styles.css

* {
    transition: all 0.2s;
}

.players,
.controls,
.history {
    width: 90%;
    margin: 2em auto;
    padding: 32px 16px;
    box-sizing: border-box;
    display: flex;
    box-shadow: 0px 0px 5px 0px rgba(0, 0, 0, 0.3);
}

.players {
    justify-content: space-around;
    flex-wrap: wrap;
}

.players .player {
    margin: 8px;
}

.player .name {
    text-transform: uppercase;
    color: #555;
    text-align: center;
}

.player .health {
    width: 400px;
    height: 40px;
    background-color: #bbb;
    border-radius: 2px;
    box-shadow: 0px 0px 10px 0px rgba(0, 0, 0, 0.5);

    position: relative;
}

.health .currentHealth {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    width: 100%;
    background-color: #4CAF50;

    transition: width 500ms ease-out;
}

.health .healthCounter {
    color: #fff;
    z-index: 10;
    position: absolute;
    top: 50%;
    left: 10px;
    transform: translateY(-50%);
}

.controls {
    justify-content: center;
    flex-wrap: wrap;
    padding-top: 4px;
    padding-bottom: 4px;
}

.controls .btn {
    margin: 4px 8px;
    padding: 8px 16px;
    text-align: center;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 1.2em;
    cursor: pointer;
    color: white;
}

.controls .btn:hover {
    box-shadow: 0px 1px 1px 0px rgba(0, 0, 0, 0.5);
    transform: translateY(-1px);
}

.controls .btn:hover:active {
    transform: translateY(1px);
    box-shadow: 0px 0px 1px 0px rgba(0, 0, 0, 0.5);
}

.btn.start {
    background-color: teal;
}

.btn.atack {
    background-color: #F44336;
}

.btn.special {
    background-color: #3F51B5;
}

.btn.health {
    background-color: #4CAF50;
}

.btn.giveup {
    background-color: #9E9E9E;
}

.history {
    flex-direction: column;
}

.history .result {
    display: flex;
    justify-content: center;
    align-items: center;

    height: 40px;
    padding-bottom: 32px;
    margin-bottom: 32px;
    border-bottom: 1px solid #ccc;

    text-transform: uppercase;
    font-size: 1.4em;
    color: #555;
}

.history .historyItem {
    padding: 8px 16px;
    font-size: 1.2em;
    text-transform: uppercase;
    text-align: center;
    margin: 2px 0;
}

.history .you {
    background-color: #40C4FF;
    color: #01579B;
}

.history .monster {
    background-color: #FF5252;
    color: #B71C1C;
}