body {
  font-family: 'Inter', sans-serif;
  background-color: #f0f4f8;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  padding: 1rem;
  box-sizing: border-box;
}
.converter-container {
  background-color: #ffffff;
  border-radius: 1.5rem;
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
              0 10px 10px -5px rgba(0, 0, 0, 0.04);
  padding: 2.5rem;
  width: 100%;
  max-width: 550px;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}
h1 {
  color: #2d3748;
  font-size: 2.5rem;
  font-weight: bold;
  text-align: center;
  margin-bottom: 1rem;
}
.input-group, .select-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
label {
  font-weight: 600;
  color: #4a5568;
  font-size: 1rem;
}
input[type="number"], select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid #cbd5e0;
  border-radius: 0.75rem;
  font-size: 1.1rem;
  outline: none;
  background-color: #f7fafc;
  color: #2d3748;
  transition: border-color 0.2s;
}
input:focus, select:focus {
  border-color: #3b82f6;
}
.select-row {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}
.select-row > div {
  flex: 1;
  min-width: 120px;
}
.result-display {
  background-color: #e2e8f0;
  color: #1a202c;
  font-size: 2rem;
  font-weight: bold;
  text-align: center;
  padding: 1.5rem;
  border-radius: 0.75rem;
  min-height: 4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  word-break: break-all;
}
.reset-button {
  background-color: #e53e3e;
  color: #ffffff;
  padding: 0.75rem 1.5rem;
  border-radius: 0.75rem;
  font-size: 1.1rem;
  font-weight: bold;
  cursor: pointer;
  transition: background-color 0.2s, transform 0.1s;
  align-self: center;
}
.reset-button:hover {
  background-color: #c53030;
  transform: translateY(-2px);
}
.reset-button:active {
  transform: translateY(0);
}