:root {
  /* surfaces — page is faintly tinted, CARDS ARE PURE WHITE so they read lighter */
  --page: #FAFBFB;
  --card: #FFFFFF;
  --sunken: #F4F7F6;
  --border: #E4E9E7;
  --border-strong: #CFD6D3;

  /* ink — all values below meet WCAG AA on --page */
  --ink: #0A192F;
  /* 15.9:1 */
  --body: #44536A;
  /* 8.1:1  */
  --muted: #63718A;
  /* 5.2:1  */

  /* accent */
  --accent: #059669;
  /* fills, dots, rules */
  --accent-text: #047857;
  /* 5.4:1 — any green TEXT uses this, never --accent */
  --accent-dim: rgba(5, 150, 105, .08);
  --accent-line: rgba(5, 150, 105, .22);

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'Space Mono', ui-monospace, monospace;

  --r-sm: 6px;
  --r-md: 14px;
  --r-lg: 24px;
  --r-pill: 100px;
  --shadow: 0 1px 2px rgba(10, 25, 47, .04), 0 10px 30px rgba(10, 25, 47, .05);
  --shadow-lift: 0 2px 4px rgba(10, 25, 47, .05), 0 18px 44px rgba(10, 25, 47, .09);
  --nav-h: 64px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 24px)
}

body {
  background: var(--page);
  color: var(--body);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden
}

::selection {
  background: var(--accent);
  color: #fff
}

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

/* ambient glow */
.glow {
  position: fixed;
  top: -25vh;
  left: 50vw;
  width: 90vw;
  height: 90vw;
  max-width: 1400px;
  max-height: 1400px;
  background: radial-gradient(circle, rgba(5, 150, 105, .055) 0%, rgba(250, 251, 251, 0) 68%);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
  transform: translateX(-50%)
}

h1,
h2,
h3,
h4 {
  font-weight: 700;
  letter-spacing: -.04em;
  color: var(--ink);
  line-height: 1.12
}

a {
  color: inherit
}

.wrap {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 clamp(20px, 5vw, 56px);
  position: relative;
  z-index: 1
}

.mono {
  font-family: var(--font-mono);
  font-size: .68rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted)
}

.mono-ink {
  color: var(--ink)
}

.lead {
  font-size: 1.2rem;
  line-height: 1.55;
  color: var(--body);
  letter-spacing: -.01em
}

/* ---------- navbar ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--nav-h);
  background: rgba(250, 251, 251, .78);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--border)
}

.nav-in {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 clamp(20px, 5vw, 56px);
  height: 100%;
  display: flex;
  align-items: center;
  gap: 20px
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -.05em;
  color: var(--ink);
  text-decoration: none
}

.logo-mark {
  width: 20px;
  height: 20px;
  background: var(--ink);
  border-radius: 2px;
  position: relative;
  overflow: hidden
}

.logo-mark::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 8px;
  height: 8px;
  background: var(--page);
  transform: translate(-50%, -50%);
  border-radius: 1px
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  margin-left: auto;
  height: 100%
}

.nav-link,
.nav-link:link,
.nav-link:visited {
  position: relative;
  display: flex;
  align-items: center;
  height: 100%;
  font-size: .9rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
  letter-spacing: -.005em;
  transition: color .18s ease
}

.nav-link:hover {
  color: var(--ink)
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1.5px;
  background: var(--ink);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform .22s cubic-bezier(.4, 0, .2, 1)
}

.nav-link:hover::after {
  transform: scaleX(.4)
}

.nav-link[aria-current="page"] {
  color: var(--ink);
  font-weight: 600
}

.nav-link[aria-current="page"]::after {
  transform: scaleX(1)
}

.nav-toggle {
  display: none;
  background: none;
  border: 0;
  padding: 8px;
  margin-left: auto;
  cursor: pointer;
  color: var(--ink)
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 1.5px;
  background: currentColor;
  border-radius: 2px;
  transition: transform .22s, opacity .18s
}

.nav-toggle span+span {
  margin-top: 5px
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg)
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg)
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: var(--r-pill);
  font-weight: 600;
  font-size: .92rem;
  font-family: inherit;
  text-decoration: none;
  cursor: pointer;
  border: none;
  transition: all .2s ease
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  padding: 14px 26px;
  box-shadow: 0 4px 14px rgba(5, 150, 105, .18)
}

.btn-primary:hover {
  background: #047857;
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(5, 150, 105, .28)
}

.btn-ghost {
  background: var(--card);
  color: var(--ink);
  border: 1px solid var(--border-strong);
  padding: 8px 16px;
  font-size: .86rem
}

.btn-ghost:hover {
  border-color: var(--ink)
}

.btn-sm {
  padding: 9px 18px;
  font-size: .86rem
}

.nav-cta {
  padding: 8px 20px;
  font-size: .88rem;
  height: auto;
  letter-spacing: -.01em;
  background: var(--ink);
  color: #fff;
  box-shadow: none
}

.nav-cta:hover {
  background: #1E293B;
  box-shadow: none;
  transform: translateY(-1px)
}

/* ---------- badge ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 11px;
  border-radius: var(--r-sm);
  background: var(--card);
  border: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: .66rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  width: fit-content
}

.badge-accent {
  border-color: var(--accent-line);
  background: var(--accent-dim);
  color: var(--accent-text)
}

.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  flex: none
}

/* ---------- page header ---------- */
.phead {
  padding-top: 88px
}

.phead h1 {
  font-size: clamp(2.4rem, 5.2vw, 3.6rem);
  margin: 20px 0 18px;
  max-width: 16ch
}

.phead .lead {
  max-width: 60ch
}

.meta {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 12px;
  margin-top: 40px
}

.meta-cell {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 16px 18px;
  box-shadow: var(--shadow)
}

.meta-val {
  display: block;
  margin-top: 5px;
  font-size: .95rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -.01em;
  overflow-wrap: anywhere
}

/* ---------- doc layout ---------- */
.doc {
  display: grid;
  grid-template-columns: 236px minmax(0, 1fr);
  gap: 56px;
  align-items: start
}

.doc-solo {
  display: block;
  max-width: 760px
}

.rail {
  position: sticky;
  top: calc(var(--nav-h) + 40px);
  max-height: calc(100vh - var(--nav-h) - 72px);
  display: flex;
  flex-direction: column;
  padding: 8px 0 8px
}

.rail-scroll {
  flex: 1;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
  padding-right: 4px
}

.rail-scroll::-webkit-scrollbar {
  width: 3px
}

.rail-scroll::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 100px
}

.rail-prog {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--border)
}

.rail-track {
  height: 3px;
  border-radius: 100px;
  background: var(--sunken);
  margin-top: 8px;
  overflow: hidden
}

.rail-fill {
  height: 100%;
  width: 0;
  border-radius: 100px;
  background: var(--accent);
  transition: width .12s linear
}

.rail-group {
  margin-bottom: 20px
}

.rail-group>.mono {
  display: block;
  margin-bottom: 7px
}

.rail a {
  display: flex;
  gap: 9px;
  padding: 6px 11px;
  border-radius: var(--r-sm);
  font-size: .845rem;
  font-weight: 500;
  color: var(--body);
  text-decoration: none;
  line-height: 1.4;
  transition: all .18s
}

.rail a:hover {
  background: var(--sunken);
  color: var(--ink)
}

.rail a.on {
  background: var(--sunken);
  color: var(--ink);
  font-weight: 600
}

.rail-n {
  font-family: var(--font-mono);
  font-size: .66rem;
  color: var(--muted);
  padding-top: 2px;
  flex: none
}

.rail a.on .rail-n {
  color: var(--accent-text)
}

.sec {
  padding-top: 72px
}

.doc,
.doc-solo {
  padding-top: 24px
}

.sec:first-child {
  padding-top: 8px
}

.sec-n {
  display: block;
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .1em;
  color: var(--muted);
  margin-bottom: 7px
}

.sec h2 {
  font-size: clamp(1.4rem, 2.6vw, 1.85rem);
  margin-bottom: 16px
}

.sec h3 {
  font-size: 1.08rem;
  letter-spacing: -.03em;
  margin: 26px 0 8px
}

.prose p {
  max-width: 68ch;
  margin-bottom: 14px
}

.prose ul {
  max-width: 68ch;
  margin-bottom: 14px;
  list-style: none
}

.prose li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 7px
}

.prose li::before {
  content: '';
  position: absolute;
  left: 4px;
  top: 11px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--border-strong)
}

.prose strong {
  color: var(--ink);
  font-weight: 600
}

.prose a {
  color: var(--ink);
  font-weight: 500;
  text-decoration: none;
  border-bottom: 1px solid var(--border-strong);
  transition: all .18s
}

.prose a:hover {
  color: var(--accent-text);
  border-bottom-color: var(--accent)
}

/* btn-primary inside .prose must stay white — overrides the generic .prose a rule */
.prose a.btn-primary,
.prose a.btn-primary:hover {
  color: #fff;
  border-bottom: none
}

/* ---------- cards ---------- */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 24px;
  box-shadow: var(--shadow);
  transition: all .2s ease
}

.card:hover {
  box-shadow: var(--shadow-lift);
  transform: translateY(-2px)
}

.card h4 {
  font-size: 1.02rem;
  letter-spacing: -.03em;
  margin: 9px 0 7px
}

.card p {
  font-size: .9rem;
  line-height: 1.6;
  margin: 0
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 14px;
  margin: 24px 0
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 18px
}

.note {
  background: var(--card);
  border: 1px solid var(--accent-line);
  border-radius: var(--r-md);
  padding: 24px;
  margin: 26px 0;
  box-shadow: var(--shadow)
}

.note-h {
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: -.04em;
  color: var(--ink);
  margin: 9px 0 0;
  max-width: 32ch;
  line-height: 1.2
}

.note p {
  margin-top: 10px;
  font-size: .94rem;
  max-width: 60ch
}

.row {
  display: flex;
  gap: 18px;
  align-items: baseline;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 16px 20px;
  margin-bottom: 8px;
  max-width: 72ch;
  box-shadow: var(--shadow)
}

.row-k {
  flex: none;
  width: 96px;
  font-family: var(--font-mono);
  font-size: .66rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted)
}

.row-b {
  margin: 0;
  font-size: .93rem
}

/* ---------- table ---------- */
.panel {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  overflow: hidden;
  margin: 24px 0;
  box-shadow: var(--shadow)
}

.panel-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border)
}

.panel-scroll {
  overflow-x: auto
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 680px
}

th {
  text-align: left;
  padding: 11px 20px;
  background: var(--sunken);
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: .64rem;
  font-weight: 400;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap
}

td {
  padding: 17px 20px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
  font-size: .9rem
}

tr:last-child td {
  border-bottom: 0
}

tbody tr:hover td {
  background: var(--sunken)
}

.rec {
  font-family: var(--font-mono);
  font-size: .7rem;
  color: var(--muted);
  white-space: nowrap
}

.cat {
  display: block;
  font-size: .95rem;
  font-weight: 600;
  letter-spacing: -.02em;
  color: var(--ink);
  margin-bottom: 3px
}

.cat-eg {
  display: block;
  font-size: .84rem;
  line-height: 1.55;
  color: var(--muted);
  max-width: 36ch
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 5px
}

/* ---------- search ---------- */
.filters {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border)
}

.search {
  flex: 1 1 210px;
  min-width: 0;
  background: var(--sunken);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 10px 16px;
  color: var(--ink);
  font-family: inherit;
  font-size: .9rem
}

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

.search:focus {
  outline: none;
  border-color: var(--accent);
  background: var(--card)
}

.ftypes {
  display: flex;
  flex-wrap: wrap;
  gap: 5px
}

.ftype {
  cursor: pointer;
  border-radius: var(--r-pill);
  padding: 5px 12px;
  font-family: var(--font-mono);
  font-size: .64rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--muted);
  transition: all .18s
}

.ftype:hover {
  border-color: var(--border-strong);
  color: var(--ink)
}

.ftype[aria-pressed="true"] {
  background: var(--ink);
  border-color: var(--ink);
  color: #fff
}

.empty {
  padding: 36px 20px
}

.empty p {
  margin-top: 8px;
  max-width: 52ch;
  font-size: .94rem
}

/* ---------- routes ---------- */
.routes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 14px;
  margin: 24px 0
}

.route {
  display: flex;
  flex-direction: column;
  gap: 7px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  padding: 24px;
  text-decoration: none;
  box-shadow: var(--shadow);
  transition: all .2s
}

.route:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lift);
  border-color: var(--accent-line)
}

.route-a {
  font-family: var(--font-mono);
  font-size: .9rem;
  color: var(--ink);
  overflow-wrap: anywhere
}

.route:hover .route-a {
  color: var(--accent-text)
}

.route-b {
  font-size: .875rem;
  line-height: 1.6;
  color: var(--body)
}

/* ---------- footer ---------- */
footer {
  border-top: 1px solid var(--border);
  padding: 56px 0 64px;
  margin-top: 96px;
  background: var(--card);
  position: relative;
  z-index: 1
}

.foot {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 40px
}

.foot-cols {
  display: flex;
  gap: 56px;
  flex-wrap: wrap
}

.foot-col {
  display: flex;
  flex-direction: column;
  gap: 11px;
  align-items: flex-start
}

.foot-col a {
  color: var(--body);
  text-decoration: none;
  font-size: .875rem;
  transition: color .18s
}

.foot-col a:hover {
  color: var(--ink)
}

@media(max-width:920px) {
  .nav-links {
    position: fixed;
    inset: var(--nav-h) 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    height: auto;
    background: var(--card);
    border-bottom: 1px solid var(--border);
    padding: 6px clamp(20px, 5vw, 56px) 14px;
    box-shadow: var(--shadow);
    display: none
  }

  .nav-links.open {
    display: flex
  }

  .nav-link {
    height: auto;
    padding: 13px 2px;
    font-size: 1rem;
    border-bottom: 1px solid var(--border)
  }

  .nav-link:last-child {
    border-bottom: 0
  }

  .nav-link::after {
    display: none
  }

  .nav-toggle {
    display: block
  }

  .doc {
    grid-template-columns: minmax(0, 1fr);
    gap: 0
  }

  .rail {
    display: none
  }

  .phead {
    padding-top: 44px;
    padding-bottom: 4px
  }

  .row {
    flex-direction: column;
    gap: 6px
  }

  .row-k {
    width: auto
  }

  .foot {
    flex-direction: column;
    gap: 32px
  }

  .foot-cols {
    flex-direction: column;
    gap: 32px
  }

  .grid,
  .grid-2 {
    grid-template-columns: 1fr
  }
}

@media(prefers-reduced-motion:reduce) {
  * {
    transition: none !important;
    animation: none !important
  }

  html {
    scroll-behavior: auto
  }
}