:root {
  --jk-ink: #0B2B24;
  --jk-panel: #10382F;
  --jk-line: #1F5E4E;
  --jk-gold: #C9A227;
  --jk-gold-lite: #E3C567;
  --jk-vermilion: #C8402F;
  --jk-text: #F2EFE6;
  --jk-muted: #93A79F;
  --jk-black: #061713;
  --jk-paper: #E8E2D2;

  --jk-font-sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --jk-font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  --jk-wrap-width: 1368px;
  --jk-gutter: clamp(16px, 4vw, 24px);
  --jk-ease: 220ms ease-out;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 92px;
  background: var(--jk-black);
}

body {
  margin: 0;
  overflow-x: hidden;
  min-height: 100vh;
  background-color: var(--jk-ink);
  background-image:
    linear-gradient(90deg, rgba(31, 94, 78, .16) 1px, transparent 1px),
    linear-gradient(180deg, rgba(31, 94, 78, .16) 1px, transparent 1px);
  background-size: 96px 96px;
  color: var(--jk-text);
  font-family: var(--jk-font-sans);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg, video { max-width: 100%; height: auto; }

h1, h2, h3, h4 {
  margin: 0 0 .6em;
  color: var(--jk-text);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -.015em;
}

h1 { font-size: clamp(2.4rem, 6vw, 5rem); letter-spacing: -.03em; }
h2 { font-size: clamp(1.35rem, 2.4vw, 2rem); }
h3 { font-size: 1.15rem; }
h4 { font-size: 1rem; }

p { margin: 0 0 1.1em; }

a { color: var(--jk-gold-lite); text-decoration: none; }
a:hover { color: var(--jk-text); }

ul, ol { margin: 0 0 1.1em; }

button { font: inherit; color: inherit; }

::selection { background: var(--jk-gold); color: var(--jk-black); }

:focus-visible {
  outline: 2px solid var(--jk-gold-lite);
  outline-offset: 3px;
  border-radius: 2px;
}

#main-content { display: block; }

.jk-wrap {
  width: 100%;
  max-width: var(--jk-wrap-width);
  margin-inline: auto;
  padding-inline: var(--jk-gutter);
}

/* ---------- skip link ---------- */
.jk-skip {
  position: absolute;
  top: -80px;
  left: 16px;
  z-index: 300;
  display: inline-block;
  padding: 10px 18px;
  background: var(--jk-gold);
  color: var(--jk-black);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .08em;
  text-decoration: none;
  transition: top var(--jk-ease);
}

.jk-skip:focus,
.jk-skip:focus-visible {
  top: 16px;
  color: var(--jk-black);
}

/* ---------- header ---------- */
.jk-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(6, 23, 19, .94);
  border-bottom: 1px solid var(--jk-line);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.jk-header__grid {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  column-gap: 28px;
  min-height: 68px;
}

.jk-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
  color: var(--jk-text);
  text-decoration: none;
}

.jk-brand__mark {
  position: relative;
  display: block;
  flex: none;
  width: 32px;
  height: 32px;
  border: 1px solid var(--jk-line);
  border-radius: 50%;
}

.jk-brand__mark::before {
  content: "";
  position: absolute;
  inset: 8px;
  border: 1px solid var(--jk-gold);
  border-radius: 50%;
}

.jk-brand__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 6px;
  height: 6px;
  margin: -3px 0 0 -3px;
  border-radius: 50%;
  background: var(--jk-vermilion);
}

.jk-brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.jk-brand__name {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: .18em;
  color: var(--jk-text);
}

.jk-brand__tag {
  margin-top: 4px;
  font-family: var(--jk-font-mono);
  font-size: 10.5px;
  letter-spacing: .16em;
  color: var(--jk-muted);
}

/* ---------- command-bar nav ---------- */
.jk-nav { justify-self: center; }

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

.jk-nav__item { position: relative; }

.jk-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 10px 9px;
  color: var(--jk-muted);
  font-size: 13.5px;
  letter-spacing: .05em;
  white-space: nowrap;
  text-decoration: none;
  transition: color var(--jk-ease);
}

.jk-nav__label { display: inline-block; }

.jk-nav__index {
  font-family: var(--jk-font-mono);
  font-size: 10.5px;
  letter-spacing: .06em;
  color: var(--jk-line);
  transition: color var(--jk-ease);
}

.jk-nav__link::after {
  content: "";
  position: absolute;
  left: 9px;
  right: 9px;
  bottom: 3px;
  height: 2px;
  background: var(--jk-gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--jk-ease);
}

.jk-nav__link:hover { color: var(--jk-text); }
.jk-nav__link:hover::after { transform: scaleX(1); }
.jk-nav__link:hover .jk-nav__index { color: var(--jk-gold); }

.jk-nav__link[aria-current="page"] { color: var(--jk-text); }
.jk-nav__link[aria-current="page"]::after { transform: scaleX(1); }
.jk-nav__link[aria-current="page"] .jk-nav__index { color: var(--jk-gold); }

.jk-nav__link[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 50%;
  width: 5px;
  height: 5px;
  margin-top: -2.5px;
  border-radius: 50%;
  background: var(--jk-vermilion);
}

/* ---------- utility ---------- */
.jk-header__utility {
  display: flex;
  align-items: center;
  gap: 16px;
  justify-self: end;
}

.jk-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 6px 11px;
  border: 1px solid var(--jk-line);
  font-family: var(--jk-font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  white-space: nowrap;
}

.jk-status__dot {
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background: var(--jk-vermilion);
  animation: jk-pulse 2.6s ease-out infinite;
}

@keyframes jk-pulse {
  0% { box-shadow: 0 0 0 0 rgba(200, 64, 47, .5); }
  70% { box-shadow: 0 0 0 7px rgba(200, 64, 47, 0); }
  100% { box-shadow: 0 0 0 0 rgba(200, 64, 47, 0); }
}

.jk-status__label { color: var(--jk-muted); }
.jk-status__value { color: var(--jk-gold-lite); }

/* ---------- buttons ---------- */
.jk-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border: 1px solid transparent;
  font-family: var(--jk-font-sans);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .08em;
  line-height: 1.2;
  white-space: nowrap;
  text-decoration: none;
  cursor: pointer;
  transition: background-color var(--jk-ease), color var(--jk-ease), border-color var(--jk-ease);
}

.jk-btn--gold {
  background: var(--jk-gold);
  border-color: var(--jk-gold);
  color: var(--jk-black);
}

.jk-btn--gold:hover,
.jk-btn--gold:focus-visible {
  background: var(--jk-gold-lite);
  border-color: var(--jk-gold-lite);
  color: var(--jk-black);
}

.jk-btn--ghost {
  background: transparent;
  border-color: var(--jk-line);
  color: var(--jk-gold-lite);
}

.jk-btn--ghost:hover,
.jk-btn--ghost:focus-visible {
  border-color: var(--jk-gold);
  color: var(--jk-text);
}

/* ---------- nav toggle ---------- */
.jk-nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  background: transparent;
  border: 1px solid var(--jk-line);
  color: var(--jk-text);
  font-size: 13px;
  letter-spacing: .1em;
  cursor: pointer;
  transition: border-color var(--jk-ease), color var(--jk-ease);
}

.jk-nav-toggle:hover { border-color: var(--jk-gold); }

.jk-nav-toggle__bars {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 18px;
  height: 12px;
  flex: none;
}

.jk-nav-toggle__bars span {
  display: block;
  height: 2px;
  background: var(--jk-gold);
  transition: transform var(--jk-ease), opacity var(--jk-ease);
}

.jk-nav-toggle[aria-expanded="true"] .jk-nav-toggle__bars span:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}

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

.jk-nav-toggle[aria-expanded="true"] .jk-nav-toggle__bars span:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

/* ---------- reading progress ---------- */
.jk-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
  pointer-events: none;
}

.jk-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--jk-gold) 0%, var(--jk-gold-lite) 100%);
  transform: scaleX(0);
  transform-origin: left center;
  will-change: transform;
}

/* ---------- footer ---------- */
.jk-footer {
  margin-top: 80px;
  background: var(--jk-black);
  border-top: 1px solid var(--jk-line);
  color: var(--jk-muted);
}

.jk-footer__inner {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 2fr);
  gap: 44px 64px;
  padding-block: 56px 26px;
}

.jk-footer__brand { min-width: 0; }

.jk-footer__name {
  margin: 0;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: .2em;
  color: var(--jk-text);
}

.jk-footer__tagline {
  margin: 8px 0 0;
  font-family: var(--jk-font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--jk-muted);
}

.jk-footer__contact {
  display: grid;
  gap: 7px;
  margin: 24px 0 0;
  font-family: var(--jk-font-mono);
  font-size: 13px;
  letter-spacing: .04em;
}

.jk-footer__contact-row {
  display: grid;
  grid-template-columns: 5.5em minmax(0, 1fr);
  gap: 12px;
  margin: 0;
}

.jk-footer__contact-row dt {
  color: var(--jk-muted);
  opacity: .78;
}

.jk-footer__contact-row dd {
  margin: 0;
  color: var(--jk-text);
  overflow-wrap: anywhere;
}

.jk-footer__nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 32px 24px;
  align-content: start;
}

.jk-footer__title {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 18px;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: .22em;
  color: var(--jk-gold);
}

.jk-footer__title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--jk-line);
}

.jk-footer__list {
  display: grid;
  gap: 11px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.jk-footer__link {
  position: relative;
  display: inline-block;
  padding-left: 0;
  color: var(--jk-muted);
  font-size: 14.5px;
  letter-spacing: .03em;
  text-decoration: none;
  transition: color var(--jk-ease), padding-left var(--jk-ease);
}

.jk-footer__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0;
  height: 1px;
  background: var(--jk-gold);
  transition: width var(--jk-ease);
}

.jk-footer__link:hover {
  color: var(--jk-text);
  padding-left: 16px;
}

.jk-footer__link:hover::before { width: 10px; }

.jk-footer__meta {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  margin-top: 6px;
  padding-top: 22px;
  border-top: 1px solid var(--jk-line);
  font-family: var(--jk-font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--jk-muted);
}

.jk-footer__meta p { margin: 0; }
.jk-footer__legal { color: var(--jk-muted); }
.jk-footer__copy { color: var(--jk-gold-lite); }

/* ---------- shared page primitives ---------- */
.jk-section {
  position: relative;
  padding-block: 64px;
}

.jk-sec-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 16px;
  margin-bottom: 28px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--jk-line);
}

.jk-sec-num {
  font-family: var(--jk-font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--jk-gold);
}

.jk-sec-title {
  margin: 0;
  font-size: clamp(1.35rem, 2.4vw, 2rem);
}

.jk-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 18px 0 0;
  list-style: none;
  font-family: var(--jk-font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--jk-muted);
}

.jk-crumbs li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.jk-crumbs li + li::before {
  content: "/";
  color: var(--jk-line);
}

.jk-crumbs a { color: var(--jk-muted); }
.jk-crumbs a:hover { color: var(--jk-gold-lite); }
.jk-crumbs [aria-current="page"] { color: var(--jk-text); }

.jk-prose { max-width: 42em; }
.jk-prose p { max-width: 34em; }
.jk-prose h2 { margin-top: 1.8em; }
.jk-prose h3 { margin-top: 1.5em; }
.jk-prose ul,
.jk-prose ol { max-width: 34em; padding-left: 1.25em; }
.jk-prose li { margin-bottom: .5em; }

.jk-grid {
  display: grid;
  gap: 24px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.jk-grid--2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.jk-grid--3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* ---------- image containers ---------- */
.jk-media {
  position: relative;
  display: block;
  overflow: hidden;
  isolation: isolate;
  aspect-ratio: 16 / 9;
  background: var(--jk-panel);
  border: 1px solid var(--jk-line);
}

.jk-media > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.72) brightness(.78) contrast(1.05);
}

.jk-media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(31, 94, 78, .38) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 94, 78, .38) 1px, transparent 1px);
  background-size: 56px 56px;
  opacity: .55;
  mix-blend-mode: screen;
}

.jk-media--wide { aspect-ratio: 21 / 9; }
.jk-media--tall { aspect-ratio: 4 / 5; }
.jk-media--square { aspect-ratio: 1 / 1; }

.jk-media--framed::before {
  content: "";
  position: absolute;
  inset: 10px;
  z-index: 2;
  border: 1px solid rgba(201, 162, 39, .38);
  pointer-events: none;
}

.jk-media-cap {
  margin: 10px 0 0;
  font-family: var(--jk-font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--jk-muted);
}

/* ---------- scroll-linked index ---------- */
.jk-index-link {
  color: var(--jk-muted);
  transition: color var(--jk-ease);
}

.jk-index-link.is-current,
.jk-index-link[aria-current="true"] {
  color: var(--jk-gold);
}

/* ---------- reveal ---------- */
html.jk-js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 520ms ease-out, transform 520ms ease-out;
}

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

/* ---------- responsive ---------- */
@media (max-width: 1079px) {
  .jk-header__grid {
    grid-template-columns: minmax(0, 1fr) auto auto;
    column-gap: 14px;
  }

  .jk-nav-toggle { display: inline-flex; }

  .jk-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    justify-self: stretch;
    max-height: calc(100vh - 68px);
    overflow-y: auto;
    padding: 12px var(--jk-gutter) 22px;
    background: var(--jk-black);
    border-bottom: 1px solid var(--jk-line);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity var(--jk-ease), transform var(--jk-ease), visibility var(--jk-ease);
  }

  .jk-nav[data-open] {
    visibility: visible;
    opacity: 1;
    transform: none;
  }

  .jk-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .jk-nav__link {
    padding: 14px 4px;
    font-size: 15.5px;
    letter-spacing: .06em;
    border-bottom: 1px solid rgba(31, 94, 78, .55);
  }

  .jk-nav__link::after {
    left: 4px;
    right: auto;
    bottom: -1px;
    width: 46px;
  }

  .jk-nav__link[aria-current="page"]::before { left: -6px; }

  .jk-nav__index { font-size: 11px; }
}

@media (max-width: 899px) {
  .jk-footer__inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 40px;
    padding-block: 44px 24px;
  }

  .jk-footer__nav { gap: 28px 18px; }
  .jk-footer { margin-top: 64px; }
}

@media (max-width: 639px) {
  body { font-size: 16px; }

  .jk-status { display: none; }

  .jk-brand__name { font-size: 16px; letter-spacing: .14em; }
  .jk-brand__mark { width: 28px; height: 28px; }
  .jk-brand__mark::before { inset: 7px; }

  .jk-btn { padding: 9px 14px; font-size: 13px; letter-spacing: .06em; }

  .jk-section { padding-block: 46px; }
  .jk-grid { gap: 18px; }
}

@media (max-width: 479px) {
  .jk-brand__tag { display: none; }
  .jk-nav-toggle { padding: 9px 11px; }
  .jk-nav-toggle__text { display: none; }

  .jk-footer__nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .jk-footer__contact-row { grid-template-columns: minmax(0, 1fr); gap: 2px; }
  .jk-footer__meta { font-size: 11.5px; gap: 8px 18px; }
}

/* ---------- motion preferences ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

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

  .jk-progress__bar { transition: none; }
}