/* ═══════════════════════════════════════════
   LAYOUT — shared components across all pages
   ═══════════════════════════════════════════ */

/* ─── Page wrapper ─── */
.page {
  position: relative;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  overflow: hidden;
}

/* ─── Animated grid background (из корневого index.html, используется на главной и 404) ─── */
.grid-background {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(59, 130, 246, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59, 130, 246, 0.03) 1px, transparent 1px);
  background-size: 50px 50px;
  animation: gridMove 20s linear infinite;
  pointer-events: none;
  z-index: 0;
}

@keyframes gridMove {
  0%   { transform: translate(0, 0); }
  100% { transform: translate(50px, 50px); }
}

/* ─── Grid background (matches main page) ─── */
.grid-bg {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(to right,  #80808012 1px, transparent 1px),
    linear-gradient(to bottom, #80808012 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
  z-index: 0;
}

/* ─── Gradient orb ─── */
.orb {
  position: fixed;
  width: 480px;
  height: 480px;
  border-radius: var(--radius-full);
  filter: blur(96px);
  pointer-events: none;
  z-index: 0;
  animation: orb-pulse 4s ease-in-out infinite;
}

.orb--tr {
  top: -10%;
  right: -5%;
  background: oklch(0.985 0 0 / 0.04);
}

.orb--bl {
  bottom: -10%;
  left: -5%;
  background: oklch(0.985 0 0 / 0.03);
}

/* Точный аналог орба с главной страницы Next.js:
   absolute top-1/4 right-1/4 w-96 h-96 bg-primary/10 blur-3xl animate-pulse */
.orb--hero {
  position: absolute;
  top: 25%;
  right: 25%;
  width: 384px;
  height: 384px;
  background: oklch(0.985 0 0 / 0.1);
  filter: blur(64px);
  animation: orb-pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes orb-pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.6; }
}

/* ─── Container ─── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}

/* ─── Header ─── */
.header {
  position: relative;
  z-index: 100;
  height: var(--header-h);
  margin-top: var(--sp-6);
  border-bottom: 1px solid var(--color-border);
  background-color: transparent;
}

.nav {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  transition: opacity var(--t-fast);
}

.nav__logo:hover {
  opacity: 0.8;
}

.nav__logo-accent {
  color: #3b82f6;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}

.nav__link {
  padding: var(--sp-2) var(--sp-3);
  font-size: 0.875rem;
  color: var(--color-muted-fg);
  border-radius: var(--radius-md);
  transition: color var(--t-fast), background-color var(--t-fast);
}

.nav__link:hover,
.nav__link--active {
  color: var(--color-fg);
  background-color: var(--color-secondary);
}

/* ─── Mobile burger menu (slide-in drawer) ─── */
/* The checkbox is the real, keyboard-operable control. On desktop it is fully
   hidden; on mobile it is visually hidden but kept in the tab order so keyboard
   and screen-reader users can open the drawer (Space toggles it). */
.nav__toggle { display: none; }
.nav__burger { display: none; }
.nav__backdrop { display: none; }

@media (max-width: 640px) {
  .nav { position: relative; }
  .nav__logo,
  .nav__burger { position: relative; z-index: 95; }

  /* Keyboard-focusable but visually hidden; the burger label is the visual proxy
     and handles pointer input via its `for` association. */
  .nav__toggle {
    display: block;
    position: absolute;
    top: 0;
    right: 0;
    width: 1px;
    height: 1px;
    margin: 0;
    opacity: 0;
    pointer-events: none;
  }
  .nav__toggle:focus-visible ~ .nav__burger {
    outline: 2px solid var(--color-fg);
    outline-offset: 3px;
  }

  /* Lock page scroll while the drawer is open */
  html:has(.nav__toggle:checked),
  body:has(.nav__toggle:checked) { overflow: hidden; overscroll-behavior: none; }

  /* Burger button */
  .nav__burger {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 0 10px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background-color: var(--color-secondary);
    cursor: pointer;
    transition: border-color var(--t-fast);
  }
  .nav__burger:hover { border-color: var(--color-muted-fg); }
  .nav__burger span {
    display: block;
    height: 2px;
    width: 100%;
    background-color: var(--color-fg);
    border-radius: 2px;
    transition: transform var(--t-fast), opacity var(--t-fast);
  }
  .nav__toggle:checked ~ .nav__burger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav__toggle:checked ~ .nav__burger span:nth-child(2) { opacity: 0; }
  .nav__toggle:checked ~ .nav__burger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  /* Dimmed backdrop — click to close */
  .nav__backdrop {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 80;
    background-color: rgba(0, 0, 0, 0.55);
    opacity: 0;
    pointer-events: none;
    cursor: default;
    touch-action: none;
    transition: opacity var(--t-base);
  }
  .nav__toggle:checked ~ .nav__backdrop {
    opacity: 1;
    pointer-events: auto;
  }

  /* Slide-in panel */
  .nav__links {
    position: fixed;
    top: 0;
    right: 0;
    z-index: 85;
    height: 100%;
    width: 80%;
    max-width: 320px;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: var(--sp-1);
    padding: calc(var(--header-h) + var(--sp-6)) var(--sp-5) var(--sp-8);
    background-color: var(--color-secondary);
    border-left: 1px solid var(--color-border);
    box-shadow: -24px 0 60px rgba(0, 0, 0, 0.5);
    transform: translateX(100%);
    pointer-events: none;
    overflow-y: auto;
    overscroll-behavior: contain;
    transition: transform var(--t-base);
  }
  .nav__toggle:checked ~ .nav__links {
    transform: translateX(0);
    pointer-events: auto;
  }
  .nav__link {
    display: block;
    padding: var(--sp-3);
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--color-muted-fg);
    border-radius: var(--radius-md);
    transition: color var(--t-fast), background-color var(--t-fast);
  }
  .nav__link:hover,
  .nav__link--active {
    color: var(--color-fg);
    background-color: var(--color-bg);
  }
}

/* ─── Footer ─── */
.footer {
  position: relative;
  z-index: 1;
  flex-shrink: 0;
  border-top: 1px solid var(--color-border);
  padding: var(--sp-4) 0;
  margin-top: 0;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--sp-4);
}

.footer__copy {
  font-size: 0.8125rem;
  font-family: var(--font-mono);
  color: var(--color-muted-fg);
}

.footer__links {
  display: flex;
  gap: var(--sp-4);
}

.footer__link {
  font-size: 0.8125rem;
  color: var(--color-muted-fg);
  transition: color var(--t-fast);
}

.footer__link:hover {
  color: var(--color-fg);
}

/* On narrow screens the copy and the link row stack — center both instead of
   leaving them ragged against the left edge. */
@media (max-width: 640px) {
  .footer__inner {
    flex-direction: column;
    justify-content: center;
    text-align: center;
    gap: var(--sp-3);
  }

  .footer__links {
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--sp-3) var(--sp-4);
  }
}

/* ─── Badge / Pill ─── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-4);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-muted-fg);
  background-color: oklch(0.269 0 0 / 0.5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  backdrop-filter: blur(4px);
}

.badge__dot {
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background-color: var(--color-primary);
  animation: orb-pulse 2s ease-in-out infinite;
}

/* ─── Tag (category label) ─── */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 2px var(--sp-2);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-muted-fg);
  background-color: var(--color-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: color var(--t-fast), border-color var(--t-fast);
}

.tag:hover {
  color: var(--color-fg);
  border-color: oklch(0.5 0 0);
}

/* ─── Button ─── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-6);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1;
  border-radius: var(--radius-lg);
  transition: all var(--t-fast);
  cursor: pointer;
}

.btn--primary {
  background-color: var(--color-primary);
  color: var(--color-primary-fg);
  border: 1px solid transparent;
}

.btn--primary:hover {
  opacity: 0.9;
}

.btn--ghost {
  background-color: oklch(0.269 0 0 / 0.5);
  color: var(--color-muted-fg);
  border: 1px solid var(--color-border);
}

.btn--ghost:hover {
  color: var(--color-fg);
  border-color: var(--color-primary);
  background-color: var(--color-secondary);
}

.btn--sm {
  padding: var(--sp-2) var(--sp-4);
  font-size: 0.8125rem;
}

/* ─── Section header ─── */
.section-header {
  position: relative;
  z-index: 1;
  padding: var(--sp-16) 0 var(--sp-12);
  text-align: center;
}

.section-header__badge {
  margin-bottom: var(--sp-6);
}

.section-header__title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: var(--sp-4);
}

.section-header__desc {
  font-size: 1.125rem;
  color: var(--color-muted-fg);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ─── Divider ─── */
.divider {
  height: 1px;
  background-color: var(--color-border);
  margin: var(--sp-12) 0;
}

/* ─── Back link ─── */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: 0.875rem;
  color: var(--color-muted-fg);
  transition: color var(--t-fast);
}

.back-link:hover {
  color: var(--color-fg);
}

.back-link__arrow {
  transition: transform var(--t-fast);
}

.back-link:hover .back-link__arrow {
  transform: translateX(-3px);
}

/* ─── Main content offset (below sticky header) ─── */
.main {
  position: relative;
  z-index: 1;
  flex: 1 0 auto;
  padding-bottom: var(--sp-12);
}

/* ─── Keyboard focus indicator ─── */
:focus-visible {
  outline: 2px solid var(--color-fg);
  outline-offset: 2px;
}
/* Don't show the ring for mouse/touch activation. */
:focus:not(:focus-visible) {
  outline: none;
}

/* ─── Reduced motion ─── */
/* Decorative loops (grid drift, orb pulse, dot blink) and entrance transitions
   collapse to a near-instant, final-state jump for users who ask for less motion. */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-delay: 0s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}