ボタン48

$BLOCK_NAME: '.button-48';

// 変数
// https://developer.mozilla.org/ja/docs/Web/CSS/@property
@property --angle {
  syntax: '<angle>';
  inherits: false;
  initial-value: 0deg;
}

#{ $BLOCK_NAME } {
  position: relative;
  display: block;
  width: 320px;
  height: 64px;
  padding: 4px;
  border-radius: 9999px;
  background: #222;

  &::before {
    position: absolute;
    inset: 0;
    display: block;
    content: '';
    border-radius: 9999px;
    z-index: 1;
    opacity: 0;
    background: conic-gradient(
      from var(--angle),
      #222,
      #939393,
      #222,
      #939393,
      #222
    );
  }

  &__inner {
    position: relative;
    display: flex;
    width: 100%;
    height: 100%;
    align-items: center;
    justify-content: center;
    background: #fff;
    border-radius: 9999px;
    z-index: 2;
  }

  @media (any-hover: hover) {
    &::before {
      transition: opacity 0.3s;
    }
    &:hover::before {
      opacity: 1;
      animation: gradient-spin 3s linear 0s infinite;
    }
  }
}

@keyframes gradient-spin {
  0% {
    --angle: 0deg;
  }

  100% {
    --angle: 360deg;
  }
}