/* ============================
   BookScan Shared Styles
   ============================ */

/* --- Design Tokens (Light) --- */
:root {
  --color-primary: #0f172a;
  --color-secondary: #2563eb;
  --color-accent: #06b6d4;
  --color-glow: rgba(37, 99, 235, 0.34);
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-surface-2: #f1f5f9;
  --color-text: #0f172a;
  --color-text-muted: #475569;
  --color-border: #e2e8f0;
  --color-success: #059669;
  --color-warning: #d97706;
  --color-danger: #dc2626;
  --gradient-main: linear-gradient(135deg, #2563eb 0%, #06b6d4 45%, #3b82f6 100%);
  --ambient-light: radial-gradient(circle at 15% 15%, rgba(37, 99, 235, 0.1), transparent 45%), radial-gradient(circle at 85% 20%, rgba(6, 182, 212, 0.09), transparent 38%);
  --ambient-dark: radial-gradient(circle at 20% 20%, rgba(34, 211, 238, 0.18), transparent 45%), radial-gradient(circle at 80% 30%, rgba(96, 165, 250, 0.16), transparent 40%);
  --noise-pattern: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140' viewBox='0 0 140 140'%3E%3Cg fill='%230f172a' fill-opacity='0.45'%3E%3Ccircle cx='7' cy='10' r='1'/%3E%3Ccircle cx='31' cy='25' r='1'/%3E%3Ccircle cx='61' cy='8' r='1'/%3E%3Ccircle cx='87' cy='34' r='1'/%3E%3Ccircle cx='114' cy='21' r='1'/%3E%3Ccircle cx='128' cy='55' r='1'/%3E%3Ccircle cx='16' cy='71' r='1'/%3E%3Ccircle cx='43' cy='58' r='1'/%3E%3Ccircle cx='74' cy='83' r='1'/%3E%3Ccircle cx='95' cy='67' r='1'/%3E%3Ccircle cx='121' cy='94' r='1'/%3E%3Ccircle cx='11' cy='118' r='1'/%3E%3Ccircle cx='39' cy='105' r='1'/%3E%3Ccircle cx='68' cy='131' r='1'/%3E%3Ccircle cx='102' cy='120' r='1'/%3E%3Ccircle cx='133' cy='111' r='1'/%3E%3C/g%3E%3C/svg%3E");
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.1);
  --shadow-lg: 0 18px 48px rgba(15, 23, 42, 0.14);
  --shadow-glow: 0 0 0 1px rgba(37, 99, 235, 0.24), 0 0 36px rgba(37, 99, 235, 0.28);
  --ease-standard: cubic-bezier(0.2, 0.8, 0.2, 1);
  --ease-emphasized: cubic-bezier(0.16, 1, 0.3, 1);
  --dur-base: 280ms;
  --dur-slow: 420ms;
  --container-max: 1440px;
  --container-gutter: clamp(14px, 2.4vw, 26px);
  --section-space: clamp(3.5rem, 7.2vw, 6.25rem);
  --section-space-tight: clamp(2.25rem, 4vw, 3.75rem);
}

/* --- Design Tokens (Dark) --- */
html[data-theme="dark"] {
  --color-primary: #e5edfb;
  --color-secondary: #60a5fa;
  --color-accent: #22d3ee;
  --color-glow: rgba(34, 211, 238, 0.38);
  --color-bg: #020617;
  --color-surface: #0f172a;
  --color-surface-2: #16223a;
  --color-text: #f1f5f9;
  --color-text-muted: #c0ccdc;
  --color-border: #334155;
  --color-success: #34d399;
  --color-warning: #fbbf24;
  --color-danger: #f87171;
  --shadow-sm: 0 1px 2px rgba(2, 6, 23, 0.4);
  --shadow-md: 0 8px 24px rgba(2, 6, 23, 0.45);
  --shadow-lg: 0 18px 48px rgba(2, 6, 23, 0.6);
  --shadow-glow: 0 0 0 1px rgba(96, 165, 250, 0.32), 0 0 42px rgba(34, 211, 238, 0.24);
}

/* --- Reset & Base --- */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", sans-serif;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background: var(--color-bg);
  color: var(--color-text);
  transition: background-color var(--dur-base) var(--ease-standard), color var(--dur-base) var(--ease-standard);
  line-height: 1.68;
}

h1,
h2,
h3 {
  text-wrap: balance;
}

html[data-theme="dark"] h1,
html[data-theme="dark"] h2,
html[data-theme="dark"] h3 {
  text-shadow: 0 1px 0 rgba(2, 6, 23, 0.5), 0 14px 34px rgba(6, 182, 212, 0.14);
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-secondary);
  outline-offset: 2px;
}

/* --- Ambient Background --- */
.page-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
  background-image: var(--ambient-light);
  transition: opacity var(--dur-slow) var(--ease-standard);
}
html[data-theme="dark"] .page-bg { background-image: var(--ambient-dark); }

.page-bg::before,
.page-bg::after {
  content: "";
  position: absolute;
  inset: -10%;
  pointer-events: none;
}

.page-bg::before {
  background-image:
    radial-gradient(circle at 14% 18%, rgba(34, 211, 238, 0.24), transparent 36%),
    radial-gradient(circle at 82% 16%, rgba(37, 99, 235, 0.22), transparent 40%),
    radial-gradient(circle at 54% 84%, rgba(14, 165, 233, 0.16), transparent 35%),
    radial-gradient(circle, rgba(148, 197, 255, 0.17) 1px, transparent 1px);
  background-size: auto, auto, auto, 26px 26px;
  opacity: 0;
  transition: opacity var(--dur-slow) var(--ease-standard);
}

html[data-theme="dark"] .page-bg::before {
  opacity: 0.7;
}

.page-bg::after {
  background-image: var(--noise-pattern);
  background-size: 140px 140px;
  opacity: 0.028;
  mix-blend-mode: multiply;
}

html[data-theme="dark"] .page-bg::after {
  opacity: 0.04;
  mix-blend-mode: screen;
}

.mesh {
  background-image: linear-gradient(rgba(148, 163, 184, 0.12) 1px, transparent 1px), linear-gradient(90deg, rgba(148, 163, 184, 0.12) 1px, transparent 1px);
  background-size: 28px 28px;
}

/* --- Site Header --- */
.site-header {
  transition: background-color var(--dur-base) var(--ease-standard), border-color var(--dur-base) var(--ease-standard), box-shadow var(--dur-base) var(--ease-standard);
  border-bottom: 1px solid transparent;
}
.site-header.is-scrolled {
  background: color-mix(in srgb, var(--color-bg) 72%, transparent);
  border-color: color-mix(in srgb, var(--color-border) 70%, transparent);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
}

/* --- Logo --- */
.logo-mark {
  position: relative;
  width: 28px;
  height: 28px;
  border-radius: 9px;
  background: var(--gradient-main);
  box-shadow: var(--shadow-glow);
  overflow: hidden;
}
.logo-mark::after {
  content: "";
  position: absolute;
  inset: 1px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.45);
}

/* --- Navigation Links --- */
.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 14px;
  border-radius: 10px;
  font-size: 0.92rem;
  color: var(--color-text-muted);
  transition: color var(--dur-base) var(--ease-standard), background-color var(--dur-base) var(--ease-standard);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 18%;
  right: 18%;
  bottom: 6px;
  height: 1.5px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--color-secondary) 88%, transparent);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--dur-base) var(--ease-standard);
}

.nav-link:hover,
.nav-link.is-active {
  color: var(--color-text);
  background: color-mix(in srgb, var(--color-secondary) 12%, transparent);
}

.nav-link:hover::after,
.nav-link.is-active::after {
  transform: scaleX(1);
}

/* --- Buttons --- */
.btn-primary,
.btn-secondary,
.btn-ghost {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  height: 44px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform var(--dur-base) var(--ease-emphasized), box-shadow var(--dur-base) var(--ease-standard), background-color var(--dur-base) var(--ease-standard), border-color var(--dur-base) var(--ease-standard), color var(--dur-base) var(--ease-standard);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 18px;
}

.btn-primary::before,
.btn-secondary::before {
  content: "";
  position: absolute;
  top: -180%;
  left: -36%;
  width: 38%;
  height: 420%;
  background: linear-gradient(120deg, transparent 10%, rgba(255, 255, 255, 0.45) 48%, transparent 90%);
  transform: translateX(-240%) rotate(16deg);
  opacity: 0;
  pointer-events: none;
}

.btn-primary {
  color: #fff;
  background: var(--gradient-main);
  box-shadow: var(--shadow-md), 0 0 0 1px color-mix(in srgb, var(--color-secondary) 42%, transparent);
  animation: cta-pulse 4s var(--ease-standard) infinite;
}

.btn-primary:hover {
  transform: translateY(-1px) scale(1.01);
  box-shadow: var(--shadow-lg), 0 0 0 1px color-mix(in srgb, var(--color-secondary) 62%, transparent), 0 0 30px var(--color-glow);
}

.btn-primary:hover::before {
  opacity: 0.95;
  animation: cta-shimmer 920ms var(--ease-emphasized) 1;
}

.btn-secondary {
  color: var(--color-text);
  background: color-mix(in srgb, var(--color-surface-2) 94%, transparent);
  border: 1px solid var(--color-border);
  animation: cta-pulse 4s var(--ease-standard) infinite;
}

.btn-secondary:hover {
  color: var(--color-secondary);
  border-color: color-mix(in srgb, var(--color-secondary) 56%, var(--color-border));
  transform: translateY(-1px) scale(1.01);
  box-shadow: 0 10px 30px color-mix(in srgb, var(--color-secondary) 22%, transparent);
}

.btn-secondary:hover::before {
  opacity: 0.75;
  animation: cta-shimmer 920ms var(--ease-emphasized) 1;
}

.btn-ghost {
  color: var(--color-text-muted);
  border: 1px solid transparent;
  background: transparent;
}
.btn-ghost:hover {
  color: var(--color-text);
  background: color-mix(in srgb, var(--color-secondary) 10%, transparent);
}

/* --- Mobile Menu --- */
.mobile-menu-btn {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 4px;
}
.mobile-menu-btn span {
  width: 16px;
  height: 2px;
  border-radius: 99px;
  background: var(--color-text);
  transition: transform var(--dur-base) var(--ease-standard), opacity var(--dur-base) var(--ease-standard);
}
.mobile-menu-btn[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.mobile-menu-btn[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.mobile-menu-btn[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.mobile-panel {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-8px) scaleY(0.98);
  transform-origin: top;
  transition: transform var(--dur-base) var(--ease-standard), opacity var(--dur-base) var(--ease-standard);
  will-change: transform, opacity;
}
.mobile-panel.open {
  opacity: 1;
  transform: translateY(0) scaleY(1);
  visibility: visible;
  pointer-events: auto;
}

.panel-glass {
  margin: 8px 12px 0;
  border: 1px solid color-mix(in srgb, var(--color-border) 72%, transparent);
  border-radius: 16px;
  background: color-mix(in srgb, var(--color-surface) 78%, transparent);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  box-shadow: var(--shadow-md);
}

/* --- Section Layout --- */
.section-pad {
  padding-top: var(--section-space);
  padding-bottom: var(--section-space);
}
.section-pad-compact {
  padding-top: var(--section-space-tight);
  padding-bottom: var(--section-space-tight);
}

main > .section-pad,
main > .section-pad-compact {
  position: relative;
}

main > .section-pad + .section-pad::before,
main > .section-pad + .section-pad-compact::before,
main > .section-pad-compact + .section-pad::before,
main > .section-pad-compact + .section-pad-compact::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  width: min(92%, var(--container-max));
  height: 1px;
  transform: translateX(-50%);
  background: linear-gradient(90deg, transparent 0%, color-mix(in srgb, var(--color-secondary) 32%, var(--color-border)) 18%, color-mix(in srgb, var(--color-accent) 36%, var(--color-border)) 52%, color-mix(in srgb, var(--color-secondary) 26%, var(--color-border)) 82%, transparent 100%);
  opacity: 0.7;
}

.section-eyebrow {
  display: inline-flex;
  align-items: center;
  border: 1px solid color-mix(in srgb, var(--color-secondary) 42%, var(--color-border));
  background: color-mix(in srgb, var(--color-secondary) 10%, transparent);
  color: var(--color-secondary);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  height: 30px;
  padding: 0 12px;
}
.section-title {
  font-size: clamp(1.65rem, 2.8vw, 2.85rem);
  line-height: 1.15;
  font-weight: 700;
  margin-top: 18px;
  margin-bottom: 14px;
  letter-spacing: -0.04em;
}
.section-desc {
  color: var(--color-text-muted);
  max-width: 68ch;
  font-size: clamp(0.96rem, 1.12vw, 1.08rem);
  line-height: 1.72;
}

/* --- Card Base --- */
.card-base {
  position: relative;
  isolation: isolate;
  height: 100%;
  border-radius: 16px;
  border: 1px solid transparent;
  background: color-mix(in srgb, var(--color-surface) 90%, transparent);
  box-shadow: var(--shadow-sm);
  transition: transform var(--dur-base) var(--ease-emphasized), box-shadow var(--dur-base) var(--ease-standard), border-color var(--dur-base) var(--ease-standard);
}

.card-base::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg, color-mix(in srgb, var(--color-secondary) 45%, var(--color-border)), color-mix(in srgb, var(--color-accent) 42%, transparent), color-mix(in srgb, var(--color-secondary) 30%, var(--color-border)));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0.56;
  transition: opacity var(--dur-base) var(--ease-standard);
  pointer-events: none;
}

.card-base > * {
  position: relative;
  z-index: 1;
}

.card-base:hover {
  transform: translateY(-4px) scale(1.02);
  box-shadow: 0 18px 44px color-mix(in srgb, var(--color-primary) 16%, transparent), 0 0 0 1px color-mix(in srgb, var(--color-secondary) 46%, transparent);
  border-color: transparent;
}

.card-base:hover::before {
  opacity: 0.95;
}

:is(.article-card, .metric-card, .spec-card, .solution-row, .form-card, .info-card, .map-card) {
  position: relative;
  isolation: isolate;
  border: 1px solid transparent;
}

:is(.article-card, .metric-card, .spec-card, .solution-row, .form-card, .info-card, .map-card)::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(140deg, color-mix(in srgb, var(--color-secondary) 40%, var(--color-border)), color-mix(in srgb, var(--color-accent) 36%, transparent), color-mix(in srgb, var(--color-secondary) 26%, var(--color-border)));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0.54;
  transition: opacity var(--dur-base) var(--ease-standard);
  pointer-events: none;
}

:is(.article-card, .metric-card, .spec-card, .solution-row, .form-card, .info-card, .map-card) > * {
  position: relative;
  z-index: 1;
}

:is(.article-card, .metric-card, .spec-card, .solution-row, .form-card, .info-card, .map-card):hover::before {
  opacity: 0.9;
}

/* --- Reveal Animation --- */
.reveal {
  opacity: 0;
  transform: translateY(12px) scale(0.985);
  filter: blur(1px);
  transition: opacity var(--dur-slow) var(--ease-standard), transform var(--dur-slow) var(--ease-standard), filter var(--dur-slow) var(--ease-standard);
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  filter: blur(0);
}

/* --- Link Underline --- */
.link-underline {
  position: relative;
  color: var(--color-secondary);
  font-weight: 600;
  font-size: 0.92rem;
  width: fit-content;
}
.link-underline::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1.5px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--dur-base) var(--ease-standard);
}
.card-base:hover .link-underline::after,
.link-underline:hover::after {
  transform: scaleX(1);
}

/* --- Footer --- */
.footer-link {
  position: relative;
  color: var(--color-text-muted);
  text-underline-offset: 3px;
  transition: color var(--dur-base) var(--ease-standard);
}

.footer-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--dur-base) var(--ease-standard);
}

.footer-link:hover {
  color: var(--color-text);
}

.footer-link:hover::after {
  transform: scaleX(1);
}

/* --- Social Icons --- */
.social-icon {
  width: 34px;
  height: 34px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: border-color var(--dur-base) var(--ease-standard), color var(--dur-base) var(--ease-standard), transform var(--dur-base) var(--ease-standard);
}
.social-icon:hover {
  color: var(--color-secondary);
  border-color: color-mix(in srgb, var(--color-secondary) 50%, var(--color-border));
  transform: translateY(-2px);
}
.social-icon svg {
  width: 16px;
  height: 16px;
}

/* --- Breadcrumb --- */
.breadcrumb {
  padding: 12px 0 0;
}
.breadcrumb-list {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.82rem;
  color: var(--color-text-muted);
}
.breadcrumb-list a {
  color: var(--color-text-muted);
  transition: color var(--dur-base) var(--ease-standard);
}
.breadcrumb-list a:hover { color: var(--color-secondary); }
.breadcrumb-sep {
  color: var(--color-border);
  font-size: 0.7rem;
}
.breadcrumb-current {
  color: var(--color-text);
  font-weight: 500;
}

/* --- Back to Top --- */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  z-index: 40;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface) 88%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity var(--dur-base) var(--ease-standard), transform var(--dur-base) var(--ease-standard), border-color var(--dur-base) var(--ease-standard), color var(--dur-base) var(--ease-standard);
  box-shadow: var(--shadow-sm);
}
.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}
.back-to-top:hover {
  color: var(--color-secondary);
  border-color: color-mix(in srgb, var(--color-secondary) 50%, var(--color-border));
}
.back-to-top svg {
  width: 18px;
  height: 18px;
}

body.mobile-menu-open {
  overflow: hidden;
}

.mobile-panel .nav-link {
  min-height: 44px;
  justify-content: flex-start;
  width: 100%;
  border-radius: 12px;
}

@media (min-width: 768px) {
  body.mobile-menu-open {
    overflow: auto;
  }
}

@media (max-width: 767px) {
  .back-to-top {
    right: 16px;
    bottom: 16px;
  }
}

/* --- Article Cover Placeholder --- */
.article-cover {
  aspect-ratio: 16 / 9;
  border-radius: 12px;
  background: linear-gradient(140deg, color-mix(in srgb, var(--color-secondary) 34%, transparent), color-mix(in srgb, var(--color-accent) 28%, transparent));
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--dur-slow) var(--ease-standard);
}
.article-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.2), transparent 55%);
}
.article-cover svg {
  position: relative;
  z-index: 1;
  width: 40px;
  height: 40px;
  opacity: 0.35;
  color: var(--color-text);
}
html[data-theme="dark"] .article-cover svg {
  color: #e2e8f0;
  opacity: 0.4;
}

/* --- Motion Keyframes --- */
@keyframes cta-pulse {
  0%,
  100% {
    box-shadow: var(--shadow-md), 0 0 0 0 rgba(37, 99, 235, 0);
  }
  50% {
    box-shadow: var(--shadow-lg), 0 0 0 8px color-mix(in srgb, var(--color-glow) 36%, transparent);
  }
}

@keyframes cta-shimmer {
  0% {
    transform: translateX(-240%) rotate(16deg);
  }
  100% {
    transform: translateX(420%) rotate(16deg);
  }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 1ms !important;
    scroll-behavior: auto !important;
  }
  .reveal {
    opacity: 1;
    transform: none;
    filter: none;
  }
}