/* ===== RESET ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { min-height: 100vh; line-height: 1.6; -webkit-font-smoothing: antialiased; }
img, svg { display: block; max-width: 100%; }
ul, ol { list-style: none; }
a { text-decoration: none; color: inherit; }
button { font: inherit; border: none; background: none; cursor: pointer; color: inherit; }
:focus-visible { outline: 3px solid #F4A261; outline-offset: 3px; border-radius: 4px; }

/* ===== CSS VARIABLES ===== */
:root {
  --color-red: #E63946;
  --color-blue: #1D3557;
  --color-gold: #F4A261;
  --color-dark: #121212;
  --color-cream: #F1FAEE;
  --color-brown: #2B2D42;
  --color-red-dark: #A62C3B;
  --color-red-gradient: linear-gradient(135deg, #E63946, #b81f2d);
  --font-primary: 'Work Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-weight-heading: 900;
  --font-weight-body: 400;
  --scale: 1.25;
  --nav-width: 280px;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 32px;
  --radius-pill: 9999px;
  --transition: 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --shadow-nav: 4px 0 24px rgba(0,0,0,0.5);
  --shadow-card: 0 4px 20px rgba(0,0,0,0.25);
}

/* ===== CHINESE TYPOGRAPHY ===== */
html { font-size: 16px; }
body {
  font-family: var(--font-primary);
  font-weight: var(--font-weight-body);
  background: var(--color-dark);
  color: var(--color-cream);
  line-height: 1.7;
  word-break: break-word;
}
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-heading);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--color-cream);
}
h1 { font-size: clamp(2.2rem, 5vw, 3.8rem); }
h2 { font-size: clamp(1.8rem, 4vw, 2.8rem); }
h3 { font-size: clamp(1.4rem, 3vw, 2rem); }
h4 { font-size: clamp(1.2rem, 2.5vw, 1.5rem); }
p { max-width: 70ch; margin-bottom: 1rem; }
a { color: var(--color-gold); transition: color var(--transition); }
a:hover { color: var(--color-red); }

/* ===== SKIP LINK ===== */
.skip-link {
  position: fixed;
  top: -100%;
  left: 0;
  z-index: 9999;
  padding: 0.75rem 1.5rem;
  background: var(--color-red);
  color: var(--color-cream);
  font-weight: 700;
  font-size: 1rem;
  border-radius: 0 0 var(--radius-sm) 0;
  transition: top var(--transition);
}
.skip-link:focus { top: 0; }

/* ===== SITE HEADER (SIDEBAR) ===== */
.site-header {
  position: fixed;
  left: 0;
  top: 0;
  width: var(--nav-width);
  height: 100vh;
  background: var(--color-blue);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-nav);
  overflow-y: auto;
}
.site-header__inner {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 2rem 1.5rem;
  gap: 2rem;
}
.brand-mark {
  font-size: 1.8rem;
  font-weight: var(--font-weight-heading);
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--color-cream);
  display: flex;
  align-items: center;
  gap: 0.1em;
}
.brand-mark__accent { color: var(--color-red); }
.brand-mark__gold { color: var(--color-gold); }
.brand-mark--footer { font-size: 1.4rem; }

/* ===== NAVIGATION ===== */
.site-nav { flex: 1; }
.nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}
.nav-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.7rem 1rem;
  border-radius: var(--radius-pill);
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-cream);
  transition: background var(--transition), color var(--transition), transform var(--transition);
  position: relative;
}
.nav-link .nav-index {
  font-weight: 400;
  font-size: 0.75rem;
  opacity: 0.5;
  min-width: 1.8em;
  font-feature-settings: "tnum";
}
.nav-link:hover {
  background: rgba(244, 162, 97, 0.15);
  color: var(--color-gold);
  transform: translateX(4px);
}
.nav-link[aria-current="page"] {
  background: var(--color-red);
  color: var(--color-cream);
  font-weight: 800;
  box-shadow: 0 2px 12px rgba(230, 57, 70, 0.4);
}
.nav-link[aria-current="page"] .nav-index { opacity: 0.8; }

/* ===== CTA BUTTON ===== */
.btn-prime {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 2rem;
  background: var(--color-red);
  color: var(--color-cream);
  font-weight: 800;
  font-size: 1rem;
  border-radius: var(--radius-pill);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  text-align: center;
  letter-spacing: 0.02em;
}
.btn-prime:hover {
  background: var(--color-red-dark);
  color: var(--color-cream);
  transform: scale(1.02);
  box-shadow: 0 4px 20px rgba(230, 57, 70, 0.45);
}

/* ===== NAV TOGGLE (mobile) ===== */
.nav-toggle {
  display: none;
  align-self: flex-end;
  font-size: 1.6rem;
  color: var(--color-cream);
  padding: 0.25rem 0.5rem;
  line-height: 1;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.05);
}
.nav-toggle:hover { background: rgba(255,255,255,0.12); }
.mobile-bar-btn {
  display: none;
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 999;
  padding: 0.6rem;
  background: var(--color-blue);
  border-radius: var(--radius-sm);
  box-shadow: 0 2px 12px rgba(0,0,0,0.4);
  flex-direction: column;
  gap: 4px;
}
.mobile-bar-btn__line {
  display: block;
  width: 22px;
  height: 3px;
  background: var(--color-cream);
  border-radius: 2px;
  transition: transform var(--transition);
}
.mobile-bar-btn:hover .mobile-bar-btn__line { background: var(--color-gold); }

/* ===== SITE FOOTER ===== */
.site-footer {
  margin-left: var(--nav-width);
  background: var(--color-dark);
  border-top: 2px solid rgba(230, 57, 70, 0.25);
  padding: 2.5rem 2rem;
}
.site-footer__inner {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem 2.5rem;
}
.footer-brand { grid-column: 1 / -1; }
.footer-tagline {
  font-size: 0.9rem;
  opacity: 0.6;
  margin-top: 0.25rem;
  letter-spacing: 0.04em;
}
.footer-links {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  align-items: center;
}
.footer-link {
  color: var(--color-gold);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: border-color var(--transition), color var(--transition);
}
.footer-link:hover {
  border-bottom-color: var(--color-red);
  color: var(--color-red);
}
.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.9rem;
  opacity: 0.7;
}
.footer-contact__item { white-space: nowrap; }
.footer-address {
  font-size: 0.85rem;
  opacity: 0.5;
  grid-column: 1 / -1;
}
.footer-note {
  font-size: 0.85rem;
  opacity: 0.5;
  grid-column: 1 / -1;
  font-style: italic;
  border-left: 3px solid var(--color-red);
  padding-left: 1rem;
}
.footer-icp {
  font-size: 0.8rem;
  opacity: 0.4;
  grid-column: 1 / -1;
  padding-top: 0.5rem;
  border-top: 1px solid rgba(255,255,255,0.06);
}

/* ===== BREADCRUMB ===== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.6rem;
  padding: 0.75rem 0;
  font-size: 0.85rem;
  opacity: 0.7;
  margin-bottom: 1.5rem;
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.6rem;
}
.breadcrumb li { display: inline; }
.breadcrumb li + li::before {
  content: "/";
  margin-right: 0.4rem;
  opacity: 0.4;
}
.breadcrumb a { color: var(--color-gold); }
.breadcrumb a:hover { color: var(--color-red); }
.breadcrumb [aria-current="page"] { color: var(--color-cream); font-weight: 600; }

/* ===== CONTENT CONTAINER ===== */
.content-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 2rem 3rem;
  width: 100%;
}

/* ===== GRID SYSTEM ===== */
.grid {
  display: grid;
  grid-template-columns: repeat(var(--grid-cols, 3), 1fr);
  gap: 1.5rem;
}
.grid-item {
  background: rgba(29, 53, 87, 0.4);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  border: 1px solid rgba(244, 162, 97, 0.1);
  backdrop-filter: blur(4px);
  transition: transform var(--transition), border-color var(--transition);
}
.grid-item:hover {
  transform: translateY(-4px);
  border-color: var(--color-gold);
}

/* ===== PROGRESS BAR ===== */
.progress-bar {
  position: fixed;
  top: 0;
  left: var(--nav-width);
  height: 4px;
  background: var(--color-red-gradient);
  z-index: 998;
  width: 0%;
  transition: width 0.1s linear;
  border-radius: 0 2px 2px 0;
}

/* ===== MAIN CONTENT OFFSET ===== */
#main-content {
  margin-left: var(--nav-width);
  background: var(--color-dark);
  min-height: 100vh;
  position: relative;
  padding-top: 0;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  :root { --nav-width: 240px; }
  .site-header__inner { padding: 1.5rem 1.25rem; gap: 1.5rem; }
  .brand-mark { font-size: 1.5rem; }
  .nav-link { font-size: 0.9rem; padding: 0.6rem 0.85rem; }
}

@media (max-width: 768px) {
  :root { --nav-width: 0px; }
  .site-header {
    position: fixed;
    left: 0;
    top: 0;
    width: 280px;
    height: 100vh;
    transform: translateX(-100%);
    transition: transform var(--transition);
    box-shadow: 4px 0 40px rgba(0,0,0,0.7);
  }
  .site-header[data-open] { transform: translateX(0); }
  .site-header__inner { padding: 1.5rem 1.25rem; gap: 1.5rem; }
  .nav-toggle { display: block; }
  .mobile-bar-btn { display: flex; }
  .brand-mark { font-size: 1.6rem; }
  .nav-link { font-size: 1rem; padding: 0.75rem 1rem; }
  #main-content { margin-left: 0; padding-top: 0; }
  .site-footer { margin-left: 0; padding: 2rem 1.25rem; }
  .site-footer__inner {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .footer-links { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
  .footer-contact__item { white-space: normal; }
  .progress-bar { left: 0; }
  .content-container { padding: 1.5rem 1.25rem 2rem; }
  .grid { --grid-cols: 1; }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .grid { --grid-cols: 2; }
}

@media (min-width: 1025px) {
  .grid { --grid-cols: 3; }
}

/* ===== FOCUS VISIBLE ENHANCEMENT ===== */
:focus-visible { outline-color: var(--color-gold); }
.nav-link:focus-visible { outline-offset: 2px; }
.btn-prime:focus-visible { outline-offset: 3px; }

/* ===== PREFERS REDUCED MOTION ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .progress-bar { display: none; }
  .site-header { transition: none; }
  .nav-link:hover { transform: none; }
  .grid-item:hover { transform: none; }
  .btn-prime:hover { transform: none; }
}

/* ===== SLANT DECORATION (side header) ===== */
.site-header::after {
  content: '';
  position: absolute;
  bottom: 0;
  right: 0;
  width: 100%;
  height: 24px;
  background: linear-gradient(135deg, transparent 50%, rgba(230, 57, 70, 0.3) 50%);
  pointer-events: none;
}

/* ===== IMAGE CONTAINER (placeholder rule) ===== */
.img-frame {
  background: var(--color-blue);
  border-radius: var(--radius-md);
  overflow: hidden;
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255,255,255,0.2);
  font-size: 0.85rem;
  border: 1px solid rgba(244, 162, 97, 0.08);
}

/* ===== UTILITY ===== */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }