html{
  height: auto;
  min-height: 100%;
  display: flex;
}

body {
  background-image: url(../img/bg_demo.jpg);
  background-color: rgb(234, 234, 242);
  background-size: cover;
  display: flex;
  flex-flow: wrap;
  flex: 0 0 100%;
  position: relative;
  z-index: 0;
  height: auto;
    background-position: 100% 0;
    background-size: cover;
    background-repeat: no-repeat;
}
body:after {
    /* background: rgba(0,0,0,0.6); */
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    /* content: ''; */
    z-index: -1;
}

#demo h2,
.conteiner_skins>div,
.logo_container {
  text-align: center;
  float: none;
  display: inline-block;
  margin: auto;
}
.conteiner_skins>div{
  font-size: 14px;
}
.logo_container {
    color: #fff;
    display: flex;
    flex: 0 0 100%;
    flex-flow: column;
    text-align: center;
    align-content: center;
    align-self: flex-start;
    align-items: center;
    justify-content: center;
    justify-items: center;
    justify-self: center;
    padding-top: 3%;
}

.conteiner_skins{
  margin: auto;
  text-align: center;
  font-size: 0;
}

.bg_mac,
.btn_border,
.img_scroll {
  display: inline-block;
}

.btn_border,
.btn_border:active,
.btn_border:hover,
.btn_border:focus {
  background: 0 0;
  text-decoration: none;
}

.btn_border {
  border: 1px solid #db1d70;
  color: #fff;
  height: 55px;
  line-height: 53px;
  padding: 0 20px;
  position: relative;
  text-transform: uppercase;
  z-index: 0;
  text-decoration: none;
  margin-bottom: 10px;
}

.btn_border:before {
  -moz-transition: all .2s linear;
  -o-transition: all .2s linear;
  background: #db1d70;
  content: '';
  display: block;
  height: 100%;
  left: 0;
  position: absolute;
  top: 0;
  -webkit-transition: all .2s linear;
  transition: all .2s linear;
  width: 0;
  z-index: -1;
}
.btn_border:hover:before {
  width: 100%;
}

#demo {
  color: #fff;
    flex: 0 0 100%;
    align-items: flex-start;
    flex-flow: column;
    display: flex;
    padding-bottom:30px;
}

#demo h2 {
    font-size: 24px;
    font-weight: 300;
    line-height: 1.7;
    margin: 60px auto 5pc;
    max-width: 45pc;
}

#demo h2 span {
  font-weight: 700;
}

.bg_mac {
  background: url(../img/mac_bg.png) center top no-repeat;
  background-size: 100%;
  height: 326px;
  margin-bottom: 30px;
  position: relative;
  width: 404px;
}

.img_scroll {
  height: 212px;
  left: 0;
  position: absolute;
  right: 0;
  top: 16px;
  transition: background-position 1s linear;
  will-change: background-position;
}

.skin_1 .img_scroll {
  background: url(../img/skin_1.jpg) center 0 no-repeat;
}

.skin_2 .img_scroll {
  background: url(../img/skin_2.jpg) center 0 no-repeat;
}

.skin_3 .img_scroll {
  background: url(../img/skin_3.jpg) center 0 no-repeat;
}

.bg_mac:hover .img_scroll,
.bg_mac:focus .img_scroll {
  background-position: center 100%;
  transition: background-position 2.5s linear;
}

@media (max-width:1399px) {
  .bg_mac {
    height: 279px;
    width: 346px;
  }

  .img_scroll {
    background-size: 100%;
    height: 179px;
    left: 14px;
    right: 14px;
    top: 14px;
  }
}

@media (max-width:1199px) {
  .bg_mac {
    height: 231px;
    width: 286px;
  }

  .img_scroll {
    height: 147px;
    left: 9pt;
    right: 11px;
    top: 9pt;
  }
}

.logo_container img{
    width: 155px;
    border-radius: 8px;
    overflow: hidden;
}

@media (max-width:1024px) {
  .logo_container img{
    max-width:100%;
    display;flex;
    width: 100px;
  }
  #demo h2 {
    margin: 30px auto;
  }
}

@media (max-width:991px) {
  .conteiner_skins>div {
    float: none;
    margin: 0 auto 30px;
    max-width: 404px;
  }
}

@media (max-width:767px) {
  #demo h2 {
    font-size: 1pc;
  }

  .btn_border {
    font-size: 13px;
  }
}

@media (max-width:380px) {
  .bg_mac {
    height: 218px;
    width: 273px;
  }

  .img_scroll {
    height: 140px;
  }

  .btn_border {
  }
}