:root {
  --bd-green: #0B3D2E;
  --bd-gold: #D4AF37;
  --bd-red: #8B0000;
  --bd-cream: #F5F0E6;
  --bd-lgreen: #2E8B57;
  --bd-gray: #A99E8E;
  --bd-orange: #FF6B35;
  --bd-black: rgba(0, 0, 0, 0.8);
  --bd-serif: "Noto Serif SC", "Source Han Serif", "Songti SC", "STSong", serif;
  --bd-sans: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", sans-serif;
  --bd-mono: "Roboto Mono", "SFMono-Regular", "Consolas", monospace;
  --bd-header-h: 88px;
  --bd-radius-xl: 22px;
  --bd-radius-lg: 16px;
  --bd-radius-md: 12px;
  --bd-radius-sm: 8px;
  --bd-space-1: 8px;
  --bd-space-2: 16px;
  --bd-space-3: 24px;
  --bd-space-4: 40px;
  --bd-space-5: 72px;
  --bd-ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--bd-sans);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--bd-cream);
  background-color: var(--bd-green);
  background-image: repeating-linear-gradient(
    45deg,
    rgba(212, 175, 55, 0.032) 0,
    rgba(212, 175, 55, 0.032) 1px,
    transparent 1px,
    transparent 22px
  );
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

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

a {
  color: var(--bd-gold);
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--bd-serif);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.02em;
  text-wrap: balance;
}

address {
  font-style: normal;
}

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

::selection {
  background: var(--bd-gold);
  color: var(--bd-green);
}

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

.skip-link {
  position: fixed;
  top: -80px;
  left: 16px;
  z-index: 1500;
  display: inline-flex;
  align-items: center;
  padding: 10px 22px;
  background: var(--bd-gold);
  color: var(--bd-green);
  font-family: var(--bd-sans);
  font-weight: 700;
  font-size: 0.88rem;
  text-decoration: none;
  border-radius: 0 0 14px 4px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
  transition: top 0.3s var(--bd-ease);
}

.skip-link:focus {
  top: 0;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1400;
  width: 100%;
  height: 3px;
  pointer-events: none;
}

.scroll-progress-bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--bd-gold), var(--bd-orange));
  border-radius: 0 3px 3px 0;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: var(--bd-space-2);
  pointer-events: none;
}

.header-inner {
  position: relative;
  max-width: 1360px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(8px, 2vw, 24px);
  padding: 6px 8px 6px clamp(16px, 3vw, 32px);
  background: rgba(11, 61, 46, 0.9);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border: 1px solid rgba(212, 175, 55, 0.3);
  border-radius: 999px;
  box-shadow:
    0 4px 6px rgba(0, 0, 0, 0.2),
    0 18px 50px rgba(0, 0, 0, 0.28);
  pointer-events: auto;
}

.brand-flag {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  flex-shrink: 0;
}

.brand-ball {
  position: relative;
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, var(--bd-lgreen), var(--bd-green) 72%);
  border: 2px solid var(--bd-gold);
  overflow: hidden;
}

.brand-ball::after {
  content: "";
  position: absolute;
  inset: -30% -70%;
  background: linear-gradient(
    135deg,
    transparent 40%,
    var(--bd-gold) 40%,
    var(--bd-gold) 58%,
    transparent 58%
  );
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-family: var(--bd-serif);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--bd-cream);
  white-space: nowrap;
}

.brand-en {
  font-family: var(--bd-mono);
  font-size: 0.58rem;
  font-weight: 500;
  letter-spacing: 0.26em;
  color: var(--bd-gray);
  text-transform: uppercase;
  white-space: nowrap;
  margin-top: 2px;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  display: block;
  padding: 9px 14px;
  font-family: var(--bd-sans);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: rgba(245, 240, 230, 0.82);
  text-decoration: none;
  border-radius: 999px;
  transition: color 0.25s var(--bd-ease), background 0.25s var(--bd-ease);
}

.nav-link:hover {
  color: var(--bd-gold);
  background: rgba(212, 175, 55, 0.1);
}

.nav-link[aria-current="page"] {
  color: var(--bd-gold);
  background: rgba(212, 175, 55, 0.16);
  box-shadow: inset 0 0 0 1px rgba(212, 175, 55, 0.35);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.btn-upgrade {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  font-family: var(--bd-sans);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1;
  color: var(--bd-green);
  background: var(--bd-orange);
  border-radius: 999px 999px 999px 6px;
  text-decoration: none;
  box-shadow: 0 4px 16px rgba(255, 107, 53, 0.32);
  transition: transform 0.3s var(--bd-ease), box-shadow 0.3s var(--bd-ease), background 0.3s var(--bd-ease);
}

.btn-upgrade::before {
  content: "";
  width: 8px;
  height: 8px;
  background: var(--bd-green);
  transform: rotate(45deg);
  border-radius: 2px;
  transition: transform 0.3s var(--bd-ease);
}

.btn-upgrade:hover {
  background: #ff8355;
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(255, 107, 53, 0.4);
}

.btn-upgrade:hover::before {
  transform: rotate(45deg) scale(1.25);
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: 1px solid rgba(212, 175, 55, 0.45);
  border-radius: 50%;
  cursor: pointer;
  transition: border-color 0.25s var(--bd-ease), background 0.25s var(--bd-ease);
}

.nav-toggle:hover {
  background: rgba(212, 175, 55, 0.12);
  border-color: var(--bd-gold);
}

.nav-toggle-box {
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: center;
}

.toggle-line {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--bd-cream);
  border-radius: 2px;
  transition: transform 0.35s var(--bd-ease), opacity 0.2s var(--bd-ease);
}

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

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

.nav-toggle[aria-expanded="true"] .toggle-line:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.site-footer {
  position: relative;
  z-index: 1;
  margin-top: var(--bd-space-5);
  background-color: #082E22;
  border-top: 1px solid rgba(212, 175, 55, 0.18);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--bd-gold) 0%,
    var(--bd-gold) 140px,
    var(--bd-red) 140px,
    var(--bd-red) 164px,
    transparent 164px
  );
  opacity: 0.85;
}

.footer-top {
  max-width: 1240px;
  margin: 0 auto;
  padding: var(--bd-space-5) 32px var(--bd-space-4);
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.4fr;
  gap: var(--bd-space-5);
}

.footer-brand {
  min-width: 0;
}

.brand-flag--footer {
  margin-bottom: 18px;
}

.brand-flag--footer .brand-ball {
  width: 42px;
  height: 42px;
}

.brand-flag--footer .brand-name {
  font-size: 1.8rem;
  letter-spacing: 0.1em;
}

.footer-tagline {
  max-width: 32em;
  font-size: 0.88rem;
  line-height: 1.85;
  color: var(--bd-gray);
}

.footer-heading {
  position: relative;
  font-family: var(--bd-serif);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--bd-gold);
  padding-bottom: 10px;
  margin-bottom: 16px;
  border-bottom: 1px solid rgba(212, 175, 55, 0.16);
}

.footer-heading::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 30px;
  height: 3px;
  background: var(--bd-red);
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  display: inline-block;
  padding: 2px 0;
  font-size: 0.88rem;
  color: rgba(245, 240, 230, 0.72);
  text-decoration: none;
  transition: color 0.25s var(--bd-ease), transform 0.25s var(--bd-ease);
}

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

.footer-contact .footer-links li {
  font-size: 0.86rem;
  color: rgba(245, 240, 230, 0.68);
  line-height: 1.7;
}

.footer-bottom {
  max-width: 1240px;
  margin: 0 auto;
  padding: 20px 32px;
  border-top: 1px solid rgba(212, 175, 55, 0.14);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  font-size: 0.82rem;
  color: var(--bd-gray);
}

.footer-copy,
.footer-note {
  margin: 0;
}

.to-top-btn {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 1200;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  background: rgba(11, 61, 46, 0.94);
  border: 1px solid var(--bd-gold);
  border-radius: 14px 4px 14px 4px;
  color: var(--bd-gold);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: opacity 0.35s var(--bd-ease), transform 0.35s var(--bd-ease),
              visibility 0.35s, background 0.25s, color 0.25s;
}

.to-top-btn::before {
  content: "↑";
  font-family: var(--bd-mono);
  font-size: 21px;
  font-weight: 700;
  line-height: 1;
}

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

.to-top-btn:hover {
  background: var(--bd-gold);
  color: var(--bd-green);
}

#main-content {
  position: relative;
  z-index: 1;
  min-height: 70vh;
  padding-top: calc(var(--bd-header-h) + var(--bd-space-2));
}

.container {
  width: min(1240px, calc(100% - 48px));
  margin-inline: auto;
}

.content-section {
  padding-block: var(--bd-space-5);
}

.split-layout {
  display: grid;
  grid-template-columns: minmax(260px, 0.8fr) minmax(0, 1.6fr);
  gap: clamp(24px, 5vw, 64px);
  align-items: start;
}

.split-aside {
  position: sticky;
  top: calc(var(--bd-header-h) + 24px);
  z-index: 5;
}

.split-main {
  min-width: 0;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--bd-space-4);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--bd-space-4);
}

.clip-panel {
  background: var(--bd-cream);
  color: var(--bd-green);
  border-radius: 20px 6px 20px 6px;
  padding: clamp(20px, 4vw, 36px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.22);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--bd-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--bd-gold);
}

.kicker::before {
  content: "";
  width: 26px;
  height: 2px;
  background: currentColor;
  flex-shrink: 0;
}

.section-title {
  font-family: var(--bd-serif);
  font-weight: 700;
  font-size: clamp(1.7rem, 3vw, 2.6rem);
  line-height: 1.25;
  color: var(--bd-cream);
  margin-bottom: var(--bd-space-2);
}

.display-title {
  font-family: var(--bd-serif);
  font-weight: 800;
  font-size: clamp(2.6rem, 6vw, 5rem);
  line-height: 1.08;
  letter-spacing: 0.01em;
  color: var(--bd-cream);
  margin-bottom: var(--bd-space-3);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 28px;
  font-family: var(--bd-sans);
  font-weight: 700;
  font-size: 0.93rem;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--bd-green);
  background: var(--bd-gold);
  border: none;
  border-radius: 999px 999px 999px 6px;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.3s var(--bd-ease), transform 0.3s var(--bd-ease),
              box-shadow 0.3s var(--bd-ease);
}

.btn:hover {
  background: #e2c04c;
  transform: translateY(-2px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.25);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
  padding: 0;
  margin: 0 0 var(--bd-space-3);
  font-size: 0.85rem;
}

.breadcrumb a {
  color: var(--bd-gold);
  text-decoration: none;
  transition: color 0.2s var(--bd-ease);
}

.breadcrumb a:hover {
  color: #e2c04c;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.breadcrumb li + li::before {
  content: "/";
  margin: 0 8px;
  color: var(--bd-gray);
}

.img-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: 18px 4px 18px 4px;
  background-color: var(--bd-lgreen);
  background-image:
    radial-gradient(circle at 72% 28%, rgba(212, 175, 55, 0.55) 0%, transparent 36%),
    linear-gradient(135deg, var(--bd-green) 0%, var(--bd-lgreen) 100%);
}

.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(
    -45deg,
    rgba(255, 255, 255, 0.09) 0,
    rgba(255, 255, 255, 0.09) 2px,
    transparent 2px,
    transparent 18px
  );
  pointer-events: none;
}

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

@media (max-width: 1023px) {
  :root {
    --bd-header-h: 82px;
  }

  .nav-toggle {
    display: flex;
  }

  .header-nav {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 10px;
    background: rgba(11, 61, 46, 0.97);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(212, 175, 55, 0.28);
    border-radius: 20px 20px 20px 6px;
    box-shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
    display: none;
    z-index: 100;
  }

  .header-nav[data-open] {
    display: flex;
    animation: navDrop 0.28s var(--bd-ease);
  }

  .header-nav .nav-link {
    padding: 13px 18px;
    font-size: 0.95rem;
    text-align: left;
    border-radius: 12px;
    border-bottom: 1px solid rgba(212, 175, 55, 0.08);
  }

  .header-nav .nav-link:last-child {
    border-bottom: none;
  }

  .split-layout {
    grid-template-columns: 1fr;
  }

  .split-aside {
    position: static;
  }

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

  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: var(--bd-space-4);
    padding: var(--bd-space-4) 24px;
  }
}

@keyframes navDrop {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 767px) {
  :root {
    --bd-header-h: 76px;
  }

  .site-header {
    padding: 10px;
  }

  .header-inner {
    padding-left: 16px;
  }

  .brand-en {
    display: none;
  }

  .brand-name {
    font-size: 1.15rem;
  }

  .btn-upgrade {
    padding: 10px 14px;
    font-size: 0.82rem;
  }

  .btn-upgrade::before {
    width: 6px;
    height: 6px;
  }

  .container {
    width: min(100% - 32px, 1240px);
  }

  .content-section {
    padding-block: var(--bd-space-4);
  }

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

  .footer-top {
    grid-template-columns: 1fr;
    padding: var(--bd-space-4) 20px;
  }

  .footer-bottom {
    padding: 16px 20px;
    flex-direction: column;
    justify-content: center;
    text-align: center;
  }
}

@media (max-width: 600px) {
  .btn-upgrade {
    font-size: 0.76rem;
    padding: 9px 11px;
  }

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

  .brand-ball {
    width: 30px;
    height: 30px;
  }

  .to-top-btn {
    right: 16px;
    bottom: 16px;
    width: 42px;
    height: 42px;
  }
}

@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;
  }
}