雷达扫描效果 CSS+JS

            
            html, body {
  height: 100vh;
}

body {
  background: #001413;
  overflow: hidden;
  display: grid;
  place-items: center;
}

.radar {
  --size: 450px;
  --color: #15fcd8;
  
  width: var(--size);
  height: var(--size);
  margin: auto;
  border: 3px solid var(--color);
  border-radius: 50%;
  background:
    /* 4) guides */
    linear-gradient(transparent 0 49.75%, var(--color) 49.75% 50%, transparent 50% 100%),
    linear-gradient(to right, transparent 0 49.75%, var(--color) 49.75% 50%, transparent 50% 100%),
    /* 3) radar */
    radial-gradient(
      transparent 0% 25%,
      var(--color) 25.5% 25.75%, transparent 26% 50%,
      var(--color) 50.5% 50.75%, transparent 51% 75%,
      var(--color) 75.5% 75.75%, transparent 76% 100%),
    /* 2.5) fondo tapar grid */
    radial-gradient(#00767211, #002421 65%),
    /* 2) grid */
    repeating-linear-gradient(to right, #0e817a77 0 1px, transparent 1.5px 25px),
    repeating-linear-gradient(#0e817a77 0 1px, transparent 1.5px 25px),
    /* 1) background */
    radial-gradient(#007672 0, #002421 65%);
  position: relative;
  mix-blend-mode: difference; /* color-dodge; */
}

.dot { 
  width: var(--size);
  height: var(--size);
  background: var(--color);
  border-radius: 50%;
  position: absolute;
  filter: blur(1px);
  opacity: 0.5;
  left: var(--x);
  top: var(--y);
  animation: disappear 1s ease-in-out forwards;
}

.radar::before {
  --dark-color: color-mix(in srgb, var(--color), transparent 85%);
  
  content: "";
  display: block;
  background: var(--dark-color);
  width: 100%;
  height: 100%;
  border-radius: 50%;
  position: absolute;
  filter: blur(1px);
  animation: pulse 1.25s infinite 0.25s;
}

.radar::after {
  --radar-color: color-mix(in srgb, var(--color), transparent 50%);
  
  content: "";
  display: block;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: conic-gradient(transparent 0, var(--radar-color) 0.1turn 0.15turn, transparent 0.25turn);
  mix-blend-mode: plus-lighter;
  animation: move-radar 5s linear infinite;
}

@keyframes move-radar {
  from { rotate: -0.125turn; }
  to { rotate: 0.875turn; }
}

@keyframes pulse {
  0% { scale: 1; }
  100% { scale: 1.15; opacity: 0; }
}

@keyframes disappear {
  to { opacity: 0; }
}

.mute {
  position: absolute;
  top: 1rem;
  right: 1rem;
}

.mute { 
  cursor: pointer;
  
  & input { display: none }
  & img { width: 48px }
  & input:checked ~ .on,
  & input:not(:checked) ~ .off { 
    display: none;
  }
}
        

            
            const radar = document.querySelector(".radar");
const muted = document.querySelector(".mute input");
/* https://freesound.org/people/unfa/sounds/584179/ */
const beep = new Audio("https://cdn.freesound.org/previews/584/584179_1038806-lq.mp3");

const addDot = () => {
  if (Math.random() > 0.5) return;
  const dot = document.createElement("div");
  dot.classList.add("dot");
  const x = Math.floor(Math.random() * 100);
  const y = Math.floor(Math.random() * 100);
  const size = 10 + Math.floor(Math.random() * 10);
  dot.style.setProperty("--x", `${x}%`);
  dot.style.setProperty("--y", `${y}%`);
  dot.style.setProperty("--size", `${size}px`);
  radar.append(dot);
  setTimeout(() => dot.remove(), 2000);
}

setInterval(() => {
  if (!muted.checked) {
    beep.currentTime = 0;
    beep.play();
  }
  addDot();
}, 1250);