/* Blockquotes */
.content blockquote {
  margin: 22px 0;
  padding: 16px 22px;
  border-left: 3px solid var(--magenta);
  background: rgba(255, 62, 230, 0.06);
  border-radius: 0 10px 10px 0;
  color: var(--text);
}
.content blockquote p:last-child { margin-bottom: 0; }
.content blockquote strong:first-child { color: var(--magenta); }

/* HR */
.content hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 48px 0;
}

/* Highlight CTA box (last section) */
.cta-card {
  margin: 64px 0 0;
  padding: 36px 32px;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(255, 62, 230, 0.12) 0%, rgba(44, 182, 255, 0.12) 100%);
  border: 1px solid var(--border-strong);
  position: relative;
  overflow: hidden;
}
.cta-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 0%, rgba(255, 62, 230, 0.18), transparent 60%);
  pointer-events: none;
}
.cta-card > * { position: relative; z-index: 1; }
.cta-card h3 {
  font-size: 22px;
  margin: 0 0 10px;
  color: #fff;
}
.cta-card p {
  color: var(--text-soft);
  margin: 0 0 18px;
}

/* ====== Footer ====== */
footer {
  position: relative;
  z-index: 1;
  background: var(--surface-2);
  border-top: 1px solid var(--border);
  color: var(--text-soft);
  padding: 48px 24px;
  margin-top: 24px;
}
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 32px;
}
.footer-block h4 {
  color: #fff;
  margin: 0 0 14px;
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-weight: 600;
}
.footer-block p, .footer-block a {
  margin: 6px 0;
  color: var(--text-soft);
  font-size: 14.5px;
  border-bottom-color: transparent;
}
.footer-block a:hover { color: var(--cyan); }
.footer-bottom {
  max-width: 1100px;
  margin: 32px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 12.5px;
  color: var(--muted);
  text-align: center;
  letter-spacing: 0.04em;
}