html {
    height: 100%;
}
body {
    margin: 0;
    padding: 0;
    overflow: hidden;
}

.back {
    background-image: linear-gradient(120deg, #0093E9, #55afec, #ff5e00, 
    #970500); 
    width: 100%;
    height: auto;
    background-size: 400% 400%;
    animation: backc 20s ease-in-out infinite;
}

.logo img {
    width: 24.378%;
    float: right;
    margin: 0px 150px 0px 0px;
    z-index: 2;
}

a {
    text-decoration: none;
    color: white;
    display: inline-block;
    height: 75px;
    margin: 100px 0px 0px 85px;

}

.core {
    margin: 342px 0px 0px 20%;
}

h2 {
    font-family: 'Abel', sans-serif;
    font-weight: 200;
    text-align: center;
    margin: 0px;
    font-size: 60px ;
    color: rgb(236, 237, 250);
    letter-spacing: 5px;
    transition: 1s;
    width: 300px;
}

p {
    text-align: center;
    width: 300px;
    font-family: 'abel';
    color: white;
    margin: 0px;
    font-size: 100%;
}
.start{
    font-family: 'abel';
    font-size: 40px;
    border: 2px solid white;
    padding: 10px;
    width: 110px;
    color: white;
    letter-spacing: 4px;
    border-radius: 10px;
    transition: .7s;
    margin: 0px;
    animation: str 15s ease-in-out infinite;
}

h3:hover {
    transition: .5s;
    transform: translateY(15px);
    background-color: transparent;
    z-index: 1;
}

.block div {
    position: absolute;
    height: 60px;
    width: 60px;
    background-color: transparent;
    border: 3px solid white;
}

.block div:nth-child(1){
    top: 12%;
    left: 32%;
    animation: animate 13s linear infinite;
}

.block div:nth-child(2){
    top: 30%;
    left: 50%;
    animation: animate 6s linear infinite;
}
.block div:nth-child(3){
    top: 55%;
    left: 60%;
    animation: animate 13s linear infinite;
}
.block div:nth-child(4){
    top: 30%;
    left: 20%;
    animation: animate 4s linear infinite;
}
.block div:nth-child(5){
    top: 75%;
    left: 46%;
    animation: animate 4s linear infinite;
}
.block div:nth-child(6){
    top: 11%;
    left: 72%;
    animation: animate 4s linear infinite;
}
.block div:nth-child(7){
    top: 84%;
    left: 32%;
    animation: animate 10s linear infinite;
}
.block div:nth-child(8){
    top: 70%;
    left: 75%;
    animation: animate 10s linear infinite;
}
.block div:nth-child(9){
    top: 50%;
    left: 85%;
    animation: animate 7s linear infinite;
}
.block div:nth-child(10){
    top: 70%;
    left: 7%;
    animation: animate 4s linear infinite;
}

@keyframes animate{
    0%{
        transform: scale(0) translateY(0) rotate(0deg);
        opacity: 1;
        z-index: -1;
    }
    100%{
        transform: scale(1.3) translateY(-90px) rotate(360deg);
        opacity: 0;
        z-index: -1;
    }
}

@keyframes backc{
    0%{ 
        background-position: 0 50%;
    }

    50%{
        background-position: 100% 50%;
    }
    100%{
        background-position: 0 50%;
    }
}

@keyframes str {
    0%{
        border: 2px solid white;
        color: white;
    }
   
    50% {
        border: 2px solid black;
        color: black;
    }

    100%{
        border: 2px solid white;
        color: white;
    }
}

@media (max-width: 1650px) {

    body {
        overflow: scroll;
    }

    .logo {
        display: flex;
        float: none;
        justify-content: center;
        margin-top: 50px;
    }

    .logo img {
        width: 400px;
        margin: 0px;
    }

    .core {
       display: flex;
       flex-direction: column;
       margin: 220px 0px 0px 0px;
       align-items: center;
       height: auto;
       justify-content: space-between;
    }

    h2 {
        font-size: 50px;
    }

    p {
        font-size: 20px;
    }

    a {
        margin: 150px 0px 100px 0px;
    }

    .link-start {
        margin-top: 50px;
    }
}

@media (max-width: 1000px) {
    .logo img {
        width: 300px;
    }

    h2 {
        font-size: 40px;
    }

    p {
        font-size: 17px;
    }

    .logo {
        margin: 150px;
    }
    .block div:nth-child(5){
        display: none;
    }
    .block div:nth-child(3){
        display: none;
    }
    .block div:nth-child(4){
        display: none;
    }
    .block div:nth-child(10){
        top: 50%;
    }
}

@media (max-width: 600px) {
    .logo img {
        width: 285px;
    }

    h2 {
        font-size: 40px;

    }

    .core {
        justify-content: start;
        margin-top: 50px;
    }

    .logo {
        margin: 100px 0px 80px 0px;
    }

    .block div:nth-child(8){
        display: none;
    }

    .block div:nth-child(6){
        display: none;
    }

    .start {
        font-size: 6.6vw;
        width: auto;
    }

}

@media (max-width: 400px) {
    h2 {
        font-size: 10vw;
    }

    p {
        font-size: 15px;
        margin: 50px 0px 0px 0px;
    }

    a {
        height: 62px;
    }

    .start {
        font-size: 30px;
        width: auto;
    }

    .logo img {
        width: 70%;
    }
}