/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; -webkit-text-size-adjust: 100%; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Inter', 'Helvetica Neue', Arial, sans-serif; line-height: 1.6; color: #f0f4f8; background: #0B1A34; min-height: 100vh; }
img, svg { display: block; max-width: 100%; height: auto; }
a { color: #00FF84; text-decoration: none; transition: color 0.2s ease; }
a:hover, a:focus-visible { color: #F5B041; }
ul { list-style: none; }
:focus-visible { outline: 2px solid #00FF84; outline-offset: 2px; }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; } html { scroll-behavior: auto; } }

/* === CSS Variables === */
:root {
  --color-deep-space: #0B1A34;
  --color-deep-blue: #0F2B5C;
  --color-fluorescent-green: #00FF84;
  --color-gold: #F5B041;
  --color-light-blue: #3A6EA5;
  --color-white: #FFFFFF;
  --color-dark-charcoal: #1A1A2E;
  --color-medium-steel: #2D3748;
  --color-bg-primary: var(--color-deep-space);
  --color-text-primary: #f0f4f8;
  --color-text-secondary: #b0c4de;
  --color-accent: var(--color-fluorescent-green);
  --color-accent-alt: var(--color-gold);
  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Source Sans Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --header-height: 80px;
  --content-max-width: 1200px;
  --content-padding: 1.5rem;
  --nav-toggle-size: 40px;
}

/* === Helper: Content Width === */
.content-width { max-width: var(--content-max-width); margin-left: auto; margin-right: auto; padding-left: var(--content-padding); padding-right: var(--content-padding); }

/* === Skip Link === */
.skip-link { position: absolute; top: -999px; left: 0; z-index: 999; background: var(--color-accent); color: var(--color-deep-space); padding: 0.5rem 1rem; font-weight: 700; }
.skip-link:focus { top: 0; }

/* === Progress Bar (滚动进度) === */
.progress-bar { position: fixed; top: 0; left: 0; width: 0%; height: 4px; background: linear-gradient(90deg, var(--color-fluorescent-green), var(--color-gold)); z-index: 1000; transition: width 0.1s linear; }
@media (prefers-reduced-motion: reduce) { .progress-bar { transition: none; } }

/* === Header === */
.site-header { position: sticky; top: 0; z-index: 200; background: linear-gradient(135deg, var(--color-deep-space) 0%, var(--color-deep-blue) 100%); border-bottom: 1px solid rgba(255,255,255,0.08); backdrop-filter: blur(6px); }
.header-inner { max-width: var(--content-max-width); margin: 0 auto; padding: 0 var(--content-padding); display: flex; align-items: center; justify-content: space-between; height: var(--header-height); position: relative; }
.brand { display: flex; align-items: baseline; gap: 1rem; }
.brand-link { font-family: var(--font-heading); font-size: 1.5rem; font-weight: 800; color: var(--color-white); letter-spacing: 1px; font-style: italic; text-shadow: 0 0 8px rgba(0,255,132,0.3); }
.brand-link:hover { color: var(--color-accent); }
.slogan { font-size: 0.8rem; color: var(--color-accent-alt); font-weight: 400; letter-spacing: 2px; text-transform: uppercase; display: none; }
@media (min-width: 768px) { .slogan { display: inline; } }

/* 导航 */
.nav-toggle { display: flex; flex-direction: column; justify-content: center; align-items: center; width: var(--nav-toggle-size); height: var(--nav-toggle-size); background: transparent; border: 1px solid rgba(255,255,255,0.2); border-radius: 6px; cursor: pointer; appearance: none; gap: 5px; padding: 6px; z-index: 210; }
.nav-toggle .toggle-bar { display: block; width: 100%; height: 2px; background: var(--color-white); transition: transform 0.3s ease, opacity 0.3s ease; }
.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(1) { transform: rotate(45deg) translate(3px, 3px); }
.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .toggle-bar:nth-child(3) { transform: rotate(-45deg) translate(3px, -3px); }
@media (prefers-reduced-motion: reduce) { .nav-toggle .toggle-bar { transition: none; } }

.site-nav { position: absolute; top: 100%; left: 0; width: 100%; background: linear-gradient(180deg, var(--color-deep-space), var(--color-deep-blue)); border-bottom: 1px solid rgba(255,255,255,0.08); max-height: 0; overflow: hidden; transition: max-height 0.4s ease, opacity 0.3s ease; opacity: 0; }
.site-nav[data-open] { max-height: 500px; opacity: 1; }
.nav-layer-top { padding: 1rem var(--content-padding) 0.5rem; border-bottom: 1px solid rgba(255,255,255,0.05); }
.nav-tagline { font-size: 0.85rem; color: var(--color-accent-alt); font-style: italic; letter-spacing: 1px; }
.nav-layer-bottom { padding: 0.5rem var(--content-padding) 1rem; }
.nav-list { display: flex; flex-direction: column; gap: 0.5rem; }
.nav-item { }
.nav-link { display: block; padding: 0.6rem 1rem; font-family: var(--font-heading); font-weight: 600; font-size: 1rem; color: var(--color-text-primary); border-radius: 6px; transition: background 0.2s, color 0.2s; }
.nav-link:hover, .nav-link:focus-visible { background: rgba(0,255,132,0.15); color: var(--color-accent); }
.nav-link[aria-current="page"] { background: rgba(0,255,132,0.1); color: var(--color-accent); border-left: 3px solid var(--color-accent); padding-left: calc(1rem - 3px); }

@media (min-width: 768px) {
  .nav-toggle { display: none; }
  .site-nav { position: static; max-height: none; opacity: 1; overflow: visible; background: transparent; border-bottom: none; display: flex; flex-direction: column; width: auto; }
  .header-inner { gap: 2rem; }
  .nav-layer-top { padding: 0; border-bottom: none; }
  .nav-layer-bottom { padding: 0; }
  .nav-list { flex-direction: row; gap: 0.25rem; }
  .nav-link { padding: 0.5rem 1rem; font-size: 0.95rem; }
  .nav-tagline { display: none; }
}

/* === Footer === */
.site-footer { background: linear-gradient(135deg, var(--color-dark-charcoal), var(--color-deep-space)); border-top: 1px solid rgba(255,255,255,0.06); padding: 2.5rem var(--content-padding) 1rem; color: var(--color-text-secondary); }
.footer-inner { max-width: var(--content-max-width); margin: 0 auto; display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
.footer-brand-link { font-family: var(--font-heading); font-size: 1.3rem; font-weight: 800; font-style: italic; color: var(--color-white); text-shadow: 0 0 6px rgba(0,255,132,0.2); }
.footer-brand-link:hover { color: var(--color-accent); }
.footer-nav-list { display: flex; flex-wrap: wrap; gap: 1rem; }
.footer-nav-list a { font-size: 0.9rem; color: var(--color-light-blue); transition: color 0.2s; }
.footer-nav-list a:hover { color: var(--color-accent); }
.footer-contact { display: flex; flex-direction: column; gap: 0.4rem; }
.footer-contact a { color: var(--color-accent); }
.footer-contact a:hover { color: var(--color-accent-alt); }
.footer-legal { font-size: 0.8rem; color: #6c7a8d; line-height: 1.5; }
.icp { margin-bottom: 0.25rem; }
.footer-year { max-width: var(--content-max-width); margin: 1.5rem auto 0; padding-top: 1rem; border-top: 1px solid rgba(255,255,255,0.05); text-align: center; font-size: 0.8rem; color: #5a6a7a; }
@media (min-width: 640px) {
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .footer-contact { grid-column: 1 / -1; }
}
@media (min-width: 1024px) {
  .footer-inner { grid-template-columns: 1fr 1fr 1fr; }
  .footer-contact { grid-column: auto; }
}

/* === 通用按钮、面包屑等基础组件 === */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 0.75rem 1.5rem; font-family: var(--font-heading); font-weight: 700; font-size: 0.95rem; border-radius: 8px; border: none; cursor: pointer; transition: background 0.2s, transform 0.1s, box-shadow 0.2s; background: var(--color-accent); color: var(--color-deep-space); box-shadow: 0 0 12px rgba(0,255,132,0.3); }
.btn:hover { background: #00cc6a; box-shadow: 0 0 20px rgba(0,255,132,0.5); transform: scale(1.02); }
.btn:focus-visible { outline: 2px solid var(--color-accent-alt); outline-offset: 2px; }
.btn-outline { background: transparent; border: 2px solid var(--color-accent); color: var(--color-accent); box-shadow: none; }
.btn-outline:hover { background: var(--color-accent); color: var(--color-deep-space); }

.breadcrumb { display: flex; flex-wrap: wrap; gap: 0.5rem; font-size: 0.85rem; color: var(--color-text-secondary); }
.breadcrumb a { color: var(--color-light-blue); }
.breadcrumb .current { color: var(--color-accent); }

/* === 图像容器基础规则（页面专属使用） === */
.image-container { position: relative; overflow: hidden; border-radius: 8px; background: var(--color-medium-steel); aspect-ratio: 16 / 9; }
.image-container img { width: 100%; height: 100%; object-fit: cover; }
.image-container.loading::before { content: ''; display: block; position: absolute; inset: 0; background: linear-gradient(135deg, var(--color-deep-blue), var(--color-medium-steel)); animation: shimmer 1.5s infinite; }
@keyframes shimmer { 0% { opacity: 0.6; } 50% { opacity: 1; } 100% { opacity: 0.6; } }

/* === 首页特定布局（简略） */
.page-home .hero { padding: 3rem var(--content-padding); background: linear-gradient(135deg, rgba(15,43,92,0.6), transparent); }
.page-home .hero-title { font-family: var(--font-heading); font-size: clamp(2.5rem, 8vw, 4.5rem); font-weight: 900; font-style: italic; line-height: 1.1; color: var(--color-white); text-shadow: 0 0 20px rgba(0,255,132,0.2); }
.page-home .hero-sublime { font-size: 1.2rem; color: var(--color-accent); margin-top: 0.5rem; }

/* === 响应式微调 === */
@media (max-width: 767px) {
  .header-inner { height: 60px; }
  :root { --header-height: 60px; }
  .brand-link { font-size: 1.2rem; }
}