style.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    font-weight: 500;
}

html {
    font-size: 10px;
}

body {
    background-image: linear-gradient(75deg, #5372F0, #6C757D);
}

main {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

main .container {
    width: 440px;
    border-radius: .7rem;
    background: #fff;
    box-shadow: 0 1rem 2rem rgba(0, 0, 0, 0.08);
    margin: 1rem;
}

main .container h1 {
    font-size: 3rem;
    padding: 1.6rem 2.5rem;
    border-bottom: 1px solid #ccc;
}

main .container .content {
    margin: 2rem;
}

main .container .content .word {
    user-select: none;
    font-size: 4.2rem;
    text-align: center;
    font-weight: bold;
    font-family: monospace;
    text-transform: uppercase;
    letter-spacing: 2rem;
    word-break: break-all;
    pointer-events: none;
}

main .container .content .details {
    margin: 2.5rem 0 2rem;
}

.details p {
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.details p b {
    font-weight: 500;
}

main .container .content input {
    padding: 1.5rem;
    width: 100%;
    margin-bottom: 2rem;
    font-size: 1.6rem;
    border-radius: .5rem;
    border: 1px solid #bfbfbf;
    outline: none;
}

.content input:focus {
    box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.08);
}

.content input::placeholder {
    color: #aaa;
}

.content input:focus::placeholder {
    color: #bfbfbf;
}

main .container .content .buttons {
    margin-bottom: 3rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

main .container .content .buttons button {
    padding: 1.8rem;
    font-size: 1.6rem;
    cursor: pointer;
    border: none;
    outline: none;
    color: #fff;
    border-radius: .5rem;
    width: calc(100% / 2 - 8px);
    transition: all .3s ease;
}

.buttons button:active {
    transform: scale(0.97);
}

.buttons .refresh-word {
    background: #6C757D;
}

.buttons .refresh-word:hover {
    background: #5f666d;
}

.buttons .check-word {
    background: #5372F0;
}

.buttons .check-word:hover {
    background: #2c52ed;
}

@media screen and (max-width:450px) {
    html {
        font-size: 9px;
    }

    main .container h1 {
        font-size: 2.4rem;
    }

    main .container .content .word {
        font-size: 2.8rem;
    }
}