/* =========================================================
   Aviation MRO Pipeline & Compliance Automation — design system
   Light, professional aviation theme:
   sky/steel blue primary, titanium warm accent, cloud surfaces.
   ========================================================= */

:root {
  /* palette */
  --color-bg: #f4f7fb;
  --color-bg-elev: #ffffff;
  --color-bg-soft: #eaf1fa;
  --color-surface-tint: #f6f9fd;
  --color-border: #d6e1ee;
  --color-border-strong: #b8c8dd;

  --color-text: #14233a;
  --color-text-soft: #4a5b75;
  --color-text-muted: #6b7a92;

  --color-primary: #0a4d8c;
  --color-primary-strong: #073968;
  --color-primary-soft: #e3eef9;
  --color-primary-accent: #1d6fb8;

  --color-accent: #e07a00;       /* titanium */
  --color-accent-soft: #fff3df;
  --color-success: #1f8a4c;
  --color-success-soft: #e3f5ea;
  --color-warning: #c47a00;
  --color-danger: #b53939;

  --color-code-bg: #f3f6fb;
  --color-code-text: #1f3550;
  --color-inline-code-bg: #eaf1fa;
  --color-inline-code-text: #0a4d8c;

  /* typography */
  --font-sans: "Inter", "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont,
    "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", ui-monospace, "Menlo",
    "Consolas", monospace;

  --fs-base: clamp(16px, 0.92vw + 13px, 18px);
  --lh-base: 1.65;

  /* layout */
  --container-max: min(1400px, 92vw);
  --container-narrow: min(1100px, 92vw);
  --header-height: 72px;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 2px rgba(11, 47, 92, 0.06), 0 1px 1px rgba(11, 47, 92, 0.04);
  --shadow-md: 0 10px 30px -12px rgba(11, 47, 92, 0.18),
    0 4px 12px -6px rgba(11, 47, 92, 0.1);
  --shadow-lg: 0 30px 60px -24px rgba(11, 47, 92, 0.25),
    0 8px 16px -8px rgba(11, 47, 92, 0.12);

  --transition: 180ms ease;
}

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

html {
  scroll-padding-top: calc(var(--header-height) + 16px);
  scroll-behavior: smooth;
}

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

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  color: var(--color-text);
  background: linear-gradient(180deg, var(--color-bg) 0%, #eef3fa 100%);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1 0 auto;
  width: 100%;
}

img,
svg {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  background-image: linear-gradient(currentColor, currentColor);
  background-size: 0% 1.5px;
  background-repeat: no-repeat;
  background-position: 0 100%;
  transition: color var(--transition), background-size var(--transition);
}
a:hover,
a:focus-visible {
  color: var(--color-primary-accent);
  background-size: 100% 1.5px;
}
a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--color-primary);
  color: #fff;
  padding: 0.6em 1em;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  z-index: 100;
}
.skip-link:focus {
  left: 1rem;
  top: 0;
}

.container {
  width: var(--container-max);
  margin-inline: auto;
}

/* -------------------- header / nav -------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: var(--header-height);
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--color-text);
  font-weight: 700;
  background-image: none;
}
.site-brand:hover {
  color: var(--color-primary);
}
.site-brand .logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  box-shadow: var(--shadow-sm);
}
.site-brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}
.site-brand__title {
  font-size: 1rem;
  letter-spacing: 0.01em;
}
.site-brand__subtitle {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  font-weight: 500;
}

.primary-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 0.25rem;
}
.primary-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 0.85rem;
  border-radius: var(--radius-md);
  color: var(--color-text-soft);
  font-weight: 600;
  font-size: 0.92rem;
  background-image: none;
  transition: background-color var(--transition), color var(--transition),
    transform var(--transition);
}
.primary-nav__link:hover {
  background: var(--color-primary-soft);
  color: var(--color-primary);
  transform: translateY(-1px);
}
.primary-nav__link.is-active {
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow-sm);
}
.primary-nav__icon svg {
  width: 18px;
  height: 18px;
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.5rem;
  cursor: pointer;
  flex-direction: column;
  gap: 4px;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
}
.nav-toggle__bar {
  width: 20px;
  height: 2px;
  background: var(--color-primary);
  display: block;
}

@media (max-width: 860px) {
  .nav-toggle {
    display: inline-flex;
  }
  .primary-nav {
    position: absolute;
    inset: var(--header-height) 0 auto 0;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transform: translateY(-150%);
    transition: transform var(--transition);
    padding: 0.75rem 0;
  }
  .primary-nav.is-open {
    transform: translateY(0);
  }
  .primary-nav__list {
    flex-direction: column;
    gap: 0.25rem;
    padding: 0 1rem;
  }
  .primary-nav__link {
    width: 100%;
  }
}

/* -------------------- footer -------------------- */
.site-footer {
  margin-top: 4rem;
  background: linear-gradient(180deg, #ffffff 0%, #eaf1fa 100%);
  border-top: 1px solid var(--color-border);
}
.site-footer__inner {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 2rem;
  padding: 2.5rem 0 2rem;
}
.site-footer__brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.site-footer__brand .logo {
  width: 44px;
  height: 44px;
  border-radius: 10px;
}
.site-footer__tagline {
  margin: 0;
  color: var(--color-text-soft);
  font-weight: 600;
}
.site-footer__heading {
  margin: 0 0 0.5rem;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
}
.site-footer__nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.35rem;
}
.site-footer__copy {
  grid-column: 1 / -1;
  margin: 0;
  border-top: 1px solid var(--color-border);
  padding-top: 1rem;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}
@media (max-width: 640px) {
  .site-footer__inner {
    grid-template-columns: 1fr;
  }
}

/* -------------------- home page -------------------- */
.hero {
  padding: clamp(2.5rem, 5vw, 5rem) 0 clamp(2rem, 4vw, 4rem);
}
.hero__logo-row {
  display: flex;
  justify-content: center;
  margin-bottom: 2rem;
}
.hero__logo-row .logo {
  width: clamp(180px, 22vw, 320px);
  height: clamp(180px, 22vw, 320px);
  border-radius: 36px;
  box-shadow: var(--shadow-lg);
}
.hero__title {
  font-size: clamp(2rem, 3.4vw + 1rem, 3.6rem);
  line-height: 1.1;
  margin: 0 0 0.75rem;
  text-align: center;
  background: linear-gradient(
    90deg,
    var(--color-primary) 0%,
    var(--color-primary-accent) 55%,
    var(--color-accent) 100%
  );
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__tag {
  text-align: center;
  margin: 0 0 2rem;
  color: var(--color-text-soft);
  font-size: 1.1rem;
}
.hero__copy {
  margin: 0 0 2.25rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 32ch), 1fr));
  gap: 1.25rem 2rem;
  font-size: 1.02rem;
}
.hero__copy p {
  margin: 0;
}

.cta-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin: 0 0 1rem;
}
.cta {
  display: inline-flex;
  align-items: center;
  gap: 0.85rem;
  padding: 1.1rem 1.2rem;
  background: var(--color-bg-elev);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
  background-image: none;
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
}
.cta:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-accent);
  color: var(--color-text);
}
.cta__icon {
  flex: none;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  color: #fff;
}
.cta__icon--blue {
  background: linear-gradient(135deg, #1d6fb8, #0a4d8c);
}
.cta__icon--amber {
  background: linear-gradient(135deg, #f5a623, #e07a00);
}
.cta__icon--teal {
  background: linear-gradient(135deg, #2bb1a7, #16847b);
}
.cta__icon--violet {
  background: linear-gradient(135deg, #7b5cff, #4a35c5);
}
.cta__icon svg {
  width: 24px;
  height: 24px;
}
.cta__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.cta__title {
  font-weight: 700;
  font-size: 1rem;
}
.cta__sub {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.section-cards {
  margin: 3rem auto 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.25rem;
}
.section-card {
  background: var(--color-bg-elev);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition),
    border-color var(--transition);
}
.section-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-accent);
}
.section-card h3 {
  margin: 0 0 0.4rem;
  font-size: 1.15rem;
  color: var(--color-primary);
}
.section-card p {
  margin: 0 0 1rem;
  color: var(--color-text-soft);
}
.section-card ul {
  margin: 0;
  padding-left: 1.1rem;
  display: grid;
  gap: 0.3rem;
}

/* -------------------- content / prose -------------------- */
.page-shell {
  width: var(--container-max);
  margin: 2rem auto 3rem;
  display: grid;
  gap: 1.75rem;
}

.breadcrumbs {
  font-size: 0.9rem;
}
.breadcrumbs__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.5rem;
  padding: 0;
  margin: 0;
  color: var(--color-text-muted);
}
.breadcrumbs__item {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}
.breadcrumbs__sep {
  color: var(--color-border-strong);
}
.breadcrumbs__current {
  color: var(--color-text);
  font-weight: 600;
}

.content-article {
  background: var(--color-bg-elev);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: clamp(1.25rem, 2.5vw, 2.5rem);
}
.content-article__header {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}
.page-title {
  margin: 0;
  font-size: clamp(1.75rem, 1.4vw + 1.2rem, 2.6rem);
  line-height: 1.15;
  background: linear-gradient(
    90deg,
    var(--color-primary) 0%,
    var(--color-primary-accent) 55%,
    var(--color-accent) 100%
  );
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.page-lede {
  margin: 0.6rem 0 0;
  color: var(--color-text-soft);
  font-size: 1.05rem;
}

.prose {
  font-size: 1.02rem;
  line-height: var(--lh-base);
}
.prose > * + * {
  margin-top: 1.1rem;
}
.prose h2,
.prose h3,
.prose h4 {
  position: relative;
  scroll-margin-top: calc(var(--header-height) + 16px);
}
.prose h2 {
  font-size: 1.55rem;
  margin-top: 2.25rem;
  padding-left: 0.85rem;
  border-left: 4px solid var(--color-accent);
  color: var(--color-primary-strong);
}
.prose h3 {
  font-size: 1.25rem;
  margin-top: 1.85rem;
  color: var(--color-primary);
}
.prose h4 {
  font-size: 1.05rem;
  margin-top: 1.5rem;
  color: var(--color-primary-strong);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.prose p {
  margin: 0;
}
.prose strong {
  color: var(--color-primary-strong);
}
.prose ul,
.prose ol {
  padding-left: 1.4rem;
  display: grid;
  gap: 0.4rem;
}
.prose li::marker {
  color: var(--color-accent);
}
.prose blockquote {
  border-left: 4px solid var(--color-primary-accent);
  background: var(--color-primary-soft);
  padding: 0.85rem 1.1rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--color-text-soft);
  margin: 1.25rem 0;
}
.prose .header-anchor {
  color: inherit;
  background-image: none;
}
.prose .header-anchor:hover {
  color: var(--color-accent);
}

/* inline code — soft tinted, no border */
.prose :not(pre) > code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--color-inline-code-bg);
  color: var(--color-inline-code-text);
  padding: 0.1em 0.42em;
  border-radius: 4px;
  border: none;
}

/* block code */
.prose pre,
pre[class*="language-"] {
  position: relative;
  background: var(--color-code-bg) !important;
  color: var(--color-code-text) !important;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1rem 1rem 1rem 1rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  line-height: 1.55;
  box-shadow: inset 0 1px 0 rgba(11, 47, 92, 0.03);
}
.prose pre code {
  background: transparent;
  color: inherit;
  padding: 0;
  font-size: inherit;
  border-radius: 0;
}

.copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  background: var(--color-bg-elev);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--color-primary);
  padding: 0.3rem 0.6rem;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--transition), background-color var(--transition);
}
.prose pre:hover .copy-btn,
.copy-btn:focus-visible {
  opacity: 1;
}
.copy-btn:hover {
  background: var(--color-primary-soft);
}
.copy-btn.is-copied {
  background: var(--color-success-soft);
  color: var(--color-success);
  border-color: var(--color-success);
  opacity: 1;
}

/* tables */
.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-elev);
  box-shadow: var(--shadow-sm);
}
.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}
.prose th,
.prose td {
  text-align: left;
  padding: 0.7rem 0.9rem;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}
.prose th {
  background: var(--color-primary-soft);
  color: var(--color-primary-strong);
  font-weight: 700;
  border-bottom: 2px solid var(--color-primary-accent);
}
.prose tbody tr:nth-child(even) {
  background: var(--color-surface-tint);
}

/* task lists (markdown-it-task-lists) */
.prose .task-list-item {
  list-style: none;
  padding-left: 0;
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
}
.prose .task-list-item::marker {
  content: "";
}
.prose ul.contains-task-list {
  padding-left: 0;
}
.prose .task-list-item-checkbox {
  appearance: none;
  -webkit-appearance: none;
  width: 1.1rem;
  height: 1.1rem;
  border: 2px solid var(--color-border-strong);
  border-radius: 4px;
  background: var(--color-bg-elev);
  cursor: pointer;
  position: relative;
  flex: none;
  margin-top: 0.2rem;
  transition: background-color var(--transition), border-color var(--transition);
}
.prose .task-list-item-checkbox:hover {
  border-color: var(--color-primary);
}
.prose .task-list-item-checkbox:checked {
  background: var(--color-primary);
  border-color: var(--color-primary);
}
.prose .task-list-item-checkbox:checked::after {
  content: "";
  position: absolute;
  inset: 1px 0 0 4px;
  width: 5px;
  height: 10px;
  border-right: 2px solid #fff;
  border-bottom: 2px solid #fff;
  transform: rotate(45deg);
}
.prose .task-list-item-checkbox:checked + label,
.prose .task-list-item.is-checked > label,
.prose .task-list-item.is-checked {
  text-decoration: line-through;
  color: var(--color-text-muted);
}

/* mermaid placeholder */
pre.mermaid {
  background: var(--color-bg-elev);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1rem;
  text-align: center;
  overflow-x: auto;
}
pre.mermaid svg {
  max-width: 100%;
  height: auto;
}

/* details/accordion for FAQs */
.prose details {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-elev);
  padding: 0.4rem 1rem;
}
.prose details + details {
  margin-top: 0.5rem;
}
.prose details summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--color-primary-strong);
  padding: 0.5rem 0;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.prose details summary::-webkit-details-marker {
  display: none;
}
.prose details summary::before {
  content: "+";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.4rem;
  height: 1.4rem;
  border-radius: 50%;
  background: var(--color-primary-soft);
  color: var(--color-primary);
  font-weight: 700;
  transition: transform var(--transition);
}
.prose details[open] summary::before {
  content: "−";
}

/* related & child cards */
.related-block {
  background: var(--color-bg-elev);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}
.related-block__title {
  margin: 0 0 1rem;
  font-size: 1.15rem;
  color: var(--color-primary-strong);
  border-left: 4px solid var(--color-accent);
  padding-left: 0.75rem;
}
.related-grid {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.85rem;
}
.related-card {
  display: block;
}
.related-card__link {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 0.9rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface-tint);
  color: var(--color-text);
  height: 100%;
  background-image: none;
  transition: transform var(--transition), border-color var(--transition),
    background-color var(--transition);
}
.related-card__link:hover {
  transform: translateY(-2px);
  border-color: var(--color-primary-accent);
  background: var(--color-primary-soft);
  color: var(--color-primary-strong);
}
.related-card__title {
  font-weight: 700;
}
.related-card__desc {
  font-size: 0.88rem;
  color: var(--color-text-muted);
}
.related-card__link:hover .related-card__desc {
  color: inherit;
}

/* reduced motion */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}