:root {
  --bg: #0b1013;
  --bg-2: #12191d;
  --sidebar: #090d10;
  --paper: #161e23;
  --ink: #e8eee9;
  --muted: #8b9a94;
  --faint: #5d6b66;
  --line: rgba(232, 238, 233, 0.1);
  --teal: #2ec4b6;
  --teal-dim: rgba(46, 196, 182, 0.12);
  --amber: #e8b84a;
  --amber-dim: rgba(232, 184, 74, 0.12);
  --rose: #e07a6a;
  --rose-dim: rgba(224, 122, 106, 0.12);
  --sidebar-w: 280px;
  --radius: 14px;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Noto Sans SC", "IBM Plex Mono", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  letter-spacing: 0.01em;
}

a { color: var(--teal); text-decoration: none; }
a:hover { text-decoration: underline; }
a.card { color: inherit; text-decoration: none; }
a.card:hover {
  text-decoration: none;
  border-color: rgba(46, 196, 182, 0.45);
}
img { max-width: 100%; display: block; }
button, input, select { font-family: inherit; }
code, .mono {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
}

.app {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  min-height: 100%;
}

/* —— sidebar / tree —— */
.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  background: var(--sidebar);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  z-index: 30;
}
.brand {
  padding: 22px 20px 14px;
  border-bottom: 1px solid var(--line);
}
.brand .mark {
  font-family: "IBM Plex Mono", monospace;
  font-size: 10px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--teal);
}
.brand h1 {
  font-family: "Instrument Serif", "Noto Serif SC", serif;
  font-weight: 400;
  font-size: 26px;
  margin: 6px 0 0;
  letter-spacing: -0.02em;
}
.brand p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.search {
  margin: 12px 14px 4px;
  position: relative;
}
.search input {
  width: 100%;
  background: var(--bg-2);
  border: 1px solid var(--line);
  color: var(--ink);
  border-radius: 10px;
  padding: 8px 10px 8px 32px;
  font-size: 13px;
  outline: none;
}
.search input:focus { border-color: rgba(46, 196, 182, 0.45); }
.search svg {
  position: absolute;
  left: 10px;
  top: 9px;
  opacity: 0.45;
}

.tree {
  flex: 1;
  overflow: auto;
  padding: 8px 10px 24px;
  font-size: 13.5px;
}
.tree::-webkit-scrollbar { width: 8px; }
.tree::-webkit-scrollbar-thumb { background: rgba(255,255,255,.08); border-radius: 8px; }

.t-dir, .t-leaf { user-select: none; }
.t-row {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 8px;
  border-radius: 8px;
  color: var(--muted);
  cursor: pointer;
  line-height: 1.4;
}
.t-row:hover { background: rgba(255,255,255,.04); color: var(--ink); }
.t-row.active {
  background: var(--teal-dim);
  color: var(--ink);
}
.t-row.active .t-name { color: var(--ink); }
.t-twist {
  width: 14px;
  color: var(--faint);
  font-family: "IBM Plex Mono", monospace;
  font-size: 10px;
}
.t-icon { width: 14px; opacity: 0.7; flex: none; }
.t-name { flex: 1; min-width: 0; }
.t-kids {
  margin-left: 11px;
  padding-left: 10px;
  border-left: 1px dashed rgba(232, 238, 233, 0.12);
}
.t-kids.collapsed { display: none; }
.t-count {
  font-family: "IBM Plex Mono", monospace;
  font-size: 10px;
  color: var(--faint);
}

.sidebar footer {
  padding: 12px 16px 16px;
  border-top: 1px solid var(--line);
  color: var(--faint);
  font-size: 11px;
  font-family: "IBM Plex Mono", monospace;
}

.menu-btn {
  display: none;
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 40;
  background: var(--paper);
  border: 1px solid var(--line);
  color: var(--ink);
  border-radius: 10px;
  padding: 8px 10px;
}

/* —— main —— */
.main {
  min-width: 0;
  background:
    radial-gradient(900px 420px at 80% -10%, rgba(46, 196, 182, 0.07), transparent 55%),
    var(--bg);
}
.article {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 40px 96px;
  animation: in 0.35s ease;
}
@keyframes in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

.crumb {
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--faint);
  margin-bottom: 22px;
}
.crumb span { color: var(--muted); }

.kicker {
  color: var(--teal);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  margin-bottom: 10px;
  font-family: "IBM Plex Mono", monospace;
}
h2.page-title {
  font-family: "Instrument Serif", "Noto Serif SC", serif;
  font-weight: 400;
  font-size: clamp(36px, 5vw, 56px);
  line-height: 1.12;
  margin: 0 0 14px;
  letter-spacing: -0.025em;
}
.lede {
  color: var(--muted);
  font-size: 18px;
  max-width: 640px;
  margin: 0 0 28px;
}

.hero-fig {
  margin: 0 0 28px;
  border-radius: 18px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: #000;
}
.hero-fig img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}
.hero-fig.ratio-4-3 img { aspect-ratio: 4 / 3; }
.hero-fig.contain { background: #eef1ef; }
.hero-fig.contain img {
  object-fit: contain;
  background: #eef1ef;
}
.hero-fig figcaption {
  font-size: 12px;
  color: var(--muted);
  padding: 10px 14px 12px;
  background: var(--bg-2);
}

.split {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 28px;
  align-items: start;
  margin: 28px 0;
}
.split.reverse { grid-template-columns: 0.95fr 1.05fr; }
.split.reverse .split-copy { order: 2; }
.split img {
  border-radius: 16px;
  border: 1px solid var(--line);
  aspect-ratio: 4 / 3;
  object-fit: cover;
  width: 100%;
  background: #eef1ef;
}
.split.contain img { object-fit: contain; }
.split-copy h3 {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: 28px;
  margin: 0 0 10px;
}

.prose p { color: #d3ddd8; margin: 0 0 14px; }
.prose p:last-child { margin-bottom: 0; }

.callout {
  border-left: 3px solid var(--teal);
  background: var(--teal-dim);
  padding: 14px 16px;
  border-radius: 0 12px 12px 0;
  margin: 22px 0;
  color: #d7e8e4;
}
.callout.warn {
  border-left-color: var(--amber);
  background: var(--amber-dim);
}
.callout.soft {
  border-left-color: var(--rose);
  background: var(--rose-dim);
}

.meta {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
  margin: 8px 0 28px;
}
.meta div { background: var(--bg-2); padding: 14px 16px; }
.meta dt {
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  font-family: "IBM Plex Mono", monospace;
}
.meta dd { margin: 4px 0 0; font-size: 14px; }

.cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin: 22px 0;
}
.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 16px 14px;
}
.card.span-2 { grid-column: 1 / -1; }
.card .tag {
  display: inline-block;
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--teal);
  font-family: "IBM Plex Mono", monospace;
  margin-bottom: 8px;
}
.card h3 { margin: 0 0 8px; font-size: 17px; font-weight: 500; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }
.card .price {
  margin-top: 10px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
  color: var(--amber);
}
.pill {
  display: inline-block;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--muted);
  margin-right: 4px;
}
.pill.yes { color: var(--teal); border-color: rgba(46,196,182,.35); }
.pill.no { color: var(--rose); border-color: rgba(224,122,106,.35); }
.pill.mid { color: var(--amber); border-color: rgba(232,184,74,.35); }

table.sheet {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  margin: 18px 0 28px;
}
.sheet th, .sheet td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.sheet th {
  color: var(--muted);
  font-weight: 500;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h3.sec {
  font-family: "Instrument Serif", serif;
  font-weight: 400;
  font-size: 28px;
  margin: 36px 0 12px;
}

/* —— configurator —— */
.kit {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 20px;
  margin: 8px 0 28px;
}
.kit h3 { margin: 0 0 14px; font-size: 16px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.chip {
  background: transparent;
  border: 1px solid var(--line);
  color: var(--muted);
  border-radius: 999px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 13px;
}
.chip.on {
  background: var(--teal-dim);
  border-color: rgba(46,196,182,.45);
  color: var(--ink);
}
.kit-out { margin-top: 8px; }
.kit-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
}
.kit-item:last-child { border-bottom: 0; }
.kit-item .why { color: var(--muted); font-size: 13px; }
.kit-total {
  margin-top: 12px;
  display: flex;
  justify-content: space-between;
  font-family: "IBM Plex Mono", monospace;
  color: var(--amber);
}

.empty {
  color: var(--muted);
  padding: 40px 0;
}

@media (max-width: 920px) {
  .app { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed;
    transform: translateX(-100%);
    transition: transform .22s ease;
    width: min(86vw, 320px);
  }
  .sidebar.open { transform: none; box-shadow: 20px 0 60px rgba(0,0,0,.45); }
  .menu-btn { display: block; }
  .article { padding: 64px 20px 80px; }
  .split, .split.reverse { grid-template-columns: 1fr; }
  .split.reverse .split-copy { order: 0; }
  .cards { grid-template-columns: 1fr; }
  .meta { grid-template-columns: 1fr 1fr; }
}