:root {
  --font-main: monospace;
  --text-main: #e5e5e5;
  --bg-body: #1d1e2c;
  --bg-button: #1985a1;
  --ripple-button: #0b5fdd;
  --shadow-button: #0b5fdd66;
}

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
  border: none;
  outline: none;
}

body {
  background-color: var(--bg-body);
  color: var(--text-main);
  font-family: var(--font-main);
  width: 100%;
  min-height: 100vh;
}
main {
  width: 100%;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 40px 20px;
}

.button-ripple-effect {
  width: 100%;
}
.button-ripple-effect__title {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 40px;
}
.button-ripple-effect__btn {
  background-color: var(--bg-button);
  color: var(--text-main);
  font-size: 1.4rem;
  font-weight: 600;
  display: block;
  padding: 15px 30px;
  margin: 0 auto;
  border-radius: 10px;
  position: relative;
  overflow: hidden;
  cursor: pointer;
}
.button-ripple-effect__btn:focus-visible {
  box-shadow: 0 0 0 4px var(--shadow-button);
}
.button-ripple-effect__text-btn {
  position: relative;
  z-index: 100;
}
.button-ripple-effect__ripple-btn {
  background-color: var(--ripple-button);
  width: 100px;
  height: 100px;
  border-radius: 50%;
  position: absolute;
  z-index: 10;
  scale: 0;
  translate: -50% -50%;
  animation: ripple 0.5s linear forwards;
  pointer-events: none;
}
@keyframes ripple {
  from {
    scale: 0;
    opacity: 1;
  }
  to {
    scale: 4;
    opacity: 0;
  }
}