* {
  box-sizing: border-box;
}
html, body { margin: 0; padding: 0; }

/* Turquoise grid paper background with silver hacker vibe */
:root {
  --grid: rgba(0, 212, 212, 0.25);
  --glass: rgba(255, 255, 255, 0.14);
  --silver: #cbd5e1;
  --bg: #0b1118;
  --cta: linear-gradient(135deg, rgba(0,214,214,0.95), rgba(120,180,190,0.95));
  --shadow: 0 10px 28px rgba(0,0,0,0.4);
}
body {
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Inter, Arial;
  color: #e6f7ff;
  background-color: var(--bg);
  background-image:
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px),
    linear-gradient(to right, var(--grid) 1px, transparent 1px);
  background-size: 40px 40px;
  min-height: 100vh;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
main {
  display: grid;
  place-items: center;
  padding: 2rem 1rem;
  min-height: 70vh;
}
.image-frame {
  width: min(92vw, 720px);
  padding: 1rem;
  border-radius: 16px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.25);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  box-shadow: 0 8px 40px rgba(0,0,0,0.5);
  outline: 1px solid rgba(255,255,255,0.25);
}
.image-frame img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.5);
}
@media (min-width: 640px) {
  main { padding: 3rem 2rem; }
  .image-frame { width: min(700px, 60vw); }
}
footer {
  padding: 1.25rem;
  text-align: center;
  color: #e6f5ff;
  font-size: 0.95rem;
}
.product-ad {
  display: inline-block;
  padding: 0.6rem;
  border-radius: 12px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.25);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  margin-top: 0.75rem;
}
.product-ad h3 { font-size: 1rem; margin: 0 0 0.25rem; color: #eaf7ff; }
.product-ad a { text-decoration: none; }
.product-ad a p {
  margin: 0;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  color: #eaffff;
  font-weight: 700;
  background: var(--cta);
  border: 1px solid rgba(255,255,255,0.8);
  box-shadow: 0 6px 14px rgba(0,0,0,0.45);
  display: inline-block;
}
.product-ad a:hover p { transform: translateY(-1px); }
footer p { margin-top: 0.5rem; opacity: 0.9; }

/* Accessibility: clear focus styles for keyboard navigation */
a:focus-visible, button:focus-visible {
  outline: 2px solid #2dd4bf;
  outline-offset: 2px;
  border-radius: 4px;
}