* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f4f6f8;
  color: #17202a;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px;
}

.header {
  margin-bottom: 24px;
}

.header h1 {
  margin: 0 0 8px;
  font-size: 36px;
}

.header p {
  margin: 0;
  color: #5f6b7a;
}

.card {
  background: #ffffff;
  border: 1px solid #d8dee6;
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 18px;
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.06);
}

.card h2 {
  margin: 0 0 12px;
  font-size: 22px;
}

.helper {
  margin-top: -4px;
  color: #5f6b7a;
}

input {
  width: 100%;
  max-width: 320px;
  padding: 10px 12px;
  margin: 6px 8px 6px 0;
  border: 1px solid #c7d0da;
  border-radius: 8px;
  font-size: 14px;
}

button {
  padding: 10px 14px;
  margin: 6px 8px 6px 0;
  border: none;
  border-radius: 8px;
  background: #1f4fd8;
  color: #ffffff;
  font-weight: 600;
  cursor: pointer;
}

button:hover {
  background: #183fb0;
}

pre {
  background: #111827;
  color: #e5e7eb;
  padding: 14px;
  border-radius: 10px;
  overflow-x: auto;
  min-height: 64px;
}