* { box-sizing: border-box; }
body {
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #6f86d6, #48c6ef);
  color: #222;
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.app-container {
  width: min(95vw, 380px);
  background: #ffffffdd;
  border-radius: 14px;
  padding: 24px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.16);
  text-align: center;
}
input {
  width: 100%;
  margin-bottom: 12px;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 8px;
}
.buttons {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
  margin-bottom: 12px;
}
button {
  padding: 10px;
  border: none;
  border-radius: 8px;
  background: #2a74d2;
  color: white;
  font-size: 14px;
  cursor: pointer;
}
button:hover { background: #1f5ab9; }
#result { font-weight: bold; }