Нужно чтобы footer__bg был за всеми элементами, НО без posstion:absolute
<footer class="footer">
<div class="container">
<div class="footer__left-bar">
<div class="line footer__line"></div>
<span class="subtitle footer__subtitle">Контакты</span>
<h3 class="footer__title">Свяжитесь с нами</h3>
<a href="mailto:mail@savvinakim.com?subject=Заказ проекта" class="footer__email">mail@savvinakim.com<a/>
<button class="footer__btn">Звонок</button>
<a href="https://vk.com/savvinakim" target="_blank"><img src="img/sn1.png" alt="" class="footer__sn1"></a>
<a href="https://instagram.com/akim41k/" target="_blank"><img src="img/sn2.png" alt="" class="footer__sn"></a>
<a href="https://youtube.com/channel/UCUG4Vvf33Fq43bhS_DrS7IA?view_as=subscriber" target="_blank"><img src="img/sn3.png" alt="" class="footer__sn"></a>
</div>
<form action="" method="POST" class="footer__form">
<span class="footer__form__title">Заказать проект</span>
<input type="text" placeholder="Ваше имя" class="footer__form__name">
<input type="tel" placeholder="+7 (999) 999-99-99" class="footer__form__phone-number">
<input type="email" placeholder="Электронная почта" class="footer__form__email">
<button type="submit" class="footer__form__btn">Отправить</button>
</form>
</div>
<div class="footer__bg"></div>
</footer>
.footer
color: #fff
&__title
margin-top: 30px
font-size: 44px
+bold
&__email
margin-top: 30px
font-size: 32px
color: #fff
text-decoration: none
+medium
&__sn
margin: 30px 0 0 32px
&__btn
margin-top: 30px
&__form
display: flex
flex-direction: column
width: 598px
height: 592px
margin-left: 232px
box-shadow: 0 10px 50px 0 #00000010
background-color: #fff
*
margin: auto
&__title
margin-top: 60px
font-size: 44px
color: #000
+bold
input
padding: 25px
width: 478px
height: 80px
border: solid 2px #e3e3e3
font-size: 26px
color: #e3e3e3
&:focus
border-color: #777
color: #777
outline: none
&__btn
margin-bottom: 60px
&__bg
height: 493px
background: #444
