:root {
  --bg:        #080c12;
  --bg2:       #0d1420;
  --bg3:       #111c2e;
  --surface:   #0f1e30;
  --border:    rgba(0,210,210,0.12);
  --border-hi: rgba(0,210,210,0.35);
  --cyan:      #00d2d2;
  --cyan-dim:  rgba(0,210,210,0.15);
  --cyan-glow: rgba(0,210,210,0.25);
  --text:      #cdd8e8;
  --text-dim:  #6a7f99;
  --text-faint:#2e3f55;
  --mono:      'JetBrains Mono', monospace;
  --sans:      'DM Sans', sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0,0,0,0.07) 2px,
    rgba(0,0,0,0.07) 4px
  );
  pointer-events: none;
  z-index: 9999;
}

::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border-hi); border-radius: 2px; }

img { max-width: 100%; display: block; }

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 10001;
  transform: translateY(-140%);
  background: var(--cyan);
  color: var(--bg);
  border: 2px solid var(--cyan);
  padding: 8px 12px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-decoration: none;
  text-transform: uppercase;
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
  box-shadow: 0 0 0 4px rgba(0,210,210,0.12);
}

/* NAV */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px;
  height: 60px;
  border-bottom: 1px solid var(--border);
  background: rgba(8,12,18,0.85);
  backdrop-filter: blur(12px);
}

.nav-logo {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.1em;
  text-decoration: none;
}
.nav-logo span { color: var(--text-dim); font-weight: 300; }

.nav-actions {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-links {
  display: flex;
  gap: 36px;
  list-style: none;
}

.nav-links a {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  text-decoration: none;
  text-transform: uppercase;
  transition: color 0.2s;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 1px;
  background: var(--cyan);
  transition: width 0.2s;
}

.nav-links a:hover        { color: var(--cyan); }
.nav-links a:hover::after { width: 100%; }
.nav-links a.active        { color: var(--cyan); }
.nav-links a.active::after { width: 100%; }

.nav-search {
  width: 38px;
  height: 34px;
  border: 1px solid var(--border);
  background: rgba(0,210,210,0.03);
  color: var(--text-dim);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition: border-color 0.2s, color 0.2s, background 0.2s, box-shadow 0.2s;
}

.nav-search:hover,
.nav-search[aria-expanded="true"] {
  border-color: var(--border-hi);
  color: var(--cyan);
  background: var(--cyan-dim);
  box-shadow: 0 0 18px rgba(0,210,210,0.08);
}

.nav-search-icon {
  width: 13px;
  height: 13px;
  border: 2px solid currentColor;
  border-radius: 50%;
  position: relative;
  display: block;
}
.nav-search-icon::after {
  content: '';
  width: 7px;
  height: 2px;
  background: currentColor;
  position: absolute;
  right: -6px;
  bottom: -4px;
  transform: rotate(45deg);
  transform-origin: center;
}

.nav-search-key {
  display: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
  z-index: 101;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-dim);
  border-radius: 2px;
  transition: all 0.2s;
}

/* LAYOUT */
main { padding-top: 60px; }

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 48px;
}

/* PAGE HEADER (listing pages) */
.page-header {
  padding: 80px 0 64px;
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
}

.section-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.section-label::before { content: '//'; color: var(--text-faint); }

.page-title {
  font-family: var(--mono);
  font-size: clamp(28px, 3vw, 48px);
  font-weight: 700;
  color: #e8f0f8;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 16px;
}

.section-divider {
  width: 48px;
  height: 2px;
  background: var(--cyan);
  margin-top: 16px;
  margin-bottom: 24px;
  position: relative;
}
.section-divider::after {
  content: '';
  position: absolute;
  right: -8px; top: -3px;
  width: 8px; height: 8px;
  background: var(--cyan);
  clip-path: polygon(0 50%, 50% 0, 100% 50%, 50% 100%);
}

.page-subtitle {
  font-family: var(--sans);
  font-size: 17px;
  color: var(--text-dim);
  line-height: 1.8;
  font-weight: 300;
  max-width: 600px;
}

/* BREADCRUMB (knowledge listing + article pages) */
.breadcrumb {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-faint);
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--text-dim); text-decoration: none; border: none; transition: color 0.2s; }
.breadcrumb a:hover { color: var(--cyan); border: none; }
.breadcrumb .sep { color: var(--text-faint); }
.breadcrumb .current { color: var(--text); }

/* SEARCH PALETTE */
body.search-open { overflow: hidden; }

.site-search-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
}

.site-search-overlay[hidden] { display: none; }

.site-search-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(3,7,12,0.78);
  backdrop-filter: blur(10px);
}

.site-search-dialog {
  position: relative;
  width: min(760px, calc(100vw - 32px));
  max-height: min(720px, calc(100vh - 56px));
  margin: 76px auto 0;
  border: 1px solid var(--border-hi);
  background: rgba(8,12,18,0.98);
  box-shadow: 0 22px 80px rgba(0,0,0,0.45), 0 0 36px rgba(0,210,210,0.08);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.site-search-box {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  background: var(--bg2);
}

.site-search-icon {
  width: 15px;
  height: 15px;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  position: relative;
  display: block;
}
.site-search-icon::after {
  content: '';
  width: 8px;
  height: 2px;
  background: var(--cyan);
  position: absolute;
  right: -7px;
  bottom: -4px;
  transform: rotate(45deg);
}

.site-search-box input {
  width: 100%;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--text);
  font-family: var(--mono);
  font-size: 17px;
}
.site-search-box input::placeholder { color: var(--text-faint); }
.site-search-box input:disabled { opacity: 0.55; }

.site-search-clear,
.site-search-close {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-dim);
  font-family: var(--mono);
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}
.site-search-clear {
  width: 34px;
  height: 32px;
  font-size: 17px;
}
.site-search-close {
  padding: 7px 10px;
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.site-search-clear:hover,
.site-search-close:hover {
  border-color: var(--border-hi);
  color: var(--cyan);
  background: var(--cyan-dim);
}
.site-search-clear[hidden] { display: none; }

.site-search-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--border);
}

.site-search-filters {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.site-search-filter {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 5px 12px;
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}
.site-search-filter:hover,
.site-search-filter.active {
  border-color: var(--border-hi);
  color: var(--cyan);
  background: var(--cyan-dim);
}

.site-search-summary {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-faint);
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.site-search-results {
  overflow-y: auto;
  padding: 2px;
}

.site-search-result {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 18px 22px;
  text-decoration: none;
  transition: border-color 0.2s, background 0.2s;
}
.site-search-result + .site-search-result { margin-top: 2px; }
.site-search-result:hover,
.site-search-result:focus {
  border-color: var(--border-hi);
  background: var(--bg3);
  outline: none;
}

.site-search-result-meta {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--cyan);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.site-search-result h2 {
  font-family: var(--sans);
  font-size: 17px;
  color: var(--text);
  font-weight: 400;
  line-height: 1.35;
  margin-bottom: 6px;
}

.site-search-result p {
  color: var(--text-dim);
  font-size: 13px;
  line-height: 1.65;
  font-weight: 300;
}

.site-search-empty {
  border: 1px dashed var(--border);
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  padding: 24px;
}

/* FOOTER */
footer {
  border-top: 1px solid var(--border);
  padding: 32px 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-copy {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-faint);
  letter-spacing: 0.06em;
}

.footer-hash {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-faint);
  letter-spacing: 0.08em;
}

/* FADE-IN */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }

  .fade-in {
    opacity: 1;
    transform: none;
  }
}

/* MOBILE */
@media (max-width: 700px) {
  nav { padding: 0 20px; }
  .nav-actions { gap: 14px; }
  .nav-toggle { display: flex; }
  .nav-search { width: 36px; height: 32px; }
  .nav-links {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 60px; left: 0; right: 0;
    background: rgba(8,12,18,0.98);
    border-bottom: 1px solid var(--border);
    padding: 12px 20px 20px;
    gap: 2px;
    backdrop-filter: blur(12px);
  }
  .nav-links.open { display: flex; }
  .nav-links li a { padding: 10px 0; display: block; border-bottom: 1px solid var(--border); }
  .nav-links li:last-child a { border-bottom: none; }

  .container { padding: 0 20px; }
  .page-header { padding: 48px 0 40px; }
  .page-title { font-size: clamp(24px, 7vw, 36px); }
  .page-subtitle { font-size: 15px; }

  .site-search-dialog {
    width: calc(100vw - 24px);
    max-height: calc(100vh - 32px);
    margin-top: 16px;
  }
  .site-search-box {
    grid-template-columns: auto 1fr auto;
    gap: 12px;
    padding: 14px;
  }
  .site-search-box input { font-size: 14px; }
  .site-search-close { display: none; }
  .site-search-toolbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
    padding: 12px 14px;
  }
  .site-search-summary { white-space: normal; }
  .site-search-result { padding: 16px; }

  footer { padding: 24px 20px; flex-direction: column; gap: 8px; text-align: center; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }
  nav { padding: 0 16px; }
  footer { padding: 20px 16px; }
}