body {
      font-family: system-ui, sans-serif;
      background: #0f172a;
      color: #e5e7eb;
      margin: 0;
    }

    nav {
      background: #020617;
      border-bottom: 1px solid #1e293b;
    }

    .nav-inner {
      max-width: 600px;
      margin: auto;
      padding: 1rem 2rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .logo {
      font-weight: 700;
      letter-spacing: 0.3px;
    }

    .nav-links a {
      color: #94a3b8;
      text-decoration: none;
      margin-left: 1.2rem;
      font-size: 0.95rem;
    }

    .nav-links a:hover {
      color: #e5e7eb;
    }

    main {
      padding: 20px;
      max-width: 700px;
      margin: auto;
      line-height: 1.6;
    }

    h1 {
      margin-bottom: 0.5rem;
      margin-left: 10px;
    }

    input {
      width: 100%;
      padding: 0.8rem;
      font-size: 1.1rem;
      border-radius: 6px;
      border: none;
      margin: 1rem 0;
    }

    .result {
      background: #020617;
      padding: 1rem;
      border-radius: 8px;
      line-height: 1.6;
    }

    .bad { color: #f87171; }
    .good { color: #4ade80; }

    small {
      color: #94a3b8;
    }