:root {
  --canvas: #080d13;
  --canvas-top: #0d1625;
  --panel: #161e27;
  --panel-soft: #19212b;
  --panel-deep: #0c1421;
  --stroke: #2b3541;
  --stroke-strong: #3b4756;
  --text: #f4f7f9;
  --text-soft: #c3cad2;
  --text-muted: #9ca8b6;
  --lime: #91d438;
  --lime-soft: #b3ed67;
  --plan: #ff7898;
  --spec: #91d75d;
  --layout: #63b7ff;
  --general: #c294ff;
  color-scheme: dark;
}

* { scrollbar-color: #5c6672 var(--panel-deep); }
body {
  background:
    radial-gradient(ellipse 54rem 38rem at -7% -3%, rgba(47, 104, 84, .38) 0%, rgba(25, 71, 69, .2) 44%, transparent 72%),
    radial-gradient(ellipse 70rem 46rem at 68% -14%, rgba(24, 43, 82, .45) 0%, transparent 70%),
    linear-gradient(180deg, #0d1729 0%, #0a111a 36rem, var(--canvas) 100%);
  background-attachment: fixed;
  color: var(--text);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
}
button, input, a { font-family: inherit; }

.topbar {
  height: 64px;
  padding: 0 18px;
  background: rgba(10, 16, 25, .94);
  border-top: 5px solid #05070a;
  border-bottom: 1px solid rgba(255,255,255,.06);
  backdrop-filter: blur(18px);
}
.brand {
  width: 326px;
  height: 59px;
  padding: 0 8px;
  border: 0;
  gap: 10px;
}
.brand > span { width: 34px; height: 34px; border: 0; }
.brand > span img { width: 34px !important; height: 34px !important; }
.brand b { font-size: 13px; letter-spacing: -.01em; }
.brand small { color: var(--text-muted); font-size: 9px; letter-spacing: .12em; }
.search {
  width: min(560px, 43vw);
  height: 39px;
  margin-left: 14px;
  border: 1px solid var(--stroke);
  border-radius: 9px;
  background: var(--panel-deep);
}
.search:focus-within { border-color: var(--lime); box-shadow: 0 0 0 3px rgba(145,212,56,.12); }
.search span { color: var(--text-muted); }
.search input { color: var(--text); font-size: 14px; }
.search input::placeholder { color: #64707e; }
.status { color: var(--text-muted); }

.rail {
  top: 64px;
  width: 326px;
  padding: 10px;
  background: rgba(10, 16, 24, .98);
  border-right: 1px solid var(--stroke);
}
.rail-title {
  height: 48px;
  padding: 0 10px;
  border: 0;
  color: var(--text-muted);
  font-size: 10px;
}
.rail-title b { color: var(--lime-soft); }
.rail nav { height: calc(100% - 48px); padding: 0 0 60px; }
.rail button {
  width: 100%;
  margin: 0 0 7px;
  padding: 11px 12px;
  grid-template-columns: 34px 1fr;
  gap: 7px;
  color: var(--text) !important;
  background: var(--panel-deep) !important;
  border: 1px solid var(--stroke);
  border-left: 3px solid var(--category, var(--stroke-strong));
  border-radius: 10px;
}
.rail button[data-category="pro-plan"] { --category: var(--plan); background: linear-gradient(90deg, rgba(255,120,152,.11), var(--panel-deep) 34%) !important; }
.rail button[data-category="spec-plan"] { --category: var(--spec); background: linear-gradient(90deg, rgba(145,215,93,.11), var(--panel-deep) 34%) !important; }
.rail button[data-category="layout"] { --category: var(--layout); background: linear-gradient(90deg, rgba(99,183,255,.11), var(--panel-deep) 34%) !important; }
.rail button[data-category="general"] { --category: var(--general); background: linear-gradient(90deg, rgba(194,148,255,.11), var(--panel-deep) 34%) !important; }
.rail button:hover { border-color: #4b5868; transform: translateX(2px); }
.rail button.active { filter: none; background: var(--panel-soft) !important; border-color: var(--category); box-shadow: 0 0 0 2px color-mix(in srgb, var(--category) 15%, transparent); }
.rail button > span { color: var(--category, var(--text-muted)) !important; font-size: 10px; font-weight: 800; }
.rail strong { color: var(--text) !important; font-size: 12px; letter-spacing: .01em; text-transform: none; }
.rail small { color: #b4bdc8 !important; font-size: 10px; }

.workspace { margin-left: 326px; padding-top: 64px; }
.workspace-head {
  min-height: 214px;
  padding: 52px clamp(24px, 5vw, 74px) 30px;
  align-items: end;
}
.workspace-head small, .chapter-kicker { color: var(--lime); font-weight: 800; letter-spacing: .16em; }
.workspace-head h1 { margin: 11px 0 10px; color: var(--text); font-size: clamp(42px, 6vw, 78px); letter-spacing: -.055em; }
.workspace-head p { color: var(--text-soft); font-size: 15px; }
.toggle {
  padding: 3px;
  border: 1px solid var(--stroke);
  border-radius: 10px;
  background: var(--panel-deep);
}
.toggle button { color: var(--text-soft); border-radius: 7px; text-transform: none; letter-spacing: 0; font-size: 12px; font-weight: 700; }
.toggle .active { background: var(--lime); color: #17230b; }

.reader { margin: 0 clamp(18px, 5vw, 74px) 44px; }
.chapter {
  --category: var(--general);
  padding: clamp(28px, 4.2vw, 58px);
  color: var(--text);
  background: linear-gradient(145deg, color-mix(in srgb, var(--category) 5%, var(--panel)) 0, var(--panel) 38%);
  border: 1px solid var(--stroke);
  border-top: 3px solid var(--category);
  border-radius: 16px;
  box-shadow: 0 24px 65px rgba(0,0,0,.26);
}
.chapter[data-category="pro-plan"] { --category: var(--plan); background: linear-gradient(145deg, rgba(255,120,152,.07), var(--panel) 38%); }
.chapter[data-category="spec-plan"] { --category: var(--spec); background: linear-gradient(145deg, rgba(145,215,93,.07), var(--panel) 38%); }
.chapter[data-category="layout"] { --category: var(--layout); background: linear-gradient(145deg, rgba(99,183,255,.07), var(--panel) 38%); }
.chapter[data-category="general"] { --category: var(--general); background: linear-gradient(145deg, rgba(194,148,255,.07), var(--panel) 38%); }
.chapter.index {
  background: linear-gradient(145deg, rgba(194,148,255,.075), #1a232d 38%);
}
.chapter-kicker { color: var(--category); }
.chapter h1 { color: var(--text); text-transform: none; font-size: clamp(38px, 5vw, 68px); }
.deck { color: var(--text-soft); font-size: 17px; line-height: 1.55; }
.prose h2 { color: var(--text); border-top-color: var(--stroke); font-size: 18px; letter-spacing: .01em; text-transform: none; }
.prose h3 { color: var(--text); }
.prose > p, .steps { color: var(--text-soft); font-family: inherit; font-size: 16px; line-height: 1.72; }
.steps {
  margin: 12px 0 24px;
  padding-left: 1.45rem;
}
.steps li {
  margin: 5px 0;
  padding-left: 5px;
}
.steps li::marker {
  color: var(--category);
  font-size: 1.05em;
}
.chapter-link {
  border: 1px solid var(--stroke);
  border-radius: 999px;
  background: var(--lime);
  color: #162208;
  text-transform: none;
  letter-spacing: 0;
}
.chapter-link:hover { background: var(--lime-soft); }
.visual { top: 80px; }
.media, .placeholder, .icon {
  color: var(--text);
  border-color: var(--stroke);
  border-radius: 12px;
  background: var(--panel-deep);
}
.media button { background: var(--panel-deep); }
.media figcaption { color: var(--text-muted); text-transform: none; }
.placeholder { background: var(--panel-deep); }
.placeholder span { background: var(--category); color: #0c1117; }
.placeholder strong, .placeholder p { background: transparent; color: var(--text-soft); }
.icon { background: var(--panel-deep); }
.icon p { color: var(--text-muted); }
.index .prose > h2 {
  color: var(--text) !important;
  background: var(--panel-deep) !important;
  border: 1px solid var(--stroke) !important;
  border-left: 4px solid var(--category) !important;
  border-radius: 8px;
}
.index .prose > h2[data-category="pro-plan"] { --category: var(--plan); }
.index .prose > h2[data-category="spec-plan"] { --category: var(--spec); }
.index .prose > h2[data-category="layout"] { --category: var(--layout); }
.index .prose > h2[data-category="general"] { --category: var(--general); }
.index .chapter-link, .index .chapter-link[data-category] {
  color: var(--text) !important;
  background: var(--panel-deep) !important;
  border-color: var(--stroke);
  border-radius: 9px;
  text-transform: none;
  letter-spacing: 0;
}
.index .chapter-link:hover { border-color: var(--lime); background: var(--panel-soft) !important; }
dialog { background: rgba(3,6,10,.94); }
dialog button { border-radius: 999px; background: var(--panel); border-color: var(--stroke); }

@media (max-width: 1000px) {
  .topbar { height: 60px; padding: 0 8px; }
  .brand { height: 55px; min-width: 185px; }
  .rail { top: 60px; }
  .workspace { margin-left: 0; padding-top: 60px; }
}
@media (max-width: 650px) {
  .brand { min-width: 52px; }
  .brand b { display: none; }
  .search { margin-right: 4px; }
  .workspace-head { min-height: 0; padding: 34px 18px 22px; }
  .workspace-head h1 { font-size: 43px; }
  .reader { margin: 0 10px 28px; }
  .chapter { padding: 26px 18px 34px; border: 1px solid var(--stroke); border-top: 3px solid var(--category); border-radius: 13px; }
  .rail { width: min(326px, 90vw); }
}