/* ===== Cell Biology – Dark Science Theme ===== */
:root {
  --bg-primary:   #0a0e17;
  --bg-secondary: #111827;
  --surface-1:    #1a2236;
  --surface-2:    #232d44;
  --surface-3:    #2c3a56;
  --accent:       #00e5a0;
  --accent-dim:   #00b87d;
  --accent-glow:  rgba(0,229,160,.25);
  --secondary:    #38bdf8;
  --tertiary:     #a78bfa;
  --warning:      #fbbf24;
  --error:        #f87171;
  --text-primary: #e2e8f0;
  --text-secondary:#94a3b8;
  --text-muted:   #64748b;
  --border:       rgba(255,255,255,.06);
  --radius:       12px;
  --radius-sm:    8px;
  --radius-lg:    20px;
  --shadow:       0 4px 24px rgba(0,0,0,.4);
  --font-sans:    'Inter', system-ui, -apple-system, sans-serif;
  --font-mono:    'JetBrains Mono', 'Fira Code', monospace;
  --transition:   .3s cubic-bezier(.4,0,.2,1);
}

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

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

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

::selection {
  background: var(--accent);
  color: var(--bg-primary);
}

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb {
  background: var(--surface-3);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover { background: var(--accent-dim); }

a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--secondary); }

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

h1, h2, h3, h4 { font-weight: 700; line-height: 1.25; }