:root
{
    --background: #121212;
    --colour: #00ffff;

     
}

body
{
    background-color:var(--background);
    height: 100%;
}
.container-a {
    display: flex;
    flex-direction: column;
    width: 330px;
    height: 350px;
    margin: 15% auto 0;
    align-items: center;
}

.container-b {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    width: 330px;
    height: 330px;

    justify-items: center;  /* horizontal centering inside each cell */
    align-items: center;    /* vertical centering inside each cell */
}

h1
{
    width: 100%;
    color: white;
    text-align: center;
    margin: 0;
    text-shadow: 1px 1px 4px var(--colour);
}
.loader
{
  width: 100px;
  aspect-ratio: 1;
  border-radius: 50%;
}

.l-a 
{
  rotate: 180deg;
  background: 
    radial-gradient(farthest-side,var(--colour) 95%,#0000) 50% 1px/24px 24px no-repeat,
    radial-gradient(farthest-side,#0000 calc(100% - 14px),var(--background) 0);
  animation: la 3s infinite ease-in-out;
  box-shadow: var(--colour) 1px 2px 3px;

}

.l-b 
{
  rotate: 180deg;
  background: 
    radial-gradient(farthest-side,var(--colour)95%,#0000) 50% 1px/24px 24px no-repeat,
    radial-gradient(farthest-side,#0000 calc(100% - 14px),var(--background) 0);
  animation: lb 3s infinite ease-in-out;
  box-shadow: var(--colour) 1px 2px 3px;

}
.l-c 
{
  background: 
    radial-gradient(farthest-side,var(--colour) 95%,#0000) 50% 1px/24px 24px no-repeat,
    radial-gradient(farthest-side,#0000 calc(100% - 14px),var(--background) 0);
  animation: lc 3s infinite ease-in-out;
  box-shadow: var(--colour) 1px 2px 3px;


}
.l-d 
{
  background: 
    radial-gradient(farthest-side,var(--colour) 95%,#0000) 50% 1px/24px 24px no-repeat,
    radial-gradient(farthest-side,#0000 calc(100% - 14px),var(--background) 0);
    animation: ld 3s infinite ease-out;
    box-shadow: var(--colour) 1px 2px 3px;


}
@keyframes la {to{transform: rotate(2turn)}}
@keyframes lb {to{transform: rotate(-1turn)}}
@keyframes lc {to{transform: rotate(-1turn)}}
@keyframes ld {to{transform: rotate(2turn)}}