body {
  background: linear-gradient(135deg, #667eea, #764ba2);
  display: flex;
  height: 100vh;
  justify-content: center;
  align-items: center;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
  color: #333;
}

.container {
  background-color: #ffffffdd;
  color: #333;
  padding: 40px 50px;
  border-radius: 15px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
  text-align: center;
  width: 580px;
  max-width: 110vw;

  transition: box-shadow 0.3s ease;
}

.container:hover {
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.25);
}

h1 {
  margin-bottom: 25px;
  font-weight: 700;
  font-size: 2.2rem;
  color: #4a4a4a;
}

.currency-container {
  padding: 15px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.currency-container select {
  padding: 10px 15px;
  border-radius: 8px;
  border: 1px solid #ccc;
  font-size: 1rem;
  cursor: pointer;
  transition: border-color 0.3s ease;
  background-color: #f9f9f9;
  color: #333;
  width: 40%;
  min-width: 120px;
}

.currency-container select:hover,
.currency-container select:focus {
  border-color: #667eea;
  outline: none;
}

.currency-container input {
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 1.3rem;
  text-align: right;
  color: #333;
  padding: 6px 10px;
  width: 50%;
  min-width: 120px;
  transition: border-color 0.3s ease;
}

.currency-container input:focus {
  border-color: #667eea;
  outline: none;
  background-color: #fff;
}

.currency-container input[disabled] {
  background-color: #e9e9e9;
  color: #999;
  cursor: not-allowed;
}

.exchange-rate {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 20px;
  color: #555;
  user-select: none;
  transition: color 0.3s ease;
}

.exchange-rate.loading {
  color: #667eea;
}

.exchange-rate.error {
  color: #e74c3c;
}

select:focus,
input:focus {
  outline: 0;
}

@media (max-width: 600px) {
  .container {
    width: 90%;
    padding: 15px 20px;
  }

  .currency-container {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
  }

  .currency-container select,
  .currency-container input {
    width: 100%;
    min-width: auto;
    margin: 0;
  }

  h1 {
    font-size: 1.5rem;
    margin-bottom: 15px;
  }
}

footer {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  text-align: center;
  padding: 10px 0;
  color: #666;
  font-size: 0.9rem;
  background-color: #f0f0f0;
  user-select: none;
  box-shadow: 0 -1px 5px rgba(0,0,0,0.1);
  z-index: 1000;
}

body {
  padding-bottom: 40px; /* space for fixed footer */
}