/* =========================================================
   LittoralAI Experience — Awwwards-grade enhancements
   Dark/light · transitions · skeletons · a11y · empty states
   ========================================================= */

:root {
  --shadow-soft: 0 18px 50px rgba(15, 23, 42, 0.08);
  --shadow-lift: 0 28px 60px rgba(15, 23, 42, 0.14);
  --focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.35);
  --transition-page: 480ms cubic-bezier(0.22, 1, 0.36, 1);
  color-scheme: light;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --primary: #E2E8F0;
  --primary-soft: #CBD5E1;
  --secondary: #60A5FA;
  --secondary-deep: #93C5FD;
  --accent: #FBBF24;
  --accent-deep: #F59E0B;
  --bg: #070B14;
  --bg-soft: #0F1623;
  --surface: rgba(20, 28, 44, 0.72);
  --line: rgba(226, 232, 240, 0.1);
  --muted: #94A3B8;
  --text: #E8EEF9;
  --glass-bg: rgba(15, 22, 35, 0.65);
  --glass-border: rgba(255, 255, 255, 0.08);
  --glass-blur: blur(20px) saturate(140%);
  --shadow-soft: 0 18px 50px rgba(0, 0, 0, 0.35);
  --shadow-lift: 0 28px 60px rgba(0, 0, 0, 0.45);
  --focus-ring: 0 0 0 3px rgba(96, 165, 250, 0.4);
}

html[data-theme="dark"] .page-atmosphere {
  background:
    radial-gradient(900px 480px at 8% -5%, rgba(37, 99, 235, 0.18), transparent 55%),
    radial-gradient(700px 420px at 95% 8%, rgba(245, 158, 11, 0.12), transparent 50%),
    linear-gradient(180deg, #070B14 0%, #0B1220 50%, #070B14 100%);
}

html[data-theme="dark"] .site-header {
  background: rgba(7, 11, 20, 0.72);
  border-bottom-color: var(--line);
}

html[data-theme="dark"] .site-header.is-scrolled {
  background: rgba(7, 11, 20, 0.88);
  box-shadow: var(--shadow-soft);
}

html[data-theme="dark"] .navbar-toggler-icon {
  filter: invert(1);
}

html[data-theme="dark"] .book-card,
html[data-theme="dark"] .glass,
html[data-theme="dark"] .plan-card,
html[data-theme="dark"] .pricing-card,
html[data-theme="dark"] .category-tile,
html[data-theme="dark"] .testimonial-card,
html[data-theme="dark"] .author-card {
  background: var(--surface);
  border-color: var(--line);
  box-shadow: var(--shadow-soft);
}

html[data-theme="dark"] .form-control,
html[data-theme="dark"] .form-select,
html[data-theme="dark"] .nav-search input {
  background: rgba(15, 22, 35, 0.9);
  border-color: var(--line);
  color: var(--text);
}

html[data-theme="dark"] .site-footer {
  background: #05080f;
  border-top-color: var(--line);
}

/* Focus visibility (WCAG) */
:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

.btn:focus-visible,
.nav-link:focus-visible,
.brand:focus-visible {
  box-shadow: var(--focus-ring);
}

/* Theme toggle */
.theme-toggle {
  width: 2.35rem;
  height: 2.35rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  color: var(--text);
  display: inline-grid;
  place-items: center;
  cursor: pointer;
  transition: transform .25s var(--ease), background .25s var(--ease), border-color .25s var(--ease);
}

.theme-toggle:hover {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--secondary) 40%, var(--line));
}

.theme-toggle .icon-sun { display: none; }
html[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
html[data-theme="dark"] .theme-toggle .icon-sun { display: inline; }

/* Page transition curtain */
.page-transition {
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 30% 20%, rgba(37, 99, 235, 0.18), transparent 45%),
    radial-gradient(circle at 70% 80%, rgba(245, 158, 11, 0.14), transparent 40%),
    var(--bg);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-page), visibility var(--transition-page);
}

.page-transition.is-active {
  opacity: 1;
  visibility: visible;
  pointer-events: all;
}

.page-transition-mark {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--secondary), var(--accent));
  box-shadow: var(--shadow-lift);
  animation: littoralaiPulse 1.1s var(--ease) infinite;
}

@keyframes littoralaiPulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(0.92); opacity: .75; }
}

/* Reveal on scroll */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
  will-change: opacity, transform;
}

[data-reveal].is-revealed,
html.reduced-motion [data-reveal] {
  opacity: 1;
  transform: none;
}

/* Skeletons */
.skeleton {
  position: relative;
  overflow: hidden;
  background: color-mix(in srgb, var(--muted) 14%, transparent);
  border-radius: 12px;
}

.skeleton::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent,
    color-mix(in srgb, #fff 35%, transparent),
    transparent
  );
  transform: translateX(-100%);
  animation: skeletonShine 1.25s infinite;
}

html[data-theme="dark"] .skeleton::after {
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.08),
    transparent
  );
}

@keyframes skeletonShine {
  100% { transform: translateX(100%); }
}

.skeleton-card {
  display: grid;
  gap: .75rem;
}

.skeleton-cover {
  aspect-ratio: 2 / 3;
  border-radius: var(--radius);
}

.skeleton-line {
  height: .85rem;
  border-radius: 999px;
}

.skeleton-line.w-70 { width: 70%; }
.skeleton-line.w-40 { width: 40%; }
.skeleton-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1.25rem;
}

/* Empty states */
.empty-state {
  text-align: center;
  padding: clamp(2.5rem, 6vw, 4rem) 1.25rem;
  color: var(--muted);
  border: 1px dashed var(--line);
  border-radius: calc(var(--radius) + 4px);
  background:
    radial-gradient(420px 180px at 50% 0%, color-mix(in srgb, var(--secondary) 12%, transparent), transparent 70%),
    var(--surface);
  backdrop-filter: var(--glass-blur);
}

.empty-state-art {
  width: min(220px, 70vw);
  margin: 0 auto 1.25rem;
  opacity: .95;
}

.empty-state h3 {
  margin: 0 0 .4rem;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--text);
  font-size: clamp(1.25rem, 2vw, 1.55rem);
}

.empty-state p {
  margin: 0 auto 1.25rem;
  max-width: 34rem;
}

.empty-state .btn {
  margin-inline: .25rem;
}

/* Premium error pages */
.error-stage {
  min-height: 100dvh;
  display: grid;
  place-items: center;
  padding: 2rem 1rem;
  position: relative;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
}

.error-stage::before {
  content: "";
  position: absolute;
  inset: -20%;
  background:
    radial-gradient(circle at 20% 20%, color-mix(in srgb, var(--secondary) 18%, transparent), transparent 40%),
    radial-gradient(circle at 80% 70%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 42%);
  pointer-events: none;
}

.error-card {
  position: relative;
  width: min(560px, 100%);
  padding: clamp(1.75rem, 4vw, 2.5rem);
  border-radius: 24px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: var(--glass-blur);
  box-shadow: var(--shadow-lift);
  text-align: center;
}

.error-card .error-art {
  width: min(240px, 70%);
  margin: 0 auto 1.25rem;
}

.error-card .error-code {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(3.5rem, 10vw, 5.5rem);
  letter-spacing: -.06em;
  line-height: 1;
  background: linear-gradient(120deg, var(--secondary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin: 0;
}

.error-card h1 {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3vw, 1.75rem);
  margin: .65rem 0 .4rem;
  letter-spacing: -.02em;
}

.error-card p {
  color: var(--muted);
  margin: 0 0 1.4rem;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .65rem;
  justify-content: center;
}

.error-actions .btn {
  border-radius: 999px;
  padding: .65rem 1.25rem;
  font-weight: 600;
}

.error-theme {
  position: absolute;
  top: 1rem;
  right: 1rem;
}

/* Micro-interaction utilities */
.magnetic-btn {
  transition: transform .25s var(--ease);
}

.book-card,
.plan-card,
.pricing-card,
.category-tile {
  transition: transform .35s var(--ease), box-shadow .35s var(--ease), border-color .35s var(--ease);
}

.book-card:hover,
.plan-card:hover,
.pricing-card:hover,
.category-tile:hover {
  box-shadow: var(--shadow-lift);
}

/* Soft glass panels */
.glass-panel {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  backdrop-filter: var(--glass-blur);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .page-transition,
  [data-reveal],
  .skeleton::after,
  .page-transition-mark {
    animation: none !important;
    transition: none !important;
  }
  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

/* Mobile polish */
@media (max-width: 768px) {
  .nav-actions .btn-ghost span,
  .nav-actions .btn-outline-primary {
    font-size: .85rem;
  }
  .theme-toggle {
    width: 2.15rem;
    height: 2.15rem;
  }
}