/* ============================================================
   Neptura — Site Shell CSS
   Header, footer, shared layout primitives.
   Depends on colors_and_type.css (tokens).
   ============================================================ */

/* Reset */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(1200px 600px at 15% -5%, rgba(59, 130, 246, 0.08), transparent 60%),
    radial-gradient(900px 500px at 110% 10%, rgba(16, 185, 129, 0.06), transparent 55%),
    var(--surface-900);
  background-attachment: fixed;
}

main {
  flex: 1;
}

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

/* ============================================================
   Layout primitives
   ============================================================ */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

@media (min-width: 900px) {
  .container {
    padding: 0 var(--space-10);
  }
}

.section {
  padding: var(--space-20) 0;
}

.section-sm {
  padding: var(--space-12) 0;
}

/* ============================================================
   Site header
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-8);
  padding: var(--space-4) var(--space-6);
  background: rgba(11, 14, 20, 0.78);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--hairline);
}

@media (min-width: 900px) {
  .site-header {
    padding: var(--space-4) var(--space-10);
  }
}

.site-brand {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-3);
  border-bottom: 0;
}

.site-brand:hover {
  border-bottom: 0;
}

.site-brand img {
  display: block;
}

.brand-suffix {
  color: var(--fg-3);
  font-size: 10px;
  letter-spacing: var(--ls-uppercase);
  text-transform: uppercase;
}

.site-nav {
  display: none;
  align-items: center;
  justify-content: center;
  gap: var(--space-8);
}

@media (min-width: 900px) {
  .site-nav {
    display: flex;
  }
}

.site-nav a {
  color: var(--fg-2);
  font-size: var(--fs-body-sm);
  font-weight: var(--fw-medium);
  letter-spacing: 0.01em;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition:
    color var(--dur-fast) var(--ease-standard),
    border-color var(--dur-fast) var(--ease-standard);
}

.site-nav a:hover {
  color: var(--fg-1);
  border-bottom-color: var(--hairline-strong);
}

.site-nav a[aria-current="page"] {
  color: var(--signal-green);
  border-bottom-color: var(--signal-green);
}

.site-header-aux {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
}

.lang-toggle {
  background: transparent;
  border: 1px solid var(--hairline-strong);
  color: var(--fg-2);
  padding: 6px 10px;
  border-radius: var(--radius-1);
  font-size: 11px;
  letter-spacing: var(--ls-uppercase);
  cursor: pointer;
  transition: border-color var(--dur-fast), color var(--dur-fast);
}

.lang-toggle:hover {
  border-color: var(--neptura-blue);
  color: var(--fg-1);
}

.lang-toggle .lang-sep {
  color: var(--fg-4);
  margin: 0 4px;
}

[data-lang-flag] {
  color: var(--signal-green);
}

/* ============================================================
   Footer
   ============================================================ */
.site-footer {
  margin-top: var(--space-24);
  border-top: 1px solid var(--hairline);
  background: linear-gradient(180deg, transparent 0%, rgba(0, 0, 0, 0.3) 100%);
  padding: var(--space-16) 0 var(--space-8);
}

.site-footer-grid {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-6);
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
}

@media (min-width: 720px) {
  .site-footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-12);
    padding: 0 var(--space-10);
  }
}

.sf-col {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.sf-col-brand {
  gap: var(--space-4);
}

.sf-col a {
  color: var(--fg-2);
  font-size: var(--fs-body-sm);
  border-bottom: 0;
  transition: color var(--dur-fast);
}

.sf-col a:hover {
  color: var(--signal-green);
}

.sf-col h6.eyebrow {
  margin-bottom: var(--space-2);
}

.sf-tagline {
  color: var(--fg-2);
  font-size: var(--fs-body-sm);
  margin: 0;
  max-width: 32ch;
  line-height: 1.5;
}

.sf-muted {
  color: var(--fg-4);
  font-size: 11px;
  line-height: 1.6;
  margin: 0;
}

.site-footer-base {
  max-width: 1280px;
  margin: var(--space-12) auto 0;
  padding: var(--space-6) var(--space-6) 0;
  border-top: 1px solid var(--hairline);
  display: flex;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

@media (min-width: 900px) {
  .site-footer-base {
    padding: var(--space-6) var(--space-10) 0;
  }
}

/* ============================================================
   Shared components
   ============================================================ */

/* ---- Eyebrow block with leading dot --- */
.eyebrow-lead {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-sans);
  font-size: var(--fs-caption);
  font-weight: var(--fw-semibold);
  letter-spacing: var(--ls-uppercase);
  text-transform: uppercase;
  color: var(--fg-3);
}

.eyebrow-lead::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--signal-green);
  border-radius: 50%;
  box-shadow: var(--glow-green);
}

.eyebrow-lead.blue::before { background: var(--neptura-blue); box-shadow: var(--glow-blue); }
.eyebrow-lead.orange::before { background: var(--alert-orange); box-shadow: var(--glow-orange); }
.eyebrow-lead.violet::before { background: var(--data-4); box-shadow: 0 0 24px rgba(139, 92, 246, 0.35); }

/* ---- Chip / Tag --- */
.chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 4px 10px;
  border: 1px solid var(--hairline-strong);
  border-radius: var(--radius-1);
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-2);
  background: rgba(255, 255, 255, 0.02);
  white-space: nowrap;
}

.chip.chip-id {
  border-color: var(--neptura-blue);
  color: var(--neptura-blue);
}

.chip.chip-status {
  border-color: var(--signal-green);
  color: var(--signal-green);
}

.chip.chip-status::before {
  content: "";
  width: 6px; height: 6px;
  background: var(--signal-green);
  border-radius: 50%;
  box-shadow: var(--glow-green);
  animation: pulse 2.2s infinite ease-in-out;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.55; }
}

.chip.chip-trl {
  border-color: var(--hairline-strong);
  color: var(--fg-1);
}

.chip.chip-trl-hi { border-color: var(--signal-green); color: var(--signal-green); }
.chip.chip-trl-md { border-color: var(--alert-orange); color: var(--alert-orange); }
.chip.chip-trl-lo { border-color: var(--fg-4); color: var(--fg-3); }

/* ---- Button --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 14px 22px;
  font-family: var(--font-sans);
  font-size: var(--fs-body-sm);
  font-weight: var(--fw-semibold);
  letter-spacing: 0.02em;
  border-radius: var(--radius-1);
  border: 1px solid transparent;
  background: transparent;
  color: var(--fg-1);
  cursor: pointer;
  text-decoration: none;
  transition:
    background var(--dur-fast),
    border-color var(--dur-fast),
    color var(--dur-fast),
    box-shadow var(--dur-fast),
    transform var(--dur-fast);
}

.btn:hover { border-bottom: 1px solid transparent; }

.btn-primary {
  background: var(--signal-green);
  color: var(--fg-invert);
}

.btn-primary:hover {
  background: #0fc987;
  box-shadow: var(--glow-green);
  transform: translateY(-1px);
}

.btn-ghost {
  border-color: var(--hairline-strong);
  color: var(--fg-1);
}

.btn-ghost:hover {
  border-color: var(--fg-1);
  background: rgba(255, 255, 255, 0.04);
}

.btn-arrow::after {
  content: "→";
  margin-left: 4px;
  transition: transform var(--dur-fast);
}

.btn-arrow:hover::after {
  transform: translateX(3px);
}

/* ---- Hairline section divider w/ label --- */
.hairline-label {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-4);
  color: var(--fg-3);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: var(--ls-uppercase);
  text-transform: uppercase;
  margin: var(--space-16) 0 var(--space-8);
}

.hairline-label::before,
.hairline-label::after {
  content: "";
  height: 1px;
  background: var(--hairline);
}

/* ---- Card --- */
.card {
  background: var(--surface-800);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-3);
  padding: var(--space-6);
  transition:
    border-color var(--dur-base),
    transform var(--dur-base),
    box-shadow var(--dur-base);
}

.card:hover {
  border-color: var(--hairline-strong);
  transform: translateY(-2px);
}

/* ---- Data bar --- */
.data-bar {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0;
  border: 1px solid var(--hairline);
  border-radius: var(--radius-2);
  overflow: hidden;
  background: var(--surface-800);
}

.data-bar-item {
  padding: var(--space-5);
  border-right: 1px solid var(--hairline);
}

.data-bar-item:last-child { border-right: 0; }

.data-bar-item .label {
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: var(--ls-uppercase);
  text-transform: uppercase;
  color: var(--fg-3);
  margin-bottom: 6px;
}

.data-bar-item .value {
  font-family: var(--font-sans);
  font-size: 22px;
  font-weight: var(--fw-bold);
  color: var(--fg-1);
  letter-spacing: -0.01em;
  line-height: 1.1;
}

.data-bar-item .value.mono {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: var(--fw-medium);
}

/* ---- Utility --- */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}
.grid-3 { display: grid; grid-template-columns: 1fr; gap: var(--space-6); }
.grid-4 { display: grid; grid-template-columns: 1fr; gap: var(--space-6); }

@media (min-width: 720px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1000px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); gap: var(--space-8); }
  .grid-4 { grid-template-columns: repeat(4, 1fr); gap: var(--space-6); }
}

.stack-2 > * + * { margin-top: var(--space-2); }
.stack-3 > * + * { margin-top: var(--space-3); }
.stack-4 > * + * { margin-top: var(--space-4); }
.stack-6 > * + * { margin-top: var(--space-6); }
.stack-8 > * + * { margin-top: var(--space-8); }
.stack-12 > * + * { margin-top: var(--space-12); }

.text-mono { font-family: var(--font-mono); }
.text-tabular { font-variant-numeric: tabular-nums; }
.text-muted { color: var(--fg-3); }

/* Hash / ID ribbon --- */
.hash-ribbon {
  position: relative;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-4);
  letter-spacing: 0.04em;
}

/* Soft section eyebrow numbering */
.section-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-4);
  letter-spacing: 0.08em;
}

/* ============================================================
   In-page navigation (per-tech subnav)
   ============================================================ */
.page-subnav {
  position: sticky;
  top: 62px;
  z-index: calc(var(--z-sticky) - 1);
  background: rgba(11, 14, 20, 0.85);
  backdrop-filter: blur(12px) saturate(140%);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
  border-bottom: 1px solid var(--hairline);
}
.page-subnav-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-6);
  overflow-x: auto;
  scrollbar-width: none;
}
.page-subnav-inner::-webkit-scrollbar { display: none; }
@media (min-width: 900px) {
  .page-subnav-inner { padding: 0 var(--space-10); }
}
.page-subnav-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: var(--ls-uppercase);
  text-transform: uppercase;
  color: var(--fg-4);
  padding-right: var(--space-2);
  border-right: 1px solid var(--hairline);
  white-space: nowrap;
  flex-shrink: 0;
}
.page-subnav-list {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: 1;
}
.page-subnav-list a {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 14px 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--fg-3);
  text-decoration: none;
  letter-spacing: 0.04em;
  border-bottom: 2px solid transparent;
  transition: color var(--dur-fast), border-color var(--dur-fast);
  white-space: nowrap;
}
.page-subnav-list a .num {
  color: var(--fg-4);
  font-size: 10px;
}
.page-subnav-list a:hover {
  color: var(--fg-1);
}
.page-subnav-list a.active {
  color: var(--signal-green);
  border-bottom-color: var(--signal-green);
}
.page-subnav-list a.active .num { color: var(--signal-green); }

/* Standardised section heading (replaces ad-hoc <h3 style=...>) */
.sec-heading {
  font-family: var(--font-sans);
  font-size: var(--fs-h2);
  font-weight: var(--fw-bold);
  letter-spacing: -0.015em;
  line-height: 1.05;
  color: var(--fg-1);
  margin: 0 0 var(--space-4) 0;
  max-width: 22ch;
}
.sec-subheading {
  font-family: var(--font-sans);
  font-size: var(--fs-h3);
  font-weight: var(--fw-semibold);
  letter-spacing: -0.005em;
  color: var(--fg-1);
  margin: var(--space-4) 0 var(--space-3) 0;
}

/* Anchor offset so sticky subnav doesn't cover headings */
section[id], [data-anchor] {
  scroll-margin-top: 120px;
}