* {
    font-family: tahoma;
}

span {
    background-color: rgba(255, 300, 0, 0.5);
    width: 100px;
    height: 100px;
    text-align: center;
    padding: 10px;
    border: 1px solid;
}

/* inline */
span.inline {
    display: inline;
}

/* block */
span.block {
    display: block;
}

/* inline-block */
span.inline-block {
    display: inline-block;
}

/* flex */
.flex-container {
    background-color: aqua;
    display: flex;
    flex-wrap: wrap;
    height: 200px;
    padding: 10px;
    text-align: center;
    justify-content: center;
}

.flex-item {
    background-color: azure;
    display: flex;
    width: 100px;
    height: 100px;
    margin: 10px;
}