:root {
  --color-bg: #0D0221;
  --color-primary: #FFD700;
  --color-secondary: #00E5FF;
  --color-danger: #8B0000;
  --color-text: #F5F5F5;
  --color-text-dim: #B0B0B0;
  --color-card: #1A0B2E;
  --gradient-accent: linear-gradient(135deg, #FFD700, #00E5FF);
  --gradient-bg: linear-gradient(180deg, #0D0221 0%, #1A0B2E 100%);
  --font-headline: 'Noto Serif SC', 'Source Han Serif SC', 'Songti SC', 'SimSun', serif;
  --font-body: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', monospace;
  --radius-lg: 20px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --radius-pill: 999px;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2rem;
  --space-6: 3rem;
  --space-7: 4rem;
  --space-8: 6rem;
  --container-width: 1240px;
  --header-upper-height: 36px;
  --header-main-height: 72px;
  --transition: 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --shadow-primary: 0 4px 20px rgba(255, 215, 0, 0.25);
  --shadow-secondary: 0 0 20px rgba(0, 229, 255, 0.2);
  --shadow-card: 0 6px 30px rgba(255, 215, 0, 0.08);
  --glow-text: 0 0 12px rgba(255, 215, 0, 0.6);
  --glow-secondary: 0 0 12px rgba(0, 229, 255, 0.5);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 215, 0, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 215, 0, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: -1;
}

img, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-secondary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-primary);
}

button {
  font-family: inherit;
}

:focus-visible {
  outline: 3px solid var(--color-secondary);
  outline-offset: 3px;
  border-radius: 4px;
}

#main-content {
  scroll-margin-top: 120px;
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

.main-content {
  min-height: 60vh;
  padding: var(--space-6) 0 var(--space-8);
}

.section {
  margin-bottom: var(--space-7);
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 3000;
  padding: 10px 24px;
  background: var(--color-primary);
  color: var(--color-bg);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-primary);
  transition: top 0.3s ease;
}

.skip-link:focus-visible {
  top: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13, 2, 33, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: transparent;
  z-index: 1100;
  pointer-events: none;
}

.scroll-progress-bar {
  display: block;
  height: 100%;
  width: 0%;
  background: var(--gradient-accent);
  box-shadow: 0 0 10px rgba(255, 215, 0, 0.7);
  border-radius: 0 3px 3px 0;
  transition: width 0.1s linear;
}

.header-upper {
  background: rgba(13, 2, 33, 0.9);
  border-bottom: 1px solid rgba(255, 215, 0, 0.12);
  font-size: 0.875rem;
  color: var(--color-text-dim);
}

.header-upper-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: var(--header-upper-height);
  gap: var(--space-3);
}

.brand-tagline {
  letter-spacing: 0.08em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-size: 0.8rem;
}

.favorite-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: none;
  border: 1px solid rgba(255, 215, 0, 0.4);
  border-radius: var(--radius-pill);
  padding: 2px 14px;
  color: var(--color-primary);
  font-size: 0.78rem;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.favorite-btn:hover {
  background: rgba(255, 215, 0, 0.15);
  box-shadow: var(--shadow-primary);
}

.favorite-btn--active {
  background: rgba(255, 215, 0, 0.25);
  box-shadow: var(--shadow-primary);
}

.favorite-icon {
  font-size: 0.9rem;
  line-height: 1;
}

.header-main {
  background: rgba(13, 2, 33, 0.9);
  border-bottom: 1px solid rgba(0, 229, 255, 0.15);
}

.header-main-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  height: var(--header-main-height);
}

.site-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}

.site-logo:hover {
  color: inherit;
}

.logo-hex {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 38px;
  background: linear-gradient(135deg, rgba(255, 215, 0, 0.2), rgba(0, 229, 255, 0.1));
  border: 2px solid var(--color-primary);
  clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
  color: var(--color-primary);
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 1.3rem;
  line-height: 1;
  text-shadow: var(--glow-text);
  transition: all var(--transition);
}

.site-logo:hover .logo-hex {
  background: linear-gradient(135deg, rgba(255, 215, 0, 0.4), rgba(0, 229, 255, 0.2));
  box-shadow: 0 0 20px rgba(255, 215, 0, 0.4);
}

.logo-hex--small {
  width: 34px;
  height: 30px;
  font-size: 1rem;
  border-width: 1.5px;
}

.logo-text {
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 1.4rem;
  color: var(--color-text);
  letter-spacing: 0.05em;
}

.site-logo:hover .logo-text {
  color: var(--color-primary);
  text-shadow: var(--glow-text);
}

.site-nav .nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
}

.nav-head {
  display: none;
}

.nav-link {
  position: relative;
  display: inline-block;
  padding: 8px 16px;
  color: var(--color-text);
  font-size: 0.95rem;
  font-weight: 400;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  transition: all var(--transition);
}

.nav-link:hover {
  color: var(--color-primary);
  background: rgba(255, 215, 0, 0.08);
  text-shadow: var(--glow-text);
}

.nav-link[aria-current="page"] {
  color: var(--color-primary);
  background: rgba(255, 215, 0, 0.1);
  border-color: rgba(255, 215, 0, 0.35);
  text-shadow: var(--glow-text);
  box-shadow: inset 0 0 12px rgba(255, 215, 0, 0.05);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  background: none;
  border: 1px solid rgba(255, 215, 0, 0.4);
  border-radius: var(--radius-md);
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
  transition: all var(--transition);
}

.nav-toggle:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-primary);
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-primary);
  border-radius: 2px;
  transition: all var(--transition);
}

.site-footer {
  position: relative;
  background: var(--gradient-bg);
  border-top: 1px solid rgba(255, 215, 0, 0.2);
  padding-top: var(--space-6);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-accent);
  box-shadow: 0 0 20px rgba(255, 215, 0, 0.4);
  z-index: 2;
}

.site-footer::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 215, 0, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 215, 0, 0.03) 1px, transparent 1px);
  background-size: 44px 44px;
  pointer-events: none;
  z-index: 0;
}

.site-footer > .container {
  position: relative;
  z-index: 1;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.6fr;
  gap: var(--space-5);
  padding-bottom: var(--space-5);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  width: fit-content;
}

.footer-logo:hover .logo-text {
  color: var(--color-primary);
  text-shadow: var(--glow-text);
}

.footer-desc {
  font-size: 0.9rem;
  color: var(--color-text-dim);
  line-height: 1.8;
  max-width: 340px;
}

.footer-title {
  font-family: var(--font-headline);
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.06em;
  margin-bottom: var(--space-3);
  text-shadow: var(--glow-text);
  position: relative;
  padding-bottom: 8px;
}

.footer-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 28px;
  height: 2px;
  background: var(--gradient-accent);
  border-radius: 2px;
}

.footer-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-list a {
  color: var(--color-text-dim);
  font-size: 0.9rem;
  transition: all var(--transition);
}

.footer-list a:hover {
  color: var(--color-secondary);
  text-shadow: var(--glow-secondary);
  padding-left: 4px;
}

.footer-contact-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 0.9rem;
}

.footer-contact-list li {
  display: flex;
  gap: 10px;
  line-height: 1.6;
}

.contact-label {
  color: var(--color-text-dim);
  flex-shrink: 0;
  min-width: 32px;
  font-size: 0.8rem;
  letter-spacing: 0.04em;
}

.contact-label::after {
  content: ':';
  color: var(--color-primary);
}

.footer-contact-list span:last-child {
  color: var(--color-text);
  word-break: break-all;
}

.footer-trust {
  position: relative;
  z-index: 1;
  border-top: 1px solid rgba(255, 215, 0, 0.08);
  border-bottom: 1px solid rgba(255, 215, 0, 0.08);
  padding: 12px 0;
  background: rgba(13, 2, 33, 0.5);
}

.footer-trust p {
  font-size: 0.82rem;
  color: var(--color-text-dim);
  text-align: center;
  letter-spacing: 0.03em;
}

.footer-bottom {
  position: relative;
  z-index: 1;
  padding: 16px 0 20px;
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 24px;
  font-size: 0.8rem;
  color: var(--color-text-dim);
}

.footer-bottom p {
  margin: 0;
}

.footer-icp a {
  color: var(--color-text-dim);
  font-size: 0.8rem;
}

.footer-icp a:hover {
  color: var(--color-primary);
  text-shadow: var(--glow-text);
}

.footer-guide {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  opacity: 0.8;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 28px;
  border-radius: var(--radius-pill);
  border: none;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition);
  line-height: 1.4;
}

.btn-primary {
  background: var(--gradient-accent);
  color: var(--color-bg);
  box-shadow: 0 0 24px rgba(255, 215, 0, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 32px rgba(255, 215, 0, 0.5);
  color: var(--color-bg);
}

.btn-primary:active {
  transform: translateY(0);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  padding: 14px 0;
  font-size: 0.85rem;
  color: var(--color-text-dim);
}

.breadcrumb li + li::before {
  content: '›';
  margin-right: 8px;
  color: var(--color-text-dim);
  opacity: 0.6;
}

.breadcrumb a {
  color: var(--color-secondary);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

.breadcrumb [aria-current="page"] {
  color: var(--color-text);
}

.page-title {
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: clamp(2rem, 4vw, 3.2rem);
  color: var(--color-text);
  line-height: 1.2;
  letter-spacing: 0.04em;
  text-shadow: 0 0 20px rgba(255, 215, 0, 0.3);
  margin-bottom: var(--space-3);
}

.page-title::after {
  content: '';
  display: block;
  width: 64px;
  height: 3px;
  background: var(--gradient-accent);
  border-radius: 3px;
  margin-top: 12px;
  box-shadow: 0 0 12px rgba(255, 215, 0, 0.5);
}

.page-abstract {
  font-size: 1.05rem;
  color: var(--color-text-dim);
  max-width: 640px;
  line-height: 1.8;
  margin-bottom: var(--space-5);
}

.card {
  background: var(--color-card);
  border: 1px solid rgba(255, 215, 0, 0.12);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-card);
  transition: all var(--transition);
}

.card:hover {
  border-color: rgba(255, 215, 0, 0.3);
  box-shadow: 0 8px 40px rgba(255, 215, 0, 0.15);
  transform: translateY(-3px);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(255, 215, 0, 0.3);
  background: transparent;
  color: var(--color-text-dim);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-body);
}

.chip:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  box-shadow: 0 0 14px rgba(255, 215, 0, 0.2);
}

.chip[data-active] {
  background: var(--gradient-accent);
  color: var(--color-bg);
  border-color: transparent;
  font-weight: 500;
  box-shadow: 0 0 18px rgba(255, 215, 0, 0.35);
}

.accordion {
  border: 1px solid rgba(255, 215, 0, 0.12);
  border-radius: var(--radius-lg);
  background: var(--color-card);
  overflow: hidden;
}

.accordion-item {
  border-bottom: 1px solid rgba(255, 215, 0, 0.08);
}

.accordion-item:last-child {
  border-bottom: none;
}

.accordion-header {
  width: 100%;
  background: none;
  border: none;
  padding: 18px 20px;
  font-size: 0.98rem;
  font-weight: 400;
  color: var(--color-text);
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  transition: all var(--transition);
  font-family: var(--font-body);
}

.accordion-header:hover {
  color: var(--color-primary);
  background: rgba(255, 215, 0, 0.04);
}

.accordion-icon {
  font-size: 1.2rem;
  transition: transform var(--transition);
  flex-shrink: 0;
  color: var(--color-primary);
}

.accordion-item[data-open] .accordion-icon {
  transform: rotate(45deg);
}

.accordion-panel {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition);
}

.accordion-item[data-open] .accordion-panel {
  max-height: 600px;
}

.accordion-panel-inner {
  padding: 0 20px 20px;
  color: var(--color-text-dim);
  font-size: 0.92rem;
  line-height: 1.8;
}

@media (max-width: 1023px) {
  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    width: min(320px, 85vw);
    height: 100dvh;
    background: rgba(13, 2, 33, 0.98);
    border-left: 1px solid rgba(255, 215, 0, 0.25);
    padding: 0;
    transform: translateX(100%);
    transition: transform var(--transition);
    z-index: 200;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }

  .site-nav[data-open] {
    transform: translateX(0);
    box-shadow: -12px 0 40px rgba(13, 2, 33, 0.9);
  }

  .nav-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid rgba(255, 215, 0, 0.15);
    background: rgba(255, 215, 0, 0.06);
  }

  .nav-title {
    font-family: var(--font-headline);
    font-weight: 700;
    color: var(--color-primary);
    text-shadow: var(--glow-text);
  }

  .nav-close {
    width: 36px;
    height: 36px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: 1px solid rgba(255, 215, 0, 0.4);
    border-radius: var(--radius-md);
    color: var(--color-primary);
    font-size: 1.3rem;
    line-height: 1;
    cursor: pointer;
    transition: all var(--transition);
  }

  .nav-close:hover {
    background: rgba(255, 215, 0, 0.15);
    box-shadow: var(--shadow-primary);
  }

  .site-nav .nav-list {
    flex-direction: column;
    padding: 12px 16px;
    gap: 4px;
  }

  .site-nav .nav-link {
    display: block;
    width: 100%;
    padding: 13px 16px;
    font-size: 1rem;
    border-radius: var(--radius-md);
    border: none;
  }

  .site-nav .nav-link[aria-current="page"] {
    background: rgba(255, 215, 0, 0.14);
    border-color: rgba(255, 215, 0, 0.3);
  }

  .nav-toggle[data-open] .nav-toggle-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle[data-open] .nav-toggle-bar:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle[data-open] .nav-toggle-bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-4);
  }

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 767px) {
  .container {
    padding: 0 16px;
  }

  :root {
    --header-upper-height: 32px;
    --header-main-height: 60px;
  }

  .brand-tagline {
    display: none;
  }

  .header-upper-inner {
    justify-content: center;
  }

  .logo-text {
    font-size: 1.15rem;
  }

  .logo-hex {
    width: 36px;
    height: 32px;
    font-size: 1.05rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .footer-bottom-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .footer-guide {
    font-size: 0.7rem;
  }

  .page-title {
    font-size: 1.7rem;
  }

  .page-abstract {
    font-size: 0.95rem;
  }

  .card {
    padding: var(--space-4);
  }
}

@media (min-width: 1024px) {
  .site-nav {
    display: block;
  }

  .site-nav .nav-list {
    display: flex;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  html {
    scroll-behavior: auto;
  }

  .card:hover {
    transform: none;
  }

  .btn-primary:hover {
    transform: none;
  }
}

::selection {
  background: rgba(255, 215, 0, 0.3);
  color: var(--color-text);
}