body {
    font-family: Arial, sans-serif;
    margin: 20px;
    background-color: #f9f9f9;
}

h1 {
    text-align: center;
    color: #333;
}

#problems-container {
    max-width: 600px;
    margin: 0 auto;
    border-color: black;
}

.problem {
    background-color: white;
    padding: 15px;
    border-radius: 5px;
        box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
    height:75vh;
   }

input {
    width: 350px;
    height:50 px;
    padding: 5px;
    margin-right: 10px;
}

button {
   background-color: #7bd389;
  border: none;
  padding: 10px 18px;
  font-size: 16px;
  border-radius: 10px;
  cursor: pointer;
  color: #1f3b2d;
  font-weight: 600;
    
    
}

button:hover {
    button:hover {
  transform: scale(1.05);
  opacity: 0.9;
}

}

.result {
    margin-top: 10px;
    font-weight: bold;
}
@media (min-width:480px) and (max-width: 768px) {#problems-container {
   width: 550px;
    margin: 0 auto;
    border-color: black;
} .bloc{padding:5px;}}