/* ===== 变量与基础 ===== */
:root {
  --ky-bg-deep: #0A192F;
  --ky-bg-panel: #1E3A5F;
  --ky-bg-paper: #F5EFE0;
  --ky-gold: #D4AF37;
  --ky-gold-soft: rgba(212, 175, 55, 0.16);
  --ky-cyan: #00E5FF;
  --ky-cyan-soft: rgba(0, 229, 255, 0.08);
  --ky-orange: #FF8A00;
  --ky-red: #FF3D5A;
  --ky-text-primary: #F0F4F8;
  --ky-text-secondary: #A0AAB8;
  --ky-border: rgba(212, 175, 55, 0.22);
  --ky-border-light: rgba(240, 244, 248, 0.1);
  --ky-font-heading: 'Orbitron', 'Rajdhani', 'Microsoft YaHei', sans-serif;
  --ky-font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --ky-font-data: 'Consolas', 'Courier New', monospace;
  --ky-content-max: 1200px;
  --ky-content-narrow: 880px;
  --ky-transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 120px;
}

body {
  font-family: var(--ky-font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--ky-text-primary);
  background-color: var(--ky-bg-deep);
  background-image:
    linear-gradient(rgba(240, 244, 248, 0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(240, 244, 248, 0.02) 1px, transparent 1px);
  background-size: 40px 40px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

#main-content {
  flex: 1;
  width: 100%;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--ky-font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--ky-text-primary);
}

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

a:hover {
  color: var(--ky-gold);
}

address {
  font-style: normal;
}

ul, ol {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

::selection {
  background: var(--ky-gold);
  color: var(--ky-bg-deep);
}

:focus-visible {
  outline: 2px solid var(--ky-cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ===== 布局工具 ===== */
.container {
  width: 100%;
  max-width: var(--ky-content-max);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: clamp(3rem, 7vw, 6rem) 0;
}

.section-narrow {
  max-width: var(--ky-content-narrow);
  margin: 0 auto;
  padding: 0 24px;
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--ky-font-data);
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ky-cyan);
  margin-bottom: 14px;
}

.kicker::before {
  content: '';
  display: block;
  width: 28px;
  height: 2px;
  background: linear-gradient(90deg, var(--ky-gold), transparent);
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 3rem);
  font-weight: 300;
  letter-spacing: 0.06em;
  line-height: 1.15;
  margin-bottom: 12px;
}

.section-desc {
  color: var(--ky-text-secondary);
  font-size: 1rem;
  line-height: 1.8;
  max-width: 640px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 24px;
  font-family: var(--ky-font-body);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--ky-text-primary);
  border: 1px solid var(--ky-border);
  background: transparent;
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: color var(--ky-transition), background var(--ky-transition), border-color var(--ky-transition), filter var(--ky-transition);
}

.btn:hover {
  border-color: var(--ky-gold);
  color: var(--ky-gold);
  background: var(--ky-gold-soft);
}

.btn-cta {
  background: linear-gradient(135deg, var(--ky-orange), var(--ky-red));
  border: none;
  color: #FFFFFF;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.btn-cta:hover {
  background: linear-gradient(135deg, var(--ky-red), var(--ky-orange));
  color: #FFFFFF;
  border: none;
  filter: brightness(1.08);
}

.btn-ghost {
  border: 1px solid var(--ky-gold);
  color: var(--ky-gold);
}

.btn-ghost:hover {
  background: var(--ky-gold);
  color: var(--ky-bg-deep);
}

/* ===== 越层链接 ===== */
.skip-link {
  position: fixed;
  top: 8px;
  left: -9999px;
  z-index: 300;
  background: var(--ky-gold);
  color: var(--ky-bg-deep);
  font-weight: 700;
  font-size: 0.85rem;
  padding: 10px 18px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
  transition: none;
}

.skip-link:focus {
  left: 8px;
  outline: 2px solid var(--ky-cyan);
  outline-offset: -4px;
}

/* ===== 头部 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 25, 47, 0.96);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.site-header::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--ky-gold) 25%, var(--ky-cyan) 60%, transparent);
  opacity: 0.35;
  pointer-events: none;
}

.header-topbar {
  background: linear-gradient(90deg, var(--ky-bg-deep), var(--ky-bg-panel));
  border-bottom: 1px solid var(--ky-border-light);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--ky-text-secondary);
}

.topbar-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  max-width: var(--ky-content-max);
  margin: 0 auto;
  padding: 4px 24px;
}

.topbar-tagline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}

.topbar-tagline::before {
  content: '';
  width: 18px;
  height: 2px;
  background: var(--ky-gold);
  flex-shrink: 0;
}

.topbar-meta {
  font-family: var(--ky-font-data);
  font-size: 0.7rem;
  color: var(--ky-gold);
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.header-main {
  background: transparent;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  max-width: var(--ky-content-max);
  margin: 0 auto;
  padding: 0 24px;
  min-height: 76px;
  position: relative;
}

/* ===== 品牌 ===== */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand:hover {
  color: inherit;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  font-family: var(--ky-font-heading);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--ky-gold);
  background:
    linear-gradient(135deg, rgba(212, 175, 55, 0.15), transparent 60%),
    var(--ky-bg-panel);
  border: 1px solid var(--ky-gold);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  line-height: 1;
  transition: background var(--ky-transition), color var(--ky-transition);
}

.brand:hover .brand-mark {
  background: linear-gradient(135deg, var(--ky-gold), var(--ky-gold-soft));
  color: var(--ky-bg-deep);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-name {
  font-family: var(--ky-font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--ky-text-primary);
}

.brand-en {
  font-family: var(--ky-font-heading);
  font-size: 0.56rem;
  font-weight: 400;
  letter-spacing: 0.42em;
  text-transform: uppercase;
  color: var(--ky-gold);
  margin-top: 2px;
}

/* ===== 导航 ===== */
.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  position: relative;
  display: inline-block;
  padding: 10px 12px;
  font-family: var(--ky-font-body);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--ky-text-primary);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--ky-transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 4px;
  height: 2px;
  background: linear-gradient(90deg, var(--ky-gold), var(--ky-cyan));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--ky-transition);
}

.nav-link:hover {
  color: var(--ky-cyan);
}

.nav-link:hover::after {
  transform: scaleX(1);
}

.nav-link[aria-current="page"] {
  color: var(--ky-gold);
}

.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  background: linear-gradient(90deg, var(--ky-gold), transparent);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

/* ===== 移动导航按钮 ===== */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--ky-border);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--ky-text-primary);
  transition: transform 0.3s ease, opacity 0.3s ease, background 0.3s ease;
}

.nav-toggle:hover .nav-toggle-bar {
  background: var(--ky-gold);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== 页头与面包屑 ===== */
.page-hero {
  position: relative;
  padding: clamp(3.5rem, 10vw, 7rem) 0 clamp(2.5rem, 6vw, 4rem);
  background: linear-gradient(180deg, rgba(30, 58, 95, 0.35), transparent);
  border-bottom: 1px solid var(--ky-border-light);
}

.page-hero-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 300;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

.page-hero-desc {
  color: var(--ky-text-secondary);
  max-width: 560px;
}

.breadcrumb {
  padding: 16px 0;
  font-size: 0.82rem;
  color: var(--ky-text-secondary);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: '/';
  font-family: var(--ky-font-data);
  font-size: 0.7rem;
  color: var(--ky-gold);
}

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

.breadcrumb-link:hover {
  color: var(--ky-cyan);
}

.breadcrumb-current {
  color: var(--ky-gold);
  font-weight: 600;
}

/* ===== 框景与卡片 ===== */
.hero-window {
  position: relative;
  border: 1px solid var(--ky-gold-soft);
  background: linear-gradient(145deg, rgba(30, 58, 95, 0.35), rgba(10, 25, 47, 0.8));
  clip-path: polygon(0 0, calc(100% - 28px) 0, 100% 28px, 100% 100%, 28px 100%, 0 calc(100% - 28px));
  padding: clamp(2rem, 5vw, 4rem);
}

.hero-window::before,
.hero-window::after {
  content: '';
  position: absolute;
  width: 32px;
  height: 32px;
  pointer-events: none;
  z-index: 1;
}

.hero-window::before {
  top: 8px;
  left: 8px;
  border-top: 2px solid var(--ky-cyan);
  border-left: 2px solid var(--ky-cyan);
}

.hero-window::after {
  bottom: 8px;
  right: 8px;
  border-bottom: 2px solid var(--ky-cyan);
  border-right: 2px solid var(--ky-cyan);
}

.archive-card {
  position: relative;
  background: linear-gradient(145deg, var(--ky-bg-panel), rgba(30, 58, 95, 0.6));
  border: 1px solid var(--ky-border-light);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 16px 100%, 0 calc(100% - 16px));
  padding: 28px;
  transition: border-color var(--ky-transition), transform var(--ky-transition), background var(--ky-transition);
}

.archive-card:hover {
  border-color: var(--ky-gold);
  transform: translateY(-2px);
  background: linear-gradient(145deg, rgba(30, 58, 95, 0.8), rgba(10, 25, 47, 0.9));
}

.data-chip {
  display: inline-block;
  font-family: var(--ky-font-data);
  font-size: 0.82rem;
  color: var(--ky-cyan);
  background: var(--ky-cyan-soft);
  border: 1px solid rgba(0, 229, 255, 0.2);
  padding: 2px 10px;
  letter-spacing: 0.04em;
}

.tag {
  display: inline-block;
  font-family: var(--ky-font-body);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--ky-gold);
  border: 1px solid var(--ky-gold);
  background: transparent;
  padding: 3px 12px;
  text-decoration: none;
  transition: background var(--ky-transition), color var(--ky-transition);
}

.tag:hover {
  background: var(--ky-gold);
  color: var(--ky-bg-deep);
}

.img-frame {
  position: relative;
  overflow: hidden;
  background: var(--ky-bg-panel);
  min-height: 160px;
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 20px 100%, 0 calc(100% - 20px));
}

.img-frame img {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 160px;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.img-frame:hover img {
  transform: scale(1.02);
}

.gold-rule {
  display: block;
  width: 72px;
  height: 2px;
  background: linear-gradient(90deg, var(--ky-gold), var(--ky-red));
  border: none;
  margin: 20px 0;
}

.note-panel {
  background: rgba(212, 175, 55, 0.06);
  border-left: 3px solid var(--ky-gold);
  padding: 16px 20px;
  font-size: 0.9rem;
  color: var(--ky-text-secondary);
  line-height: 1.8;
}

/* ===== 页脚 ===== */
.site-footer {
  position: relative;
  background: linear-gradient(180deg, var(--ky-bg-deep), #060D1A);
  margin-top: auto;
}

.footer-ornament {
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--ky-gold) 15%, var(--ky-red) 35%, var(--ky-cyan) 55%, var(--ky-gold) 80%, transparent);
  opacity: 0.6;
}

.footer-main {
  max-width: var(--ky-content-max);
  margin: 0 auto;
  padding: clamp(3rem, 6vw, 5rem) 24px 2.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 40px;
}

.footer-col {
  min-width: 0;
}

.footer-col-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.brand-footer .brand-mark {
  width: 52px;
  height: 52px;
  font-size: 1.3rem;
}

.brand-footer .brand-name {
  font-size: 1.6rem;
}

.brand-footer .brand-en {
  font-size: 0.6rem;
  letter-spacing: 0.34em;
}

.footer-tagline {
  font-family: var(--ky-font-heading);
  font-size: 0.8rem;
  letter-spacing: 0.24em;
  color: var(--ky-gold);
  text-transform: uppercase;
}

.footer-statement {
  font-size: 0.9rem;
  color: var(--ky-text-secondary);
  line-height: 1.8;
  max-width: 320px;
}

.footer-title {
  font-family: var(--ky-font-body);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--ky-gold);
  text-transform: uppercase;
  margin-bottom: 16px;
  position: relative;
  padding-bottom: 8px;
}

.footer-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 24px;
  height: 2px;
  background: linear-gradient(90deg, var(--ky-gold), transparent);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--ky-text-secondary);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: color var(--ky-transition), padding-left var(--ky-transition);
}

.footer-links a::before {
  content: '>';
  font-family: var(--ky-font-data);
  font-size: 0.7rem;
  color: var(--ky-gold);
  opacity: 0;
  transition: opacity var(--ky-transition);
}

.footer-links a:hover {
  color: var(--ky-cyan);
  padding-left: 8px;
}

.footer-links a:hover::before {
  opacity: 1;
}

.footer-address {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-contact-item {
  font-size: 0.9rem;
  color: var(--ky-text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.footer-contact-label {
  font-family: var(--ky-font-data);
  font-size: 0.72rem;
  color: var(--ky-cyan);
  border: 1px solid var(--ky-border);
  padding: 1px 6px;
  flex-shrink: 0;
  margin-top: 2px;
  transition: border-color var(--ky-transition), color var(--ky-transition);
}

.footer-contact-item:hover .footer-contact-label {
  border-color: var(--ky-gold);
  color: var(--ky-gold);
}

.footer-contact-value {
  font-size: 0.88rem;
  line-height: 1.6;
  word-break: break-all;
}

.footer-bottom {
  background: rgba(0, 0, 0, 0.2);
  border-top: 1px solid var(--ky-border-light);
}

.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  max-width: var(--ky-content-max);
  margin: 0 auto;
  padding: 16px 24px;
  font-size: 0.8rem;
  color: var(--ky-text-secondary);
}

.footer-copyright {
  font-family: var(--ky-font-data);
  font-size: 0.78rem;
}

.footer-icp {
  font-family: var(--ky-font-data);
  font-size: 0.78rem;
  color: var(--ky-gold);
}

.footer-legal {
  display: flex;
  gap: 16px;
}

.footer-legal a {
  font-size: 0.78rem;
  color: var(--ky-text-secondary);
  text-decoration: none;
}

.footer-legal a:hover {
  color: var(--ky-cyan);
}

/* ===== 返回顶部 ===== */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 150;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  line-height: 1;
  color: var(--ky-gold);
  background: var(--ky-bg-panel);
  border: 1px solid var(--ky-gold);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s, background 0.3s ease, color 0.3s ease;
}

.back-top:hover {
  background: var(--ky-gold);
  color: var(--ky-bg-deep);
}

.back-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* ===== 平板 / 移动端 ===== */
@media (max-width: 920px) {
  .nav-toggle {
    display: flex;
  }

  .header-inner {
    min-height: 64px;
    padding: 8px 16px;
  }

  .header-topbar {
    height: auto;
  }

  .topbar-inner {
    padding: 3px 16px;
  }

  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 90;
    background: var(--ky-bg-deep);
    border-bottom: 2px solid var(--ky-gold);
    max-height: 0;
    overflow: hidden;
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.4);
    transition: max-height 0.4s ease;
  }

  .main-nav[data-open] {
    max-height: 480px;
    border-bottom: 2px solid var(--ky-gold);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 4px 16px 16px;
  }

  .nav-link {
    display: block;
    padding: 14px 12px;
    border-bottom: 1px solid var(--ky-border-light);
    font-size: 1rem;
    white-space: normal;
  }

  .nav-link::after {
    display: none;
  }

  .nav-link[aria-current="page"] {
    color: var(--ky-gold);
    background: var(--ky-gold-soft);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 16px;
  }

  .topbar-meta {
    display: none;
  }

  .topbar-inner {
    justify-content: center;
    padding: 3px 16px;
  }

  .header-cta .btn {
    padding: 8px 14px;
    font-size: 0.78rem;
  }

  .btn {
    padding: 8px 16px;
    font-size: 0.85rem;
  }

  .brand-en {
    letter-spacing: 0.28em;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer-bottom-inner {
    justify-content: center;
    text-align: center;
    padding: 16px;
  }

  .footer-legal {
    justify-content: center;
    width: 100%;
  }

  .back-top {
    right: 16px;
    bottom: 16px;
    width: 40px;
    height: 40px;
  }
}

@media (max-width: 380px) {
  .brand-en {
    display: none;
  }

  .header-actions .btn-cta {
    padding: 8px 10px;
    font-size: 0.74rem;
    letter-spacing: 0.06em;
  }
}

/* ===== 动效偏好 ===== */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition: none !important;
    animation: none !important;
  }

  .archive-card:hover {
    transform: none;
  }

  .img-frame:hover img {
    transform: none;
  }

  .back-top {
    transition: none;
  }
}