:root {
  --c-pitch: #04211D;
  --c-locker: #0A2F28;
  --c-glass: #10403A;
  --c-white: #E6F4F1;
  --c-index: #8FB3AC;
  --c-neon: #3BF0D0;
  --c-neon-deep: #12B39A;
  --c-orange: #FF7A1A;
  --c-timer: #FFD166;
  --c-grid: #2A5A52;
  --font-display: "Oswald", "Barlow Condensed", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", "Menlo", "Consolas", "Courier New", monospace;
  --step-0: 13px;
  --step-1: 15px;
  --step-2: 17px;
  --step-3: 21px;
  --step-4: 28px;
  --step-5: clamp(30px, 4.4vw, 40px);
  --step-6: clamp(40px, 7vw, 64px);
  --step-7: clamp(56px, 11vw, 96px);
  --step-8: clamp(72px, 16vw, 132px);
  --gutter: 24px;
  --max-w: 1440px;
  --grid-line: rgba(42, 90, 82, 0.35);
  --hairline: rgba(42, 90, 82, 0.22);
  --glass-line: rgba(143, 179, 172, 0.28);
  --radius: 2px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

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

body {
  margin: 0;
  background-color: var(--c-pitch);
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 24px 24px;
  background-position: 0 0;
  color: var(--c-white);
  font-family: var(--font-body);
  font-size: var(--step-2);
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.06;
  margin: 0 0 0.5em;
  color: var(--c-white);
}

h1 { font-size: var(--step-7); }
h2 { font-size: var(--step-5); }
h3 { font-size: var(--step-3); letter-spacing: 0.04em; }

p { margin: 0 0 1em; }

a {
  color: var(--c-neon);
  text-decoration: none;
  transition: color 160ms var(--ease), border-color 160ms var(--ease), background-color 160ms var(--ease);
}

a:hover { color: var(--c-white); }

ul, ol { margin: 0; padding: 0; list-style: none; }

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

table { border-collapse: collapse; width: 100%; }

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

::selection {
  background: var(--c-neon);
  color: var(--c-pitch);
}

/* ---------- shell ---------- */
.site-shell {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 200;
  padding: 10px 16px;
  background: var(--c-orange);
  color: var(--c-pitch);
  font-size: var(--step-0);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 700;
  transition: top 160ms var(--ease);
}

.skip-link:focus {
  top: 12px;
  color: var(--c-pitch);
}

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(4, 33, 29, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-line);
}

.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 14px var(--gutter);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.header-left {
  display: flex;
  align-items: baseline;
  gap: 14px;
  flex-wrap: wrap;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--c-white);
}

.brand-mark {
  width: 12px;
  height: 12px;
  background: var(--c-neon);
  box-shadow: 0 0 0 3px rgba(59, 240, 208, 0.16);
  flex: none;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--step-3);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.brand-tagline {
  font-size: var(--step-0);
  letter-spacing: 0.16em;
  color: var(--c-index);
  text-transform: uppercase;
}

.brand-icp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.06em;
  color: var(--c-index);
  font-variant-numeric: tabular-nums;
}

.header-right {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 18px;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--glass-line);
  color: var(--c-white);
  font-size: var(--step-0);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: rgba(16, 64, 58, 0.4);
}

.nav-toggle-bars {
  position: relative;
  width: 16px;
  height: 2px;
  background: var(--c-neon);
  display: block;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: var(--c-neon);
  transition: transform 180ms var(--ease);
}

.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-5px) rotate(-45deg); }

.site-nav {
  width: 100%;
  max-height: 0;
  overflow: hidden;
  transition: max-height 220ms var(--ease);
}

.site-nav[data-open] { max-height: 460px; }

.nav-list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--hairline);
}

.nav-item { border-bottom: 1px solid var(--hairline); }

.nav-link {
  display: block;
  padding: 12px 2px;
  font-family: var(--font-display);
  font-size: var(--step-1);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-index);
}

.nav-link:hover,
.nav-link:focus-visible { color: var(--c-neon); }

.nav-link[aria-current="page"] {
  color: var(--c-neon);
  border-left: 2px solid var(--c-neon);
  padding-left: 10px;
}

.header-utility {
  display: flex;
  align-items: center;
  gap: 10px 16px;
  flex-wrap: wrap;
  width: 100%;
}

.nav-cta { flex: none; }

.header-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 6px 12px;
  border: 1px solid var(--glass-line);
  background: rgba(10, 47, 40, 0.6);
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.04em;
  color: var(--c-timer);
  font-variant-numeric: tabular-nums;
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--c-orange);
  animation: pulse 3s var(--ease) infinite;
}

.status-label {
  color: var(--c-index);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.status-time { color: var(--c-timer); }

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(255, 122, 26, 0.5); }
  50% { box-shadow: 0 0 0 7px rgba(255, 122, 26, 0); }
}

.scroll-progress {
  height: 2px;
  width: 0;
  background: linear-gradient(90deg, var(--c-neon), var(--c-orange));
  transition: width 120ms linear;
}

/* ---------- layout frame ---------- */
.page-frame {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 32px var(--gutter) 64px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.rail-aside {
  position: relative;
  border-left: 1px solid var(--hairline);
  padding-left: 16px;
}

.rail-index {
  display: flex;
  flex-direction: row;
  gap: 12px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.08em;
  color: var(--c-index);
  text-transform: uppercase;
}

.content-flow {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.rail-status {
  position: sticky;
  top: 96px;
  align-self: start;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px 10px;
  border: 1px solid var(--glass-line);
  background: rgba(10, 47, 40, 0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.rail-label {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--c-index);
}

.rail-change {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-pitch);
  background: var(--c-orange);
  padding: 8px 4px;
}

/* ---------- sections ---------- */
.section { position: relative; }

.section-head {
  display: flex;
  flex-direction: column;
  gap: 6px;
  border-top: 1px solid var(--hairline);
  padding-top: 14px;
  margin-bottom: 20px;
}

.section-index {
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--c-index);
}

.section-title { margin: 0; font-size: var(--step-5); }

.section-sub {
  margin: 0;
  color: var(--c-index);
  font-size: var(--step-1);
  max-width: 46ch;
}

/* ---------- cards ---------- */
.grid-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gutter);
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 18px;
  background: var(--c-locker);
  border: 1px solid var(--hairline);
  transition: border-color 180ms var(--ease), transform 180ms var(--ease);
}

.card:hover {
  border-color: var(--c-neon);
  transform: translateY(-2px);
}

.card-tag {
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-index);
}

.card-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--step-3);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.card-meta {
  font-family: var(--font-mono);
  font-size: var(--step-0);
  color: var(--c-timer);
  font-variant-numeric: tabular-nums;
}

.card-body { color: var(--c-index); font-size: var(--step-1); margin: 0; }

.card.is-filtered-out { display: none; }

/* ---------- tags ---------- */
.tag {
  display: inline-block;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: 1px solid var(--glass-line);
  color: var(--c-index);
}

.tag-accent { border-color: var(--c-neon); color: var(--c-neon); }

.tag-change {
  background: var(--c-orange);
  border-color: var(--c-orange);
  color: var(--c-pitch);
  font-weight: 700;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid var(--glass-line);
  font-family: var(--font-display);
  font-size: var(--step-1);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-white);
  background: transparent;
  transition: border-color 160ms var(--ease), background-color 160ms var(--ease), color 160ms var(--ease);
}

.btn-primary {
  background: var(--c-orange);
  border-color: var(--c-orange);
  color: var(--c-pitch);
  font-weight: 700;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--c-timer);
  border-color: var(--c-timer);
  color: var(--c-pitch);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  border-color: var(--c-neon);
  color: var(--c-neon);
}

/* ---------- breadcrumb ---------- */
.breadcrumb { margin-bottom: 18px; }

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-index);
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 8px;
  color: var(--c-grid);
}

.breadcrumb-item a { color: var(--c-index); }
.breadcrumb-item a:hover { color: var(--c-neon); }
.breadcrumb-item [aria-current="page"] { color: var(--c-white); }

/* ---------- prose ---------- */
.prose {
  max-width: 40ch;
  color: var(--c-white);
}

.prose p { color: rgba(230, 244, 241, 0.86); }
.prose h2, .prose h3 { margin-top: 1.4em; }
.prose ul { list-style: none; }
.prose li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 8px;
  color: rgba(230, 244, 241, 0.86);
}
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 8px;
  height: 1px;
  background: var(--c-neon);
}

/* ---------- panel ---------- */
.panel {
  border: 1px solid var(--hairline);
  background: var(--c-glass);
  margin-bottom: 10px;
}

.panel-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  text-align: left;
  font-family: var(--font-display);
  font-size: var(--step-2);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--c-white);
}

.panel-trigger::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--c-neon);
  font-size: var(--step-3);
  line-height: 1;
}

.panel-trigger[aria-expanded="true"]::after { content: "–"; }

.panel-body {
  overflow: hidden;
  max-height: 0;
  transition: max-height 180ms var(--ease);
}

.panel-body[data-open] { max-height: 640px; }

.panel-body-inner {
  padding: 0 16px 16px;
  color: var(--c-index);
  font-size: var(--step-1);
}

/* ---------- timeline ---------- */
.timeline {
  position: relative;
  padding-left: 22px;
  border-left: 1px solid var(--c-grid);
}

.timeline-item { position: relative; padding-bottom: 22px; }

.timeline-item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 8px;
  width: 9px;
  height: 9px;
  background: var(--c-pitch);
  border: 1px solid var(--c-neon);
}

.timeline-time {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.1em;
  color: var(--c-timer);
  font-variant-numeric: tabular-nums;
}

.timeline-text { margin: 4px 0 0; color: var(--c-index); }

/* ---------- filter bar ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.filter-btn {
  padding: 7px 14px;
  border: 1px solid var(--glass-line);
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-index);
  background: rgba(10, 47, 40, 0.5);
}

.filter-btn:hover { border-color: var(--c-neon); color: var(--c-neon); }

.filter-btn[aria-pressed="true"] {
  background: var(--c-neon);
  border-color: var(--c-neon);
  color: var(--c-pitch);
}

.filter-empty {
  display: none;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  color: var(--c-orange);
  letter-spacing: 0.06em;
}

.filter-empty[data-visible] { display: block; }

/* ---------- media ---------- */
.media-frame {
  position: relative;
  width: 100%;
  aspect-ratio: var(--ratio, 16 / 9);
  overflow: hidden;
  background:
    linear-gradient(160deg, rgba(59, 240, 208, 0.14), rgba(4, 33, 29, 0.9)),
    repeating-linear-gradient(90deg, rgba(42, 90, 82, 0.5) 0 1px, transparent 1px 48px),
    var(--c-locker);
  border: 1px solid var(--glass-line);
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media-frame figcaption {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 10px;
  background: rgba(4, 33, 29, 0.86);
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.08em;
  color: var(--c-index);
  text-transform: uppercase;
}

/* ---------- reveal ---------- */
.js-reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 420ms var(--ease), transform 420ms var(--ease);
}

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

/* ---------- footer ---------- */
.site-footer {
  margin-top: 48px;
  background: var(--c-locker);
  border-top: 1px solid var(--glass-line);
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 40px var(--gutter) 28px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.footer-brand { display: flex; flex-direction: column; gap: 10px; }

.footer-closing {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--step-3);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--c-neon);
}

.footer-note { margin: 0; color: var(--c-index); font-size: var(--step-1); max-width: 34ch; }

.footer-col-title {
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-index);
  margin: 0 0 10px;
  font-weight: 400;
}

.footer-list { display: flex; flex-direction: column; gap: 8px; }

.footer-link {
  color: var(--c-white);
  font-size: var(--step-1);
}

.footer-link:hover { color: var(--c-neon); }

.footer-text { color: var(--c-index); font-size: var(--step-1); }

.footer-base {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 16px var(--gutter) 32px;
  border-top: 1px solid var(--hairline);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  justify-content: space-between;
}

.footer-legal,
.footer-copy {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.06em;
  color: var(--c-index);
  font-variant-numeric: tabular-nums;
}

/* ---------- to top ---------- */
.to-top {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 120;
  padding: 10px 14px;
  background: var(--c-glass);
  border: 1px solid var(--glass-line);
  color: var(--c-white);
  font-family: var(--font-mono);
  font-size: var(--step-0);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms var(--ease), border-color 180ms var(--ease);
}

.to-top[data-visible] { opacity: 1; pointer-events: auto; }
.to-top:hover { border-color: var(--c-neon); color: var(--c-neon); }

/* ---------- responsive ---------- */
@media (min-width: 640px) {
  .grid-cards[data-cols="2"] { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-cards[data-cols="3"] { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-cards[data-cols="4"] { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .header-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 16px var(--gutter);
  }
  .header-right { flex: 1; justify-content: flex-end; flex-wrap: nowrap; }
  .nav-toggle { display: none; }
  .site-nav {
    width: auto;
    max-height: none;
    overflow: visible;
  }
  .nav-list {
    flex-direction: row;
    border-top: 0;
    gap: 20px;
  }
  .nav-item { border-bottom: 0; }
  .nav-link { padding: 6px 0; font-size: var(--step-0); }
  .nav-link[aria-current="page"] {
    border-left: 0;
    padding-left: 0;
    border-bottom: 2px solid var(--c-neon);
  }
  .header-utility { width: auto; flex-wrap: nowrap; }
  .page-frame {
    grid-template-columns: 3fr 9fr;
    gap: 40px;
    padding-top: 48px;
  }
  .rail-index { flex-direction: column; }
  .grid-cards[data-cols="3"] { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .grid-cards[data-cols="4"] { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .footer-inner { grid-template-columns: 2fr 1fr 1fr 1fr 1fr; }
}

@media (min-width: 1200px) {
  .page-frame { grid-template-columns: 3fr 8fr 1fr; }
  .rail-aside { padding-left: 20px; }
}

@media (max-width: 899px) {
  .rail-status {
    position: static;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding: 10px 14px;
  }
  .rail-label,
  .rail-change { writing-mode: horizontal-tb; }
  .rail-change { padding: 4px 10px; }
  .to-top { bottom: 72px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .js-reveal { opacity: 1; transform: none; }
}