body {
    padding: 0 64px;
    font-family: 'Roboto', sans-serif;
}

.container {
    max-width: 800px;
    margin: auto;
    padding: 16px;
}

#nb-selector {
    padding: 16px;
    background-color: lightblue;
}

#nb-selector form {
    margin: 0;
}

#nb-selector form * {
    display: inline;
}

iframe {
    display: block;       /* iframes are inline by default */
    border: 1px;         /* Reset default border */
    height: 100vh;        /* Viewport-relative units */
    width: 100%;
}

.with-love {
    color: #f00;
    display: inline-block;
    margin: 0 5px;
    animation: icon-animate 1.33s ease-in-out infinite;
}

@-moz-keyframes icon-animate {

    0%,
    100% {
        transform: scale(1);
    }

    10%,
    30% {
        transform: scale(0.9);
    }

    20%,
    40%,
    60%,
    80% {
        transform: scale(1.1);
    }

    50%,
    70% {
        transform: scale(1.1);
    }
}

@-webkit-keyframes icon-animate {

    0%,
    100% {
        transform: scale(1);
    }

    10%,
    30% {
        transform: scale(0.9);
    }

    20%,
    40%,
    60%,
    80% {
        transform: scale(1.1);
    }

    50%,
    70% {
        transform: scale(1.1);
    }
}

@-o-keyframes icon-animate {

    0%,
    100% {
        transform: scale(1);
    }

    10%,
    30% {
        transform: scale(0.9);
    }

    20%,
    40%,
    60%,
    80% {
        transform: scale(1.1);
    }

    50%,
    70% {
        transform: scale(1.1);
    }
}

@keyframes icon-animate {

    0%,
    100% {
        transform: scale(1);
    }

    10%,
    30% {
        transform: scale(0.9);
    }

    20%,
    40%,
    60%,
    80% {
        transform: scale(1.1);
    }

    50%,
    70% {
        transform: scale(1.1);
    }
}