:root {
    --bg: #0f172a;          /* fundo escuro */
    --card: #1e293b;        /* cartões */
    --accent: #f1f5f9;      /* texto principal */
    --muted: #94a3b8;       /* texto secundário */
    --primary: #6366f1;     /* roxo vibrante */
    --secondary: #06b6d4;   /* azul turquesa */
    --radius: 14px;
    --shadow: 0 8px 20px rgba(0,0,0,0.6);
    font-family: 'Inter', sans-serif;
  }
  
  body {
    margin: 0;
    background: var(--bg);
    color: var(--accent);
  }
  
  .topbar {
    background: linear-gradient(90deg, #1e293b, #0f172a); /* gradiente escuro */
    color: #fff;
    padding: 20px 28px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0,0,0,0.7);
  }
  
  .brand {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.5px;
  }
  
  .menu a {
    color: #fff;
    text-decoration: none;
    margin-left: 24px;
    font-weight: 600;
    transition: transform 0.2s, opacity 0.2s;
  }
  
  .menu a:hover {
    opacity: 0.85;
    transform: scale(1.05);
  }
  
  
  .container {
    max-width: 1000px;
    margin: 40px auto;
    padding: 0 20px;
  }
  
  .category {
    background: var(--card);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 28px;
    box-shadow: var(--shadow);
    transition: transform 0.25s, box-shadow 0.25s;
  }
  
  .category:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 28px rgba(0,0,0,0.8);
  }
  
  .category h2 {
    margin-top: 0;
    color: var(--primary);
    font-size: 1.3rem;
    border-bottom: 3px solid var(--secondary);
    padding-bottom: 8px;
  }
  
  .links {
    list-style: none;
    padding: 0;
    margin: 0;
  }
  
  .links li {
    margin: 16px 0;
  }
  
  .links a {
    text-decoration: none;
    color: var(--accent);
    font-weight: 600;
    display: inline-block;
    margin-bottom: 6px;
    transition: color 0.2s;
  }
  
  .links a:hover {
    color: var(--secondary);
  }
  
  .links code {
    display: block;
    background: #0f172a;
    padding: 10px 14px;
    border-radius: 8px;
    font-size: 0.9rem;
    color: var(--muted);
    border-left: 4px solid var(--primary);
    transition: background 0.2s;
  }
  
  .links code:hover {
    background: #1e293b;
  }
  
  .footer {
    text-align: center;
    padding: 24px;
    color: var(--muted);
    font-size: 0.9rem;
  }