:root{
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface2: #f9fafc;
  --text: #0f172a;
  --muted: rgba(15, 23, 42, 0.62);
  --line: rgba(15, 23, 42, 0.10);
  --shadow: 0 10px 28px rgba(15, 23, 42, 0.10);
  --radius: 16px;
  --accent: #2563eb;
  --accent2: #16a34a;

  --codebg: #f1f5f9;
  --codefg: #0b1220;
  --codeborder: rgba(15,23,42,.12);
  --inlinecodebg: rgba(37,99,235,.08);
  --inlinecodeborder: rgba(37,99,235,.16);

  --maxw: min(1560px, calc(100vw - 48px));
  --toc-w: 300px;

  --scroll-offset: 14px;
  --toc-top: 12px;
}

*{ box-sizing: border-box; }
html{ background: var(--bg); }
body{
  margin:0;
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  color: var(--text);
  line-height: 1.65;

  background: var(--bg);
  position: relative;
  isolation: isolate;
  overflow-x: hidden;
}

body::before{
  content:"";
  position: fixed;
  inset: -140px;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(1200px 600px at 70% -10%, rgba(37,99,235,.10) 0%, rgba(37,99,235,0) 60%),
    radial-gradient(900px 500px at 10% 0%, rgba(22,163,74,.09) 0%, rgba(22,163,74,0) 55%);
  background-repeat: no-repeat;
  background-position: 70% -10%, 10% 0%;
  transform: translateZ(0);
}

a{ color: var(--accent); text-decoration: none; }
a:hover{ text-decoration: underline; }

.topbar{
  border-bottom: 1px solid var(--line);
  background: rgba(255,255,255,.70);
  backdrop-filter: blur(10px);
}
.topbar-inner{
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 16px 18px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: 14px;
}
.brand{
  display:flex;
  align-items:center;
  gap: 12px;
  min-width: 0;
}
.logo{
  width: 34px; height: 34px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: var(--shadow);
  flex: 0 0 auto;
}
.brand-text{ min-width:0; }
.brand-title{
  font-weight: 700;
  letter-spacing: -0.02em;
  font-size: 16px;
  line-height: 1.2;
  margin:0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--text);
}
.brand-sub{
  margin: 2px 0 0;
  font-size: 12.5px;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.top-actions{
  display:flex;
  align-items:center;
  gap:10px;
  flex: 0 0 auto;
}
.chip{
  display:inline-flex;
  align-items:center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.85);
  color: var(--muted);
  font-size: 12.5px;
  white-space: nowrap;
}
.chip strong{ color: var(--text); font-weight: 600; }
.btn{
  display:inline-flex;
  align-items:center;
  gap: 8px;
  padding: 9px 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.85);
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
  user-select:none;
}
.btn:hover{ border-color: rgba(37,99,235,.35); text-decoration:none; }
.btn:active{ transform: translateY(1px); }

.mobile-toc-btn{ display:none; }
@media (max-width: 980px){
  .mobile-toc-btn{ display:inline-flex; }
}

.wrap{
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 16px 18px 28px;
  display:grid;
  grid-template-columns: minmax(260px, var(--toc-w)) 1fr;
  gap: 16px;
  align-items: start;
}
.sidebar{
  position: sticky;
  top: var(--toc-top);
  align-self: start;
  max-height: calc(100vh - (var(--toc-top) * 2));
  overflow:auto;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.90);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 14px 12px;
}
.content{
  min-width: 0;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 26px;
}
@media (min-width: 1400px){
  .content{ padding: 34px 34px; }
}
@media (max-width: 980px){
  .wrap{ grid-template-columns: 1fr; }
  .sidebar{ display:none; position: relative; top:auto; max-height:none; }
  .sidebar.open{ display:block; }
  .content{ padding: 22px 18px; }
}

.toc-head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: 10px;
  padding: 0 6px 10px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 10px;
}
.toc-title{
  font-size: 12px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .12em;
  margin:0;
}
.toc-search{
  width: 100%;
  margin: 10px 6px 6px;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: var(--surface2);
  outline:none;
  font-size: 13px;
  color: var(--text);
}

.toc a{
  display:block;
  padding: 7px 10px;
  border-radius: 10px;
  color: var(--muted);
  text-decoration:none;
  border: 1px solid transparent;
}
.toc a:hover{
  background: var(--surface2);
  color: var(--text);
  border-color: rgba(37,99,235,.20);
}
.toc a.active{
  background: rgba(37,99,235,.10);
  border-color: rgba(37,99,235,.25);
  color: var(--text);
}

.toc{ margin-top: 6px; }
.toc .toc-item{ margin: 4px 4px; }

.toc details.toc-acc{
  margin: 4px 4px;
  border-radius: 12px;
  border: 1px solid transparent;
  overflow: hidden;
}

.toc details.toc-acc[open]{
  border-color: rgba(15,23,42,.10);
  background: rgba(249,250,252,.75);
}

.toc details.toc-acc > summary{
  list-style: none;
  cursor: pointer;
  display:flex;
  align-items:center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: 12px;
  border: 1px solid transparent;
  user-select:none;
}
.toc details.toc-acc > summary::-webkit-details-marker{ display:none; }

.toc details.toc-acc > summary:hover{
  background: var(--surface2);
  border-color: rgba(37,99,235,.18);
}

.toc .toc-caret{
  width: 10px;
  height: 10px;
  border-right: 2px solid rgba(15,23,42,.40);
  border-bottom: 2px solid rgba(15,23,42,.40);
  transform: rotate(-45deg);
  transition: transform .16s ease;
  flex: 0 0 auto;
  margin-left: 2px;
}

.toc details.toc-acc[open] .toc-caret{
  transform: rotate(45deg);
}

.toc details.toc-acc > summary > a{
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  flex: 1 1 auto;
}

.toc details.toc-acc[open] > summary > a{
  color: var(--text);
  font-weight: 600;
}

.toc ul{ list-style:none; padding-left: 0; margin: 0; }
.toc li{ margin: 0; }

.toc details.toc-acc > ul{
  padding: 4px 12px 10px 12px;
}

.toc ul ul a{ padding-left: 22px; font-size: 13px; }
.toc ul ul ul a{ padding-left: 34px; font-size: 12.8px; }

h1,h2,h3,h4,h5{
  line-height: 1.22;
  letter-spacing: -0.02em;
  margin: 1.15em 0 .5em;
  scroll-margin-top: var(--scroll-offset);
}
h1{ font-size: 30px; margin-top: 0; }
h2{
  font-size: 22px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}
h3{ font-size: 20px; }
p{ margin: .7em 0; }
hr{ border:none; border-top: 1px solid var(--line); margin: 22px 0; }

.h-anchor{
  opacity: 0;
  margin-left: 10px;
  font-size: 0.9em;
  color: rgba(37,99,235,.65);
  text-decoration:none !important;
}
h1:hover .h-anchor, h2:hover .h-anchor, h3:hover .h-anchor, h4:hover .h-anchor { opacity: 1; }

code{
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono","Courier New", monospace;
  font-size: 0.94em;
}
:not(pre) > code{
  background: var(--inlinecodebg);
  border: 1px solid var(--inlinecodeborder);
  border-radius: 10px;
  padding: .16em .46em;
  color: #0b1220;
}

pre{
  position: relative;
  background: var(--codebg);
  color: var(--codefg);
  border: 1px solid var(--codeborder);
  border-radius: 16px;
  padding: 14px 14px;
  overflow:auto;
  box-shadow: inset 0 0 0 1px rgba(15,23,42,.03);
}
pre code{ color: inherit !important; }
pre code span{ color: inherit; }
pre code span.kw{ color:#1d4ed8; font-weight:600; }
pre code span.dt{ color:#0f766e; }
pre code span.dv, pre code span.bn, pre code span.fl{ color:#b45309; }
pre code span.ch, pre code span.st{ color:#047857; }
pre code span.co{ color: rgba(15,23,42,.55); font-style: italic; }
pre code span.ot{ color:#7c3aed; }
pre code span.al{ color:#b91c1c; font-weight:700; }
pre code span.fu{ color:#0ea5e9; }

.copy-btn{
  position:absolute;
  top: 10px;
  right: 10px;
  display:inline-flex;
  align-items:center;
  gap: 8px;
  padding: 7px 10px;
  font-size: 12px;
  border-radius: 12px;
  border: 1px solid rgba(15,23,42,.14);
  background: rgba(255,255,255,.88);
  color: rgba(15,23,42,.72);
  cursor:pointer;
  user-select:none;
}
.copy-btn:hover{
  background: rgba(255,255,255,.98);
  color: rgba(15,23,42,.92);
  border-color: rgba(37,99,235,.22);
}

.content p > img,
.content figure > img,
.content p > a > img,
.content figure a > img{
  max-width: 100%;
  height: auto;
  max-height: 68vh;
  object-fit: contain;
  display: block;
  margin: 12px auto;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: var(--surface2);
  padding: 8px;
  box-shadow: 0 8px 22px rgba(15,23,42,.08);
}
.content figure{ margin: 16px 0; }
.content figcaption{
  text-align: center;
  font-size: 12.5px;
  color: var(--muted);
  margin-top: 8px;
}

table{
  width:100%;
  border-collapse: collapse;
  margin: 14px 0;
  overflow:hidden;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--surface);
}
th,td{
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
th{
  text-align:left;
  font-weight: 600;
  background: var(--surface2);
}
tr:last-child td{ border-bottom:none; }

blockquote{
  margin: 14px 0;
  padding: 12px 14px;
  border-left: 4px solid rgba(37,99,235,.55);
  background: rgba(37,99,235,.06);
  border-radius: 14px;
}
blockquote p{ margin: .55em 0; }

.footer{
  margin-top: 26px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12.5px;
  display:flex; justify-content:space-between; gap:10px; flex-wrap:wrap;
}

::selection { background: rgba(37,99,235,.18); }