* {
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    margin: 0;
    height: 100vh;
    overflow: hidden;
    background: radial-gradient(rgb(12, 77, 129), rgb(4, 6, 49));
}

.counter {
    position: fixed;
    transform: translate(-50%, -50%);
    left: 50%;
    top: 50%;
    text-align: center;
    text-transform: uppercase;
}
.counter h3 {
    color: rgb(0, 247, 255);
    font-size: 2em;
    margin-bottom: 4em;
}

.counter.hidden {
    transform: translate(-50%, -50%) scale(0);
    animation: hide 0.50s ease-out;
}

@keyframes hide {
    0% {
        transform: translate(-50%, -50%) scale(1)
    } 
    100% {
        transform: translate(-50%, -50%) scale(0)
    }
    
}

.end-countdown h1 {
    position: fixed;
    transform: translate(-50%, -50%);
    left: 50%;
    top: 45%;
    transform: translate(-50%, -50%) scale(0);
    color: rgb(240, 236, 0);
    font-size: 4em;
}

.end-countdown h1.shown {
    transform: translate(-50%, -50%) scale(1);
    animation: show 1s ease-in-out;
} 

.end-countdown h2 {
    position: absolute;
    top: 80%;
    left: 50%;
    transform: translateX(-50%);
    color: rgb(97, 223, 240);
}

.end-countdown h2.hide {
    display: none;
}

.set-timer.hide {
    display: none;
}




@keyframes show {
    0% {
        color: rgb(14, 14, 27);
        transform: translate(-50%, -50%) scale(0)
    } 
    43% {
        color: rgb(59, 99, 99);
        transform: translate(-50%, -50%) scale(4.3)
    }
    100% {
        color: rgb(240, 236, 0);;
        transform: translate(-50%, -50%) scale(1.5)
    }
    
}

.numbers {
    font-size: 6em;
    overflow: hidden;
    width: 40vw;
    height: 20vh;
    font-weight: 600;
    color: rgb(116, 159, 240);
}


.numbers .nums {
    position: absolute;
    top: 50%;
    left: 50%;
    font-size: 1.6em;
    transform: translate(-150%, -50%) scale(0);
    
}

.nums.visible {
    transform: translate(-50%, -50%);
    animation: slideIn 0.5s ease-in;
}
.nums.start {
    animation: slideIn 0.5s ease-in;
}
.nums.invisible {
    animation: slideOut 0.5s ease-out;
}

@keyframes slideIn {
    0% {
        transform: translate(-150%, -50%) scale(0);
    }
    25% {
        color:rgb(3, 141, 196);
        transform: translate(-125%, -50%) scale(0.25);
    }
    50% {
        color: rgb(58, 196, 250);
        transform: translate(-100%, -50%) scale(0.50);
    }
    75% {
        color: rgb(58, 196, 250);
        transform: translate(-75%, -50%) scale(0.75);
    }
    100% {
        color: rgb(167, 215, 255);
        transform: translate(-50%, -50%) scale(1);
    }
    
}

@keyframes slideOut {
    0% {
        color: rgb(167, 215, 255);
        transform: translate(-25%, -50%) scale(1);
    }
    25% {
        color: rgb(58, 196, 250);
        transform: translate(0%, -50%) scale(0.75);
    }
    50% {
        color: rgb(58, 196, 250);
        transform: translate(25%, -50%) scale(0.50);
    }
    75% {
        color:rgb(3, 141, 196);
        transform: translate(50%, -50%) scale(0.25);
    }
    100% {
        transform: translate(75%, -50%) scale(0);
    }
    
}

.run {
    margin: 0 auto;
    color: white;
    justify-content: center;
    width: 300px;
    background: rgb(68, 68, 73);
    height: 3em;
    width: 9em;
    position: absolute;
    top: 70%;
    left: 50%;
    transform: translateX(-50%);
    font-size: 1.2em;
    cursor: pointer;
    border: none;
    border-radius: 5px 10px;
}
.run:hover {
    transform: translateX(-50%);
    background-color:rgb(0, 189, 247)
}

.run:active {
    transform: translateX(-50%) scale(0.98);
}

.run.hide {
    display: none;
}

.set-timer {
    display: flex;
    align-items: center;
    justify-content: space-around;  
    width: 200px;
    position: absolute;
    top: 90%;
    left: 50%;
    transform: translateX(-50%);
    transition: 0.43s;
}





.set-timer button {
    color: white;
    border: none;
    height: 1.5em;
    width: 1.5em;
    font-size: 2em;
    font-weight: 700;
    cursor: pointer;
    border-radius: 10%;
}



.set-timer button:hover {
    opacity: 0.7;
}

.set-timer button:active {
    transform: scale(0.85);
}

.set-timer .dec {
    background-color: rgb(0, 189, 247);
}

.set-timer .inc {
    background-color: rgb(17, 86, 107);
}

.set-timer span {
    font-size: 2.2em;
    font-weight: 700;
    color: rgb(0, 147, 206);
}