/vignette v2

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
  <title>Blue Radial Gradient</title>
  <style>
    :root {
      /* Tweak these to your taste */
      --center: #5fb3ff;   /* bright center blue */
      --mid:    #2a7bd6;   /* mid blue */
      --edge:   #0b2a4f;   /* darkest edge */
    }

    html, body {
      height: 100%;
      margin: 0;
    }

    body {
      /* Fallback color */
      background-color: var(--edge);

      /* Radial gradient: bright in the center, dark at the edges */
      background-image: radial-gradient(
        circle at 50% 50%,  /* center point (you can move it) */
        var(--center) 0%,
        var(--mid) 40%,
        var(--edge) 100%
      );

      /* Make sure it covers the whole viewport */
      min-height: 100vh;
      color: white;
      display: grid;
      place-items: center;
      font-family: system-ui, sans-serif;
    }

    .card {
      background: rgba(255,255,255,0.06);
      backdrop-filter: blur(6px);
      border: 1px solid rgba(255,255,255,0.15);
      border-radius: 14px;
      padding: 2rem 2.4rem;
      max-width: 48rem;
      text-align: center;
    }
  </style>
</head>
<body>
  <div class="card">
    <h1>Blue Vignette</h1>
    <p>Darker outside, brighter center using a CSS radial-gradient.</p>
  </div>
</body>
</html>