:root {
  --brand: #0a66ff;
  --brand-strong: #0058ef;
  --text: #111827;
  --bg: #f3f8ff;
  --surface: #ffffff;
  --surface-soft: #eef5ff;
  --muted: #5b6472;
  --border: #d2dced;
  --shadow: 0 24px 60px rgba(0, 60, 160, 0.12);
  --footer-bg: #eef4ff;
  --transition: 0.28s ease;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 15% 10%, rgba(10, 102, 255, 0.16), transparent 34%),
    radial-gradient(circle at 85% 0%, rgba(10, 102, 255, 0.12), transparent 30%),
    var(--bg);
  line-height: 1.7;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

a {
  color: var(--brand);
}

header,
footer {
  background: var(--footer-bg);
  border-bottom: 1px solid var(--border);
}

footer {
  border-top: 1px solid var(--border);
  border-bottom: none;
}

.top-nav,
.footer-inner,
.page-shell {
  width: min(1100px, calc(100% - 2rem));
  margin: 0 auto;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  padding: 1rem 0;
}

.brand {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--brand);
  text-decoration: none;
  letter-spacing: 0.01em;
}

.nav-link {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  opacity: 0.88;
}

.nav-link:hover,
.brand:hover {
  text-decoration: underline;
}

.grow {
  flex: 1;
}

.nav-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.42rem 0.68rem;
  border-radius: 999px;
  border: 1px solid rgba(10, 102, 255, 0.25);
  background: rgba(10, 102, 255, 0.1);
  color: var(--brand-strong);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.82rem;
}

.page-shell {
  padding: 1.25rem 0 2.5rem;
}

.page-hero,
.page-card,
.link-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.page-hero {
  padding: 1.5rem;
  background: linear-gradient(155deg, var(--surface) 0%, var(--surface-soft) 100%);
}

.page-hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.8rem, 3vw, 2.55rem);
  line-height: 1.15;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 0.6rem;
  color: var(--brand-strong);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.lead {
  color: var(--muted);
  font-size: 1.04rem;
  max-width: 68ch;
}

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-top: 1rem;
}

.meta-pill {
  padding: 0.36rem 0.62rem;
  border-radius: 999px;
  background: rgba(10, 102, 255, 0.1);
  border: 1px solid rgba(10, 102, 255, 0.22);
  color: var(--brand-strong);
  font-size: 0.8rem;
  font-weight: 700;
}

.page-card {
  margin-top: 1rem;
  padding: 1.35rem;
}

.page-card h2 {
  margin: 0 0 0.5rem;
  font-size: 1.25rem;
  line-height: 1.25;
}

.page-card h3 {
  margin: 1rem 0 0.35rem;
  font-size: 1.02rem;
}

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

.page-card p:first-of-type {
  margin-top: 0;
}

.page-card p:last-child {
  margin-bottom: 0;
}

.page-card ul,
.page-card ol {
  padding-left: 1.25rem;
}

.content-grid,
.link-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.link-grid {
  margin-top: 1rem;
}

.link-card {
  padding: 1.1rem;
}

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

.link-card p {
  margin-bottom: 0.8rem;
  color: var(--muted);
}

.link-card a {
  font-weight: 700;
  text-decoration: none;
}

.article-search-strip {
  margin-top: 1rem;
}

.article-search-inline {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.6rem;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 0.7rem 0.85rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.article-search-icon {
  color: var(--muted);
}

.article-search-trigger {
  border: none;
  outline: none;
  width: 100%;
  background: transparent;
  color: var(--text);
  font-size: 1rem;
  font-weight: 600;
}

.article-search-trigger::placeholder {
  color: var(--muted);
}

.article-search-hint {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 0.78rem;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.15rem 0.4rem;
}

body.search-open {
  overflow: hidden;
}

.article-search-overlay {
  position: fixed;
  inset: 0;
  z-index: 1200;
  display: none;
  padding: min(6vh, 3rem) 1rem 1.25rem;
  background: rgba(7, 15, 28, 0.72);
  backdrop-filter: blur(5px);
}

.article-search-overlay.active {
  display: block;
}

.article-search-dialog {
  width: min(860px, 100%);
  margin: 0 auto;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: 0 38px 80px rgba(3, 10, 24, 0.38);
  overflow: hidden;
}

.article-search-head {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.55rem;
  align-items: center;
  padding: 0.75rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface-soft);
}

.article-search-input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 11px;
  background: var(--surface);
  color: var(--text);
  padding: 0.7rem 0.85rem;
  font-size: 1.02rem;
  font-weight: 600;
}

.article-search-close {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  padding: 0.58rem 0.72rem;
  font-size: 0.84rem;
  font-weight: 700;
  cursor: pointer;
}

.article-search-results {
  max-height: min(72vh, 680px);
  overflow: auto;
  display: grid;
  gap: 0.55rem;
  padding: 0.75rem;
}

.article-search-result {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  padding: 0.75rem 0.85rem;
  text-decoration: none;
  color: inherit;
  display: grid;
  gap: 0.25rem;
}

.article-search-result:hover {
  border-color: rgba(10, 102, 255, 0.55);
  background: rgba(10, 102, 255, 0.06);
}

.article-search-result h3 {
  margin: 0;
  font-size: 1rem;
  line-height: 1.3;
}

.article-search-result p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.article-search-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.2rem;
}

.article-search-tag {
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.1rem 0.5rem;
  font-size: 0.74rem;
  color: var(--muted);
}

.article-search-empty {
  border: 1px dashed var(--border);
  border-radius: 12px;
  padding: 1rem;
  color: var(--muted);
}

.toc {
  display: grid;
  gap: 0.55rem;
  margin-top: 1rem;
}

.toc a {
  font-weight: 700;
  text-decoration: none;
}

.note {
  margin-top: 0.9rem;
  padding: 0.85rem 0.95rem;
  border-radius: 14px;
  background: var(--surface-soft);
  border: 1px solid var(--border);
  color: var(--muted);
}

.cta-row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.button-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  padding: 0.62rem 0.95rem;
  font-weight: 700;
  text-decoration: none;
  border: 1px solid transparent;
}

.button-link.primary {
  background: var(--brand);
  color: #ffffff;
}

.button-link.secondary {
  background: var(--surface-soft);
  border-color: var(--border);
  color: var(--text);
}

.footer-inner {
  padding: 1rem 0 1.4rem;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.55rem;
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  padding: 0.42rem 0.68rem;
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  border: 1px solid var(--border);
}

.footer-links a:hover {
  background: var(--brand);
  color: #ffffff;
}

@media (max-width: 820px) {
  .content-grid,
  .link-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 700px) {
  .top-nav,
  .footer-inner,
  .page-shell {
    width: min(100%, calc(100% - 1.2rem));
  }

  .top-nav {
    padding: 0.85rem 0;
  }

  .page-shell {
    padding: 0.9rem 0 1.8rem;
  }

  .page-hero,
  .page-card,
  .link-card {
    border-radius: 14px;
  }
}