.modes-box{
    margin: 1em 0 4em;
    
    border: solid 2px #bababa;
    border-radius: 10px;
    padding: 10px;
    text-align: center;
}

.modes-box > div{
    padding: 20px;
}

.mode{
    margin: 0 auto;
    padding: 1em 2em;
    background: #fff;
    text-align: center;
    border-radius: 10px;
    position: relative;
    
    font-size: 1.4rem;
    font-weight: bold;
}

hr{
    border-color: #bababa;
}

select{
    background-color: #FFFEC0;
    padding: 0.4em 2em;
    border: solid 2px var(--green);
    border-radius: 10px;
    font-size: 1rem;
}


.marathon-mode {
}

@property --angle {
    syntax: "<angle>";
    initial-value: 0deg;
    inherits: false;
}

.marathon-mode::after,
.marathon-mode::before {
    content: '';
    position: absolute;
    height: 100%;
    width: 100%;
    background-image: conic-gradient(from var(--angle), #ff4545, #00ff99, #006aff, #ff0095, #ff4545);
    top: 50%;
    left: 50%;
    translate: -50% -50%;
    z-index: -1;
    padding: 3px;
    border-radius: 10px;
    animation: 3s spin linear infinite;
}

.marathon-mode::before,
.random-mode::before {
    filter: blur(1.5rem);
    opacity: 0.5;
}

@keyframes spin {
    from {
        --angle: 0deg;
    }

    to {
        --angle: 360deg;
    }
}


.random-mode {
}

.random-mode::after,
.random-mode::before {
    content: '';
    position: absolute;
    height: 100%;
    width: 100%;
    background-image: conic-gradient(from var(--angle), #fff, #000, #fff, #000, #fff);
    top: 50%;
    left: 50%;
    translate: -50% -50%;
    z-index: -1;
    padding: 3px;
    border-radius: 10px;
    animation: 3s spin linear infinite;
}