:root {
  --bg: #f4f7fb;
  --panel: #ffffff;
  --text: #152033;
  --muted: #4a5f85;
  --accent: #0d63ff;
  --accent-soft: #dbe8ff;
  --border: #d6e1f2;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: radial-gradient(circle at 0% 0%, #ffffff 0%, #eaf2ff 45%, #f4f7fb 100%);
  color: var(--text);
  font-family: "Space Grotesk", "Avenir Next", "Segoe UI", sans-serif;
}

html {
  scroll-behavior: smooth;
}

a {
  color: var(--accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

.container {
  width: min(1000px, 92vw);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in oklab, var(--panel) 80%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
}

.brand {
  font-family: "JetBrains Mono", "SFMono-Regular", Menlo, monospace;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.nav a {
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: #fff;
  text-decoration: none;
  color: var(--text);
}

.nav a[aria-current="page"] {
  background: var(--accent-soft);
  border-color: #b9ceff;
  color: #083c9b;
}

.hero {
  padding: 64px 0 28px;
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.3rem);
  line-height: 1.05;
}

.hero p {
  color: var(--muted);
  font-size: 1.08rem;
  max-width: 68ch;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.btn {
  display: inline-block;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
}

.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  margin: 24px 0 40px;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 18px;
}

.card h2,
.card h3 {
  margin-top: 0;
}

.section {
  padding: 22px 0;
}

.anchor-section {
  scroll-margin-top: 86px;
}

.section h1 {
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  margin-bottom: 8px;
}

.meta {
  color: var(--muted);
  margin-top: 0;
}

ul.clean {
  margin: 0;
  padding-left: 20px;
  line-height: 1.7;
}

.footer {
  border-top: 1px solid var(--border);
  margin-top: 34px;
  padding: 22px 0 34px;
  color: var(--muted);
}

.notice {
  margin-top: 10px;
  padding: 10px 12px;
  border: 1px dashed #b9ceff;
  border-radius: 10px;
  background: #f6f9ff;
  color: #284067;
}

@media (max-width: 760px) {
  .header-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero {
    padding-top: 40px;
  }
}