dark-theme.css

* {
  margin: 0;
  padding: 0;
  -webkit-box-sizing: border-box;
          box-sizing: border-box;
}

body {
  background-color: #171823;
}

.wrapper {
  background-image: url(img/bitmapdark.png);
}

.theme-swicher {
  -webkit-appearance: none;
     -moz-appearance: none;
          appearance: none;
}

.theme-swicher-img {
  background-image: url(img/sun.svg);
}

.todo-app__task-creation::before {
  content: url(img/oval-dark.svg);
  border: 1px solid #979797;
  border-radius: 50%;
}
.todo-app__task-creation-input {
  background: #25273d;
  color: #c8cbe7;
  -webkit-box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
          box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
  border: none;
}
.todo-app__task-list {
  background: #25273d;
  -webkit-box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
          box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
}
.todo-app__filters {
  background: #25273d;
  -webkit-box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
          box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
}
.todo-app__filters-btn {
  color: #5b5e7e;
}
.todo-app__filters-btn:hover {
  color: #e3e4f1;
}
.todo-app__counting {
  color: #5b5e7e;
}

@media screen and (max-width: 912px) {
  .todo-app__filters-buttons {
    background: #25273d;
    -webkit-box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
            box-shadow: 0px 35px 50px -15px rgba(0, 0, 0, 0.5);
  }
}
li {
  border-bottom: 1px solid #393a4b;
}

.delete-btn {
  background-image: url(img/cross-dark.svg);
}

li input[type=checkbox] {
  border: 2px solid #979797;
}

li p {
  color: #c8cbe7;
}

li p.completed {
  color: #4d5067;
}

.todo-app__filters-btn.active {
  color: #3a7cfd;
}