html, body {
  margin: 0;
  padding: 0;
  height: 200vh;           /* makes background scrollable */
  background: #fff;        /* white base */
  color: #000;
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  text-align: center;
  overflow-x: hidden;
}

/* Independent top & bottom ad areas */
.ad {
  position: fixed;
  width: 100%;
  left: 0;
  z-index: 1;
  opacity: 0.8;
  transition: opacity 0.3s ease, filter 0.3s ease;
}
.ad img {
  width: 100%;
  filter: brightness(0.9) blur(1px);
}
.ad:hover { opacity: 1; filter: none; }
.ad.top { top: 0; }
.ad.bottom { bottom: 0; }

/* Fixed center video area */
.center {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 5;
  background: #fff;
  border: 4px solid #aaa;      /* medium-gray frame */
  border-radius: 12px;
  padding: 8px;
  box-shadow: 0 0 12px rgba(0,0,0,0.2);
}
.center video {
  width: 90vw;
  max-width: 480px;
  border-radius: 8px;
}

/* Sound toggle */
#soundBtn {
  position: absolute;
  top: -55px;
  right: 10px;
  background: transparent;
  border: none;
  font-size: 40px;
  cursor: pointer;
  opacity: 0.7;
}
#soundBtn:hover { opacity: 1; }

/* Copy overlays */
.copy {
  position: absolute;
  width: 100%;
  text-align: center;
  color: #000;
  font-size: 0.9em;
  font-weight: 600;
}
.topcopy { top: -35px; }
.bottomcopy { bottom: -35px; }

/* CTA buttons */
.cta {
  display: inline-block;
  margin-top: 6px;
  padding: 6px 14px;
  border: 2px solid #666;
  border-radius: 6px;
  background: #fff;
  color: #000;
  font-size: 0.85em;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease;
}
.cta:hover {
  background: #000;
  color: #fff;
}