body {
  font-family: Arial, sans-serif;
  background: #f0f0f0;
  margin: 0;
  padding: 0;


  opacity: 0;
  animation: fadeIn 0.4s ease-in-out forwards;
}

@keyframes fadeIn {
  to {
    opacity: 1;
  }
}

.blo {
  max-width: 1000px;
  margin: 50px auto;
  background-color: white;
  border-radius: 20px;
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
  padding: 20px;
}

.header {
  background: #2f5fa6;
  color: white;
  padding: 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-radius: 10px;
}

.menu a {
  color: white;
  margin: 0 10px;
  text-decoration: none;
}

.b_1 {
  background-color: #ffffff;
  color: #2f5fa6;
  padding: 5px 17px;
  border-radius: 30px;
  border: none;
  font-size: 16px;
  cursor: pointer;
}

.b_1:hover {
  background-color: #e6e6e6;
  transition-duration: 0.5s;
}

.content {
  margin-top: 30px;
}

.section-title {
  font-size: 28px;
  font-weight: bold;
  margin-bottom: 15px;
}

.description {
  font-size: 18px;
  margin-bottom: 25px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card {
  text-align: center;
  background: #ffffff;
  border: 1px solid #ccc;
  padding: 15px;
  border-radius: 10px;
  transition: 0.3s;
}

.card:hover {
  box-shadow: 0 0 10px rgba(0,0,0,0.2);
  transform: translateY(-5px);
}

.card img {
  width: 100px;
  height: 90px;
  object-fit: cover;
  border-radius: 10px;
}

.card p {
  margin-top: 10px;
  font-weight: bold;
  font-size: 18px;
}

.grid__block{
  display: grid;
  grid-template-columns: 1fr 1fr;
  max-width: 700px;
  margin-top: 15px;
  background-color: white;
  border-radius: 20px;
  box-shadow: 0 15px 35px rgba(158, 158, 158, 0.2);
  padding: 20px;
}

.grid__item{
  border-bottom: 1px solid #3c3c3c57;
  font-size: 17px;
  font-weight: 700;
  padding: 10px;
}

.title__block{
  font-size: 24px;
  font-weight: 700;
  margin: 10px;
}

.video{
  display: flex;
  justify-content: center;
}

.title__video{
  font-size: 24px;
  font-weight: 700;
  margin: 10px;
}

.title__razvlechenie{
  font-size: 24px;
  font-weight: 700;
  margin: 10px;
}

.vopros{
  font-size: 19px;
  font-weight: 700;
  line-height: 18px;
}

.text{
  font-size: 17px;
  font-weight: 700;
  line-height: 18px;
}

.li{
  background-color: #00ff2a8a;
  width: 120px;
}

.zadanie{
  border: 4px solid #c3ff00;
  margin-bottom: 15px;
}
.title__zadanie{
  font-size: 24px;
  font-weight: 700;
  margin: 10px;
}
.zadanie__zadanie{
  font-size: 19px;
  font-weight: 700;
  line-height: 18px;
}
.list{
  font-size: 17px;
  font-weight: 700;
  line-height: 18px;
}





.footer{
  background-color: #008cff70;
  padding: 10px;
  border-radius: 2px;
  display: flex;
  justify-content: center;
}

.img img{
  width: 100px;

}

.text__flex{
  font-size: 23px;
}

.flex{
  display: flex;
  justify-content: center;
  align-items: center;
  height: 80px;
}