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

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

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

ul {
  list-style: none;
  padding: 0;
}

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

a {
  color: inherit;
  text-decoration: none;
}

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

:root {
  --color-field: #0A1428;
  --color-panel: #12224A;
  --color-primary: #00FF88;
  --color-primary-dark: #00CC66;
  --color-accent: #FF7A1A;
  --color-text: #F5F7FF;
  --color-muted: #9FA9C7;
  --color-border: #1D3B6E;
  --color-grid: #1E2D4F;
  --color-night: #05080F;
  --font-heading: "DIN Condensed", "Bebas Neue", "Noto Sans SC", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --max-width: 1440px;
  --header-h: 92px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 48px;
  --space-5: 80px;
  --radius: 24px;
  --radius-sm: 12px;
  --transition: 0.3s ease;
}

body {
  background-color: var(--color-field);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.8;
  overflow-x: hidden;
}

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

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

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

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  padding: 10px 18px;
  background: var(--color-primary);
  color: var(--color-night);
  border-radius: 999px;
  font-weight: 700;
  transform: translateY(-200%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 20, 40, 0.72);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  transition: background 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-accent) 55%, transparent 100%);
  transform: skewX(-20deg);
  transform-origin: left;
  pointer-events: none;
}

.site-header__inner {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 24px;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  position: relative;
  z-index: 1;
  transition: height 0.3s ease;
}

.site-header__brand {
  flex-shrink: 0;
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 2px;
  position: relative;
  padding-left: 16px;
}

.brand::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 8px;
  background: var(--color-primary);
  clip-path: polygon(0 0, 100% 0, 60% 100%, 0 100%);
}

.brand__name {
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 32px;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--color-text);
  text-transform: uppercase;
  transition: font-size 0.3s ease;
}

.brand__slogan {
  font-size: 11px;
  color: var(--color-muted);
  letter-spacing: 0.32em;
  text-transform: uppercase;
  line-height: 1.4;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.main-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  display: block;
  padding: 8px 16px;
  border-radius: 999px;
  color: var(--color-text);
  font-weight: 500;
  font-size: 15px;
  line-height: 1.4;
  white-space: nowrap;
  transition: background 0.2s ease, color 0.2s ease;
}

.nav-link:hover {
  background: rgba(0, 255, 136, 0.12);
  color: var(--color-primary);
}

.nav-link[aria-current="page"] {
  background: var(--color-primary);
  color: var(--color-night);
  font-weight: 700;
}

.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 20px;
  border-radius: 999px;
  background: var(--color-accent);
  color: var(--color-night);
  font-weight: 700;
  font-size: 14px;
  line-height: 1.4;
  box-shadow: 0 0 0 0 rgba(255, 122, 26, 0);
  transition: background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.action-btn::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
}

.action-btn:hover {
  background: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 255, 136, 0.25);
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-panel);
  align-items: center;
  justify-content: center;
  padding: 10px;
}

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

.nav-toggle__line + .nav-toggle__line {
  margin-top: 6px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

.site-header[data-scrolled="true"] {
  background: rgba(5, 8, 15, 0.88);
  box-shadow: 0 12px 30px rgba(5, 8, 15, 0.35);
}

.site-header[data-scrolled="true"] .site-header__inner {
  height: 68px;
}

.site-header[data-scrolled="true"] .brand__name {
  font-size: 26px;
}

.site-header[data-scrolled="true"] .main-nav {
  background: rgba(18, 34, 74, 0.8);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 4px;
  box-shadow: 0 8px 24px rgba(5, 8, 15, 0.4);
}

.site-header[data-scrolled="true"] .nav-link {
  padding: 6px 14px;
  font-size: 14px;
}

.site-header[data-scrolled="true"] .action-btn {
  padding: 6px 16px;
  font-size: 13px;
}

.site-footer {
  position: relative;
  overflow: hidden;
  background: var(--color-night);
  color: var(--color-text);
  padding: 80px 0 0;
}

.site-footer::before {
  content: "三亿体育";
  position: absolute;
  right: -0.05em;
  bottom: -0.2em;
  font-family: var(--font-heading);
  font-size: 18vw;
  font-weight: 800;
  line-height: 1;
  color: rgba(245, 247, 255, 0.03);
  pointer-events: none;
  user-select: none;
}

.site-footer__inner {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 24px;
  position: relative;
  z-index: 1;
}

.footer-top {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 48px;
  padding-bottom: 64px;
}

.footer-brand__link {
  display: inline-block;
  text-decoration: none;
}

.footer-brand__name {
  display: block;
  font-family: var(--font-heading);
  font-size: 56px;
  line-height: 1;
  font-weight: 800;
  color: var(--color-primary);
}

.footer-tagline {
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--color-muted);
}

.footer-trust {
  margin-top: 20px;
  max-width: 42ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--color-muted);
}

.footer-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-col__title {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 16px;
}

.footer-links {
  display: grid;
  gap: 10px;
}

.footer-links a {
  display: inline-block;
  color: var(--color-text);
  font-size: 15px;
  line-height: 1.6;
  transition: color 0.2s ease, transform 0.2s ease;
}

.footer-links a:hover {
  color: var(--color-primary);
  transform: translateX(4px);
}

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding: 24px 0 32px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  align-items: center;
  font-size: 14px;
  color: var(--color-muted);
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
}

.footer-contact__item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 80;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-night);
  font-size: 24px;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 12px 30px rgba(0, 255, 136, 0.3);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(16px);
  transition: opacity 0.3s ease, transform 0.3s ease, background 0.2s ease, visibility 0.3s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
}

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

.container {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 24px;
}

.section {
  position: relative;
  padding-block: clamp(64px, 10vw, 120px);
}

.section--tight {
  padding-block: 48px;
}

.section--dark {
  background: var(--color-night);
}

.section--grid-bg {
  background-image: linear-gradient(rgba(30, 45, 79, 0.3) 1px, transparent 1px), linear-gradient(90deg, rgba(30, 45, 79, 0.3) 1px, transparent 1px);
  background-size: 48px 48px;
}

.section-head {
  margin-bottom: 32px;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1;
  font-weight: 800;
  letter-spacing: 0.01em;
  text-transform: uppercase;
  color: var(--color-text);
}

.section-title--accent {
  color: var(--color-primary);
}

.section-intro {
  max-width: 680px;
  margin-top: 16px;
  color: var(--color-muted);
  font-size: 17px;
  line-height: 1.8;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 24px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.card {
  position: relative;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
  overflow: hidden;
}

.card--accent::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: skewX(-30deg);
}

.card--outline {
  background: transparent;
  border-color: var(--color-grid);
}

.card__title {
  font-family: var(--font-heading);
  font-size: 28px;
  line-height: 1.2;
  font-weight: 700;
  color: var(--color-text);
}

.card__text {
  margin-top: 12px;
  color: var(--color-muted);
  font-size: 15px;
  line-height: 1.8;
}

.card__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 20px;
  color: var(--color-primary);
  font-weight: 600;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.4;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

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

.btn--primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
}

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

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

.btn--accent {
  background: var(--color-accent);
  color: var(--color-night);
}

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

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  padding: 0;
  margin: 0 0 24px;
}

.breadcrumb__item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--color-muted);
}

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--color-primary);
}

.breadcrumb__link {
  color: var(--color-text);
  transition: color 0.2s ease;
}

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

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

.media {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.media--ratio-16-9::before {
  content: "";
  display: block;
  padding-top: 56.25%;
}

.media--ratio-4-3::before {
  content: "";
  display: block;
  padding-top: 75%;
}

.media--ratio-1-1::before {
  content: "";
  display: block;
  padding-top: 100%;
}

.media__img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(5, 8, 15, 0) 40%, rgba(5, 8, 15, 0.8) 100%);
}

.cut-corner {
  clip-path: polygon(0 0, calc(100% - 24px) 0, 100% 24px, 100% 100%, 24px 100%, 0 calc(100% - 24px));
}

.speed-lines {
  position: relative;
}

.speed-lines::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: repeating-linear-gradient(115deg, var(--color-primary) 0 10px, transparent 10px 24px);
  opacity: 0.35;
  pointer-events: none;
}

html.js [data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
  transition-delay: var(--reveal-delay, 0s);
}

html.js [data-reveal][data-revealed] {
  opacity: 1;
  transform: none;
}

.reveal-delay-1 {
  --reveal-delay: 80ms;
}

.reveal-delay-2 {
  --reveal-delay: 160ms;
}

.reveal-delay-3 {
  --reveal-delay: 240ms;
}

@media (max-width: 960px) {
  :root {
    --header-h: 72px;
  }

  .site-header__inner {
    padding-inline: 16px;
  }

  .site-header__actions {
    gap: 12px;
  }

  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: calc(var(--header-h) - 8px);
    left: 16px;
    right: 16px;
    background: var(--color-panel);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 16px;
    box-shadow: 0 20px 50px rgba(5, 8, 15, 0.6);
    display: none;
    max-height: calc(100vh - 120px);
    overflow: auto;
  }

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

  .site-header[data-scrolled="true"] .main-nav {
    border-radius: var(--radius);
    padding: 16px;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }

  .nav-link {
    font-size: 18px;
    padding: 12px 16px;
    text-align: center;
  }

  .site-header[data-scrolled="true"] .nav-link {
    font-size: 18px;
    padding: 12px 16px;
  }

  .brand__name {
    font-size: 26px;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: 32px;
    padding-bottom: 48px;
  }

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

  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-brand__name {
    font-size: 44px;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

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

@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;
  }

  html.js [data-reveal] {
    opacity: 1;
    transform: none;
  }
}