Global styles.css in src directory (partial, reformatted copy from bootswatch theme example page)

src_styles.css

pre {
    background: #f7f7f9
}

@media (min-width: 768px) {
    body>.navbar-transparent {
        box-shadow: none
    }
    body>.navbar-transparent .navbar-nav>.open>a {
        box-shadow: none
    }
}

#home {
    padding-top: 0px
}

#home .navbar {
    transition: box-shadow 200ms ease-in
}

#home .navbar-brand .nav-link {
    display: inline-block;
    margin-right: -30px
}

#home .navbar-brand img {
    display: inline-block;
    margin: 0 10px;
    width: 30px
}

#home .btn {
    padding: 0.6em 0.7em;
    box-shadow: none;
    font-size: 0.7rem
}

.bs-docs-section {
    margin-top: 4em
}

.bs-docs-section .page-header h1 {
    padding: 2rem 0;
    font-size: 3rem
}

.dropdown-menu.show[aria-labelledby="themes"] {
    display: flex;
    width: 420px;
    flex-wrap: wrap
}

.dropdown-menu.show[aria-labelledby="themes"] .dropdown-item {
    width: 33.333%
}

.dropdown-menu.show[aria-labelledby="themes"] .dropdown-item:first-child {
    width: 100%
}

.bs-component {
    position: relative
}

.bs-component+.bs-component {
    margin-top: 1rem
}

.bs-component .card {
    margin-bottom: 1rem
}

.bs-component .modal {
    position: relative;
    top: auto;
    right: auto;
    left: auto;
    bottom: auto;
    z-index: 1;
    display: block
}

.bs-component .modal-dialog {
    width: 90%
}

.bs-component .popover {
    position: relative;
    display: inline-block;
    width: 220px;
    margin: 20px
}

#source-button {
    position: absolute;
    top: 0;
    right: 0;
    z-index: 100;
    font-weight: bold
}

.nav-tabs {
    margin-bottom: 15px
}

.progress {
    margin-bottom: 10px
}

#footer {
    margin: 5em 0
}

#footer li {
    float: left;
    margin-right: 1.5em;
    margin-bottom: 1.5em
}

#footer p {
    clear: left;
    margin-bottom: 0
}

.splash {
    padding: 12em 0 6em;
    background-color: #2196F3;
    color: #fff;
    text-align: center
}

.splash .logo {
    width: 160px
}

.splash h1 {
    font-size: 3em;
    color: #fff
}

.splash #social {
    margin: 2em 0 6em
}

.splash .alert {
    margin: 2em 0;
    border: none
}

.splash .sponsor a {
    color: #fff
}

.section-tout {
    padding: 6em 0 1em;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    background-color: #eaf1f1
}

.section-tout .fa {
    margin-right: 0.2em
}

.section-tout p {
    margin-bottom: 5em
}

.section-preview {
    padding: 4em 0 4em
}

.section-preview .preview {
    margin-bottom: 4em;
    background-color: #eaf1f1
}

.section-preview .preview img {
    max-width: 100%
}

.section-preview .preview .image {
    position: relative
}

.section-preview .preview .image:before {
    box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.1);
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    content: "";
    pointer-events: none
}

.section-preview .preview .options {
    padding: 2em;
    border: 1px solid rgba(0, 0, 0, 0.05);
    border-top: none;
    text-align: center
}

.section-preview .preview .options p {
    margin-bottom: 2em
}

.section-preview .dropdown-menu {
    text-align: left
}

.section-preview .lead {
    margin-bottom: 2em
}

@media (max-width: 767px) {
    .section-preview .image img {
        width: 100%
    }
}

.sponsor img {
    max-width: 100%
}

.sponsor #carbonads {
    max-width: 240px;
    margin: 0 auto
}

.sponsor .carbon-text {
    display: block;
    margin-top: 1em;
    font-size: 12px
}

.sponsor .carbon-poweredby {
    float: right;
    margin-top: 1em;
    font-size: 10px
}

@media (max-width: 767px) {
    .splash {
        padding-top: 8em
    }
    .splash .logo {
        width: 100px
    }
    .splash h1 {
        font-size: 2em
    }
    #banner {
        margin-bottom: 2em;
        text-align: center
    }
}