@import url('https://fonts.googleapis.com/css2?family=Quicksand&display=swap');

* {
    margin: 0;
    padding: 0;
    font-family: 'Quicksand', sans-serif;
}

.hero {
    width: 100%;
    height: 100vh;
    background-image: url('./images/background.png');
    background-size: cover;
    background-position: center;
    position: relative;
    overflow: hidden;
}

.logo {
    width: 100px;
    cursor: pointer;
}

.navbar {
    /*set the width of navbar , to small to tight*/
    width: 85%;
    height: 15%;
    /*to centering the navbar*/
    margin: auto;
    /*so that container like column on table*/
    display: flex;
    /*centering an object on the div*/
    align-items: center;
    /*give an space in object*/
    justify-content: space-between;
}

button {
    color: #fbfcfd;
    padding: 10px 25px;
    background: transparent;
    border: 1px solid #fff;
    border-radius: 20px;
    outline: none;
    cursor: pointer;
}

.content {
    color: #fbfcfd;
    position: absolute;
    top: 50%;
    left: 8%;
    transform: translateY(-50%);
    z-index: 2;
}

h1 {
    font-size: 80px;
    margin: 10px 0 30px;
    line-height: 80px;
}

.sidebar {
    width: 50px;
    height: 100vh;
    background: linear-gradient(#00545d, #000729);
    position: absolute;
    top: 0;
    right: 0;
}

.menu {
    display: block;
    width: 25px;
    margin: 40px auto 0;
    cursor: pointer;
}

.social-links img,
.usefull-links img {
    width: 25px;
    margin: 5px auto;
    cursor: pointer;
}

.social-links {
    width: 50px;
    text-align: center;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
}

.usefull-links {
    width: 50px;
    text-align: center;
    position: absolute;
    bottom: 30px;
}

.bubbles img {
    width: 50px;
    animation: bubble 7s linear infinite;
}

.bubbles {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-around;
    position: absolute;
    bottom: -70px;
}

@keyframes bubble {
    0% {
        transform: translateY(0);
        opacity: 0;
    }

    50% {
        opacity: 1;
    }

    75% {
        opacity: 1;
    }

    100% {
        transform: translateY(-80vh);
    }
}

.bubbles img:nth-child(1) {
    animation-delay: 2s;
    width: 25px;
}

.bubbles img:nth-child(2) {
    animation-delay: 3s;
}

.bubbles img:nth-child(3) {
    animation-delay: 1.7s;
    width: 25px;
}

.bubbles img:nth-child(4) {
    animation-delay: 4.8s;
}

.bubbles img:nth-child(5) {
    animation-delay: 3.5s;
}

.bubbles img:nth-child(6) {
    width: 20px;
    animation-delay: 5.2s;
}

.bubbles img:nth-child(7) {
    width: 35px;
    animation-delay: 5.8s;
}