/* ============ 0. 重置与变量 ============ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-primary: #0F1B2E;
  --bg-secondary: #1A2A3F;
  --bg-deep: #101828;
  --accent: #00FF88;
  --metal: #C0C0C0;
  --gold: #FFD700;
  --white: #FFFFFF;
  --border: #3D4B5F;
  --blue: #0055FF;
  --violet: #8A2BE2;

  --font-headline: 'Orbitron', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;

  --container-max: 1240px;
  --container-pad: 32px;
  --header-h: 64px;
  --transition: 0.2s ease;
}

html {
  background: var(--bg-primary);
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  background:
    radial-gradient(1000px 500px at 85% -10%, rgba(0, 85, 255, 0.07), transparent 65%),
    radial-gradient(700px 400px at 0% 110%, rgba(138, 43, 226, 0.06), transparent 60%),
    var(--bg-primary);
  color: var(--metal);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

i {
  font-style: normal;
}

h1, h2, h3, h4 {
  font-family: var(--font-headline);
  color: var(--white);
  line-height: 1.2;
}

h1 {
  font-size: clamp(2.25rem, 6vw, 4.5rem);
  font-weight: 300;
  letter-spacing: 0.02em;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 400;
}

h3 {
  font-size: 1.3rem;
  font-weight: 500;
}

p {
  margin: 0;
}

ul {
  list-style: none;
}

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

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
}

/* ============ 1. 全局可访问性与动效 ============ */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

::selection {
  background: var(--accent);
  color: var(--bg-primary);
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border: 2px solid var(--bg-primary);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

.page-main {
  display: block;
  min-height: 60vh;
  outline: none;
}

/* ============ 2. 按钮与标签 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border: 1px solid var(--accent);
  background: transparent;
  color: var(--accent);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  line-height: 1;
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
  transition:
    background var(--transition),
    color var(--transition),
    border-color var(--transition);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-primary);
  font-weight: 700;
}

.btn-primary:hover {
  background: transparent;
  color: var(--accent);
}

.btn-outline {
  border-color: var(--border);
  color: var(--white);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-sm {
  padding: 6px 16px;
  font-size: 13px;
  clip-path: polygon(0 0, calc(100% - 9px) 0, 100% 9px, 100% 100%, 0 100%);
}

.term-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 12px;
  border: 1px solid var(--border);
  color: var(--gold);
  font-size: 12px;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.term-chip::before {
  content: '';
  width: 4px;
  height: 4px;
  background: var(--gold);
  flex-shrink: 0;
}

.term-chip--violet {
  color: var(--violet);
  border-color: var(--violet);
}

.term-chip--violet::before {
  background: var(--violet);
}

/* ============ 3. 顶部同步条 ============ */
.sync-bar {
  background: var(--bg-deep);
  border-bottom: 1px solid var(--border);
  color: var(--metal);
  font-size: 12px;
}

.sync-bar-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 5px var(--container-pad);
  display: flex;
  align-items: center;
  gap: 10px;
}

.pulse-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse-dot 2.4s ease-out infinite;
}

.sync-text {
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.sync-meta {
  margin-left: auto;
  color: var(--border);
  font-family: var(--font-headline);
  font-size: 11px;
  letter-spacing: 0.05em;
}

.sync-node {
  color: var(--accent);
}

@keyframes pulse-dot {
  0% { box-shadow: 0 0 0 0 rgba(0, 255, 136, 0.5); }
  70% { box-shadow: 0 0 0 6px rgba(0, 255, 136, 0); }
  100% { box-shadow: 0 0 0 0 rgba(0, 255, 136, 0); }
}

/* ============ 4. 页头与导航 ============ */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 500;
  background: var(--accent);
  color: var(--bg-primary);
  font-weight: 700;
  padding: 10px 18px;
}

.skip-link:focus {
  left: 0;
  color: var(--bg-primary);
}

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--blue), var(--violet));
  z-index: 400;
  pointer-events: none;
  will-change: width;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 27, 46, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 24px;
}

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

.brand-logo {
  position: relative;
  width: 52px;
  height: 40px;
  flex-shrink: 0;
}

.logo-shape {
  position: absolute;
  top: 7px;
  left: 2px;
  width: 22px;
  height: 26px;
  background: var(--accent);
  transform: skewX(-18deg);
  z-index: 1;
}

.logo-ring {
  position: absolute;
  top: 4px;
  right: 0;
  width: 30px;
  height: 30px;
  border: 2px solid var(--metal);
  border-radius: 50%;
}

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

.brand-name {
  font-family: var(--font-headline);
  font-size: 16px;
  font-weight: 600;
  color: var(--white);
  letter-spacing: 0.18em;
}

.brand-tag {
  font-size: 11px;
  color: var(--metal);
  letter-spacing: 0.12em;
}

.main-nav {
  display: block;
}

.nav-list {
  display: flex;
  gap: 2px;
}

.nav-link {
  position: relative;
  display: block;
  padding: 10px 12px;
  color: var(--metal);
  font-size: 14px;
  letter-spacing: 0.04em;
  white-space: nowrap;
  transition: color var(--transition), background var(--transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 3px;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

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

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-link[aria-current="page"] {
  color: var(--accent);
  background: rgba(0, 255, 136, 0.06);
}

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

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 36px;
  padding: 0 12px;
  background: var(--bg-deep);
  border: 1px solid var(--border);
  transition: border-color var(--transition);
}

.search-box:focus-within {
  border-color: var(--accent);
}

.search-icon {
  position: relative;
  width: 14px;
  height: 14px;
  border: 2px solid var(--accent);
  border-radius: 50%;
  flex-shrink: 0;
}

.search-icon::after {
  content: '';
  position: absolute;
  bottom: -5px;
  right: -5px;
  width: 7px;
  height: 2px;
  background: var(--accent);
  transform: rotate(45deg);
}

.search-input {
  width: 160px;
  background: transparent;
  border: none;
  outline: none;
  color: var(--white);
  font-family: var(--font-body);
  font-size: 13px;
}

.search-input::placeholder {
  color: var(--border);
}

.search-input::-webkit-search-cancel-button {
  -webkit-appearance: none;
  appearance: none;
}

.search-input:focus-visible {
  outline: none;
}

.search-kbd {
  font-family: var(--font-headline);
  font-size: 11px;
  color: var(--border);
  border: 1px solid var(--border);
  padding: 1px 6px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 1px solid var(--border);
  background: transparent;
  cursor: pointer;
}

.toggle-line {
  display: block;
  height: 2px;
  background: var(--accent);
  transition: transform var(--transition), opacity var(--transition);
}

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

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

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

/* ============ 5. 页脚 ============ */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  color: var(--metal);
  font-size: 14px;
}

.footer-contact {
  background: var(--bg-secondary);
}

.footer-contact .footer-inner {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 48px;
  align-items: start;
  padding-top: 48px;
  padding-bottom: 40px;
}

.footer-brand-copy {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.brand--footer .brand-name {
  font-size: 18px;
}

.footer-trust {
  max-width: 440px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--metal);
}

.footer-contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 18px 28px;
}

.contact-block {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.contact-label {
  font-size: 12px;
  color: var(--border);
  letter-spacing: 0.06em;
}

.contact-value {
  font-size: 14px;
  color: var(--metal);
  word-break: break-all;
}

.footer-links {
  background: var(--bg-deep);
  border-top: 1px solid var(--border);
}

.footer-links .footer-inner {
  padding-top: 20px;
  padding-bottom: 20px;
}

.footer-link-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 28px;
}

.footer-link-list a {
  display: inline-block;
  padding: 4px 0;
  color: var(--metal);
  font-size: 13px;
}

.footer-link-list a:hover {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
}

.footer-bottom .footer-inner {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px 24px;
  padding-top: 14px;
  padding-bottom: 14px;
}

.footer-icp,
.footer-copy {
  color: var(--border);
  font-size: 13px;
}

.footer-sync {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--accent);
  font-family: var(--font-headline);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.footer-sync .pulse-dot {
  width: 5px;
  height: 5px;
}

.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-deep);
  border: 1px solid var(--border);
  cursor: pointer;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity var(--transition), transform var(--transition), border-color var(--transition);
}

.back-top[data-visible] {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-top:hover {
  border-color: var(--accent);
}

.back-top i {
  width: 10px;
  height: 10px;
  border-top: 2px solid var(--accent);
  border-left: 2px solid var(--accent);
  transform: rotate(45deg);
  margin-top: 4px;
}

/* ============ 6. 页面结构组件 ============ */
.footer-inner,
.section,
.page-head-inner,
.page-breadcrumb {
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--container-pad);
  padding-right: var(--container-pad);
}

.page-head {
  padding: 48px 0 24px;
  border-bottom: 1px solid var(--border);
  position: relative;
}

.page-head-inner {
  padding-bottom: 8px;
}

.page-index {
  font-family: var(--font-headline);
  font-size: 12px;
  color: var(--accent);
  letter-spacing: 0.3em;
  text-transform: uppercase;
}

.page-title {
  margin-top: 8px;
  font-size: clamp(2rem, 5vw, 3.75rem);
  font-weight: 300;
  line-height: 1.1;
}

.page-breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
  padding-top: 16px;
  padding-bottom: 16px;
  font-size: 13px;
  color: var(--border);
}

.page-breadcrumb a {
  color: var(--metal);
}

.page-breadcrumb a:hover {
  color: var(--accent);
}

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

.crumb-sep {
  color: var(--border);
  margin: 0 4px;
}

.section {
  padding-top: 48px;
  padding-bottom: 48px;
}

.section-narrow {
  max-width: 860px;
  padding-top: 40px;
  padding-bottom: 40px;
}

.section-wide {
  max-width: 1440px;
  padding-top: 48px;
  padding-bottom: 48px;
}

.section-head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.section-tag {
  font-family: var(--font-headline);
  font-size: 12px;
  color: var(--accent);
  letter-spacing: 0.2em;
  white-space: nowrap;
}

.section-title {
  font-size: clamp(1.4rem, 3vw, 2rem);
  color: var(--white);
  font-weight: 400;
}

.section-desc {
  max-width: 720px;
  margin-top: 16px;
  color: var(--metal);
}

/* ============ 7. 数据展示组件 ============ */
.data-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.data-card {
  position: relative;
  padding: 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  transition: border-color var(--transition), background var(--transition);
}

.data-card:hover {
  border-color: var(--accent);
  background:
    linear-gradient(135deg, rgba(0, 255, 136, 0.05), rgba(138, 43, 226, 0.05)),
    var(--bg-deep);
}

.data-card-title {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--white);
  font-size: 15px;
  font-weight: 500;
  margin-bottom: 8px;
}

.data-card-value {
  font-family: var(--font-headline);
  font-size: 28px;
  font-weight: 300;
  color: var(--accent);
  letter-spacing: 0.04em;
  line-height: 1.2;
}

.data-card-meta {
  font-size: 12px;
  color: var(--border);
  margin-top: 6px;
}

.cut-panel {
  position: relative;
  padding: 28px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 0 100%);
}

.cut-panel-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-headline);
  font-size: 16px;
  color: var(--white);
  margin-bottom: 12px;
}

.cut-panel-title::before {
  content: '';
  width: 14px;
  height: 14px;
  background: var(--accent);
  clip-path: polygon(0 0, 100% 30%, 100% 100%, 0 70%);
  flex-shrink: 0;
}

.data-line {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 28px 0;
}

.data-line::before,
.data-line::after {
  content: '';
  height: 1px;
  flex: 1;
}

.data-line::before {
  background: var(--border);
}

.data-line::after {
  background: linear-gradient(to right, var(--border), transparent);
}

.data-dot {
  width: 6px;
  height: 6px;
  background: var(--accent);
  transform: rotate(45deg);
  flex-shrink: 0;
}

.ref-list {
  border-top: 1px solid var(--border);
}

.ref-list li {
  border-bottom: 1px solid var(--border);
}

.ref-list a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 4px;
  color: var(--metal);
  transition: color var(--transition), padding-left var(--transition);
}

.ref-list a::before {
  content: '→';
  color: var(--accent);
}

.ref-list a:hover {
  color: var(--accent);
  padding-left: 10px;
}

.step-list {
  counter-reset: step;
}

.step-item {
  counter-increment: step;
  display: flex;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}

.step-item::before {
  content: counter(step, decimal-leading-zero);
  font-family: var(--font-headline);
  font-size: 14px;
  color: var(--accent);
  flex-shrink: 0;
}

.faq-list {
  border-top: 1px solid var(--border);
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-question {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 16px 4px;
  text-align: left;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 500;
  color: var(--white);
  cursor: pointer;
}

.faq-question::after {
  content: '+';
  font-family: var(--font-headline);
  font-size: 18px;
  color: var(--accent);
  flex-shrink: 0;
}

.faq-item[data-open] .faq-question::after {
  content: '−';
}

.faq-answer {
  display: none;
  padding: 0 20px 16px 4px;
  color: var(--metal);
  font-size: 15px;
}

.faq-item[data-open] .faq-answer {
  display: block;
}

/* ============ 8. 图片占位容器 ============ */
.img-panel {
  position: relative;
  min-height: 240px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  overflow: hidden;
}

.img-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 3;
  background:
    linear-gradient(0deg, transparent 47%, var(--border) 48%, var(--border) 52%, transparent 53%),
    linear-gradient(90deg, transparent 47%, var(--border) 48%, var(--border) 52%, transparent 53%);
  background-size: 24px 24px;
  opacity: 0.3;
  pointer-events: none;
}

.img-panel::after {
  content: attr(data-label);
  position: relative;
  z-index: 4;
  font-family: var(--font-headline);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--border);
  text-transform: uppercase;
}

.img-panel img {
  position: absolute;
  inset: 0;
  z-index: 2;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ============ 9. 响应式 ============ */
@media (max-width: 1100px) {
  .search-box {
    display: none;
  }

  .header-inner {
    gap: 16px;
  }
}

@media (max-width: 960px) {
  .header-actions .btn {
    display: none;
  }

  .brand-tag {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--bg-deep);
    border-bottom: 1px solid var(--accent);
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
  }

  .main-nav[data-open] {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

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

  .nav-link {
    padding: 14px 12px;
    border-bottom: 1px solid var(--border);
    font-size: 15px;
  }

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

  .footer-brand-copy {
    max-width: 100%;
  }
}

@media (max-width: 640px) {
  :root {
    --container-pad: 20px;
  }

  .header-inner {
    gap: 10px;
  }

  .brand-name {
    font-size: 14px;
    letter-spacing: 0.1em;
  }

  .brand-logo {
    width: 44px;
  }

  .sync-meta {
    display: none;
  }

  .page-head {
    padding: 32px 0 16px;
  }

  .section-narrow,
  .section,
  .section-wide {
    padding-top: 32px;
    padding-bottom: 32px;
  }

  .section-head {
    flex-direction: column;
    gap: 4px;
    align-items: flex-start;
  }

  .footer-contact .footer-inner {
    padding-top: 32px;
    padding-bottom: 28px;
  }

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

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

/* ============ 10. 减少动效 ============ */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .pulse-dot {
    animation: none;
  }
}