/* ============ 1. CSS 变量 ============ */
:root {
  --color-bg-deep: #080F1E;
  --color-bg-panel: #0E1E30;
  --color-bg-float: #16293F;
  --color-accent-blue: #3C8CFF;
  --color-accent-green: #B7F542;
  --color-accent-orange: #FF8A3C;
  --color-text-bright: #EDF3FB;
  --color-text-dim: #9FB4CC;
  --color-border-fine: #294460;
  --color-data-cyan: #3BE0C9;

  --font-heading: "PingFang SC", "HarmonyOS Sans", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-body: "PingFang SC", "HarmonyOS Sans", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", "Consolas", "Roboto Mono", monospace;

  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 32px;
  --space-xl: 48px;
  --space-2xl: 72px;

  --container-max: 1200px;
  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 8px;

  --transition-fast: 140ms cubic-bezier(0.2, 0, 0.2, 1);
  --transition-base: 180ms cubic-bezier(0.2, 0, 0.2, 1);

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12);
  --shadow-md: 0 3px 10px rgba(0, 0, 0, 0.18);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.25);
  --panel-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03), 0 2px 8px rgba(3, 8, 18, 0.6);

  --focus-ring-color: var(--color-accent-orange);
}

/* ============ 2. Reset ============ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--color-bg-deep);
  color: var(--color-text-bright);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a {
  color: var(--color-accent-blue);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent-green);
}

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--color-text-bright);
}

h1 { font-size: 32px; }
h2 { font-size: 24px; }
h3 { font-size: 20px; }
h4 { font-size: 16px; }

:focus-visible {
  outline: 3px solid var(--focus-ring-color);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

::selection {
  background: rgba(183, 245, 66, 0.3);
  color: var(--color-text-bright);
}

/* ============ 3. 通用工具 ============ */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--space-md);
  padding-right: var(--space-md);
}

.main-content {
  min-height: 60vh;
  padding-top: var(--space-xl);
  padding-bottom: var(--space-2xl);
  position: relative;
  z-index: 1;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ============ 4. 跳转链接 ============ */
.skip-link {
  position: fixed;
  top: 0;
  left: var(--space-md);
  z-index: 9999;
  padding: 8px 16px;
  background: var(--color-accent-green);
  color: var(--color-bg-deep);
  font-size: 14px;
  font-weight: 700;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform var(--transition-fast);
}

.skip-link:focus {
  transform: translateY(0);
  color: var(--color-bg-deep);
  outline: 3px solid var(--color-accent-orange);
}

/* ============ 5. 全站头部 ============ */
.site-header {
  position: relative;
  z-index: 100;
  background: var(--color-bg-deep);
  border-bottom: 1px solid var(--color-border-fine);
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent-green) 0%, var(--color-accent-blue) 50%, var(--color-accent-orange) 100%);
  opacity: 0.85;
  pointer-events: none;
}

.site-header__inner {
  display: flex;
  flex-direction: column;
}

.site-header__top {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) 0;
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--color-text-bright);
  flex-shrink: 0;
}

.site-brand:hover {
  color: var(--color-text-bright);
}

.site-brand__mark {
  position: relative;
  width: 46px;
  height: 46px;
  flex-shrink: 0;
  background: linear-gradient(135deg, var(--color-accent-blue) 8%, #1e5db8 92%);
  clip-path: polygon(22% 0%, 100% 0%, 78% 100%, 0% 100%);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #eaf6ff;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 14px;
  letter-spacing: 0.02em;
}

.site-brand__mark::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(rgba(255, 255, 255, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.06) 1px, transparent 1px);
  background-size: 7px 7px;
  pointer-events: none;
}

.site-brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}

.site-brand__name {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 18px;
  color: var(--color-text-bright);
  letter-spacing: 0.01em;
}

.site-brand__meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--color-text-dim);
  text-transform: uppercase;
  margin-top: 2px;
}

.site-header__statement {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--color-text-dim);
  padding-left: var(--space-sm);
  border-left: 1px solid var(--color-border-fine);
  white-space: nowrap;
}

.site-header__live {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent-green);
  box-shadow: 0 0 0 3px rgba(183, 245, 66, 0.18);
  animation: live-pulse 2s ease-out infinite;
}

@keyframes live-pulse {
  0%, 100% { box-shadow: 0 0 0 3px rgba(183, 245, 66, 0.14); }
  50% { box-shadow: 0 0 0 8px rgba(183, 245, 66, 0.02); }
}

.site-nav-toggle {
  display: none;
  position: relative;
  z-index: 50;
  width: 42px;
  height: 40px;
  margin-left: auto;
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border-fine);
  border-radius: var(--radius-md);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  transition: border-color var(--transition-fast), background var(--transition-fast);
}

.site-nav-toggle:hover {
  border-color: var(--color-accent-blue);
  background: var(--color-bg-float);
}

.site-nav-toggle__lines {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 18px;
  align-items: center;
}

.site-nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text-bright);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast), width var(--transition-fast);
}

.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
  width: 100%;
}

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

.site-nav-toggle[aria-expanded="true"] .site-nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
  width: 100%;
}

.site-nav {
  border-top: 1px solid var(--color-border-fine);
  position: relative;
}

.site-nav::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(41, 68, 96, 0.6), transparent);
  pointer-events: none;
}

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
}

.site-nav__item {
  position: relative;
}

.site-nav__item + .site-nav__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: var(--color-border-fine);
}

.site-nav__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 14px 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text-dim);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition:
    color var(--transition-fast),
    background var(--transition-fast),
    border-color var(--transition-fast);
}

.site-nav__link:hover {
  color: var(--color-text-bright);
  background: rgba(22, 41, 63, 0.5);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-accent-green);
  border-bottom-color: var(--color-accent-green);
  background: rgba(183, 245, 66, 0.03);
}

.site-nav__index {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-text-dim);
  opacity: 0.6;
  letter-spacing: 0.06em;
  transition: opacity var(--transition-fast);
}

.site-nav__link:hover .site-nav__index {
  opacity: 1;
}

.site-nav__link[aria-current="page"] .site-nav__index {
  color: var(--color-accent-green);
  opacity: 1;
}

/* ============ 6. 全站底部 ============ */
.site-footer {
  position: relative;
  margin-top: var(--space-2xl);
  background: var(--color-bg-panel);
  border-top: 1px solid var(--color-border-fine);
  font-size: 14px;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--color-accent-blue), var(--color-accent-green), var(--color-accent-orange));
  opacity: 0.5;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 3fr 2fr 2fr 2fr 3fr;
  gap: var(--space-lg);
  padding: var(--space-xl) 0 var(--space-lg);
}

.site-footer__brand-block {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.site-footer__summary {
  font-size: 14px;
  line-height: 1.75;
  color: var(--color-text-dim);
  max-width: 360px;
}

.site-footer__col {
  display: flex;
  flex-direction: column;
}

.site-footer__title {
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 800;
  color: var(--color-text-bright);
  margin-bottom: var(--space-sm);
  letter-spacing: 0.04em;
}

.site-footer__links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.site-footer__links a {
  color: var(--color-text-dim);
  text-decoration: none;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.site-footer__links a:hover {
  color: var(--color-accent-green);
  padding-left: 4px;
}

.site-footer__contact-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.site-footer__contact-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.site-footer__contact-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-dim);
  opacity: 0.65;
}

.site-footer__contact-value {
  color: var(--color-text-bright);
  line-height: 1.5;
  word-break: break-all;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding: var(--space-sm) 0 var(--space-md);
  border-top: 1px solid var(--color-border-fine);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-dim);
}

.site-footer__copyright,
.site-footer__trust,
.site-footer__icp {
  margin: 0;
}

.site-footer__trust {
  color: var(--color-text-dim);
  opacity: 0.75;
}

.site-footer__icp {
  color: var(--color-text-dim);
}

/* ============ 7. 通用组件 ============ */
.section {
  padding-top: var(--space-xl);
  padding-bottom: var(--space-xl);
}

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}

.section-title {
  font-size: 24px;
  font-weight: 800;
}

.section-index {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--color-accent-blue);
  white-space: nowrap;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--color-accent-blue);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.panel {
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border-fine);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--panel-shadow);
}

.card {
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border-fine);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  box-shadow: var(--shadow-sm);
  transition:
    transform var(--transition-fast),
    border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--color-accent-blue);
  box-shadow: var(--shadow-md);
}

.card__title {
  font-size: 18px;
  font-weight: 800;
  margin-bottom: 8px;
}

.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-dim);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    transform var(--transition-fast),
    box-shadow var(--transition-fast),
    color var(--transition-fast);
}

.btn:active {
  transform: scale(0.98);
}

.btn--primary {
  background: var(--color-accent-green);
  color: var(--color-bg-deep);
  border-color: var(--color-accent-green);
}

.btn--primary:hover {
  background: #c9f763;
  color: var(--color-bg-deep);
  box-shadow: 0 2px 14px rgba(183, 245, 66, 0.2);
}

.btn--outline {
  background: transparent;
  color: var(--color-text-bright);
  border-color: var(--color-accent-blue);
}

.btn--outline:hover {
  background: rgba(60, 140, 255, 0.08);
  color: var(--color-accent-blue);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-dim);
  border-color: transparent;
}

.btn--ghost:hover {
  background: var(--color-bg-float);
  color: var(--color-text-bright);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-dim);
  border: 1px solid var(--color-border-fine);
  border-radius: 999px;
  background: transparent;
  line-height: 1.4;
}

.tag--orange {
  color: var(--color-accent-orange);
  border-color: rgba(255, 138, 60, 0.4);
  background: rgba(255, 138, 60, 0.08);
}

.tag--green {
  color: var(--color-accent-green);
  border-color: rgba(183, 245, 66, 0.3);
  background: rgba(183, 245, 66, 0.06);
}

.tag--blue {
  color: var(--color-accent-blue);
  border-color: rgba(60, 140, 255, 0.4);
  background: rgba(60, 140, 255, 0.08);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-text-dim);
  padding: 10px 0;
  margin-bottom: var(--space-sm);
  border-bottom: 1px solid var(--color-border-fine);
}

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

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

.breadcrumb__sep {
  opacity: 0.5;
}

.breadcrumb__current {
  color: var(--color-text-bright);
  font-weight: 600;
}

.grid {
  display: grid;
  gap: var(--space-md);
}

.grid--cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid--cols-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid--align-start {
  align-items: start;
}

.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border-fine);
  border-radius: var(--radius-md);
  aspect-ratio: 16 / 9;
}

.img-frame--4-3 {
  aspect-ratio: 4 / 3;
}

.img-frame--square {
  aspect-ratio: 1 / 1;
}

.img-frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(60, 140, 255, 0.04) 0%, transparent 45%, rgba(183, 245, 66, 0.03) 100%);
  pointer-events: none;
}

.text-block {
  font-size: 15px;
  line-height: 1.85;
  color: var(--color-text-dim);
}

.text-block h2 {
  font-size: 22px;
  margin-top: var(--space-lg);
  margin-bottom: 12px;
}

.text-block h3 {
  font-size: 18px;
  margin-top: var(--space-md);
  margin-bottom: 8px;
}

.text-block p + p {
  margin-top: var(--space-sm);
}

.text-block a {
  color: var(--color-accent-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.text-block ul {
  list-style: disc;
  padding-left: 22px;
  margin-top: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.text-block li + li {
  margin-top: 6px;
}

/* ============ 8. 返回顶部按钮 ============ */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 90;
  width: 44px;
  height: 44px;
  background: var(--color-bg-float);
  border: 1px solid var(--color-border-fine);
  border-radius: var(--radius-lg);
  color: var(--color-text-bright);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition:
    opacity var(--transition-base),
    transform var(--transition-base),
    visibility var(--transition-base),
    background var(--transition-fast),
    border-color var(--transition-fast),
    color var(--transition-fast);
}

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

.back-to-top:hover {
  background: var(--color-accent-blue);
  border-color: var(--color-accent-blue);
  color: var(--color-bg-deep);
}

.back-to-top__icon {
  width: 12px;
  height: 12px;
  border-top: 2px solid currentColor;
  border-left: 2px solid currentColor;
  transform: rotate(45deg);
  margin-top: 4px;
}

/* ============ 9. 交互协议样式 ============ */
[data-scrollspy].is-active {
  color: var(--color-accent-green);
  border-left: 2px solid var(--color-accent-green);
  padding-left: 10px;
  background: rgba(183, 245, 66, 0.04);
}

[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity 180ms cubic-bezier(0.2, 0, 0.2, 1),
    transform 180ms cubic-bezier(0.2, 0, 0.2, 1);
}

[data-reveal].is-revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ============ 10. 响应式 ============ */
@media (max-width: 1023px) {
  .site-header__statement {
    display: none;
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md) var(--space-lg);
  }

  .site-footer__brand-block {
    grid-column: 1 / -1;
  }

  .site-footer__contact {
    grid-column: 1 / -1;
  }
}

@media (max-width: 767px) {
  .site-header__top {
    padding: 12px 0;
  }

  .site-nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-bg-panel);
    border-top: 1px solid var(--color-border-fine);
    box-shadow: var(--shadow-lg);
    max-height: calc(100vh - 72px);
    overflow-y: auto;
  }

  .site-nav__list {
    flex-direction: column;
    padding: 8px 0 12px;
  }

  .site-nav__item + .site-nav__item::before {
    display: none;
  }

  .site-nav__link {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 13px 20px;
    border-left: 3px solid transparent;
    border-bottom: 1px solid rgba(41, 68, 96, 0.5);
  }

  .site-nav__link[aria-current="page"] {
    border-left-color: var(--color-accent-green);
    background: rgba(183, 245, 66, 0.04);
    border-bottom: 1px solid rgba(41, 68, 96, 0.5);
  }

  .site-header[data-open] .site-nav {
    display: block;
  }

  .site-header[data-open] .site-nav-toggle[aria-expanded="true"] {
    border-color: var(--color-accent-green);
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  .site-footer__brand-block,
  .site-footer__contact {
    grid-column: auto;
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .grid--cols-2,
  .grid--cols-3 {
    grid-template-columns: 1fr;
  }
}

/* ============ 11. 减少动态偏好 ============ */
@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;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
}