/* ==========================================================================
   Layout — page shell, header, navigation, sections, footer
   ========================================================================== */

/* --- Starfield ----------------------------------------------------------- */

.starfield {
  position: fixed;
  inset: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.9;
}

/* --- Containers ---------------------------------------------------------- */

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--wide { max-width: var(--container-wide); }
.container--text { max-width: var(--container-text); }

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

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: var(--z-header);
  height: var(--header-h);
  display: flex;
  align-items: center;
  transition: background var(--dur-base) var(--ease),
              backdrop-filter var(--dur-base) var(--ease),
              border-color var(--dur-base) var(--ease);
  border-bottom: 1px solid transparent;
}

.site-header::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(180deg, rgba(6, 6, 16, 0.92), rgba(6, 6, 16, 0.55) 70%, transparent);
  opacity: 1;
  transition: opacity var(--dur-base) var(--ease);
}

.site-header.is-scrolled {
  background: rgba(8, 8, 20, 0.82);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom-color: var(--c-line-soft);
}

.site-header.is-scrolled::after { opacity: 0; }

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  width: 100%;
  max-width: var(--container-wide);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* --- Brand --------------------------------------------------------------- */

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 0.4em;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 0.85rem + 0.9vw, 1.5rem);
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--c-text);
  text-decoration: none;
  white-space: nowrap;
}

.brand:hover { color: var(--c-text); }
.brand__last { font-weight: 700; }

.brand::after {
  content: '';
  width: 0.42em;
  height: 0.42em;
  border-radius: 50%;
  background: var(--grad-accent);
  box-shadow: 0 0 12px 1px rgba(199, 125, 255, 0.9);
  animation: pulse-dot 3.4s var(--ease-soft) infinite;
}

/* --- Primary navigation -------------------------------------------------- */

.nav { display: flex; align-items: center; gap: var(--space-2xs); }

.nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 0.6em 1.25em;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-pill);
  font-family: var(--font-display);
  font-size: var(--step--1);
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--c-text-dim);
  text-decoration: none;
  background: rgba(16, 14, 34, 0.5);
  transition: color var(--dur-fast) var(--ease),
              border-color var(--dur-fast) var(--ease),
              background var(--dur-fast) var(--ease),
              box-shadow var(--dur-base) var(--ease),
              transform var(--dur-fast) var(--ease);
}

.nav__link:hover,
.nav__link:focus-visible {
  color: #fff;
  border-color: var(--c-violet-bright);
  background: rgba(80, 40, 140, 0.35);
  box-shadow: var(--glow-violet);
  transform: translateY(-1px);
}

.nav__link[aria-current='page'] {
  color: #fff;
  border-color: var(--c-violet-bright);
  background: linear-gradient(180deg, rgba(120, 60, 200, 0.45), rgba(70, 32, 130, 0.3));
  box-shadow: var(--glow-violet);
}

.nav__link--external .nav__icon {
  width: 0.85em;
  height: 0.85em;
  opacity: 0.7;
}

/* --- Mobile navigation --------------------------------------------------- */

.nav-toggle {
  display: none;
  place-items: center;
  width: 2.85rem;
  height: 2.85rem;
  padding: 0;
  background: rgba(16, 14, 34, 0.6);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: border-color var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease);
}

.nav-toggle:hover { border-color: var(--c-violet-bright); }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 1.15rem;
  height: 2px;
  border-radius: 2px;
  background: var(--c-text);
  transition: background var(--dur-fast) var(--ease);
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: '';
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--c-text);
  transition: transform var(--dur-base) var(--ease-out), top var(--dur-base) var(--ease-out);
}

.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after  { top: 6px; }

.nav-toggle[aria-expanded='true'] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded='true'] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded='true'] .nav-toggle__bars::after  { top: 0; transform: rotate(-45deg); }

@media (max-width: 56.1875em) {
  .nav-toggle { display: grid; }

  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto;
    z-index: var(--z-drawer);
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-2xs);
    padding: var(--space-md) var(--gutter) var(--space-lg);
    background: rgba(9, 8, 22, 0.96);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--c-line);
    box-shadow: var(--shadow-lg);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--dur-base) var(--ease-out),
                opacity var(--dur-base) var(--ease),
                visibility var(--dur-base);
  }

  .nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav__link {
    justify-content: space-between;
    padding: 0.85em 1.25em;
    font-size: var(--step-0);
  }
}

/* --- Page shell ---------------------------------------------------------- */

.main { position: relative; z-index: var(--z-content); }

.section {
  position: relative;
  padding-block: var(--space-2xl);
}

.section--tight { padding-block: var(--space-xl); }
.section--flush-top { padding-top: 0; }

.section__head {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  max-width: var(--container-text);
  margin-bottom: var(--space-xl);
}

.section__head--center {
  margin-inline: auto;
  text-align: center;
  align-items: center;
}

.section__title { font-size: var(--step-4); }

/* A hairline that fades out at both ends — used between major sections. */
.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, transparent, var(--c-line), transparent);
}

/* --- Page hero (inner pages) --------------------------------------------- */

.page-hero {
  position: relative;
  padding-top: calc(var(--header-h) + var(--space-2xl));
  padding-bottom: var(--space-xl);
  text-align: center;
}

.page-hero__title {
  font-size: var(--step-5);
  font-weight: 700;
}

.page-hero__intro {
  max-width: 44ch;
  margin-inline: auto;
  margin-top: var(--space-sm);
  color: var(--c-text-dim);
  font-size: var(--step-1);
  line-height: var(--leading-snug);
}

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

.site-footer {
  position: relative;
  z-index: var(--z-content);
  margin-top: var(--space-2xl);
  padding-block: var(--space-2xl) var(--space-lg);
  border-top: 1px solid var(--c-line-soft);
  background: linear-gradient(180deg, transparent, rgba(14, 12, 32, 0.75));
}

.site-footer__grid {
  display: grid;
  gap: var(--space-xl);
  grid-template-columns: 1fr;
  align-items: start;
}

@media (min-width: 48em) {
  .site-footer__grid { grid-template-columns: 1.2fr 1fr; }
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  align-items: center;
  justify-content: space-between;
  margin-top: var(--space-xl);
  padding-top: var(--space-md);
  border-top: 1px solid var(--c-line-soft);
  font-size: var(--step--1);
  color: var(--c-text-mute);
}

.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.site-footer__links a {
  color: var(--c-text-mute);
  text-decoration: none;
}

.site-footer__links a:hover { color: var(--c-violet-bright); }