*,
*::before,
*::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
:root {
  --bg: #0a1020;
  --glass: rgba(255,255,255,.08);
  --border: rgba(200,210,225,.40);
  --text: #e8f0ff;
  --muted: #b5c0d9;
  --silver: #cbd5e1;
  --accent: #4df0ff;
}
html { font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial; font-size: 15px; }
body {
  color: var(--text);
  background: var(--bg);
  background-image:
    linear-gradient(#0a1020, #0a1020),
    repeating-linear-gradient(0deg, rgba(255,255,255,.04) 0 1px, transparent 1px 2px),
    repeating-linear-gradient(90deg, rgba(255,255,255,.03) 0 1px, transparent 1px 2px);
  min-height: 100vh;
}
main { display: grid; place-items: center; padding: 2rem 1rem; }
.image-frame {
  width: 100%;
  max-width: 860px;
  background: rgba(255,255,255,.08);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  box-shadow: 0 20px 60px rgba(0,0,0,.5);
  transition: box-shadow .25s ease;
}
.image-frame:hover { box-shadow: 0 0 0 3px rgba(79,243,255,.25), 0 24px 72px rgba(0,0,0,.6); }
.image-frame img {
  width: 100%; height: auto; display: block;
  border-radius: 10px;
  border: 1px solid rgba(255,255,255,.25);
  box-shadow: inset 0 0 0 1px rgba(0,0,0,.15);
}
footer { padding: 1.5rem 1rem; text-align: center; color: var(--text); }
.product-ad {
  display: inline-flex; flex-direction: column; align-items: center; gap: .4rem;
  background: rgba(9, 12, 40, .65);
  border: 1px solid rgba(180,190,210,.6);
  padding: .8rem 1rem;
  border-radius: 12px;
  margin: 0 auto .5rem;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  box-shadow: 0 6px 22px rgba(0,0,0,.4);
}
.product-ad h3 { margin: 0; font-size: .95rem; color: #d9e3f7; }
.product-ad a { text-decoration: none; }
.product-ad a p {
  margin: .25rem 0 0;
  padding: .55rem 1rem;
  background: rgba(255,255,255,.28);
  color: #051124;
  border-radius: 6px;
  border: 1px solid rgba(255,255,255,.75);
  font-weight: 700;
}
a, button { color: inherit; }

/* accessibility: focus styles */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

/* responsive, mobile-first scaling */
@media (min-width: 640px) {
  html { font-size: 16px; }
  .image-frame { padding: 1.25rem; }
}
@media (min-width: 980px) {
  main { padding: 3rem 1rem; }
  .image-frame { max-width: 900px; padding: 1.5rem; }
  .product-ad { font-size: 1.05rem; }
}