* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #2563eb;
  --primary-dark: #1e40af;
  --text: #1f2937;
  --text-light: #6b7280;
  --bg: #ffffff;
  --bg-alt: #f9fafb;
  --border: #e5e7eb;
  --success: #10b981;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 2rem;
}

nav a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.2s;
}

nav a:hover {
  color: var(--primary);
}

main {
  padding: 2rem 0;
  min-height: calc(100vh - 200px);
}

.hero {
  text-align: center;
  padding: 3rem 0;
}

.ip-display {
  background: var(--bg-alt);
  border: 2px solid var(--border);
  border-radius: 8px;
  padding: 2rem;
  margin: 2rem 0;
  min-height: 120px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.ip-value {
  font-size: 2rem;
  font-weight: 700;
  font-family: 'Courier New', monospace;
  color: var(--primary);
  margin-bottom: 1rem;
  word-break: break-all;
}

.ip-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 4px;
  font-size: 0.875rem;
  font-weight: 600;
  background: var(--primary);
  color: white;
  margin: 0.5rem;
}

.ip-badge.ipv6 {
  background: var(--success);
}

.copy-btn {
  background: var(--primary);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.2s;
  margin-top: 1rem;
}

.copy-btn:hover {
  background: var(--primary-dark);
}

.copy-btn:active {
  transform: scale(0.98);
}

.copy-btn.copied {
  background: var(--success);
}

section {
  margin: 3rem 0;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

h2 {
  font-size: 1.875rem;
  margin: 2rem 0 1rem;
}

h3 {
  font-size: 1.5rem;
  margin: 1.5rem 0 0.75rem;
}

p {
  margin-bottom: 1rem;
  color: var(--text-light);
}

ul, ol {
  margin-left: 2rem;
  margin-bottom: 1rem;
}

li {
  margin-bottom: 0.5rem;
  color: var(--text-light);
}

.faq-item {
  margin-bottom: 2rem;
}

.faq-question {
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.faq-answer {
  color: var(--text-light);
}

footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 4rem;
  text-align: center;
  color: var(--text-light);
  font-size: 0.875rem;
}

footer a {
  color: var(--primary);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

code {
  background: var(--bg-alt);
  padding: 0.125rem 0.375rem;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.875em;
}

pre {
  background: var(--bg-alt);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  margin: 1rem 0;
}

pre code {
  background: none;
  padding: 0;
}

.error {
  color: #dc2626;
}

.loading {
  color: var(--text-light);
}

@media (max-width: 768px) {
  nav ul {
    flex-direction: column;
    gap: 0.5rem;
  }

  h1 {
    font-size: 2rem;
  }

  .ip-value {
    font-size: 1.5rem;
  }
}