/* ===== RESET ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { min-height: 100vh; line-height: 1.6; -webkit-font-smoothing: antialiased; }
img, picture, video, canvas, svg { display: block; max-width: 100%; }
input, button, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; }
ul, ol { list-style: none; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4, h5, h6 { overflow-wrap: break-word; }
p { overflow-wrap: break-word; }

/* ===== CSS VARIABLES ===== */
:root {
  --clr-primary-100: #1A0A2E;
  --clr-primary-200: #2D1B4E;
  --clr-primary-300: #4B2C7B;
  --clr-primary-400: #6A3E99;
  --clr-gold: #F5A623;
  --clr-gold-light: #FFD773;
  --clr-neon-blue: #00D4FF;
  --clr-orange: #FF6B35;
  --clr-bg-dark: #0D0B1E;
  --clr-bg-card: #1E1A3A;
  --clr-text-primary: #FFFFFF;
  --clr-text-secondary: #BFB8D6;
  --clr-surface-overlay: rgba(255, 255, 255, 0.08);
  --clr-error: #FF4757;
  --clr-success: #2ED573;
  --clr-divider: rgba(255, 255, 255, 0.12);
  --font-heading: 'Montserrat', 'Helvetica Neue', Arial, sans-serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-weight-heading: 800;
  --font-weight-body: 400;
  --line-height-heading: 1.1;
  --line-height-body: 1.6;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 5rem;
  --max-width: 1280px;
  --header-top-height: 2.5rem;
  --header-main-height: 4rem;
  --border-radius: 8px;
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-glow-gold: 0 0 20px rgba(245, 166, 35, 0.3);
  --shadow-glow-blue: 0 0 20px rgba(0, 212, 255, 0.3);
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ===== TYPOGRAPHY BASE ===== */
body {
  font-family: var(--font-body);
  font-weight: var(--font-weight-body);
  line-height: var(--line-height-body);
  color: var(--clr-text-primary);
  background-color: var(--clr-bg-dark);
}
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--font-weight-heading);
  line-height: var(--line-height-heading);
  letter-spacing: -0.02em;
  color: var(--clr-text-primary);
}
h1 { font-size: 3rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
p { font-size: 1rem; color: var(--clr-text-secondary); }
a { transition: color var(--transition-base); }
a:hover { color: var(--clr-gold); }
::selection { background: var(--clr-gold); color: var(--clr-primary-100); }

/* ===== SKIP LINK ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  z-index: 10000;
  padding: var(--space-sm) var(--space-md);
  background: var(--clr-gold);
  color: var(--clr-primary-100);
  font-weight: 700;
  font-size: 0.875rem;
  transition: top var(--transition-base);
}
.skip-link:focus {
  top: 0;
  outline: 2px solid var(--clr-neon-blue);
  outline-offset: 2px;
}

/* ===== TOP BAR ===== */
.top-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
  height: var(--header-top-height);
  padding: 0 var(--space-md);
  background: var(--clr-primary-100);
  border-bottom: 1px solid var(--clr-divider);
  font-size: 0.75rem;
  color: var(--clr-text-secondary);
}
.top-bar__text { white-space: nowrap; }
.top-bar__link {
  color: var(--clr-gold-light);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 2px;
  text-decoration-thickness: 1px;
  transition: color var(--transition-base);
}
.top-bar__link:hover { color: var(--clr-gold); }
.top-bar__lang {
  font-size: 0.75rem;
  color: var(--clr-text-secondary);
  border: 1px solid var(--clr-divider);
  border-radius: 4px;
  padding: 0.125rem 0.5rem;
  transition: border-color var(--transition-base), color var(--transition-base);
}
.top-bar__lang:hover { border-color: var(--clr-gold); color: var(--clr-gold); }

/* ===== SITE HEADER ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 9000;
  background: rgba(13, 11, 30, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--clr-divider);
}
.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  height: var(--header-main-height);
}

/* Brand */
.site-header__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-shrink: 0;
  font-family: var(--font-heading);
  font-weight: var(--font-weight-heading);
  font-size: 1.5rem;
  color: var(--clr-text-primary);
  transition: text-shadow var(--transition-base);
}
.site-header__brand:hover { color: var(--clr-text-primary); text-shadow: 0 0 24px rgba(245, 166, 35, 0.5); }
.site-header__brand-icon { color: var(--clr-gold); font-size: 1.75rem; line-height: 1; }
.site-header__brand-name { letter-spacing: -0.03em; }

/* Navigation */
.site-header__nav ul {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}
.site-header__nav a {
  display: block;
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--clr-text-secondary);
  border-radius: var(--border-radius);
  transition: background var(--transition-base), color var(--transition-base), box-shadow var(--transition-base);
  white-space: nowrap;
}
.site-header__nav a:hover {
  color: var(--clr-text-primary);
  background: var(--clr-surface-overlay);
}
.site-header__nav a[aria-current="page"] {
  color: var(--clr-neon-blue);
  box-shadow: inset 0 -2px 0 var(--clr-neon-blue), 0 0 16px rgba(0, 212, 255, 0.15);
  background: rgba(0, 212, 255, 0.06);
}

/* Filter button */
.site-header__filter {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  margin-left: auto;
  color: var(--clr-text-secondary);
  border: 1px solid var(--clr-divider);
  border-radius: var(--border-radius);
  transition: border-color var(--transition-base), color var(--transition-base), box-shadow var(--transition-base);
  flex-shrink: 0;
}
.site-header__filter:hover {
  border-color: var(--clr-neon-blue);
  color: var(--clr-neon-blue);
  box-shadow: 0 0 16px rgba(0, 212, 255, 0.2);
}
.site-header__filter svg { display: block; }

/* Toggle button (mobile) */
.site-header__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 4px;
  width: 2.25rem;
  height: 2.25rem;
  flex-shrink: 0;
}
.site-header__toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--clr-text-primary);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}
.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(2) { opacity: 0; }
.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ===== SITE FOOTER ===== */
.site-footer {
  background: var(--clr-primary-100);
  border-top: 1px solid var(--clr-divider);
  padding: var(--space-xl) var(--space-md) var(--space-lg);
}
.site-footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-xl);
}
.site-footer__col--brand { grid-column: 1 / 2; }
.site-footer__col--links { grid-column: 2 / 3; }
.site-footer__col--contact { grid-column: 3 / 4; }

.site-footer__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-weight: var(--font-weight-heading);
  font-size: 1.5rem;
  color: var(--clr-text-primary);
  margin-bottom: var(--space-sm);
}
.site-footer__brand:hover { color: var(--clr-gold); }
.site-footer__brand-icon { color: var(--clr-gold); font-size: 1.75rem; line-height: 1; }
.site-footer__brand-name { letter-spacing: -0.03em; }

.site-footer__trust {
  font-size: 0.875rem;
  color: var(--clr-text-secondary);
  max-width: 24rem;
  line-height: var(--line-height-body);
}

.site-footer__heading {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1rem;
  color: var(--clr-gold-light);
  margin-bottom: var(--space-md);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.site-footer__links,
.site-footer__contact {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.site-footer__links a,
.site-footer__contact a {
  font-size: 0.875rem;
  color: var(--clr-text-secondary);
  transition: color var(--transition-base), padding-left var(--transition-base);
}
.site-footer__links a:hover,
.site-footer__contact a:hover {
  color: var(--clr-gold);
  padding-left: 4px;
}
.site-footer__contact li {
  font-size: 0.875rem;
  color: var(--clr-text-secondary);
}

.site-footer__bottom {
  grid-column: 1 / -1;
  margin-top: var(--space-xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--clr-divider);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  text-align: center;
}
.site-footer__icp {
  font-size: 0.75rem;
  color: var(--clr-text-secondary);
}
.site-footer__note {
  font-size: 0.75rem;
  color: var(--clr-text-secondary);
  max-width: 36rem;
}
.site-footer__copyright {
  font-size: 0.75rem;
  color: var(--clr-text-secondary);
  opacity: 0.7;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.625rem 1.5rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.875rem;
  border-radius: var(--border-radius);
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
}
.btn--primary {
  background: linear-gradient(135deg, var(--clr-gold), var(--clr-orange));
  color: var(--clr-primary-100);
  box-shadow: 0 0 20px rgba(245, 166, 35, 0.25);
}
.btn--primary:hover {
  box-shadow: 0 0 32px rgba(245, 166, 35, 0.5);
  transform: translateY(-1px);
}
.btn--outline {
  background: transparent;
  color: var(--clr-neon-blue);
  border: 1px solid var(--clr-neon-blue);
}
.btn--outline:hover {
  background: rgba(0, 212, 255, 0.1);
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.2);
  transform: translateY(-1px);
}

/* ===== BREADCRUMB ===== */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) 0;
  font-size: 0.8125rem;
  color: var(--clr-text-secondary);
}
.breadcrumb a { color: var(--clr-text-secondary); transition: color var(--transition-base); }
.breadcrumb a:hover { color: var(--clr-gold); }
.breadcrumb__separator { color: var(--clr-divider); margin: 0 var(--space-xs); }
.breadcrumb [aria-current="page"] { color: var(--clr-neon-blue); }

/* ===== CONTAINER ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ===== GRID ===== */
.grid { display: grid; gap: var(--space-lg); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 768px) {
  .grid--2, .grid--3 { grid-template-columns: 1fr; }
}
@media (min-width: 769px) and (max-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
}

/* ===== CARD ===== */
.card {
  background: var(--clr-bg-card);
  border: 1px solid var(--clr-divider);
  border-radius: var(--border-radius);
  padding: var(--space-lg);
  box-shadow: var(--shadow-card);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}
.card__title {
  font-family: var(--font-heading);
  font-weight: var(--font-weight-heading);
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
  color: var(--clr-text-primary);
}
.card__text {
  font-size: 0.9375rem;
  color: var(--clr-text-secondary);
  line-height: var(--line-height-body);
}

/* ===== SECTION ===== */
.section {
  padding: var(--space-2xl) 0;
}
.section__title {
  font-family: var(--font-heading);
  font-weight: var(--font-weight-heading);
  font-size: 2.5rem;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.03em;
  color: var(--clr-text-primary);
}
.section__subtitle {
  font-size: 1.125rem;
  color: var(--clr-text-secondary);
  max-width: 32rem;
  line-height: var(--line-height-body);
  margin-bottom: var(--space-lg);
}

/* ===== SCROLL PROGRESS ===== */
[data-scroll-progress] {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 99999;
  width: 100%;
  height: 3px;
  background: transparent;
  pointer-events: none;
}
[data-scroll-progress]::after {
  content: '';
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--clr-gold), var(--clr-neon-blue));
  transition: width 0.1s linear;
}
@media (prefers-reduced-motion: reduce) {
  [data-scroll-progress]::after { transition: none; }
}

/* ===== ACCESSIBILITY ===== */
:focus-visible {
  outline: 2px solid var(--clr-neon-blue);
  outline-offset: 2px;
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ===== RESPONSIVE: TABLET & MOBILE ===== */
@media (max-width: 1024px) {
  .site-footer__inner { grid-template-columns: 1fr 1fr; gap: var(--space-lg); }
  .site-footer__col--brand { grid-column: 1 / -1; }
  .site-footer__col--links { grid-column: 1 / 2; }
  .site-footer__col--contact { grid-column: 2 / 3; }
  .section__title { font-size: 2rem; }
  h1 { font-size: 2.25rem; }
  h2 { font-size: 1.75rem; }
}

@media (max-width: 768px) {
  :root { --header-top-height: 2.25rem; --header-main-height: 3.5rem; }

  .top-bar {
    gap: var(--space-md);
    font-size: 0.6875rem;
    padding: 0 var(--space-sm);
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  /* Mobile navigation */
  .site-header__nav {
    position: fixed;
    top: calc(var(--header-top-height) + var(--header-main-height));
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 8000;
    background: rgba(13, 11, 30, 0.98);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    display: none;
    padding: var(--space-lg) var(--space-md);
    overflow-y: auto;
  }
  .site-header__nav[data-open] { display: block; }
  .site-header__nav ul {
    flex-direction: column;
    gap: var(--space-xs);
  }
  .site-header__nav a {
    font-size: 1.125rem;
    padding: var(--space-md);
    width: 100%;
    text-align: center;
    border-bottom: 1px solid var(--clr-divider);
  }
  .site-header__nav a[aria-current="page"] {
    box-shadow: none;
    background: rgba(0, 212, 255, 0.08);
    border-bottom-color: var(--clr-neon-blue);
  }
  .site-header__toggle { display: flex; }
  .site-header__filter { margin-left: auto; }

  .site-footer__inner { grid-template-columns: 1fr; gap: var(--space-lg); }
  .site-footer__col--links { grid-column: 1 / -1; }
  .site-footer__col--contact { grid-column: 1 / -1; }
  .site-footer__bottom { margin-top: var(--space-lg); padding-top: var(--space-md); }

  .section { padding: var(--space-xl) 0; }
  .section__title { font-size: 1.75rem; }
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
}

/* ===== UTILITY ===== */
.text-gold { color: var(--clr-gold); }
.text-neon { color: var(--clr-neon-blue); }
.text-center { text-align: center; }
.mt-lg { margin-top: var(--space-lg); }
.mb-lg { margin-bottom: var(--space-lg); }