/* Reset & variables */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --dark-black: #0A0A0A;
  --wukong-gold: #F0B90B;
  --data-green: #39FF14;
  --card-gray: #1A1A1A;
  --text-white: #FFFFFF;
  --text-gray: #B0B0B0;
  --bright-gold: #FFD700;
  --deep-green: #0F9960;
  --font-heading: 'KaiTi', '楷体', 'STKaiti', serif;
  --font-body: 'Noto Sans SC', 'Microsoft YaHei', 'PingFang SC', sans-serif;
  --max-width: 1200px;
  --header-height: 80px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  line-height: 1.6;
  background: var(--dark-black);
  color: var(--text-white);
}

body {
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s, border-color 0.2s;
}

a:hover, a:focus-visible {
  color: var(--bright-gold);
}

:focus-visible {
  outline: 2px solid var(--wukong-gold);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  z-index: 1000;
  padding: 0.5rem 1rem;
  background: var(--wukong-gold);
  color: var(--dark-black);
  font-weight: 600;
  clip: rect(1px,1px,1px,1px);
}

.skip-link:focus {
  top: 0;
  clip: auto;
}

/* Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1rem;
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: rgba(10,10,10,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(240,185,11,0.3);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  gap: 1rem;
}

.brand {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  color: var(--wukong-gold);
  white-space: nowrap;
  text-shadow: 0 0 8px rgba(240,185,11,0.4);
  letter-spacing: 0.05em;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}

.nav-link {
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-gray);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.5rem 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: var(--wukong-gold);
  border-bottom-color: var(--wukong-gold);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle-icon,
.nav-toggle-icon::before,
.nav-toggle-icon::after {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-white);
  transition: transform 0.3s;
}

.nav-toggle-icon {
  position: relative;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: '';
  position: absolute;
  left: 0;
}

.nav-toggle-icon::before {
  top: -6px;
}

.nav-toggle-icon::after {
  top: 6px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.6rem 1.4rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.btn-gold {
  background: var(--wukong-gold);
  color: var(--dark-black);
  border-color: var(--wukong-gold);
}

.btn-gold:hover,
.btn-gold:focus-visible {
  background: transparent;
  color: var(--bright-gold);
  border-color: var(--bright-gold);
}

.btn-outline {
  background: transparent;
  border-color: var(--wukong-gold);
  color: var(--wukong-gold);
}

.btn-outline:hover,
.btn-outline:focus-visible {
  background: var(--wukong-gold);
  color: var(--dark-black);
}

.cta-btn {
  white-space: nowrap;
}

/* Footer */
.site-footer {
  background: var(--card-gray);
  border-top: 2px solid var(--wukong-gold);
  padding: 3rem 0 1.5rem;
  margin-top: 0; /* content will adjust */
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  gap: 2rem;
}

.footer-brand .brand {
  display: block;
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.trust-statement {
  color: var(--data-green);
  font-weight: 600;
  font-size: 1.1rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.footer-links ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-link {
  color: var(--text-gray);
  font-size: 0.9rem;
}

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

.footer-contact p {
  color: var(--text-gray);
  font-size: 0.85rem;
  margin-bottom: 0.3rem;
}

.footer-legal {
  grid-column: 1 / -1;
  text-align: center;
  border-top: 1px solid rgba(240,185,11,0.2);
  padding-top: 1rem;
  margin-top: 1rem;
  color: var(--text-gray);
  font-size: 0.8rem;
}

.copyright, .icp {
  margin-bottom: 0.3rem;
}

/* Progress bar (global) */
.progress-bar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  height: 3px;
  background: var(--data-green);
  z-index: 99;
  width: 0%;
  transition: width 0.1s linear;
}

@media (prefers-reduced-motion: reduce) {
  .progress-bar {
    transition: none;
  }
}

/* Section title */
.section-title {
  font-family: var(--font-heading);
  font-size: 2.25rem;
  color: var(--wukong-gold);
  margin-bottom: 1.5rem;
  position: relative;
  display: inline-block;
  padding-left: 1rem;
  border-left: 4px solid var(--data-green);
}

/* Card */
.card {
  background: var(--card-gray);
  border: 1px solid rgba(240,185,11,0.15);
  padding: 1.5rem;
  border-radius: 0;
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 4px 20px rgba(57,255,20,0.15);
  border-color: var(--wukong-gold);
}

/* Scroll reveal */
[data-observe] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s, transform 0.5s;
}

[data-observe][data-visible] {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  [data-observe] {
    opacity: 1;
    transform: none;
  }
}

/* Responsive */
@media (max-width: 768px) {
  :root {
    --header-height: 60px;
  }

  .header-inner {
    position: relative;
  }

  .nav-toggle {
    display: block;
    order: 2;
  }

  .nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(10,10,10,0.98);
    border-bottom: 1px solid var(--wukong-gold);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }

  .nav[data-open] {
    max-height: 400px;
  }

  .nav-list {
    flex-direction: column;
    padding: 1rem 0;
    gap: 0;
  }

  .nav-link {
    display: block;
    padding: 0.75rem 1.5rem;
    border-bottom: 1px solid rgba(240,185,11,0.1);
  }

  .nav-link[aria-current="page"] {
    background: rgba(240,185,11,0.1);
    border-left: 3px solid var(--wukong-gold);
  }

  .cta-btn {
    display: none; /* hide CTA in mobile header, could be moved to nav but keep simple */
  }

  .footer-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer-links ul {
    flex-direction: row;
    justify-content: center;
    gap: 1rem;
  }

  .section-title {
    font-size: 1.75rem;
  }
}

@media (max-width: 480px) {
  .brand {
    font-size: 1.3rem;
  }
}

/* Tablet adjustment */
@media (min-width: 769px) and (max-width: 1024px) {
  .nav-list {
    gap: 1rem;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}