@import url('https://fonts.googleapis.com/css2?family=Quicksand:wght@300;400;500;600;700&display=swap');

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

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #000;
}

section {
    position: absolute;
    width: 100vw;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2px;
    flex-wrap: wrap;
    overflow: hidden;
}

    section::before {
        content: '';
        position: absolute;
        width: 100%;
        height: 100%;
        background: linear-gradient(#000,#0f0,#000);
        animation: animate 5s linear infinite;
    }

@keyframes animate {
    0% {
        transform: translateY(-100%);
    }

    100% {
        transform: translateY(100%);
    }
}

section span {
    position: relative;
    display: block;
    width: calc(6.25vw - 2px);
    height: calc(6.25vw - 2px);
    background: #181818;
    z-index: 2;
    transition: 1.5s;
}

    section span:hover {
        background: #0f0;
        transition: 0s;
    }

section .signin {
    position: absolute;
    width: 400px;
    background: #222;
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 40px;
    border-radius: 4px;
    box-shadow: 0 15px 35px rgba(0,0,0,9);
}

    section .signin .content {
        position: relative;
        width: 100%;
        display: flex;
        justify-content: center;
        align-items: center;
        flex-direction: column;
        gap: 40px;
    }

        section .signin .content h2 {
            font-size: 2em;
            color: #0f0;
            text-transform: uppercase;
        }

        section .signin .content .form {
            width: 100%;
            display: flex;
            flex-direction: column;
            gap: 25px;
        }

            section .signin .content .form .inputBox {
                position: relative;
                width: 100%;
            }

                section .signin .content .form .inputBox input {
                    position: relative;
                    width: 100%;
                    background: #333;
                    border: none;
                    outline: none;
                    padding: 25px 10px 7.5px;
                    border-radius: 4px;
                    color: #fff;
                    font-weight: 500;
                    font-size: 1em;
                }

                section .signin .content .form .inputBox i {
                    position: absolute;
                    left: 0;
                    padding: 15px 10px;
                    font-style: normal;
                    color: #aaa;
                    transition: 0.5s;
                    pointer-events: none;
                }

.signin .content .form .inputBox input:focus ~ i,
.signin .content .form .inputBox input:valid ~ i {
    transform: translateY(-7.5px);
    font-size: 0.8em;
    color: #fff;
}

.signin .content .form .links {
    position: relative;
    width: 100%;
    display: flex;
    justify-content: space-between;
}

    .signin .content .form .links a {
        color: #fff;
        text-decoration: none;
    }

        .signin .content .form .links a:nth-child(2) {
            color: #0f0;
            font-weight: 600;
        }

.signin .content .form .inputBox input[type="submit"] {
    padding: 10px;
    background: #0f0;
    color: #000;
    font-weight: 600;
    font-size: 1.35em;
    letter-spacing: 0.05em;
    cursor: pointer;
}

input[type="submit"]:active {
    opacity: 0.6;
}

@media (max-width: 900px) {
    section span {
        width: calc(10vw - 2px);
        height: calc(10vw - 2px);
    }
}

@media (max-width: 600px) {
    section span {
        width: calc(20vw - 2px);
        height: calc(20vw - 2px);
    }
}