/* ========== Reset & Variables ========== */
*, *::before, *::after {
  box-sizing: border-box;
}

:root {
  --color-bg-deep: #0f1a3a;
  --color-bg-dark: #0a0e27;
  --color-bg-section: #142145;
  --color-neon: #39ff14;
  --color-accent: #ff6b35;
  --color-text-primary: #f2f6fc;
  --color-text-secondary: #aab8d0;
  --color-border-glow: rgba(57, 255, 20, 0.2);
  --gradient-site: linear-gradient(135deg, #0f1a3a 0%, #0a0e27 100%);
  --font-headline: Impact, "Arial Black", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-data: "Courier New", Courier, monospace;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --container-max: 1280px;
  --header-height: 72px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 40px;
  --space-5: 64px;
  --space-6: 96px;
}

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

body {
  margin: 0;
  min-height: 100vh;
  background: var(--gradient-site);
  color: var(--color-text-primary);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

:focus-visible {
  outline: 3px solid var(--color-neon);
  outline-offset: 2px;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.5em;
  font-family: var(--font-headline);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--color-text-primary);
}

p {
  margin: 0 0 1em;
}

ul, ol {
  margin: 0;
  padding: 0;
}

li {
  list-style: none;
}

a {
  color: var(--color-neon);
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
  transition: color 0.2s ease;
}

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

[id] {
  scroll-margin-top: calc(var(--header-height) + 16px);
}

/* ========== Container & Main ========== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.main-content {
  position: relative;
  min-height: 60vh;
  outline: none;
}

#main-content:focus {
  outline: none;
}

/* ========== Grid ========== */
.grid {
  display: grid;
  gap: 24px;
}

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

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

@media (max-width: 1024px) {
  .grid--3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .grid--2,
  .grid--3 {
    grid-template-columns: 1fr;
  }
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 0;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.btn--primary {
  background: var(--color-neon);
  border: 2px solid var(--color-neon);
  color: var(--color-bg-deep);
}

.btn--primary:hover {
  color: var(--color-bg-deep);
  box-shadow: 6px 6px 0 rgba(57, 255, 20, 0.3);
  transform: translate(-2px, -2px);
}

.btn--ghost {
  background: transparent;
  border: 2px solid var(--color-neon);
  color: var(--color-neon);
}

.btn--ghost:hover {
  background: rgba(57, 255, 20, 0.1);
  color: var(--color-neon);
  box-shadow: 4px 4px 0 rgba(57, 255, 20, 0.15);
}

.btn--accent {
  background: var(--color-accent);
  border: 2px solid var(--color-accent);
  color: var(--color-bg-deep);
}

.btn--accent:hover {
  color: var(--color-bg-deep);
  box-shadow: 6px 6px 0 rgba(255, 107, 53, 0.3);
  transform: translate(-2px, -2px);
}

/* ========== Breadcrumb ========== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 28px;
  padding: 0;
  list-style: none;
  font-size: 14px;
}

.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-text-secondary);
}

.breadcrumb__item:not(:last-child)::after {
  content: '/';
  color: var(--color-neon);
  font-family: var(--font-data);
}

.breadcrumb__link {
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

/* ========== Card ========== */
.card {
  background: var(--color-bg-section);
  border: 2px solid var(--color-border-glow);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.25);
  padding: 28px;
}

.card--highlight {
  border-color: var(--color-neon);
  box-shadow: 8px 8px 0 rgba(57, 255, 20, 0.1);
}

.card__title {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 900;
}

.card__body {
  margin: 0;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

@media (max-width: 640px) {
  .card {
    padding: 20px;
  }
}

/* ========== Section Head ========== */
.section-head {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
}

.section-head__bar {
  flex-shrink: 0;
  width: 10px;
  height: 36px;
  background: var(--color-neon);
  box-shadow: 4px 4px 0 rgba(57, 255, 20, 0.2);
  transform: skewX(-15deg);
}

.section-head__body {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.section-head__title {
  margin: 0;
  font-size: 32px;
  line-height: 1.1;
}

.section-head__desc {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 14px;
}

@media (max-width: 640px) {
  .section-head__title {
    font-size: 24px;
  }
}

/* ========== Data Number & Tag ========== */
.data-num {
  font-family: var(--font-data);
  font-weight: 700;
  font-size: 1.1em;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-neon);
}

.tag {
  display: inline-block;
  padding: 4px 12px;
  border: 1px solid var(--color-border-glow);
  background: rgba(57, 255, 20, 0.06);
  color: var(--color-text-primary);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.tag--accent {
  border-color: rgba(255, 107, 53, 0.5);
  background: rgba(255, 107, 53, 0.08);
  color: var(--color-accent);
}

/* ========== Media Frame ========== */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-bg-section) 0%, var(--color-bg-dark) 100%);
  border: 2px solid var(--color-border-glow);
}

.media-frame--16-9 {
  aspect-ratio: 16 / 9;
}

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

.media-frame--1-1 {
  aspect-ratio: 1 / 1;
}

.media-frame::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(-45deg, transparent 0 10px, rgba(57, 255, 20, 0.05) 10px 11px);
  pointer-events: none;
}

.media-frame::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(115deg, transparent 42%, rgba(57, 255, 20, 0.12) 50%, transparent 58%);
  pointer-events: none;
}

.media-frame img,
.media-frame > * {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ========== Skip Link ========== */
.skip-link {
  position: fixed;
  top: -80px;
  left: 16px;
  z-index: 1200;
  display: inline-block;
  padding: 12px 24px;
  background: var(--color-accent);
  color: #fff;
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.4);
  transition: top 0.2s ease;
}

.skip-link:focus-visible {
  top: 16px;
}

/* ========== Site Header ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: linear-gradient(180deg, rgba(10, 14, 39, 0.55) 0%, transparent 100%);
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.site-header.is-scrolled,
.site-header.nav-open {
  background: rgba(10, 14, 39, 0.96);
  border-bottom-color: var(--color-border-glow);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
}

.site-header__progress {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--color-neon) 0%, var(--color-accent) 100%);
  box-shadow: 0 0 12px rgba(57, 255, 20, 0.7);
  z-index: 2;
  pointer-events: none;
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 100%;
}

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

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

.site-brand__box {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  background: var(--color-neon);
  color: var(--color-bg-deep);
  font-family: var(--font-data);
  font-weight: 900;
  font-size: 15px;
  letter-spacing: 0.02em;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
  box-shadow: 4px 4px 0 rgba(57, 255, 20, 0.25);
  transition: box-shadow 0.2s ease;
}

.site-brand:hover .site-brand__box {
  box-shadow: 6px 6px 0 rgba(57, 255, 20, 0.4);
}

.site-brand__name {
  font-family: var(--font-headline);
  font-size: 21px;
  font-weight: 900;
  letter-spacing: 0.1em;
  line-height: 1;
}

.site-brand__ver {
  font-family: var(--font-data);
  font-size: 11px;
  line-height: 1;
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
  padding: 2px 6px;
}

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

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
  margin: 0;
  padding: 0;
}

.site-nav__link {
  position: relative;
  display: block;
  padding: 10px 14px;
  color: var(--color-text-primary);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.05em;
  text-decoration: none;
  transition: color 0.2s ease;
}

.site-nav__link::after {
  content: '';
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 5px;
  height: 2px;
  background: var(--color-neon);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s ease;
}

.site-nav__link:hover,
.site-nav__link[aria-current="page"] {
  color: var(--color-neon);
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 2px solid var(--color-border-glow);
  cursor: pointer;
  position: relative;
  z-index: 1002;
  transition: border-color 0.2s ease;
}

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

.nav-toggle__bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text-primary);
  transition: background 0.2s ease;
}

.nav-toggle:hover .nav-toggle__bar {
  background: var(--color-neon);
}

/* ========== Site Footer ========== */
.site-footer {
  position: relative;
  z-index: 1;
  margin-top: var(--space-6);
  background: linear-gradient(180deg, var(--color-bg-deep) 0%, var(--color-bg-dark) 100%);
  border-top: 2px solid var(--color-border-glow);
}

.site-footer::before {
  content: '';
  position: absolute;
  top: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-neon) 0%, var(--color-neon) 160px, rgba(57, 255, 20, 0.2) 160px, transparent 100%);
  pointer-events: none;
}

.site-footer__inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.4fr;
  gap: 40px;
  padding-top: 56px;
  padding-bottom: 48px;
}

.site-footer__col {
  min-width: 0;
}

.site-footer__col--brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.site-footer__col--contact {
  font-size: 14px;
}

.site-footer__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 16px;
  font-family: var(--font-headline);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: 0.06em;
  color: var(--color-text-primary);
}

.site-footer__claim {
  margin: 0;
  max-width: 34ch;
  color: var(--color-text-secondary);
  font-size: 14px;
  line-height: 1.7;
}

.site-footer__heading {
  margin: 0 0 16px;
  font-family: var(--font-data);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--color-neon);
  text-transform: uppercase;
}

.site-footer__links {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
}

.site-footer__link {
  display: inline-block;
  color: var(--color-text-secondary);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}

.site-footer__link:hover {
  color: var(--color-neon);
  transform: translateX(4px);
}

.site-footer__contact-line,
.site-footer__address,
.site-footer__time {
  margin: 0 0 8px;
  color: var(--color-text-secondary);
  font-size: 14px;
  line-height: 1.7;
}

.site-footer__bottom {
  border-top: 1px solid rgba(242, 246, 252, 0.08);
  padding: 18px 0;
}

.site-footer__bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.site-footer__copyright,
.site-footer__icp {
  margin: 0;
  font-family: var(--font-data);
  font-size: 13px;
  color: var(--color-text-secondary);
}

/* ========== Back to Top ========== */
.to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 990;
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  padding: 0;
  background: var(--color-bg-section);
  border: 2px solid var(--color-neon);
  color: var(--color-neon);
  font-family: var(--font-data);
  font-size: 20px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 0 0 rgba(57, 255, 20, 0);
  opacity: 0;
  transform: translateY(80px);
  pointer-events: none;
  transition: transform 0.3s ease, opacity 0.3s ease, background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.to-top[data-visible] {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
  box-shadow: 0 0 20px rgba(57, 255, 20, 0.15);
}

.to-top:hover {
  background: var(--color-neon);
  color: var(--color-bg-deep);
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .site-footer__inner {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 840px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(320px, 85vw);
    margin: 0;
    padding: calc(var(--header-height) + 24px) 24px 32px;
    background: linear-gradient(180deg, var(--color-bg-section) 0%, var(--color-bg-dark) 100%);
    border-left: 2px solid var(--color-border-glow);
    box-shadow: -16px 0 48px rgba(0, 0, 0, 0.55);
    overflow-y: auto;
    visibility: hidden;
    transform: translateX(105%);
    transition: transform 0.3s ease, visibility 0s linear 0.3s;
    z-index: 1001;
  }

  .site-nav[data-open] {
    visibility: visible;
    transform: translateX(0);
    transition: transform 0.3s ease;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .site-nav__link {
    padding: 14px 16px;
    font-size: 17px;
    border-left: 3px solid transparent;
  }

  .site-nav__link::after {
    display: none;
  }

  .site-nav__link:hover,
  .site-nav__link[aria-current="page"] {
    border-left-color: var(--color-neon);
    background: rgba(57, 255, 20, 0.07);
  }
}

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

  .site-footer__inner {
    grid-template-columns: 1fr;
    gap: 28px;
    padding-top: 40px;
    padding-bottom: 32px;
  }

  .site-footer__bottom-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* ========== Accessibility ========== */
@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;
  }
}