/* === RESET === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { min-height: 100vh; line-height: 1.6; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
img, picture, video, canvas, svg { display: block; max-width: 100%; }
input, button, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { overflow-wrap: break-word; }
p { overflow-wrap: break-word; }
:focus-visible { outline: 2px solid #FFA500; outline-offset: 2px; }

/* === CSS VARIABLES === */
:root {
  --color-primary: #8A2BE2;
  --color-secondary: #00BFFF;
  --color-accent: #FFA500;
  --color-dark: #0D0D2B;
  --color-light: #F0F0FF;
  --color-text: #E0E0FF;
  --color-heading: #FFFFFF;
  --color-border: #4B0082;
  --color-success: #32CD32;
  --color-warning: #FF6347;
  --font-heading: 'Courier New', 'PingFang SC', monospace;
  --font-body: -apple-system, 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  --font-pixel: 'Courier New', monospace;
  --header-height: 64px;
  --max-width: 1200px;
  --grid-gap: 1.5rem;
  --color-bg: #0D0D2B;
  --color-surface: #1A1A3E;
}

/* === CHINESE TYPOGRAPHY === */
body {
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--color-heading);
  font-weight: 700;
  line-height: 1.2;
}
h1 { font-size: 2.5rem; letter-spacing: 0.02em; }
h2 { font-size: 1.75rem; letter-spacing: 0.02em; }
h3 { font-size: 1.25rem; }
.section-title {
  position: relative;
  display: inline-block;
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
}
.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
}
.note--rotated {
  display: inline-block;
  font-family: var(--font-pixel);
  font-size: 0.75rem;
  color: var(--color-secondary);
  transform: rotate(-90deg);
  transform-origin: left center;
  white-space: nowrap;
  letter-spacing: 0.1em;
}

/* === SKIP LINK === */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  z-index: 10000;
  padding: 0.75rem 1.5rem;
  background: var(--color-dark);
  color: var(--color-heading);
  font-family: var(--font-body);
  font-size: 0.875rem;
  border: 2px solid var(--color-accent);
  transition: top 0.2s;
}
.skip-link:focus {
  top: 0;
  outline: none;
}

/* === CONTAINER === */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* === GRID === */
.grid {
  display: grid;
  gap: var(--grid-gap);
}
.grid--2col { grid-template-columns: 1fr; }
.grid--3col { grid-template-columns: 1fr; }
@media (min-width: 640px) {
  .grid--2col { grid-template-columns: 1fr 1fr; }
  .grid--3col { grid-template-columns: 1fr 1fr 1fr; }
}

/* === CARD === */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 1.5rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(138, 43, 226, 0.2);
}

/* === TAG === */
.tag {
  display: inline-block;
  font-family: var(--font-pixel);
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--color-border);
  color: var(--color-secondary);
  background: transparent;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* === BUTTON === */
.btn {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.875rem;
  padding: 0.75rem 1.75rem;
  border: 1px solid var(--color-border);
  background: transparent;
  color: var(--color-text);
  text-align: center;
  transition: all 0.25s ease;
  cursor: pointer;
}
.btn:hover {
  border-color: var(--color-primary);
  color: var(--color-heading);
}
.btn--primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-heading);
}
.btn--primary:hover {
  background: transparent;
  color: var(--color-primary);
}
.btn--accent {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-dark);
  font-weight: 700;
}
.btn--accent:hover {
  background: transparent;
  color: var(--color-accent);
}

/* === BREADCRUMB === */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.875rem;
  color: var(--color-text);
  padding: 1rem 0;
}
.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.breadcrumb__item + .breadcrumb__item::before {
  content: '/';
  color: var(--color-border);
}
.breadcrumb__link {
  color: var(--color-secondary);
  transition: color 0.2s;
}
.breadcrumb__link:hover {
  color: var(--color-primary);
}
.breadcrumb__item:last-child .breadcrumb__link {
  color: var(--color-text);
  pointer-events: none;
}

/* === PIXEL DOT DECORATION === */
.pixel-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  background: var(--color-primary);
  border: 1px solid var(--color-secondary);
  vertical-align: middle;
  flex-shrink: 0;
}

/* === HEADER === */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background: rgba(13, 13, 43, 0.95);
  border-bottom: 2px solid var(--color-primary);
  z-index: 1000;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
}
.header__brand {
  display: flex;
  align-items: center;
}
.header__logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: var(--color-primary);
  letter-spacing: 0.05em;
  transition: color 0.2s;
}
.header__logo:hover {
  color: var(--color-secondary);
}
.header__logo-text {
  font-weight: 700;
}
.header__nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
  cursor: pointer;
  z-index: 1001;
}
.nav-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-primary);
  transition: transform 0.3s ease, opacity 0.3s ease;
}
.header__nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.header__nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}
.header__nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}
.header__nav {
  display: none;
  position: absolute;
  top: var(--header-height);
  left: 0;
  width: 100%;
  background: rgba(13, 13, 43, 0.98);
  border-bottom: 2px solid var(--color-primary);
  padding: 1rem 1.5rem;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.header__nav[data-open] {
  display: block;
}
.nav__list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.nav__link {
  display: block;
  padding: 0.5rem 0.75rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--color-text);
  border-left: 2px solid transparent;
  transition: all 0.2s ease;
}
.nav__link:hover {
  color: var(--color-secondary);
  border-left-color: var(--color-secondary);
  padding-left: 1rem;
}
.nav__link[aria-current="page"] {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
  font-weight: 700;
}

/* === HEADER DESKTOP === */
@media (min-width: 768px) {
  .header__nav-toggle {
    display: none;
  }
  .header__nav {
    display: flex !important;
    position: static;
    width: auto;
    background: none;
    border-bottom: none;
    padding: 0;
    backdrop-filter: none;
  }
  .nav__list {
    flex-direction: row;
    gap: 0.25rem;
  }
  .nav__link {
    padding: 0.5rem 1rem;
    border-left: none;
    border-bottom: 2px solid transparent;
    font-size: 0.8125rem;
  }
  .nav__link:hover {
    border-left: none;
    border-bottom-color: var(--color-secondary);
    padding-left: 1rem;
  }
  .nav__link[aria-current="page"] {
    border-left: none;
    border-bottom-color: var(--color-accent);
    color: var(--color-accent);
  }
}

/* === FOOTER === */
.site-footer {
  background: var(--color-dark);
  border-top: 2px solid var(--color-primary);
  padding: 2.5rem 1.5rem 1.5rem;
  margin-top: 4rem;
}
.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
}
.footer__brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}
.footer__logo {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  color: var(--color-primary);
  letter-spacing: 0.05em;
  font-weight: 700;
}
.footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border);
}
.footer__link {
  font-size: 0.875rem;
  color: var(--color-text);
  transition: color 0.2s;
  position: relative;
}
.footer__link:hover {
  color: var(--color-secondary);
}
.footer__link + .footer__link::before {
  content: '|';
  color: var(--color-border);
  margin-right: 1.5rem;
}
.footer__info {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.footer__contact,
.footer__address,
.footer__icp {
  font-size: 0.8125rem;
  color: var(--color-text);
  opacity: 0.8;
}
.footer__contact a {
  color: var(--color-secondary);
  transition: color 0.2s;
}
.footer__contact a:hover {
  color: var(--color-accent);
}
.footer__icp {
  margin-top: 0.25rem;
}

/* === PROGRESS BAR === */
.progress-bar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  z-index: 999;
  pointer-events: none;
  transition: width 0.1s linear;
}
@media prefers-reduced-motion: reduce {
  .progress-bar {
    transition: none;
  }
}

/* === SCROLL TOP === */
.scroll-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 998;
  width: 48px;
  height: 48px;
  background: var(--color-dark);
  border: 2px solid var(--color-accent);
  color: var(--color-accent);
  font-family: var(--font-pixel);
  font-size: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
}
.scroll-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.scroll-top:hover {
  background: var(--color-accent);
  color: var(--color-dark);
}
@media prefers-reduced-motion: reduce {
  .scroll-top {
    transition: none;
  }
}

/* === RESPONSIVE === */
@media (max-width: 639px) {
  :root {
    --header-height: 56px;
  }
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.375rem; }
  .container { padding: 0 1rem; }
  .site-footer { padding: 2rem 1rem 1rem; }
  .footer__link + .footer__link::before { display: none; }
  .footer__links { flex-direction: column; gap: 0.5rem; }
}
@media (min-width: 640px) and (max-width: 1023px) {
  :root {
    --header-height: 60px;
  }
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
}
@media (min-width: 1024px) {
  :root {
    --header-height: 68px;
  }
  h1 { font-size: 2.5rem; }
  h2 { font-size: 1.75rem; }
}

/* === REDUCED MOTION === */
@media prefers-reduced-motion: reduce {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  html { scroll-behavior: auto; }
  .card:hover { transform: none; }
  .scroll-top { transition: none; }
}

/* === ACCESSIBLE === */
@media (prefers-contrast: more) {
  .nav__link[aria-current="page"] { text-decoration: underline; }
  .footer__link { text-decoration: underline; }
}

/* === IMAGE CONTAINER BASE === */
.img-container {
  position: relative;
  overflow: hidden;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}
.img-container::before {
  content: '';
  display: block;
  padding-top: 56.25%;
}
.img-container img,
.img-container .img-placeholder {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.img-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-dark) 0%, var(--color-surface) 100%);
  color: var(--color-border);
  font-family: var(--font-pixel);
  font-size: 0.75rem;
  border: 1px dashed var(--color-border);
}

/* === UTILITY === */
.text-center { text-align: center; }
.text-secondary { color: var(--color-secondary); }
.text-accent { color: var(--color-accent); }
.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.p-1 { padding: 1rem; }
.p-2 { padding: 2rem; }