* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  background: #f3f3f3;
  color: #333;
}
header {
  background-color: #02475e;
  color: #fff;
  padding: 1rem;
}
header h1 {
  margin-bottom: 0.5rem;
}
nav ul {
  list-style: none;
  display: flex;
  gap: 1rem;
}
nav a {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
}
nav a:hover,
nav a.active {
  text-decoration: underline;
}
main {
  max-width: 1000px;
  margin: 2rem auto;
  padding: 1rem;
  background-color: #fff;
  border-radius: 5px;
}
section {
  margin-bottom: 1rem;
}
h2 {
  margin-bottom: 1rem;
}
p {
  margin-bottom: 1rem;
}
ul {
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}
footer {
  text-align: center;
  background-color: #ccc;
  padding: 1rem;
  margin-top: 2rem;
  font-size: 0.9rem;
}
form#powerCalcForm {
  display: flex;
  flex-direction: column;
  max-width: 400px;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
label {
  font-weight: bold;
}
input[type="number"] {
  padding: 0.5rem;
  border: 1px solid #ccc;
  border-radius: 4px;
}
button#calculateBtn {
  padding: 0.6rem;
  background-color: #02475e;
  color: #fff;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}
button#calculateBtn:hover {
  background-color: #036280;
}
.result-box {
  border: 1px solid #ccc;
  padding: 1rem;
  border-radius: 4px;
  background-color: #e6f7ff;
}
.result-box p {
  margin: 0.5rem 0;
}
@media (max-width: 600px) {
  nav ul {
    flex-direction: column;
  }
  main {
    margin: 1rem;
    padding: 1rem;
  }
}