html {
  font-size: 14px;
}

@media (min-width: 768px) {
  html {
    font-size: 16px;
  }
}

.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
  box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
}

html {
  position: relative;
  min-height: 100%;
}

body {
  margin-bottom: 60px;
}

/* The device with borders */
.smartphone {
    position: relative;
    width: 360px;
    height: 640px;
    margin: auto;
    border: 16px black solid;
    border-top-width: 60px;
    border-bottom-width: 60px;
    border-radius: 36px;
}

    /* The horizontal line on the top of the device */
    .smartphone:before {
        content: '';
        display: block;
        width: 60px;
        height: 5px;
        position: absolute;
        top: -30px;
        left: 50%;
        transform: translate(-50%, -50%);
        background: #333;
        border-radius: 10px;
    }

    /* The circle on the bottom of the device */
    .smartphone:after {
        content: '';
        display: block;
        width: 35px;
        height: 35px;
        position: absolute;
        left: 50%;
        bottom: -65px;
        transform: translate(-50%, -50%);
        background: #333;
        border-radius: 50%;
    }

    /* The screen (or content) of the device */
    .smartphone .content {
        width: 360px;
        height: 640px;
        background: white;
    }