/* ========== 1. 变量与基础 ========== */
:root {
  --color-bg-deep: #050B1A;
  --color-bg-blue: #0A1F4D;
  --color-bg-panel: #101B33;
  --color-primary: #00E88F;
  --color-accent: #9D00FF;
  --color-text: #E6F1FF;
  --color-text-dim: #B0C4DE;
  --color-line: #1F3B66;
  --color-amber: #FFB020;
  --font-display: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", "Cascadia Code", Consolas, "Courier New", monospace;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --header-height: 72px;
  --radius: 16px;
  --radius-sm: 8px;
  --radius-pill: 999px;
  --transition: 0.3s ease;
}

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

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

body {
  min-height: 100vh;
  margin: 0;
  display: flex;
  flex-direction: column;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg-deep);
  background-image:
    linear-gradient(rgba(31, 59, 102, 0.12) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 59, 102, 0.12) 1px, transparent 1px);
  background-size: 44px 44px;
  background-position: center;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  display: block;
  flex: 1;
  outline: none;
}

#main-content {
  outline: none;
}

h1, h2, h3, h4, h5, h6, p, ul, ol, figure, blockquote, dl, dd {
  margin: 0;
  padding: 0;
}

ul, ol {
  list-style: none;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.25s ease;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}

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

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: 4px;
}

[data-hidden] {
  display: none !important;
}

/* ========== 2. 容器与通用布局 ========== */
.container {
  width: 100%;
  max-width: 1280px;
  margin-inline: auto;
  padding-inline: 1.25rem;
}

@media (min-width: 768px) {
  .container {
    padding-inline: 2rem;
  }
}

@media (min-width: 1280px) {
  .container {
    padding-inline: 2.5rem;
  }
}

.section {
  padding-block: 3rem;
}

.section--tight {
  padding-block: 1.5rem;
}

/* ========== 3. 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 600;
  line-height: 1;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease, transform 0.3s ease, color 0.3s ease;
  white-space: nowrap;
}

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

.btn-primary:hover {
  box-shadow: 0 0 24px rgba(0, 232, 143, 0.28);
  transform: translateY(-2px);
}

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

.btn-ghost:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-sm {
  padding: 0.5rem 1.25rem;
  font-size: 0.8125rem;
}

/* ========== 4. 头部 ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(5, 11, 26, 0.88);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--color-line);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  min-height: var(--header-height);
}

.site-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  flex-shrink: 0;
  padding: 0.5rem 0;
}

.site-brand__icon {
  position: relative;
  display: inline-block;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 12px rgba(0, 232, 143, 0.55);
  flex-shrink: 0;
}

.data-pulse::before,
.data-pulse::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  border: 1.5px solid var(--color-primary);
  animation: pulse-ring 2s ease-out infinite;
}

.data-pulse::after {
  animation-delay: 0.65s;
}

.site-brand__name {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  color: var(--color-text);
}

.site-brand__tagline {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.18em;
  color: var(--color-text-dim);
  padding-left: 0.5rem;
  border-left: 1px solid var(--color-line);
}

.site-nav {
  margin-left: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.site-nav__link {
  display: block;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-dim);
  position: relative;
  transition: color 0.25s ease, background-color 0.25s ease;
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0.75rem;
  right: 0.75rem;
  bottom: 0.125rem;
  height: 2px;
  border-radius: 2px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

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

.site-nav__link[aria-current="page"] {
  color: var(--color-text);
  background: rgba(0, 232, 143, 0.06);
}

.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.header-cta {
  padding: 0.5rem 0.875rem;
  font-size: 0.75rem;
}

.header-cta__pulse {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: rgba(5, 11, 26, 0.55);
  flex-shrink: 0;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 9px 10px;
  border-radius: 10px;
  border: 1px solid var(--color-line);
  background: transparent;
  transition: border-color 0.25s ease, background-color 0.25s ease;
}

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

.nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--color-text);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle[data-open] {
  border-color: var(--color-primary);
  background: rgba(0, 232, 143, 0.06);
}

.nav-toggle[data-open] .nav-toggle__bar--top {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[data-open] .nav-toggle__bar--middle {
  opacity: 0;
}

.nav-toggle[data-open] .nav-toggle__bar--bottom {
  transform: translateY(-7px) rotate(-45deg);
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1.25rem;
  z-index: 1100;
  background: var(--color-primary);
  color: var(--color-bg-deep);
  font-size: 0.875rem;
  font-weight: 700;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-pill);
  transition: top 0.3s ease;
}

.skip-link:focus {
  top: 1rem;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  z-index: 1200;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  box-shadow: 0 0 12px rgba(0, 232, 143, 0.45);
  pointer-events: none;
}

/* ========== 5. 响应式头部 ========== */
@media (max-width: 1024px) {
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(5, 11, 26, 0.97);
    border-bottom: 1px solid var(--color-line);
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    margin-left: 0;
    transition: max-height 0.4s ease-out, visibility 0s linear 0.4s;
  }

  .site-nav[data-open] {
    max-height: 440px;
    visibility: visible;
    transition: max-height 0.4s ease-out, visibility 0s;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.75rem 1.25rem 1.25rem;
  }

  .site-nav__link {
    padding: 0.875rem 1rem;
    font-size: 0.9375rem;
    border-radius: 10px;
  }

  .site-nav__link::after {
    left: 1rem;
    right: 1rem;
    bottom: 0.4rem;
  }

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

  .header-cta {
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
  }
}

@media (min-width: 768px) {
  .site-brand__tagline {
    display: inline-block;
  }

  .site-brand__name {
    font-size: 1.125rem;
  }

  .header-cta {
    padding: 0.5rem 1.25rem;
    font-size: 0.8125rem;
  }
}

@media (min-width: 1025px) {
  .site-nav__link:hover::after {
    transform: scaleX(1);
  }
}

/* ========== 6. 页脚 ========== */
.site-footer {
  position: relative;
  background: var(--color-bg-blue);
  border-top: 1px solid var(--color-line);
  margin-top: 4rem;
}

.site-footer__decor {
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-accent) 160px, transparent 180%);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  padding: 3rem 0 2.5rem;
}

@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 2.5rem 2rem;
  }
}

@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 3rem;
  }
}

.footer-col__title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.22em;
  color: var(--color-primary);
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  margin-bottom: 1rem;
}

.footer-brand__icon {
  display: inline-block;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  box-shadow: 0 0 14px rgba(0, 232, 143, 0.25);
  flex-shrink: 0;
}

.footer-brand__name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  color: var(--color-text);
}

.footer-brand__about {
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--color-text-dim);
}

.footer-brand__trust {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  margin-top: 1.25rem;
  padding: 0.75rem 1rem;
  background: rgba(5, 11, 26, 0.35);
  border-left: 2px solid var(--color-primary);
  border-radius: 0 10px 10px 0;
  font-size: 0.8125rem;
  line-height: 1.65;
  color: var(--color-text-dim);
}

.footer-brand__trust-icon {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 8px rgba(0, 232, 143, 0.6);
  flex-shrink: 0;
  margin-top: 0.45rem;
}

.footer-links li + li {
  margin-top: 0.5rem;
}

.footer-links a {
  color: var(--color-text-dim);
  font-size: 0.875rem;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-links a:hover {
  color: var(--color-text);
  padding-left: 0.25rem;
}

.footer-contact__item {
  padding: 0.625rem 0;
  border-bottom: 1px solid rgba(31, 59, 102, 0.55);
}

.footer-contact__item:first-child {
  padding-top: 0;
}

.footer-contact__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  color: var(--color-text-dim);
  margin-bottom: 0.2rem;
}

.footer-contact__value {
  font-size: 0.875rem;
  color: var(--color-text);
  word-break: break-all;
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  flex-wrap: wrap;
  padding: 1.5rem 0;
  border-top: 1px solid var(--color-line);
}

.footer-bottom__copy {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
}

.footer-bottom__icp {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-dim);
  letter-spacing: 0.08em;
}

@media (min-width: 640px) {
  .footer-bottom {
    flex-direction: row;
  }
}

/* ========== 7. 面包屑 ========== */
.breadcrumb {
  padding: 1rem 0 0;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  color: var(--color-text-dim);
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
}

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--color-line);
  font-family: var(--font-mono);
}

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

.breadcrumb__link:hover {
  color: var(--color-primary);
}

.breadcrumb__item[aria-current="page"] {
  color: var(--color-text);
  font-weight: 600;
}

/* ========== 8. 章节标题体系 ========== */
.section-header {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: start;
  grid-column-gap: 1.25rem;
  margin-bottom: 2.5rem;
}

.section-number {
  font-family: var(--font-mono);
  font-size: clamp(2.75rem, 6vw, 4.5rem);
  font-weight: 700;
  line-height: 0.9;
  color: var(--color-accent);
  letter-spacing: -0.02em;
  min-width: 2ch;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-top: 0.35rem;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 900;
  line-height: 1.2;
  color: var(--color-text);
  margin-top: 0.5rem;
}

.section-subtitle {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text-dim);
  margin-top: 0.5rem;
  max-width: 720px;
}

.page-header {
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--color-line);
  margin-bottom: 2rem;
}

.page-header__title {
  font-family: var(--font-display);
  font-size: clamp(1.875rem, 5vw, 3.5rem);
  font-weight: 900;
  line-height: 1.15;
  color: var(--color-text);
}

.page-header__desc {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text-dim);
  margin-top: 0.75rem;
  max-width: 760px;
}

/* ========== 9. 数据组件 ========== */
.data-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 640px) {
  .data-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .data-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.data-card {
  position: relative;
  background: var(--color-bg-panel);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.data-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 232, 143, 0.4);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.35), 0 0 20px rgba(0, 232, 143, 0.06);
}

.data-card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding-bottom: 0.875rem;
  border-bottom: 1px solid rgba(31, 59, 102, 0.6);
  margin-bottom: 1rem;
}

.data-card__title {
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-text);
}

.data-card__body {
  font-size: 0.875rem;
  color: var(--color-text-dim);
  line-height: 1.7;
}

.data-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  border: 1px solid rgba(157, 0, 255, 0.45);
  border-radius: 6px;
  padding: 0.2rem 0.55rem;
  background: rgba(157, 0, 255, 0.06);
}

.data-tag--warn {
  color: var(--color-amber);
  border-color: rgba(255, 176, 32, 0.45);
  background: rgba(255, 176, 32, 0.06);
}

.data-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px dashed rgba(31, 59, 102, 0.7);
}

.data-row:last-child {
  border-bottom: none;
}

.data-row__label {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
}

.data-row__value {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

.data-value {
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}

.data-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  background: rgba(0, 232, 143, 0.08);
  border-radius: var(--radius-pill);
  padding: 0.3rem 0.75rem;
}

.data-badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 8px rgba(0, 232, 143, 0.7);
  animation: badge-pulse 1.8s ease-in-out infinite;
}

.data-counter {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

.data-line {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.data-line::before,
.data-line::after {
  content: "";
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-line));
}

.data-line::after {
  background: linear-gradient(90deg, var(--color-line), transparent);
}

.data-line__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 10px rgba(0, 232, 143, 0.6);
  flex-shrink: 0;
}

.tilt-panel {
  transform: rotate(-1.2deg);
  border-radius: 20px;
  border: 1px solid var(--color-line);
  background: var(--color-bg-panel);
}

.tilt-panel--reverse {
  transform: rotate(1.2deg);
}

/* ========== 10. 图片容器 ========== */
.image-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--color-line);
  background: var(--color-bg-blue);
}

.image-frame::before {
  content: "";
  display: block;
  padding-bottom: 56.25%;
}

.image-frame--square::before {
  padding-bottom: 100%;
}

.image-frame--tall::before {
  padding-bottom: 125%;
}

.image-frame img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

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

/* ========== 11. 动画与动效 ========== */
@keyframes pulse-ring {
  0% {
    transform: scale(0.85);
    opacity: 0.7;
  }
  100% {
    transform: scale(1.7);
    opacity: 0;
  }
}

@keyframes badge-pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.5;
    transform: scale(0.8);
  }
}

/* ========== 12. 无障碍与减少动效 ========== */
@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;
  }

  .data-badge::before,
  .data-pulse::before,
  .data-pulse::after {
    animation: none !important;
  }
}