.keyboard {
            position: fixed;
            left: 0;
            bottom: 0;
            width: 100%;
            padding: 5px 0;
            background: #333;
            box-shadow: 0 0 50px rgba(0, 0, 0, 0.5);
            user-select: none;
            transition: bottom 0.4s;
        }

        .keyboard--hidden {
            bottom: -100%;
        }

        .keyboard__keys {
            text-align: center;
        }

        .keyboard__key {
            height: 45px;
            width: 6%;
            max-width: 90px;
            margin: 3px;
            border-radius: 4px;
            border: none;
            background: #fff;
            color: #333;
            font-size: 1.05rem;
            outline: none;
            cursor: pointer;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            vertical-align: top;
            padding: 0;
            -webkit-tap-highlight-color: transparent;
            position: relative;
        }

            .keyboard__key:active {
                background: rgba(255, 255, 255, 0.12);
            }

        .keyboard__key--wide {
            width: 12%;
        }

        .keyboard__key--extra-wide {
            width: 36%;
            max-width: 500px;
        }

        .keyboard__key--activatable::after {
            content: '';
            top: 10px;
            right: 10px;
            position: absolute;
            width: 8px;
            height: 8px;
            background: rgba(0, 0, 0, 0.4);
            border-radius: 50%;
        }

        .keyboard__key--active::after {
            background: #08ff00;
        }

        .keyboard__key--dark {
            background: rgba(0, 0, 0, 0.25);
        }