:root{
  --bg:#07111f;
  --bg-2:#0a1525;
  --panel:rgba(13,27,47,.78);
  --panel-solid:#0f1c30;
  --text:#eef6ff;
  --muted:#8ea0b6;
  --line:rgba(150,180,210,.14);
  --accent:#60e6c5;
  --accent-2:#74a7ff;
  --shadow:0 18px 60px rgba(0,0,0,.28);
  --radius:18px;
  --topbar:72px;
  --sidebar:270px
}
html[data-theme="light"]{
  --bg:#f6f8fc;
  --bg-2:#ffffff;
  --panel:rgba(255,255,255,.84);
  --panel-solid:#fff;
  --text:#102033;
  --muted:#66768a;
  --line:rgba(24,48,74,.12);
  --shadow:0 18px 50px rgba(24,48,74,.10)
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--text);
  font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  min-height:100vh;overflow-x:hidden
}
body::selection{background:rgba(96,230,197,.25)}
a{text-decoration:none;color:inherit}
button,input{font:inherit}
.ambient{position:fixed;border-radius:50%;filter:blur(100px);pointer-events:none;opacity:.16;z-index:-1}
.ambient-a{width:460px;height:460px;background:#00d7b1;left:-120px;top:-80px}
.ambient-b{width:520px;height:520px;background:#4278ff;right:-180px;top:160px}
.topbar{
  height:var(--topbar);position:fixed;inset:0 0 auto 0;z-index:50;
  border-bottom:1px solid var(--line);background:rgba(7,17,31,.72);backdrop-filter:blur(20px)
}
html[data-theme="light"] .topbar{background:rgba(246,248,252,.82)}
.topbar-inner{height:100%;display:flex;align-items:center;justify-content:space-between;padding:0 28px}
.brand{display:flex;align-items:center;gap:12px}
.brand-mark{
  width:38px;height:38px;border-radius:12px;display:grid;place-items:center;
  background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#06111e;font-weight:800;
  box-shadow:0 10px 30px rgba(96,230,197,.18)
}
.brand-copy{display:flex;flex-direction:column;line-height:1.1}
.brand-copy strong{font-size:.98rem}
.brand-copy small{color:var(--muted);font-size:.69rem;margin-top:4px}
.top-actions{display:flex;align-items:center;gap:10px}
.search-trigger,.icon-btn{
  border:1px solid var(--line);background:var(--panel);color:var(--muted);
  border-radius:12px;height:40px;cursor:pointer
}
.search-trigger{padding:0 12px;display:flex;align-items:center;gap:9px;min-width:235px}
.search-trigger kbd{margin-left:auto}
kbd{
  border:1px solid var(--line);background:rgba(255,255,255,.04);
  border-radius:6px;padding:2px 6px;font-size:.7rem;color:var(--muted)
}
.icon-btn{width:40px}
.app-shell{display:grid;grid-template-columns:var(--sidebar) 1fr;padding-top:var(--topbar)}
.sidebar{
  position:fixed;left:0;top:var(--topbar);bottom:0;width:var(--sidebar);
  border-right:1px solid var(--line);background:rgba(7,17,31,.48);backdrop-filter:blur(16px);
  display:flex;flex-direction:column;z-index:40
}
html[data-theme="light"] .sidebar{background:rgba(246,248,252,.72)}
.sidebar-scroll{padding:26px 18px;overflow:auto;flex:1}
.sidebar-label{font-size:.66rem;letter-spacing:.16em;color:var(--muted);font-weight:700;padding:0 10px 9px}
.sidebar-space{margin-top:22px}
.side-nav,.sidebar-notes{display:flex;flex-direction:column;gap:5px}
.side-nav a,.sidebar-notes a{
  padding:9px 10px;border-radius:10px;color:#aebcd0;font-size:.88rem;
  transition:.18s ease
}
html[data-theme="light"] .side-nav a,html[data-theme="light"] .sidebar-notes a{color:#526176}
.side-nav a:hover,.sidebar-notes a:hover,.side-nav a.active{
  background:rgba(255,255,255,.06);color:var(--text)
}
.sidebar-notes a{font-size:.82rem}
.sidebar-footer{
  padding:15px 18px;border-top:1px solid var(--line);display:flex;
  justify-content:space-between;color:var(--muted);font-size:.72rem
}
.status-dot::before{content:"";display:inline-block;width:7px;height:7px;border-radius:50%;background:#34d399;margin-right:6px}
.main{grid-column:2;min-width:0;padding:48px 54px 90px;max-width:1500px;width:100%;margin:0 auto}
.hero{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(360px,.8fr);gap:64px;align-items:center;padding:42px 0 64px}
.eyebrow{font-size:.7rem;letter-spacing:.16em;color:var(--accent);font-weight:800}
.hero h1,.page-head h1,.note-head h1{
  font-size:clamp(2.6rem,5vw,5.4rem);line-height:1.03;letter-spacing:-.055em;margin:14px 0 22px
}
.hero p,.page-head p,.note-head p{font-size:1.04rem;line-height:1.8;color:var(--muted);max-width:760px}
.hero-actions{display:flex;gap:12px;margin-top:28px}
.primary-btn,.ghost-btn{
  min-height:46px;padding:0 18px;border-radius:12px;font-weight:700;display:inline-flex;
  align-items:center;justify-content:center;cursor:pointer
}
.primary-btn{border:0;background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#06111e}
.ghost-btn{border:1px solid var(--line);background:var(--panel);color:var(--text)}
.hero-panel{
  border:1px solid var(--line);background:linear-gradient(180deg,rgba(17,31,51,.92),rgba(10,20,35,.92));
  border-radius:22px;overflow:hidden;box-shadow:var(--shadow)
}
.terminal-bar{height:45px;padding:0 14px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);color:#8394a9;font-size:.75rem}
.dots{display:flex;gap:6px}.dots span{width:9px;height:9px;border-radius:50%;background:#41506a}
.hero-panel pre{margin:0!important;border:0!important;border-radius:0!important;min-height:280px}
.content-section{padding:32px 0}
.section-heading{display:flex;justify-content:space-between;align-items:end;margin-bottom:20px}
.section-heading h2{font-size:1.8rem;margin:7px 0 0;letter-spacing:-.03em}
.category-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.category-card,.note-card{
  border:1px solid var(--line);background:var(--panel);border-radius:16px;padding:20px;
  transition:.2s ease;box-shadow:0 8px 32px rgba(0,0,0,.06)
}
.category-card:hover,.note-card:hover{transform:translateY(-3px);border-color:rgba(96,230,197,.35)}
.category-card strong{display:block;margin-bottom:6px}
.category-card span{color:var(--muted);font-size:.8rem}
.notes-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.note-card .meta{display:flex;justify-content:space-between;gap:10px;color:var(--muted);font-size:.74rem}
.note-card h3{font-size:1.04rem;line-height:1.4;margin:14px 0 8px}
.note-card p{color:var(--muted);font-size:.85rem;line-height:1.6;margin:0}
.tags{display:flex;flex-wrap:wrap;gap:7px;margin-top:15px}
.tags span{font-size:.69rem;border:1px solid var(--line);padding:4px 7px;border-radius:999px;color:#9fb0c5}
.page-head{padding:30px 0 20px}.page-head h1{font-size:3.5rem}
.note-layout{display:grid;grid-template-columns:minmax(0,1fr) 250px;gap:58px}
.note-article{min-width:0;max-width:920px}
.breadcrumb{font-size:.78rem;color:var(--muted);margin-bottom:22px}
.breadcrumb a:hover{color:var(--accent)}
.note-head{padding-bottom:28px;border-bottom:1px solid var(--line);margin-bottom:32px}
.note-head h1{font-size:clamp(2.4rem,4vw,4.3rem)}
.note-meta{display:flex;flex-wrap:wrap;gap:10px;color:var(--muted);font-size:.8rem;margin-top:18px}
.markdown-body{
  background:transparent!important;color:var(--text)!important;
  font-family:Inter,system-ui,sans-serif!important;font-size:16px!important;line-height:1.8!important
}
.markdown-body h2,.markdown-body h3{scroll-margin-top:100px}
.markdown-body pre{position:relative!important;border:1px solid var(--line)!important;border-radius:14px!important}
.markdown-body code{font-family:"JetBrains Mono",monospace!important}
.copy-btn{
  position:absolute;top:10px;right:10px;border:1px solid #31415c;background:#0d1728;color:#b7c5d8;
  border-radius:8px;padding:5px 8px;font-size:.68rem;cursor:pointer
}
.toc{position:relative}
.toc-box{position:sticky;top:105px;border-left:1px solid var(--line);padding-left:18px}
.toc-title{font-size:.65rem;letter-spacing:.14em;color:var(--muted);font-weight:800;margin-bottom:10px}
#tocList{display:flex;flex-direction:column;gap:8px}
#tocList a{font-size:.76rem;color:var(--muted);line-height:1.35}
#tocList a:hover{color:var(--accent)}
.search-modal{position:fixed;inset:0;z-index:100;display:grid;place-items:start center;padding-top:12vh}
.hidden{display:none!important}
.search-backdrop{position:absolute;inset:0;background:rgba(2,8,18,.68);backdrop-filter:blur(9px)}
.search-dialog{
  position:relative;width:min(680px,calc(100% - 28px));background:#0b1729;border:1px solid #243551;
  border-radius:18px;box-shadow:0 30px 100px rgba(0,0,0,.55);overflow:hidden
}
html[data-theme="light"] .search-dialog{background:#fff}
.search-input-wrap{height:62px;display:flex;align-items:center;gap:10px;padding:0 16px;border-bottom:1px solid var(--line)}
.search-input-wrap input{flex:1;border:0;outline:0;background:transparent;color:var(--text);font-size:1rem}
.search-results{max-height:460px;overflow:auto;padding:8px}
.search-result{padding:12px;border-radius:10px;cursor:pointer}
.search-result:hover,.search-result.active{background:rgba(255,255,255,.06)}
.search-result strong{display:block;font-size:.88rem}
.search-result small{color:var(--muted);font-size:.72rem}
.search-hint{padding:10px 14px;border-top:1px solid var(--line);color:var(--muted);font-size:.68rem}
.mobile-menu{display:none;position:fixed;right:16px;bottom:16px;z-index:60;width:46px;height:46px;border-radius:14px;border:1px solid var(--line);background:var(--panel-solid);color:var(--text)}
@media(max-width:1100px){
  .category-grid{grid-template-columns:repeat(2,1fr)}
  .notes-grid{grid-template-columns:repeat(2,1fr)}
  .hero{grid-template-columns:1fr}.hero-panel{max-width:720px}
  .note-layout{grid-template-columns:1fr}.toc{display:none}
}
@media(max-width:820px){
  :root{--sidebar:0px}
  .sidebar{transform:translateX(-100%);width:280px;transition:.2s ease}
  .sidebar.open{transform:translateX(0)}
  .main{grid-column:1;padding:34px 20px 70px}
  .mobile-menu{display:block}
  .search-trigger{min-width:auto}.search-trigger span:nth-child(2),.search-trigger kbd{display:none}
}
@media(max-width:620px){
  .topbar-inner{padding:0 16px}.brand-copy small{display:none}
  .category-grid,.notes-grid{grid-template-columns:1fr}
  .hero{padding-top:24px}.hero h1{font-size:2.8rem}
  .hero-actions{flex-direction:column;align-items:stretch}
}


/* ===== Horizontal premium navigation ===== */
.app-shell{display:block;padding-top:var(--topbar)}
.main{display:block;max-width:1380px;margin:0 auto;padding:48px 54px 90px}
.topbar-inner{max-width:1480px;margin:0 auto}
.main-nav{display:flex;align-items:center;gap:5px;margin-left:auto;margin-right:22px}
.nav-link{
  position:relative;border:0;background:transparent;color:var(--muted);
  min-height:40px;padding:0 13px;border-radius:10px;display:flex;align-items:center;
  gap:6px;font-size:.86rem;font-weight:600;cursor:pointer;transition:.18s ease
}
.nav-link:hover,.nav-link.active{color:var(--text);background:rgba(255,255,255,.055)}
.nav-link.active::after{
  content:"";position:absolute;left:13px;right:13px;bottom:3px;height:2px;
  border-radius:2px;background:linear-gradient(90deg,var(--accent),var(--accent-2))
}
.nav-dropdown{position:relative}
.chevron{font-size:.85rem;transition:transform .18s ease}
.nav-dropdown.open .chevron{transform:rotate(180deg)}
.mega-menu{
  position:absolute;top:calc(100% + 14px);right:-150px;width:min(820px,calc(100vw - 40px));
  padding:20px;background:rgba(9,20,35,.97);border:1px solid var(--line);border-radius:18px;
  box-shadow:0 28px 90px rgba(0,0,0,.45);backdrop-filter:blur(22px);
  opacity:0;visibility:hidden;transform:translateY(-8px);transition:.18s ease
}
html[data-theme="light"] .mega-menu{background:rgba(255,255,255,.98)}
.nav-dropdown.open .mega-menu{opacity:1;visibility:visible;transform:translateY(0)}
.mega-menu-head{display:flex;align-items:end;justify-content:space-between;padding:3px 4px 16px;border-bottom:1px solid var(--line)}
.mega-menu-head strong{display:block;margin-top:5px;font-size:1rem}
.mega-hint{font-size:.7rem;color:var(--muted)}
.mega-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;padding-top:14px}
.mega-category{border:1px solid var(--line);border-radius:13px;padding:14px;background:rgba(255,255,255,.025)}
.mega-category-title{
  display:flex;align-items:center;justify-content:space-between;font-size:.78rem;font-weight:800;
  color:var(--accent);margin-bottom:8px
}
.mega-category-title span{color:var(--muted);font-size:.66rem;font-weight:500}
.mega-articles{display:flex;flex-direction:column;gap:3px}
.mega-articles a{
  padding:7px 8px;border-radius:8px;font-size:.78rem;color:var(--muted);line-height:1.35;
  transition:.15s ease
}
.mega-articles a:hover{background:rgba(255,255,255,.055);color:var(--text)}
.nav-toggle{
  display:none;width:40px;height:40px;border-radius:12px;border:1px solid var(--line);
  background:var(--panel);color:var(--text);cursor:pointer
}
.about-head{max-width:850px;padding-top:50px}
.about-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:24px}
.about-card{
  border:1px solid var(--line);background:var(--panel);border-radius:18px;padding:26px;
  min-height:230px
}
.about-number{font-family:"JetBrains Mono",monospace;color:var(--accent);font-size:.75rem}
.about-card h3{font-size:1.2rem;margin:35px 0 10px}
.about-card p{color:var(--muted);font-size:.87rem;line-height:1.7}

@media(max-width:980px){
  .main-nav{
    position:absolute;left:16px;right:16px;top:calc(var(--topbar) - 2px);
    margin:0;padding:10px;background:var(--panel-solid);border:1px solid var(--line);
    border-radius:14px;box-shadow:var(--shadow);display:none;flex-direction:column;align-items:stretch
  }
  .main-nav.open{display:flex}
  .nav-link{width:100%;justify-content:space-between;padding:0 12px}
  .nav-link.active::after{display:none}
  .nav-toggle{display:block}
  .nav-dropdown{width:100%}
  .mega-menu{
    position:static;width:100%;margin-top:5px;padding:12px;box-shadow:none;
    display:none;opacity:1;visibility:visible;transform:none;background:rgba(255,255,255,.025)
  }
  .nav-dropdown.open .mega-menu{display:block}
  .mega-menu-head{display:none}
  .mega-grid{grid-template-columns:1fr;padding-top:0}
  .top-actions{margin-left:auto}
}
@media(max-width:700px){
  .search-trigger{width:40px;padding:0;justify-content:center}
  .search-trigger span:nth-child(2),.search-trigger kbd{display:none}
  .main{padding:34px 18px 70px}
  .about-grid{grid-template-columns:1fr}
}

/* Folder = horizontal menu item */
.folder-menus{display:flex;align-items:center;gap:5px}
.folder-dropdown-menu{
  position:absolute;top:calc(100% + 14px);left:50%;transform:translate(-50%,-8px);
  width:390px;padding:12px;background:rgba(9,20,35,.98);border:1px solid var(--line);
  border-radius:16px;box-shadow:0 25px 80px rgba(0,0,0,.42);backdrop-filter:blur(20px);
  opacity:0;visibility:hidden;transition:.18s ease
}
html[data-theme="light"] .folder-dropdown-menu{background:rgba(255,255,255,.98)}
.folder-dropdown.open .folder-dropdown-menu{opacity:1;visibility:visible;transform:translate(-50%,0)}
.folder-menu-head{padding:8px 9px 12px;border-bottom:1px solid var(--line)}
.folder-menu-head strong{display:block;margin-top:4px;font-size:.88rem}
.folder-menu-head small{display:block;color:var(--muted);font-size:.7rem;line-height:1.45;margin-top:6px}
.folder-article-list{display:flex;flex-direction:column;padding-top:7px}
.folder-article-list a{padding:10px;border-radius:10px;transition:.15s ease}
.folder-article-list a:hover{background:rgba(255,255,255,.055)}
.folder-article-list strong{display:block;font-size:.78rem;margin-bottom:3px}
.folder-article-list span{display:block;color:var(--muted);font-size:.68rem;line-height:1.45}
@media(max-width:980px){
  .folder-menus{display:flex;flex-direction:column;align-items:stretch;width:100%}
  .folder-dropdown-menu{
    position:static;width:100%;transform:none!important;display:none;opacity:1;visibility:visible;
    box-shadow:none;background:rgba(255,255,255,.025);margin-top:4px
  }
  .folder-dropdown.open .folder-dropdown-menu{display:block}
}

/* FIX: menu visibility / desktop fit */
@media(min-width:981px){
  .topbar-inner{gap:18px}
  .main-nav{margin-left:auto;margin-right:14px;gap:2px}
  .folder-menus{gap:2px}
  .nav-link{padding-left:10px;padding-right:10px}
  .search-trigger{min-width:190px}
}
@media(max-width:1180px) and (min-width:981px){
  .brand-copy small{display:none}
  .search-trigger span:nth-child(2),.search-trigger kbd{display:none}
  .search-trigger{min-width:40px;width:40px;padding:0;justify-content:center}
}

/* Simple horizontal folder navigation: no submenu */
.folder-menus{display:flex;align-items:center;gap:2px}
@media(max-width:980px){
  .folder-menus{display:flex;flex-direction:column;align-items:stretch;width:100%;gap:2px}
  .folder-menus .nav-link{width:100%}
}


/* Code block language label + copy toolbar */
.markdown-body pre {
  position: relative;
  padding-top: 3.2rem !important;
  overflow: auto;
}
.markdown-body pre .code-toolbar {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2.45rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 .8rem 0 1rem;
  border-bottom: 1px solid rgba(148,163,184,.18);
  background: rgba(15,23,42,.72);
  backdrop-filter: blur(8px);
}
.markdown-body pre .code-language {
  font-family: "JetBrains Mono", monospace;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  opacity: .82;
}
.markdown-body pre .copy-btn {
  position: static !important;
  margin: 0 !important;
}
[data-theme="light"] .markdown-body pre .code-toolbar {
  background: rgba(248,250,252,.92);
}