html {
  height: 100%;
  margin: 0;
  display: flex;
  flex-direction: column;
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
}

body {
  height: 100%;
  margin: 0;
  display: flex;
  flex-direction: column;
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
  background-image: url('../images/bg.jpg');
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center;
  background-attachment: fixed;
}

.bg-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: #062b36ef;
  backdrop-filter: blur(1px);
  pointer-events: none;
  z-index: 0;
  mask-image: radial-gradient(circle 200px at var(--mouse-x) var(--mouse-y), transparent 0%, black 100%);
  -webkit-mask-image: radial-gradient(circle 200px at var(--mouse-x) var(--mouse-y), transparent 0%, black 100%);
  transition: mask-position 0.05s ease;
}

main {
  position: relative;
  flex: 1;
  padding: 20px;
}

main, header, footer > *:not(.bg-overlay) {
  position: relative;
  z-index: 1; /* all other content above overlay */
}

.ad-banner {
  text-align: center;
  background: #064db6;
  color: #fff;
  padding: 15px 25px;
  font-size: 18px;
  font-weight: 600;
  margin: 20px auto;
  border-radius: 8px;
  border: 1px solid #ffeeba;
  display: block;    
  max-width: fit-content; 
  position: relative;
  cursor: pointer;
}

.ad-banner:hover{
  transform: translateY(-3%) scale(1.05);
}