html {
    box-sizing: border-box; /* Чтобы при использовании паддингов и бордеров значение ширины (размер) элементов не менялось */ 
}

*,
*::before,
*::after {
    box-sizing: inherit /* Наследование box-sizing от главного родителя, в данном случае html */ 
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    padding: 0;
    border: none;
    background-color: transparent;
    cursor: pointer;
}

ul {
    list-style: none;
}

body {
    font-family: "Inter", serif;
    color: #000;
    font-size: 16px;
    font-weight: 500;
    line-height: 1.2;
}

.container {
    max-width: 1220px;
    padding: 0 10px;
    margin: 0 auto;
}

.main__title {
    font-size: 64px;
    font-weight: 700;
    margin-bottom: 20px;
}

.header {
    position: relative;
    min-height: 100vh;    
}

.header__top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 40px 0;
}

.menu__list {
    display: flex;
    align-items: center;
    gap: 0 40px;
    font-weight: 700;
}

.menu__btn {
    padding: 15px 58px;
    border-radius: 30px;
    background-color: #000;
    color: #fff;
    font-weight: 700;
    text-transform: uppercase;
}

.header__content-images {
    text-align: center;    
    padding-bottom: 50px; /* Чтобы картинка не прилипла к низу экрана */
}

.header__content-images::before {
    content: ''; 
    position: absolute;   
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    width: 100%;
    z-index: -2;
}

.header__content-images:has(.color--black.content-item__active)::before {
    background: linear-gradient(180deg, #b6b6b6 0%, rgba(235, 235, 235, 0.00) 100%);
}
.header__content-images:has(.color--skyblue.content-item__active)::before {
    background: linear-gradient(180deg, #cadbeb 0%, rgba(235, 235, 235, 0.00) 100%);
}
.header__content-images:has(.color--green.content-item__active)::before {
    background: linear-gradient(180deg, #ddead9 0%, rgba(235, 235, 235, 0.00) 100%);
}
.header__content-images:has(.color--red.content-item__active)::before {
    background: linear-gradient(180deg, #f3d6d1 0%, rgba(235, 235, 235, 0.00) 100%);
}
.header__content-images:has(.color--white.content-item__active)::before {
    background: linear-gradient(180deg, #FAFAFA 0%, rgba(235, 235, 235, 0.00) 100%);
}

.title {
    position: absolute;
    font-size: 210px;
    font-weight: 700;
    padding-top: 110px;    
}

.title--pod {
    position: relative;
    z-index: -1;     
}

.title--s {
    display: inline-block;
    transform: translateY(60px);
}

.title--m {
    display: inline-block;
    transform: translate(-12px, 285px);
}

.title--ax {
    display: inline-block;
    position: relative;
    transform: translate(-82px, 420px);
    z-index: -1; 
}

.content-item {
    display: none;
}

.content-item.content-item__active {
    display: inline-block;
}

.choose-color {
    padding: 45px 0 180px;
    text-align: center;
}

.choose-color__title {
    margin: 0 auto 20px;
    font-size: 36px;
    font-weight: 700;
    max-width: 555px;    
}

.choose-color__text {
    max-width: 555px;
    margin: 0 auto 80px;
}

.choose-color__list {
    display: flex;
    justify-content: center;
    gap: 40px;    
}

.choose-color__btn {
    border-radius: 20px;
    border: 1px solid #777;
    padding: 50px 55px;
}

.choose-color__btn--active {
    display: none;
}

.composition {
    margin-bottom: 180px;
}

.composition__title {
    text-align: center;
}

.composition__text {
    max-width: 655px;
    text-align: center;
    margin: 0 auto 40px;
}

.composition__inner {
    max-width: 625px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
}

.composition__inner-text {
    display: flex;
    flex-direction: column;
    justify-content: space-between; 
    gap: 15px;   
}

.composition__inner-text p {
    width: 230px;    
}

.case {
    background-color: #FAFAFA;
    padding: 80px 0 100px;
    text-align: center;
}

.case__text {
    max-width: 825px;
    margin: 0 auto 40px;
}
.energy__title {
    padding-top: 160px;
    margin-bottom: 40px;
}
.energy__num {
    font-size: 210px;
    font-weight: 700;
    margin-bottom: 40px;
}
.energy__text {
    max-width: 400px;
    margin: 0 auto;
}

.audio {
    position: relative;
}

.audio::before {
    content: '';
    position: absolute;
    background-image: url(../images/audio_bg.png);
    background-repeat: no-repeat;
    background-position: top center;
    background-size: cover;
    width: 100%;
    height: 100%;
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    z-index: -2;
} /* Фоновое изображение ставим на ::before */

.audio::after {
    content: '';
    position: absolute;
    background-image: url(../images/sound.png);
    background-repeat: no-repeat;
    background-position: bottom center; 
    background-size: cover;
    width: 100%;
    height: 150vh;
    bottom: -167px;
    left: 0;
    right: 0;
    z-index: -1;
}

.audio__inner {
    min-height: 200vh;
    display: flex;
    justify-content: center;
    align-items: flex-end; 
}

.audio__box {    
    color: #fff;     
    text-align: center;
    padding-bottom: 30vh;   
}

.audio__text {
    width: 300px;
    margin-bottom: 10px;
}

.btn {
    margin-top: 25px;
    text-transform: uppercase;
    font-weight: 700;
    color: #000;
    background-color: #fff;
    padding: 15px 58px;
    border-radius: 30px;
}

.footer {
    position: relative;
    z-index: -2;

    padding: 250px 0 40px;
    background-color: #000;
    color: #fff;
    text-align: center;
    font-weight: 700;  
}

.footer__text {
    padding: 20px 0;
}

.footer__list {
    padding-top: 80px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
}

@media (max-width: 1469px) {
    .header__content-images img {
        max-width: 100%;
    }
    .title {
        font-size: 180px;
        transform: translate(129px, 29px);
    }
    .choose-color__list {
        flex-wrap: wrap; /* Если какой-л. эл-т не помещается, он переносится на след. строку */
    }
}

@media (max-width: 1349px) {
    .title {
        transform: none;
        font-size: 140px;
        padding-top: 17vh;
        left: 0;
        right: 0;
        text-align: center;
    }
    .title--pod {
        z-index: 1;
    }
    .title--s {
        transform: none;
        position: relative;
        z-index: -1;
    }
    .title--m {
        transform: none;
    }
    .title--ax {
        transform: none;
    }
}

@media (max-width: 930px) {
    .title {
        position: relative;
        font-size: 100px;
        padding-top: 0;
    }
    .title--m {
        padding-left: 15px;
    }
}

@media (max-width: 768px) {
    .title {
        font-size: 58px;
    }
    .choose-color {
        padding-bottom: 80px;    
    }
    .choose-color__list {
        gap: 16px;
    }
    .main__title {
        font-size: 36px;
    }
    .composition {
        margin-bottom: 60px;    
    }
    .case {
        padding: 60px 0;
    }
    .energy__title {
        padding-top: 60px; 
        margin-bottom: 20px; 
    }
    .energy__num {
        font-size: 110px;
        margin-bottom: 20px;    
    }
}

@media (max-width: 560px) {
    .header__top {
        align-items: flex-start;
    }
    .menu__list {
        flex-wrap: wrap;
        gap: 20px 40px;
    }
    .menu__item:first-child {
        margin-left: auto;
    }
    .menu__item-btn {
        margin-left: auto;
    }
    .menu__item-btn button {
        width: 250px;
    }
    .choose-color {
        padding-bottom: 40px;    
    }
    .choose-color__text {
        margin-bottom: 40px;
    }
    .composition__inner {
        flex-wrap: wrap;
        gap: 40px;
        justify-content: center;    
    }
    .composition__inner-text p {
        width: 100%;
    }
    .case {
        padding: 40px 0;
    }
}

@media (max-width: 414px) {
    .choose-color__title, 
    .main__title {
        font-size: 28px;        
    }
    .energy__num {
        font-size: 92px;    
    }
    .case img {
        max-width: 100%;
    }
}

@media (max-width: 404px) {
    .title {
        font-size: 50px;
    }
}