:root {
  --bg: #0a0e17;
  --bg-card: #111827;
  --accent-f: #00d4ff;
  --accent-m: #34d399;
  --text: #e8edf5;
  --text-muted: #8899aa;
  --border: rgba(255, 255, 255, 0.1);
  --font-display: 'Orbitron', sans-serif;
  --font-body: 'Inter', sans-serif;
}

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

body {
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
}

.hub-bg {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 30%, rgba(0, 212, 255, 0.07) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 70%, rgba(52, 211, 153, 0.06) 0%, transparent 50%),
    var(--bg);
  pointer-events: none;
}

.hub {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
  padding: 3rem 1.5rem 4rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.hub-header { text-align: center; margin-bottom: 2.5rem; }

.hub-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.hub-header h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin-bottom: 0.4rem;
}

.hub-meta { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 1rem; }

.hub-desc {
  max-width: 520px;
  margin: 0 auto;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.hub-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
  flex: 1;
  align-content: center;
}

@media (max-width: 640px) { .hub-cards { grid-template-columns: 1fr; } }

.hub-card {
  display: flex;
  flex-direction: column;
  padding: 1.75rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.hub-card:hover {
  transform: translateY(-4px);
}

.hub-card--felsefe:hover {
  border-color: var(--accent-f);
  box-shadow: 0 12px 40px rgba(0, 212, 255, 0.12);
}

.hub-card--matematik:hover {
  border-color: var(--accent-m);
  box-shadow: 0 12px 40px rgba(52, 211, 153, 0.12);
}

.hub-card-icon { font-size: 2.5rem; margin-bottom: 1rem; }

.hub-card h2 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin-bottom: 0.35rem;
}

.hub-card--felsefe h2 { color: var(--accent-f); }
.hub-card--matematik h2 { color: var(--accent-m); }

.hub-card-sub {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
  font-style: italic;
}

.hub-card-text {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.55;
  flex: 1;
  margin-bottom: 1.25rem;
}

.hub-card-cta {
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
}

.hub-card--felsefe .hub-card-cta { color: var(--accent-f); }
.hub-card--matematik .hub-card-cta { color: var(--accent-m); }

.hub-footer {
  margin-top: 2.5rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.hub-footer a { color: var(--text-muted); text-decoration: none; }
.hub-footer a:hover { color: var(--text); }
.hub-footer span { margin: 0 0.5rem; opacity: 0.4; }

.hub-card--ftc:hover {
  border-color: #F59E0B;
  box-shadow: 0 12px 40px rgba(245, 158, 11, 0.15);
}
.hub-card--ftc h2 { color: #F59E0B; }
.hub-card--ftc .hub-card-cta { color: #F59E0B; }