:root {
  --bg: #f9fafb;
  --surface: #ffffff;
  --surface-alt: #f1f5f9;
  --text: #0f172a;
  --text-muted: #475569;
  --border: #dbe3ee;
  --accent: #0b5fff;
  --accent-soft: #e8f0ff;
  --radius: 10px;
}

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

html {
  scroll-behavior: smooth;
}

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

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

a:hover {
  text-decoration: underline;
}

.container {
  width: 100%;
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
}

.nav-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(249, 250, 251, 0.95);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.nav-logo {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
}

.nav-links {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.nav-github {
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
}

.hero {
  padding: 72px 0 34px;
}

.hero-kicker {
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 8px;
}

h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  line-height: 1.15;
  margin-bottom: 14px;
}

.hero-sub {
  color: var(--text-muted);
  max-width: 700px;
}

.section {
  padding: 28px 0 44px;
}

.section-alt {
  background: var(--surface-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

h2 {
  font-size: 1.55rem;
  margin-bottom: 14px;
}

h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.section-lead {
  color: var(--text-muted);
  margin-bottom: 16px;
}

.card-grid {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}

.card p {
  color: var(--text-muted);
}

.steps {
  margin-left: 20px;
  margin-bottom: 16px;
}

.steps li {
  margin-bottom: 8px;
}

.note {
  color: var(--text-muted);
}

pre {
  background: #0f172a;
  color: #dbeafe;
  border-radius: var(--radius);
  padding: 14px;
  overflow-x: auto;
  border: 1px solid #1e293b;
}

code {
  font-family: Consolas, "Courier New", monospace;
  font-size: 0.92em;
}

.footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
}

.footer-inner {
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
  color: var(--text-muted);
}

.footer-bottom {
  padding: 16px 0;
  text-align: center;
  color: var(--text-muted);
}

.legal-page {
  max-width: 780px;
  margin: 0 auto;
  padding: 44px 20px 60px;
}

.legal-page h1 {
  margin-bottom: 8px;
}

.legal-page .legal-date {
  color: var(--text-muted);
  margin-bottom: 20px;
}

.legal-page h2 {
  margin-top: 22px;
}

.legal-page p,
.legal-page li {
  color: var(--text-muted);
}

.legal-page ul,
.legal-page ol {
  margin: 8px 0 8px 20px;
}

.legal-page .back-link {
  display: inline-block;
  margin-bottom: 12px;
}

@media (max-width: 900px) {
  .card-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 680px) {
  .nav-inner {
    flex-direction: column;
    height: auto;
    padding: 12px 0;
    align-items: flex-start;
  }

  .nav-links {
    flex-wrap: wrap;
  }

  .hero {
    padding-top: 36px;
  }
}