flexbox.css

/* Paleta blue/grey
  .dark-primary-color    { background: #388E3C; }
  .default-primary-color { background: #4CAF50; }
  .light-primary-color   { background: #C8E6C9; }
  .text-primary-color    { color: #FFFFFF; }
  .accent-color          { background: #607D8B; }
  .primary-text-color    { color: #212121; }
  .secondary-text-color  { color: #757575; }
  .divider-color         { border-color: #BDBDBD; }
*/


/* Základ */

html {
    font-size: large;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
    color: rgba(0, 0, 0, 0.7);
}

.page {
    max-width: 1100px;
    margin: auto;
}

p {
    margin: 0 1rem;
}


/* Společné */

.obrazek-div {
    flex: 1 1 auto;
    width: 450px;
    margin-bottom: 30px;
}

.reseni-div {
    flex: 1 1 auto;
    width: 450px;
}

.tlacitka-div {
    flex: 1 1 auto;
    width: 400px;
}

.seznam-div {
    flex: 1 1 auto;
    width: 400px;
    font-size: 1rem;
}

.poznavackaContainer {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    align-content: flex-start;
    align-items: stretch;
}

.poznavackaContainer div {
    margin: 10px;
}


/* Jumbotron */

.jumbotron {
    display: block;
    padding: 4rem 2rem;
    background-color: #4CAF50;
    color: #FFFFFF;
    border-radius: 0.4rem;
    margin-bottom: 32px;
}

h1 {
    font-weight: 300;
    font-size: 3.3rem;
    margin-top: 0;
    margin-bottom: .5rem;
}

.lead {
    font-weight: 300;
    font-size: 1rem;
    margin: 0;
    color: #c8e6c9;
}


/* Navigace */

.navbar {
    list-style-type: none;
    padding: 0 1rem;
    margin-bottom: 1rem;
    font-size: 1rem;
    border-bottom: #4CAF50 2px solid;
}

.navbar li {
    display: inline-block;
    background-color: #C8E6C9;
    border-radius: 0.6rem;
    padding: 0.5rem 1rem 0.5rem 1rem;
    margin-right: 0.5rem;
}

.navbar li a {
    color: #212121;
    text-decoration: none;
}

.navbar .navThis {
    background-color: #4CAF50;
    border-radius: 0.6rem 0.6rem 0 0;
    padding: 0.5rem 1rem 0.7rem 1rem;
}

.navbar .navThis a {
    color: #FFFFFF;
}


/* Obrazek */

.copyright {
    font-size: 1rem;
}

.obrazek-div {
    height: 300px;
}

.obrazek {
    max-height: 100%;
    max-width: 100%;
}


/* Reseni */

.card {
    border: 2px solid #BDBDBD;
    border-radius: 0.3rem;
    padding-bottom: 1rem;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.card .card-title {
    margin: 0;
    padding: 1rem;
    background-color: #e0e0e0;
    font-size: 1rem;
    font-weight: 500;
}

.card .card-text {
    font-size: 1rem;
}

.reseni {
    background-color: #607D8B;
    color: #607D8B;
    font-size: 2.3rem;
    flex-grow: 1;
    flex-basis: 130px;
}


/* Vyber */

.list-group:empty {
    display: none;
}

.reseni:hover,
.reseni.show {
    background-color: #fff;
}

.list-group-item.active:hover,
.btn:hover {
    background-color: #388E3C;
}

ul.list-group {
    list-style: none;
    margin: 0 10px;
    padding: 0;
    border: 1px solid #BDBDBD;
    border-radius: 5px;
    overflow: hidden;
}

li.list-group-item {
    padding: 10px 10px;
    border-top: 1px solid #BDBDBD;
}

li.list-group-item:first-of-type {
    border: none;
}

li.list-group-item.active+li.list-group-item.active {
    border-top: none;
    padding-top: 11px;
}

li.list-group-item.active {
    background-color: #4CAF50;
    color: white;
}


/* Tlacitka */

.tlacitka-div a {
    background-color: #4CAF50;
    border: none;
    border-radius: 0.3rem;
    color: white;
    padding: 10px 20px 10px 10px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 1rem;
}


/* Dalsi*/

.noselect {
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

.badges img {
    height: 80px
}


/* --- GALERIE --- */

.gallery {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    align-content: flex-start;
    align-items: stretch;
}

.gallery-block {
    width: 50%;
}

.gallery-image {
    width: auto;
}

.gallery-image img {
    max-width: 100%;
    display: block;
    margin: 0 auto;
}

.gallery figcaption {
    text-align: center;
}

@media screen and (max-width: 600px) {
    .gallery-block {
        width: 100%;
    }
}