:root {
  /* Colori */
  --g: #0f0;
  --bg-dots: #010;
  --bg-lines: #030;
  --bg-screen: #000100;
  --bg-light: #B3C7DD;
  --bg-dark: #000000;
  --white-hi: #f1f1f1;
  --white-low: #9d9e9f;
  --base: #ffffff;
 
  /* Parametri */
  --dot-opacity: 0.5;
  --line-opacity: 0.25;
  --radial-opacity: 0.25;
  --trail-length: 90deg;
  --blend: color-dodge;
  --speed: 20s;
}

*,
*::after,
*::before {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Montserrat', sans-serif;
}
body {
  height: 100vh;
  width: 100vw;
  margin: 0;
  background:
    linear-gradient(to top,
      var(--bg-dark), var(--bg-light));
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  justify-content: center;
  align-items: center;
  transition: all .3s ease;
}
body:has(input:checked) {
  --g: #f00;
  --bg-dots: #f00;
  --bg-lines: #700;
  --bg-screen: #100;
  --blend: darken;
  --trail-length: 210deg;
  --speed: 3s;
}
body:has(input:checked) #radar::after {
  content: '';
  backdrop-filter: blur(0.5px);
}

#radar {
  width: 75vmin;
  aspect-ratio: 1;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  background:
    linear-gradient(to bottom,
      var(--white-hi), var(--white-low));
  box-shadow: 
    inset 0 -3px 10px rgba(0,0,0,0.25),
    0 15px 18px rgba(0,0,0,0.5);
  border-radius: 50%;
  z-index: 2;
}
#radar::before, #radar::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 90%;
  aspect-ratio: 1;
  border-radius:50%;
  transition: all .3s ease;
}
#radar::before{
  z-index:-1;
  background-color: var(--bg-screen);
  background-image:
    linear-gradient(to bottom, 
      transparent calc(50%),
      hsl(from var(--bg-lines) h s l / var(--line-opacity)), 
      transparent calc(50% + 1px)),
    linear-gradient(to right, 
      transparent calc(50%),
      hsl(from var(--bg-lines) h s l / var(--line-opacity)),
      transparent calc(50% + 1px)),
    linear-gradient(45deg, 
      transparent calc(50%),
      hsl(from var(--bg-lines) h s l / var(--line-opacity)), 
      transparent calc(50% + 1px)),
    linear-gradient(-45deg, 
      transparent calc(50%),
      hsl(from var(--bg-lines) h s l / var(--line-opacity)), 
      transparent calc(50% + 1px)),
    repeating-radial-gradient(
      hsl(from var(--bg-lines) h s l / var(--radial-opacity)) 0,
      transparent 1px 2.5vmin, 
      hsl(from var(--bg-lines) h s l /  var(--radial-opacity)) calc(2.5vmin + 1px));
}
#radar::after {
  background-image: 
    conic-gradient(
      #000 var(--trail-length), var(--g) 360deg);
  mix-blend-mode: var(--blend);
  animation: rotate var(--speed) linear infinite;
}

#targets {
  width: 90%;
  height: 90%;
  position: relative;
  border-radius: 50%;
  overflow: hidden;
  background:
      radial-gradient(circle at 65% 15%, var(--bg-dots), transparent 6px),
      radial-gradient(circle at 67% 19%, var(--bg-dots), transparent 4px),
      radial-gradient(circle at 68% 16%, var(--bg-dots), transparent 6px),
      radial-gradient(circle at 59% 63%, var(--bg-dots), transparent 5px),
      radial-gradient(circle at 55% 62%, var(--bg-dots), transparent 8px),
      radial-gradient(circle at 15% 36%, var(--bg-dots), transparent 6px),
      radial-gradient(circle at 19% 39%, var(--bg-dots), transparent 4px),
      radial-gradient(circle at 32% 70%, var(--bg-dots), transparent 6px),
      radial-gradient(circle at 28% 53%, var(--bg-dots), transparent 7px),
      radial-gradient(circle at 45% 92%, var(--bg-dots), transparent 8px),
      radial-gradient(circle at 85% 36%, var(--bg-dots), transparent 6px),
      radial-gradient(circle at 89% 45%, var(--bg-dots) 3px, transparent 5px),
      radial-gradient(circle at 78% 70%, var(--bg-dots) 4px, transparent 6px),
      radial-gradient(circle at 33% 85%, var(--bg-dots) 8px, transparent 10px);
  animation: move 120s infinite linear;
  background-position: 0 0;
}
#targets::after, #targets::before {
  content: '';
  position: absolute;
  inset: 0;   
}
#targets::after {
  background:
    radial-gradient(circle at 10% 50%, var(--bg-dots), transparent 5px),
    radial-gradient(circle at 90% 50%, var(--bg-dots), transparent 5px),
    radial-gradient(circle at 60% 10%, var(--bg-dots), transparent 8px),
    radial-gradient(circle at 70% 90%, var(--bg-dots), transparent 5px);
  animation: move 200s infinite linear reverse, rotate 200s linear infinite;
}
#targets::before {
  background:
    radial-gradient(circle at 45% 50%, var(--bg-dots), transparent 4px),
    radial-gradient(circle at 49% 55%, var(--bg-dots), transparent 5px),
    radial-gradient(circle at 35% 35%, var(--bg-dots), transparent 6px),
    radial-gradient(circle at 45% 15%, var(--bg-dots), transparent 7px),
    radial-gradient(circle at 25% 35%, var(--bg-dots), transparent 8px);
  animation: move 600s infinite linear reverse, rotate 600s linear infinite;
}

@keyframes rotate {
  to {transform: translate(-50%, -50%) rotate(1turn)}
}

@keyframes move {
  to {background-position: 0 67.5vmin;}
}

#selector {
  box-shadow: inset 0 2px 4px #0007;
  background: var(--bg-dark);
  cursor: pointer;
  width: 120px;
  height: 30px;
  display: block;
  position: relative;
  appearance: none;
  border-radius: 15px;
}
#selector::before {
  content: 'Ver. 1';
  color: var(--bg-dark);
  font-weight: 700;
  font-size: 1rem;
  position: absolute;
  display: flex;
  justify-content: center;
  align-items: center;
  top: 0;
  left: 0;
  width: 60%;
  height: 100%;
  border-radius: inherit;
  background: 
    linear-gradient(to bottom,
    var(--white-hi), var(--white-low));
  transition: all .3s ease;
}
#selector:checked::before {
  content: 'Ver. 2';
  left: 40%;
}

.loader {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 6px solid var(--g);
  border-radius: 50%;
  box-sizing: border-box;
  pointer-events: none;
  z-index: 10;
  box-shadow: 0 0 24px 4px var(--g), 0 0 0 2px #0008 inset;
}