:root {
  --blue-950: #050D1A;
  --blue-900: #0A192F;
  --blue-800: #112B47;
  --blue-700: #17355A;
  --orange-500: #FF6B35;
  --orange-600: #E5541C;
  --green-400: #39FF14;
  --green-600: #1FAF0B;
  --gray-600: #4B5D67;
  --moss-500: #8A9A5B;
  --clay-500: #C8795A;
  --cream-100: #F5F0E6;
  --cream-200: #ECE4D6;
  --gray-900: #1E1E1E;

  --font-heading: 'Anton', 'Impact', 'Arial Narrow', 'Helvetica Neue', sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;

  --container-width: 1280px;
  --radius-pill: 999px;
  --radius-lg: 20px;
  --radius-md: 12px;

  --shadow-header: 0 12px 40px rgba(0, 0, 0, 0.45);
  --shadow-orange: 0 6px 20px rgba(255, 107, 53, 0.4);
  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.35);

  --ease-fast: 0.2s ease;
  --ease-base: 0.35s ease;

  --text-strong: #F5F0E6;
  --text-default: rgba(245, 240, 230, 0.82);
  --text-muted: rgba(245, 240, 230, 0.55);
}

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

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

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--cream-100);
  background: var(--blue-900);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  line-height: 1.08;
  margin: 0 0 0.5em;
  color: var(--cream-100);
}

h1 { font-size: clamp(40px, 6vw, 72px); }
h2 { font-size: clamp(30px, 4vw, 52px); }
h3 { font-size: clamp(20px, 2vw, 28px); }
h4 { font-size: 18px; }

p { margin: 0 0 1em; }

a {
  color: var(--orange-500);
  text-decoration: none;
  transition: color var(--ease-fast);
}

a:hover { color: var(--orange-600); }

ul, ol { margin: 0 0 1em; padding: 0 0 0 1.5em; }

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

button {
  font-family: inherit;
  font-size: inherit;
  border: none;
  cursor: pointer;
  padding: 0;
  background: none;
}

:focus-visible {
  outline: 3px solid var(--green-400);
  outline-offset: 3px;
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

.main-content {
  min-height: 60vh;
}

.section {
  padding: 80px 0;
  position: relative;
}

.section-cream {
  background: var(--cream-100);
  color: var(--gray-900);
}

.section-cream h1,
.section-cream h2,
.section-cream h3,
.section-cream h4 {
  color: var(--gray-900);
}

.section-cream p,
.section-cream .lead {
  color: rgba(30, 30, 30, 0.75);
}

.section-cream .section-title::after {
  background: var(--orange-500);
}

.section-dark {
  background: var(--blue-950);
  color: var(--cream-100);
}

.section-tint {
  background: rgba(255, 107, 53, 0.05);
}

.img-frame {
  position: relative;
  overflow: hidden;
  background: var(--blue-800);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(245, 240, 230, 0.12);
  aspect-ratio: 16 / 10;
}

.img-frame::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.2), transparent 55%);
  pointer-events: none;
}

.img-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: contrast(1.05);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border: 2px solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--ease-fast), background var(--ease-fast), color var(--ease-fast), border-color var(--ease-fast);
}

.btn-primary {
  background: var(--orange-500);
  color: var(--blue-900);
  box-shadow: var(--shadow-orange);
}

.btn-primary:hover {
  background: var(--orange-600);
  color: var(--blue-900);
  transform: translateY(-2px);
}

.btn-secondary {
  background: transparent;
  color: var(--cream-100);
  border-color: rgba(245, 240, 230, 0.4);
}

.btn-secondary:hover {
  border-color: var(--cream-100);
  color: var(--cream-100);
  background: rgba(245, 240, 230, 0.08);
}

.section-title {
  font-size: clamp(32px, 5vw, 56px);
  text-transform: uppercase;
  letter-spacing: 0.02em;
  margin-bottom: 16px;
}

.section-title::after {
  content: '';
  display: block;
  width: 48px;
  height: 4px;
  background: var(--orange-500);
  margin-top: 8px;
  transform: skewX(-20deg);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  list-style: none;
  padding: 0;
  margin: 0 0 24px;
  font-size: 13px;
  color: var(--text-muted);
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: '/';
  color: rgba(245, 240, 230, 0.3);
}

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

.breadcrumb-item a:hover {
  color: var(--orange-500);
}

.breadcrumb-item[aria-current="page"] {
  color: var(--orange-500);
  font-weight: 600;
}

.article-card {
  background: rgba(245, 240, 230, 0.04);
  border: 1px solid rgba(245, 240, 230, 0.08);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: transform var(--ease-base), border-color var(--ease-base), box-shadow var(--ease-base);
}

.article-card:hover {
  transform: translateY(-4px) skewX(-0.5deg);
  border-color: rgba(255, 107, 53, 0.5);
  box-shadow: var(--shadow-card);
}

.article-card h3 {
  margin-bottom: 8px;
}

.article-card p {
  color: var(--text-default);
  font-size: 15px;
  margin-bottom: 0;
}

.skip-link {
  position: fixed;
  top: -140px;
  left: 16px;
  z-index: 3000;
  background: var(--orange-500);
  color: var(--blue-900);
  font-weight: 700;
  font-size: 14px;
  padding: 12px 24px;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  transition: top var(--ease-base);
}

.skip-link:focus {
  top: 0;
  color: var(--blue-900);
}

.site-header {
  position: sticky;
  top: 14px;
  z-index: 1000;
  padding: 0 16px;
  margin-bottom: 32px;
}

.header-inner {
  position: relative;
  max-width: var(--container-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 20px;
  background: rgba(10, 25, 47, 0.94);
  border: 1px solid rgba(245, 240, 230, 0.12);
  border-radius: var(--radius-pill);
  padding: 10px 12px 10px 16px;
  box-shadow: var(--shadow-header);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
  color: var(--cream-100);
}

.brand:hover {
  color: var(--cream-100);
}

.brand-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  background: var(--orange-500);
  color: var(--blue-900);
  font-family: var(--font-heading);
  font-size: 16px;
  letter-spacing: 0.02em;
  clip-path: polygon(20% 0, 100% 0, 80% 100%, 0 100%);
  flex-shrink: 0;
}

.brand-name {
  font-family: var(--font-heading);
  font-size: 24px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  line-height: 1;
  white-space: nowrap;
}

.brand-slogan {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  border-left: 1px solid rgba(245, 240, 230, 0.2);
  padding-left: 12px;
  white-space: nowrap;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
  padding-left: 12px;
  border-left: 1px solid rgba(245, 240, 230, 0.1);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  position: relative;
  display: inline-block;
  padding: 10px 16px;
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--text-default);
  text-decoration: none;
  transition: background var(--ease-fast), color var(--ease-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 4px;
  width: 20px;
  height: 2px;
  background: var(--orange-500);
  transform: translateX(-50%) skewX(-24deg);
  opacity: 0;
  transition: opacity var(--ease-fast);
}

.nav-link:hover {
  background: rgba(255, 107, 53, 0.14);
  color: var(--cream-100);
}

.nav-link:hover::after {
  opacity: 1;
}

.nav-link[aria-current="page"] {
  background: var(--orange-500);
  color: var(--blue-900);
  font-weight: 700;
}

.nav-link[aria-current="page"]::after {
  opacity: 0;
}

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 22px;
  border-radius: var(--radius-pill);
  background: var(--orange-500);
  color: var(--blue-900);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-decoration: none;
  box-shadow: 0 4px 18px rgba(255, 107, 53, 0.4);
  transition: transform var(--ease-fast), box-shadow var(--ease-fast), background var(--ease-fast);
  white-space: nowrap;
}

.header-cta:hover {
  background: var(--orange-600);
  color: var(--blue-900);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(255, 107, 53, 0.5);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(245, 240, 230, 0.2);
  border-radius: var(--radius-md);
  cursor: pointer;
  background: transparent;
  flex-shrink: 0;
}

.nav-toggle-line {
  width: 20px;
  height: 2px;
  background: var(--cream-100);
  border-radius: 2px;
  transition: transform var(--ease-fast), opacity var(--ease-fast);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: translateY(6px) 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(-6px) rotate(-45deg);
}

@media (max-width: 991px) {
  .header-inner {
    padding: 8px 12px;
    gap: 12px;
  }

  .brand-slogan {
    display: none;
  }

  .site-nav {
    display: none;
    flex-direction: column;
    gap: 8px;
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    margin-left: 0;
    padding-left: 0;
    border-left: none;
    background: rgba(10, 25, 47, 0.98);
    border: 1px solid rgba(245, 240, 230, 0.12);
    border-radius: 20px;
    padding: 16px;
    box-shadow: var(--shadow-header);
    max-height: calc(100vh - 100px);
    overflow-y: auto;
  }

  .site-nav[data-open="true"] {
    display: flex;
  }

  .nav-list {
    flex-direction: column;
    width: 100%;
    gap: 4px;
  }

  .nav-link {
    display: block;
    width: 100%;
    text-align: center;
    padding: 14px 16px;
    font-size: 15px;
  }

  .header-cta {
    margin-left: auto;
    padding: 10px 18px;
    font-size: 12px;
  }

  .nav-toggle {
    display: flex;
  }
}

@media (max-width: 600px) {
  .site-header {
    top: 8px;
    padding: 0 10px;
    margin-bottom: 20px;
  }

  .header-inner {
    gap: 8px;
    padding: 8px 10px;
  }

  .brand-mark {
    width: 38px;
    height: 38px;
    font-size: 14px;
  }

  .brand-name {
    font-size: 20px;
  }

  .header-cta {
    padding: 8px 12px;
    font-size: 12px;
  }

  .nav-toggle {
    width: 40px;
    height: 40px;
  }
}

.site-footer {
  position: relative;
  background: linear-gradient(180deg, var(--blue-950) 0%, var(--blue-900) 100%);
  color: var(--text-default);
  margin-top: 96px;
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--orange-500) 0%, var(--green-400) 100%);
  z-index: 2;
}

.site-footer::after {
  content: 'BIYI ARENA';
  position: absolute;
  right: -40px;
  bottom: -20px;
  font-family: var(--font-heading);
  font-size: clamp(80px, 12vw, 200px);
  line-height: 1;
  color: rgba(245, 240, 230, 0.03);
  pointer-events: none;
  letter-spacing: -0.02em;
  white-space: nowrap;
  user-select: none;
}

.footer-container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 64px 24px 0;
  position: relative;
  z-index: 1;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1.2fr 0.8fr 1.2fr;
  gap: 48px;
}

.footer-brand-col {
  max-width: 360px;
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--cream-100);
  margin-bottom: 16px;
}

.footer-logo:hover {
  color: var(--cream-100);
}

.footer-logo-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--orange-500);
  color: var(--blue-900);
  font-family: var(--font-heading);
  font-size: 15px;
  clip-path: polygon(20% 0, 100% 0, 80% 100%, 0 100%);
}

.footer-logo-name {
  font-family: var(--font-heading);
  font-size: 22px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-slogan {
  font-size: 13px;
  font-weight: 500;
  color: var(--orange-500);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

.footer-desc {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 0;
}

.footer-col-title {
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--cream-100);
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
}

.footer-col-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 28px;
  height: 2px;
  background: var(--orange-500);
  transform: skewX(-24deg);
}

.footer-link-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-link-list a {
  color: var(--text-default);
  font-size: 14px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: color var(--ease-fast), transform var(--ease-fast);
}

.footer-link-list a::before {
  content: '→';
  color: var(--orange-500);
  font-size: 12px;
  transform: translateX(-4px);
  opacity: 0;
  transition: opacity var(--ease-fast), transform var(--ease-fast);
}

.footer-link-list a:hover {
  color: var(--orange-500);
  transform: translateX(4px);
}

.footer-link-list a:hover::before {
  opacity: 1;
  transform: translateX(0);
}

.footer-contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 14px;
  color: var(--text-default);
}

.footer-contact-list li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  line-height: 1.5;
  word-break: break-word;
}

.footer-contact-list li::before {
  content: '●';
  color: var(--green-400);
  font-size: 8px;
  margin-top: 6px;
  flex-shrink: 0;
}

.footer-bottom {
  border-top: 1px solid rgba(245, 240, 230, 0.08);
  padding: 20px 0;
  margin-top: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--text-muted);
}

.footer-copyright {
  margin: 0;
}

.footer-icp {
  margin: 0;
}

@media (max-width: 991px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .footer-brand-col {
    grid-column: 1 / -1;
    max-width: none;
  }
}

@media (max-width: 600px) {
  .site-footer {
    margin-top: 64px;
  }

  .footer-container {
    padding: 48px 20px 0;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
}

[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity calc(var(--ease-base) * 1.4), transform calc(var(--ease-base) * 1.4);
  will-change: opacity, transform;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

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