body {
  background-image: linear-gradient(180deg, #eee, #fff 100px, #fff);
}

.container {
  max-width: 960px;
}

.den-header {
  max-width: 700px;
}

input[type="checkbox"] {
    width: 2em;
    height: 2em;
} 

.vali-warning {
    color: red;
    font-weight: bold;
    border: 1px solid red;
    margin-top: 5px;
    margin-left: 3px;
    margin-right: 3px;
}

.vali-warning2 {
    color: red;
    font-weight: bold;
    border: 1px solid red;
    margin-top: 5px;
    margin-left: 15px;
    margin-right: 30px;
}

.bd-placeholder-img {
    font-size: 1.125rem;
    text-anchor: middle;
    -webkit-user-select: none;
    -moz-user-select: none;
    user-select: none;
}

@media (min-width: 768px) {
    .bd-placeholder-img-lg {
        font-size: 3.5rem;
    }
}

.b-example-divider {
    height: 3rem;
    background-color: rgba(0, 0, 0, .1);
    border: solid rgba(0, 0, 0, .15);
    border-width: 1px 0;
    box-shadow: inset 0 .5em 1.5em rgba(0, 0, 0, .1), inset 0 .125em .5em rgba(0, 0, 0, .15);
}

.b-example-vr {
    flex-shrink: 0;
    width: 1.5rem;
    height: 100vh;
}

.bi {
    vertical-align: -.125em;
    fill: currentColor;
}

.nav-scroller {
    position: relative;
    z-index: 2;
    height: 2.75rem;
    overflow-y: hidden;
}

    .nav-scroller .nav {
        display: flex;
        flex-wrap: nowrap;
        padding-bottom: 1rem;
        margin-top: -1px;
        overflow-x: auto;
        text-align: center;
        white-space: nowrap;
        -webkit-overflow-scrolling: touch;
    }