@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@300;400;500&family=Inter:wght@200;300;400;500;700;900&display=swap");

:root {
  --washi: #F5F1EA;
  --paper: #FAFAF7;
  --white: #F5F1EA;
  --ink: #0A0A0A;
  --secondary: #6F6A60;
  --whisper: #B5B0A6;
  --vermillion: #C8412A;
  --line: rgba(10, 10, 10, 0.12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; background: var(--washi); }
body {
  min-height: 100vh;
  background: var(--washi);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
::selection { background: var(--ink); color: var(--washi); }

.site-nav,
.chain-nav,
.kicker,
.section-label,
.next-inline {
  font-family: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  text-transform: uppercase;
}

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  justify-content: space-between;
  padding: 22px 8vw;
  color: var(--secondary);
  font-size: 10px;
  letter-spacing: 0.24em;
  pointer-events: none;
}
.site-nav nav {
  display: flex;
  gap: 24px;
  pointer-events: auto;
}
.site-nav a:hover { color: var(--vermillion); }

.chain-nav {
  position: fixed;
  left: 8vw;
  right: 8vw;
  top: 64px;
  z-index: 18;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--washi) 88%, transparent);
  backdrop-filter: blur(8px);
}
.chain-nav a {
  position: relative;
  padding: 14px 16px 12px;
  color: var(--secondary);
  font-size: 9px;
  letter-spacing: 0.18em;
  border-right: 1px solid var(--line);
}
.chain-nav a span {
  display: block;
  margin-top: 5px;
  color: var(--ink);
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: none;
}
.chain-nav a:last-child { border-right: 0; }
.chain-nav a.is-active {
  color: var(--vermillion);
}
.chain-nav a.is-active span {
  color: var(--vermillion);
}
.chain-nav a.is-active::before {
  content: "";
  position: absolute;
  left: 16px;
  bottom: -4px;
  width: 8px;
  height: 8px;
  background: var(--vermillion);
}

main {
  min-height: 100vh;
}
section {
  min-height: 100vh;
  padding: 18vh 8vw 92px;
  position: relative;
}
.section-meta {
  position: absolute;
  top: 124px;
  left: 8vw;
  right: 8vw;
  display: flex;
  justify-content: space-between;
  color: var(--secondary);
  font-family: "IBM Plex Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
}
.kicker {
  display: block;
  color: var(--vermillion);
  font-size: 10px;
  letter-spacing: 0.28em;
  font-weight: 500;
  margin-bottom: 22px;
}
.hero-title {
  max-width: 1180px;
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: clamp(38px, 4.8vw, 78px);
  font-weight: 400;
  line-height: 1.14;
  word-break: keep-all;
  overflow-wrap: normal;
  text-wrap: balance;
}
.hero-subtitle {
  max-width: 1120px;
  margin-top: 10px;
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: clamp(22px, 2.25vw, 38px);
  font-weight: 300;
  line-height: 1.34;
  letter-spacing: 0.01em;
  word-break: keep-all;
  overflow-wrap: normal;
  text-wrap: balance;
}
.hero-lead {
  max-width: 880px;
  margin-top: 26px;
  color: var(--secondary);
  font-size: clamp(16px, 1.25vw, 21px);
  line-height: 2;
  letter-spacing: 0.035em;
}

.content-grid {
  margin-top: 70px;
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: clamp(36px, 6vw, 92px);
  align-items: start;
}
.content-grid > div {
  position: relative;
}
.section-label {
  color: var(--vermillion);
  font-size: 10px;
  letter-spacing: 0.24em;
  font-weight: 500;
  transition: color 180ms ease, letter-spacing 180ms ease;
}
.content-grid > div:hover .section-label {
  color: #FA3A39;
  letter-spacing: 0.27em;
}
.panel-list {
  list-style: none;
  display: grid;
  gap: 16px;
}
.panel-list li {
  border-top: 1px solid var(--line);
  padding: 18px 0 0;
  color: var(--ink);
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: clamp(16px, 1.25vw, 22px);
  font-weight: 300;
  line-height: 1.62;
  word-break: keep-all;
  overflow-wrap: normal;
  text-wrap: balance;
  transition: background 180ms ease, border-color 180ms ease, color 180ms ease, padding-left 180ms ease, box-shadow 180ms ease;
}
.panel-list li:hover {
  border-top-color: rgba(250, 58, 57, 0.52);
  background: linear-gradient(90deg, rgba(250, 58, 57, 0.07), rgba(250, 58, 57, 0));
  box-shadow: inset 3px 0 0 rgba(250, 58, 57, 0.6);
  color: var(--ink);
  padding-left: 12px;
}
.muted-list li {
  color: var(--secondary);
}
.muted-list li:hover {
  color: var(--ink);
}
.black-zone {
  margin: 72px calc(-8vw) -92px;
  padding: clamp(52px, 6vw, 84px) 8vw 92px;
  background: var(--ink);
}
.key-abilities-label {
  margin-bottom: 22px;
  color: #FA3A39;
  font-family: "IBM Plex Mono", monospace;
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
}
.system-grid {
  margin-top: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid rgba(250, 250, 247, 0.14);
  border-left: 1px solid rgba(250, 250, 247, 0.14);
  background: transparent;
}
.system-card {
  min-height: 156px;
  padding: 24px;
  border-right: 1px solid rgba(250, 250, 247, 0.14);
  border-bottom: 1px solid rgba(250, 250, 247, 0.14);
}
.system-card h3 {
  margin: 0 0 22px;
  color: var(--washi);
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: clamp(19px, 1.28vw, 25px);
  font-weight: 500;
  line-height: 1.35;
  letter-spacing: 0.02em;
  word-break: keep-all;
  overflow-wrap: normal;
}
.system-card h3 small {
  display: inline;
  color: #F4B3A6;
  font-family: "IBM Plex Mono", monospace;
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  vertical-align: baseline;
}
.card-title-zh {
  color: var(--washi);
}
.title-sep {
  color: rgba(244, 241, 234, 0.38);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.62em;
  letter-spacing: 0.04em;
}
.system-card p {
  color: rgba(244, 241, 234, 0.72);
  font-size: 14px;
  line-height: 1.85;
}
.delivery {
  margin-top: 0;
  padding: clamp(30px, 4.2vw, 54px);
  background: var(--ink);
  color: var(--washi);
  display: grid;
  grid-template-columns: 0.28fr minmax(0, 1fr) auto;
  gap: clamp(28px, 4.5vw, 72px);
  align-items: end;
  border-top: 1px solid rgba(250, 250, 247, 0.14);
}
.delivery .section-label {
  align-self: start;
  color: #F4B3A6;
}
.delivery strong {
  display: block;
  font-family: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  max-width: 1080px;
  font-size: clamp(24px, 2.35vw, 40px);
  font-weight: 300;
  line-height: 1.34;
  word-break: keep-all;
  overflow-wrap: normal;
  text-wrap: balance;
}
.next-inline {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  border: 1px solid currentColor;
  padding: 11px 14px 10px;
  color: var(--washi);
  font-size: 10px;
  letter-spacing: 0.16em;
  transition: color 180ms ease, background 180ms ease, border-color 180ms ease;
  white-space: nowrap;
}
.next-inline:hover {
  color: #F4B3A6;
  border-color: #F4B3A6;
}

@media (max-width: 900px) {
  .site-nav { position: absolute; padding: 18px 6vw; }
  .site-nav nav { display: none; }
  .chain-nav {
    left: 0;
    right: 0;
    top: auto;
    bottom: 0;
    overflow-x: auto;
    grid-template-columns: repeat(5, 168px);
    border-top: 1px solid var(--line);
    border-bottom: 0;
  }
  .chain-nav a.is-active::before {
    top: -4px;
    bottom: auto;
  }
  section { padding: 96px 6vw 128px; min-height: auto; }
  .section-meta { position: static; margin-bottom: 48px; }
  .content-grid,
  .delivery {
    grid-template-columns: 1fr;
  }
  .delivery {
    align-items: flex-start;
  }
  .system-grid {
    grid-template-columns: 1fr;
  }
}