a{
    color: #ffcd39;
    text-decoration: none;
}

a:hover{
    color:#ffcd39;
    text-decoration: underline;
}

.navbar-nav .nav-link.active, .navbar-nav .nav-link.show {
    color: #FFF;
    font-weight: bold;
}

#home {
    position: relative;
    z-index: 1;
}
.header-area {
    height: 1080px;
    overflow: hidden;
    z-index: 1;
}

.header-area::before {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: -1;
}

.header-align-items-details {
    display: flex;
    align-items: center;
    min-height: 100%;
}
.home-text{
    color: white;
    font-size: 3em;
    text-transform: uppercase;
    text-align: center;
}

.home-text b {
    font-size: 3.5em;
}
.section-area {
    height: 1080px;
    overflow: hidden;
    z-index: 1;
}
.section-area::before {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: -1;
}
.section-align-items-details {
    display: flex;
    align-items: center;
    min-height: 100%;
}

.block{
    padding: 150px 0 150px 0;
}

.block-header {
    text-align: center;
    margin-bottom: 40px;
    text-transform: uppercase;
    font-size: 42px;
    line-height: 1.23;
    margin-left: auto;
    margin-right: auto;
}

.block-description {
    margin-bottom: 90px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
    max-width: 560px;
    font-size: 20px;
    line-height: 1.5;
}

.list-container{
    list-style: none;
    padding: 0;
    margin-bottom: 0;
    display: flex;
    flex-direction: column;
}

.list-header{
    font-weight: bold;
    font-size: 20px;
    line-height: 1.35;
    margin-bottom: 14px;
}

.list-description{
    font-size: 18px;
    line-height: 1.55;
}

.list-item:not(:first-child){
    margin-top: 50px;
}
.feature-icon {
    width: 4rem;
    height: 4rem;
    border-radius: .75rem;
}

.icon-square {
    width: 3rem;
    height: 3rem;
    border-radius: .75rem;
}
.sub-header{
    text-transform: uppercase;
    font-weight: bold;
    font-size: 20px;
    text-align: center;
}

#service, #сharacteristics, #clear{
    background: #f2f2f2;
}
.service-text{
    color: white;
    font-size: 1.5em;
    background: rgba(0, 0, 0, 0.4);
    z-index: 2;
    padding: 4rem;
}

footer{
    min-height: 300px;
    background: #000000;
    color: white;
}

@media (min-width: 100px) and (max-width: 575.97px) {
    .home-text h1{
        font-size: 1.2rem;
    }
    .home-text b{
        font-size: 2.2em;
    }
    .block{
        padding: 90px 0 90px 0;
    }
    .list-container{
        text-align: center;
    }
    .cert-img{
        padding-top: 50px;
    }
}

/*Small devices (landscape phones, 576px and up)*/
@media (min-width: 576px) and (max-width: 767.98px) {
    .home-text h1{
        font-size: 1.6rem;
    }
    .home-text b{
        font-size: 2.2em;
    }
    .cert-img{
        padding-top: 50px;
    }
}

/*Medium devices (tablets, 768px and up)*/
@media (min-width: 768px) and (max-width: 991.98px) {
    .home-text b{
        font-size: 2.5em;
    }
}

@media (min-width: 992px) and (max-width: 1199.98px) {
    .home-text b{
        font-size: 2.5em;
    }
}