/* ============================================================
   Nytel — shared chrome
   Header, footer, CTA band, buttons, and design tokens.
   Loaded by index.html, overview.html, AND the Quarto whitepaper
   (via _header-meta.html) so the site chrome has one source of truth.
   Intentionally contains NO global reset, so it is safe to load
   into the Bootstrap-based whitepaper build.
   ============================================================ */

:root {
  --navy: #0A1628;
  --navy-light: #162035;
  --teal: #2D8B8B;
  --teal-light: #E8F4F4;
  --teal-dark: #1F6B6B;
  --white: #FFFFFF;
  --bg: #F7F8FA;
  --bg-alt: #EEF0F4;
  --border: rgba(10, 22, 40, 0.10);
  --border-strong: rgba(10, 22, 40, 0.20);
  --text: #0A1628;
  --text-secondary: rgba(10, 22, 40, 0.90);
  --text-tertiary: rgba(10, 22, 40, 0.62); /* audit: raised from 0.40 for WCAG AA */
  --mono: 'IBM Plex Mono', monospace;
  --sans: 'IBM Plex Sans', system-ui, -apple-system, sans-serif;
}

/* Visible keyboard focus indicator */
:focus-visible {
  outline: 2px solid var(--teal-dark);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ---- Container ---- */

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

@media (min-width: 768px) {
  .container { padding: 0 2.5rem; }
}

/* ---- Header ---- */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1100;
  height: 3.5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  backdrop-filter: blur(12px);
  background: rgba(255,255,255,0.92);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.header-logo {
  text-decoration: none;
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.header-logo img {
  height: 20px;
  width: auto;
}

@media (min-width: 768px) {
  .header-logo img { height: 28px; }
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

@media (min-width: 768px) {
  .header-nav { gap: 2rem; }
}

.header-nav a {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.15s;
  white-space: nowrap;
}

@media (min-width: 768px) {
  .header-nav a { font-size: 0.8125rem; }
}

.header-nav a:hover {
  color: var(--text);
  text-decoration: none;
}

/* current-page indicator */
.header-nav a[aria-current="page"] {
  color: var(--teal-dark);
  font-weight: 600;
}

.header-nav .hide-mobile {
  display: none;
}

@media (min-width: 640px) {
  .header-nav .hide-mobile { display: inline; }
}

/* ---- Buttons ---- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.625rem 1.25rem;
  border: none;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
}

.btn-primary {
  background: var(--navy);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--navy-light);
  text-decoration: none;
  color: var(--white);
}

.btn-outline {
  background: transparent;
  color: var(--navy);
  border: 1px solid var(--border-strong);
}
.btn-outline:hover {
  border-color: var(--navy);
  text-decoration: none;
}

.btn-teal {
  background: var(--teal);
  color: var(--white);
}
.btn-teal:hover {
  background: var(--teal-dark);
  text-decoration: none;
  color: var(--white);
}

/* Button row (hero, CTA, footer) */
.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ---- CTA band ---- */

.cta-section {
  background: var(--navy);
  color: var(--white);
  padding: 5rem 0;
  border-bottom: none;
}

.cta-section h2 {
  color: var(--white);
  margin-bottom: 1rem;
}

.cta-section p {
  color: rgba(255,255,255,0.65);
  margin-bottom: 2rem;
}

.cta-section .btn-teal:hover {
  background: var(--teal-dark);
}

/* ---- Footer ---- */

.footer {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border);
}

.footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-left {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

.footer-right {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.footer-right a {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
}