* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f4f7fb;
  color: #172033;
  line-height: 1.8;
}

.header {
  background: #123b67;
  color: white;
  padding: 24px 16px;
  text-align: center;
}

.logo {
  color: white;
  font-size: 28px;
  font-weight: bold;
  text-decoration: none;
}

.logo span {
  color: #76e0c0;
}

.header p {
  margin-bottom: 0;
}

.container {
  width: min(100% - 32px, 680px);
  margin: 32px auto;
}

.intro {
  text-align: center;
  margin-bottom: 28px;
}

.calculator {
  background: white;
  padding: 24px;
  border-radius: 16px;
  box-shadow: 0 5px 24px #12233b12;
}

.calculator h2 {
  margin-top: 0;
}

label {
  display: block;
  margin: 16px 0 6px;
  font-weight: bold;
}

input {
  width: 100%;
  padding: 13px;
  border: 1px solid #ccd5e0;
  border-radius: 8px;
  font-size: 16px;
}

button {
  width: 100%;
  margin-top: 20px;
  padding: 14px;
  background: #147d64;
  color: white;
  border: 0;
  border-radius: 8px;
  font-size: 17px;
  cursor: pointer;
}

button:hover {
  background: #106650;
}

.result {
  margin-top: 18px;
  padding: 16px;
  background: #edf8f4;
  border-radius: 8px;
  white-space: pre-line;
}

footer {
  text-align: center;
  color: #64748b;
  padding: 20px;
  font-size: 14px;
}

@media (max-width: 480px) {
  .calculator {
    padding: 18px;
  }

  .logo {
    font-size: 24px;
  }
}
main.container {
  box-sizing: border-box;
  width: min(100%, 680px);
}

main.container input,
main.container select,
main.container button {
  box-sizing: border-box;
  max-width: 100%;
}

main.container > section {
  display: grid;
  gap: 12px;
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid #dce5e1;
}

main.container > section h2,
main.container > section p {
  margin: 0;
}

main.container > section fieldset {
  min-width: 0;
  margin: 0;
  padding: 12px;
  border: 1px solid #dce5e1;
  border-radius: 12px;
}

main.container > section select {
  width: 100%;
  min-height: 44px;
  padding: 8px;
  font: inherit;
}

@media (min-width: 600px) {
  main.container > section {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  main.container > section h2,
  #compare,
  #comparison-result {
    grid-column: 1 / -1;
  }
}