style.css

*{
    margin: 0;
    padding: 0;
}

html,body{
    height: 100%;
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande',
     'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    background-color: aliceblue;
}

#container{
    display: flex;
    height: 100%;
    align-items: center;
    flex-direction: column;
}

#game{
    width: 95%;
    max-width: 500px;
    height: 100%;
    
}

header{
    border-bottom: 2px solid #5c97cc;
}
.title{
    color:#061829;
    font-size: 2.5rem;
    font-weight: bold;
    margin: 0.4rem 0 0.4rem 0;
    text-align: center;
    
}

#board-container{
    display: flex;
    justify-content: center;
    align-items: center;
    flex-grow: 1;
    overflow: hidden;
}

#board{
    display: grid;
    grid-template-columns: repeat(5,1fr);
    gap:5px;
    padding: 10px;
    box-sizing: border-box;
}
.square{
    border: 2px solid #5c97cc;
    min-width: 60px;
    min-height: 60px;
    font-size: 2.5rem;
    font-weight: bold;
    color: #061829;

    display: flex;
    align-items: center;
    justify-content: center;
}

#keyboard-container{
    height:200px;
}

.keyboard-row{
    display:flex;
    justify-content: center;
    width: 100%;
    margin:0 auto 8px;
    touch-action: manipulation;
}

.keyboard-row button{
    font-family: inherit;
    font-weight: bold;
    border: 0;
    padding: 0;
    height: 55px;
    cursor: default;
    background-color: #5c97cc;
    color: #061829;
    flex-grow: 1;
    margin-right: 5px;
    border-radius: 4px;
}

.keyboard-row button.wide-key{
    flex-grow: 1.5;
}