html, body {
    height: 100%;
    margin: 0;
}

/* контент поверх */
body {
    position: relative;
    min-height: 100vh;
    background: transparent;
}

/* фон “приклеен” к экрану и не рвётся */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;

    background:
            linear-gradient(
                    to right,
                    rgba(0, 0, 0, 0.8) 0%,
                    rgba(0, 0, 0, 0.6) 40%,
                    rgba(0, 0, 0, 0) 100%
            ),
            url("../img/main_fon.png");

    /* ключевой момент: градиент 100%×100%, картинка cover */
    background-size: 100% 100%, cover;
    background-repeat: no-repeat, no-repeat;
    background-position: left top, center;
}

html footer {
    margin-top: 0;
}

.header__munu div.custom__menu a {
    color: #fff;
}

path.logo__text {
    fill: white;
}

.body {
    margin-top: 50px;
}

.body .custom__button_new {
    margin-top: 40px;
}

.header__menu .tel__mobile_svg path {
    fill: #fff;
}

.body h1,
.body h2,
.body p {
    color: #fff;
}

.body h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 28px;
    font-weight: 300;
}

.body h2 {
    margin: 20px 0;
    font-size: 26px;
    font-weight: 300;
}

.body p {
    font-size: 18px;
    font-weight: 300;
}

.custom__button_new {
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(211, 47, 47, 1);
    color: #fff;
    width: 272px;
    border-radius: 50px;
    min-height: 46px;
    height: auto;
    padding: 10px 0;
    transition: .3s;
}

.custom__button_new:hover {
    background: rgba(255, 0, 76, 1);
}

.katalogs .katalog__block img {
    width: 100%;
    border-radius: 15px;
}

.katalogs {
    margin-top: 80px;
    padding-bottom: 60px;
}

.katalogs .katalog__block {
    display: inline-block;
    padding: 10px;
    background: #fff;
    border-radius: 15px;
    height: 285px;
    width: 100%;
    transition: .3s;
}

.katalogs .katalog__block:hover {
    transform: scale(1.03);
    cursor: pointer;
}

.katalogs .katalog__block p {
    margin-top: 15px;
    font-size: 18px;
    text-align: center;
}

@media (max-width: 550px) {

    .katalogs .katalog__block {
        height: auto;
    }

    .katalogs .col-md-3:not(:first-child) .katalog__block {
        margin-top: 20px;
    }

}