/* ============================================================
   ToolsForEngineers.com — Engineering Blog Dashboard
   Folder-controlled sections: /posts/section-slug/post-slug/
   ============================================================ */

:root{
  --bg:#f4f7fb;
  --surface:#ffffff;
  --surface-soft:#f8fafc;
  --ink:#0f172a;
  --muted:#64748b;
  --line:#dfe7f2;
  --line-soft:#edf2f7;
  --blue:#0a66c2;
  --blue-dark:#084f99;
  --blue-soft:#eaf4ff;
  --shadow:0 14px 34px rgba(15,23,42,.075);
  --shadow-soft:0 6px 18px rgba(15,23,42,.05);
  --radius:16px;
  --sidebar:252px;
  --topbar:46px;
  --main-max:1456px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.55;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
a{color:inherit}
img{max-width:100%}
b,strong{font-weight:500}

/* ---------- Topbar ---------- */
.blog-topbar{
  position:sticky;
  top:0;
  z-index:80;
  height:var(--topbar);
  background:rgba(255,255,255,.97);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}
.blog-topbar-inner{
  height:100%;
  display:grid;
  grid-template-columns:var(--sidebar) minmax(0,1fr);
  margin:0;
  padding:0;
}
.topbar-brand-zone{
  height:100%;
  display:flex;
  align-items:center;
  gap:10px;
  padding:0 18px;
  border-right:1px solid var(--line);
  background:#fff;
  min-width:0;
}
.topbar-main-zone{
  height:100%;
  display:flex;
  align-items:center;
  justify-content:flex-end;
  gap:12px;
  padding:0 28px;
  min-width:0;
}
.blog-brand{display:flex;text-decoration:none;min-width:0;align-items:center}
.brand-wordmark{font-size:19px;line-height:1;letter-spacing:.005em;white-space:nowrap}
.brand-dark{color:#30343b;font-weight:500}
.brand-blue{color:var(--blue);font-weight:500}
.blog-toplinks{margin-left:auto;display:flex;align-items:center;gap:10px;flex:0 0 auto}
.blog-toplinks a{
  text-decoration:none;
  font-size:13px;
  border:1px solid var(--line);
  background:#fff;
  padding:7px 13px;
  border-radius:999px;
  color:#334155;
  transition:background .15s ease,border-color .15s ease,color .15s ease,transform .15s ease;
}
.blog-toplinks a:hover{border-color:rgba(10,102,194,.35);color:var(--blue);transform:translateY(-1px)}
.blog-toplinks a.main-tools-link{background:var(--blue);color:#fff;border-color:var(--blue);box-shadow:0 7px 16px rgba(10,102,194,.15)}
.blog-toplinks a.main-tools-link:hover{background:var(--blue-dark);color:#fff}
.menu-toggle{display:none;width:36px;height:36px;border:1px solid var(--line);border-radius:11px;background:#fff;cursor:pointer;align-items:center;justify-content:center;flex-direction:column;gap:5px;flex:0 0 auto}
.menu-toggle span{width:18px;height:2px;border-radius:999px;background:var(--blue);display:block}

/* ---------- Shell ---------- */
.blog-shell{display:grid;grid-template-columns:var(--sidebar) minmax(0,1fr);min-height:calc(100vh - var(--topbar))}
.blog-sidebar{border-right:1px solid var(--line);background:#fff;min-height:calc(100vh - var(--topbar));position:sticky;top:var(--topbar);align-self:start;max-height:calc(100vh - var(--topbar));overflow:auto}
.sidebar-inner{padding:12px 10px 18px}
.blog-main{min-width:0;padding:14px 24px 34px}
.container{width:100%;max-width:var(--main-max);margin:0}
.sidebar-scrim{display:none}

/* ---------- Sidebar ---------- */
.side-block{background:var(--surface);border:1px solid var(--line-soft);border-radius:14px;padding:12px;margin-bottom:12px;box-shadow:0 1px 2px rgba(15,23,42,.025)}
.side-title{font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:#0f172a;font-weight:500;margin:0 0 10px}
.side-nav{display:flex;flex-direction:column;gap:8px}
.side-item{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:9px 10px;border-radius:11px;border:1px solid var(--line-soft);background:#fff;text-decoration:none;color:#0f172a;font-size:13px;line-height:1.35;transition:background .15s ease,border-color .15s ease,color .15s ease,transform .15s ease}
.side-item:hover{border-color:rgba(10,102,194,.28);background:#f7fbff;color:var(--blue)}
.side-item.active{border-color:rgba(10,102,194,.35);background:var(--blue-soft);color:var(--blue)}
.side-count{font-size:11px;color:#64748b;font-weight:400;flex:0 0 auto}

/* ---------- General ---------- */
.muted{color:var(--muted)}
.breadcrumb{display:flex;flex-wrap:wrap;align-items:center;gap:7px;color:#64748b;font-size:12px;letter-spacing:.025em;margin:0 0 11px}
.crumb{color:#334155;text-decoration:none;font-weight:500}
.crumb:hover{color:var(--blue)}
.clear-filter{font-size:12px;color:var(--blue)}
.hero{position:relative;overflow:hidden;background:#fff;border:1px solid var(--line);border-radius:18px;padding:24px 28px;margin-bottom:22px;box-shadow:var(--shadow-soft)}
.hero h1{position:relative;z-index:1;margin:0;font-size:clamp(30px,3.5vw,46px);line-height:1.08;letter-spacing:-.035em;font-weight:500}
.hero p{position:relative;z-index:1;max-width:790px;margin:0;font-size:15.5px}
.search-panel{width:100%;background:#fff;border:1px solid var(--line);border-radius:14px;padding:8px 10px;margin-bottom:22px;box-shadow:var(--shadow-soft)}
.filter-label{font-size:12px;text-transform:uppercase;letter-spacing:.08em;color:var(--blue);margin:0 0 7px;font-weight:500}
.search{width:100%;height:34px;border:1px solid #cfe0f4;border-radius:10px;padding:0 13px;font:inherit;background:#fff;color:var(--ink);outline:none;box-shadow:none}
.search:focus{border-color:var(--blue);box-shadow:0 0 0 4px rgba(10,102,194,.10)}
.home-group{margin:24px 0 0}
.home-group-head{display:flex;align-items:end;justify-content:space-between;gap:12px;margin-bottom:12px}
.home-group-head h2{margin:0;font-size:19px;letter-spacing:-.02em;font-weight:500}
.grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}
.card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:16px;box-shadow:0 1px 2px rgba(15,23,42,.025)}
.card-title,.tool-title{margin:0;font-size:18px;line-height:1.25;letter-spacing:-.02em;font-weight:500}
.card-desc{margin:0;font-size:14px;line-height:1.58}
.btn{display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--blue);background:var(--blue);color:#fff;text-decoration:none;border-radius:999px;min-height:34px;padding:7px 14px;font-size:13px;font-weight:500;transition:background .15s ease,border-color .15s ease,transform .15s ease}
.btn:hover{background:var(--blue-dark);border-color:var(--blue-dark);transform:translateY(-1px)}

/* ---------- Tags ---------- */
.tag{display:inline-flex;align-items:center;gap:4px;padding:4px 9px;font-size:11.5px;font-weight:400;text-decoration:none;border-radius:999px;border:1px solid rgba(10,102,194,.14);background:rgba(10,102,194,.055);color:#164e82;line-height:1.4;transition:background .15s ease,border-color .15s ease,color .15s ease}
.tag:hover{background:rgba(10,102,194,.10);border-color:rgba(10,102,194,.28);color:var(--blue)}
.tag-count{font-size:10px;opacity:.65;font-weight:400}

/* ---------- Post grid ---------- */
.grid-posts .post-card{display:flex;flex-direction:column;padding:0;overflow:hidden;transition:border-color .15s ease,transform .15s ease,box-shadow .15s ease}
.post-card:hover{border-color:rgba(10,102,194,.32);transform:translateY(-2px);box-shadow:var(--shadow-soft)}
.post-cover{display:block;width:100%;aspect-ratio:16/9;background:linear-gradient(135deg,rgba(10,102,194,.10),rgba(15,23,42,.025));overflow:hidden;position:relative}
.post-cover img{width:100%;height:100%;object-fit:cover;display:block;transition:transform .35s ease}
.post-card:hover .post-cover img{transform:scale(1.035)}
.post-card-body{padding:15px 16px 16px;display:flex;flex-direction:column;gap:9px;flex:1}
.post-category{display:inline-block;font-size:10.5px;font-weight:500;letter-spacing:.07em;text-decoration:none;color:var(--blue);text-transform:uppercase;margin-bottom:1px;align-self:flex-start}
.post-category:hover{text-decoration:underline;text-underline-offset:3px}
.post-title{font-size:17px;font-weight:500}
.post-title a{text-decoration:none;color:inherit}
.post-title a:hover{color:var(--blue)}
.post-meta{font-size:12px;display:flex;align-items:center;gap:6px;flex-wrap:wrap}
.post-meta .dot{opacity:.5}
.post-tags{display:flex;flex-wrap:wrap;gap:6px;margin:8px 0 0}
.post-card-footer{margin-top:auto;display:flex;align-items:center;justify-content:space-between;gap:10px;padding-top:6px}
.post-card-footer .btn{margin-top:0;flex-shrink:0}
.post-author{font-size:11.5px;font-weight:400;text-align:right;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;opacity:.75}

/* ---------- Article page ---------- */
.article{max-width:var(--main-max);margin:8px 0 32px;background:#fff;border:1px solid var(--line);border-radius:18px;padding:28px clamp(22px,3.2vw,48px) 34px;box-shadow:var(--shadow-soft)}
.article-header{margin-bottom:20px}
.article-title{font-size:clamp(32px,3.1vw,48px);line-height:1.13;letter-spacing:-.04em;margin:8px 0 13px;font-weight:500;max-width:1220px}
.article-meta{font-size:13px;display:flex;flex-wrap:wrap;gap:6px;align-items:center}
.article-meta .dot{opacity:.5}
.article-header .post-tags{margin-top:13px}
.article-cover{display:none}
.article-body{font-size:16px;line-height:1.75;color:#1f2937;margin-top:24px;max-width:none}
.article-body>*:first-child{margin-top:0}
.article-body>*:last-child{margin-bottom:0}
.article-body h2,.article-body h3,.article-body h4{color:#111827;margin-top:1.65em;margin-bottom:.55em;line-height:1.25;letter-spacing:-.02em;font-weight:500}
.article-body h2{font-size:1.55em}
.article-body h3{font-size:1.24em}
.article-body h4{font-size:1.08em}
.article-body p{margin:0 0 1em}
.article-body ul,.article-body ol{margin:0 0 1em;padding-left:1.4em}
.article-body li{margin:.35em 0}
.article-body a{color:var(--blue);text-decoration:underline;text-underline-offset:2px}
.article-body a:hover{text-decoration-thickness:2px}
.article-body img{max-width:100%;height:auto;border-radius:12px;margin:1em 0;display:block}
.article-body figure{margin:1.4em 0}
.article-body figure img{margin:0}
.article-body figcaption{font-size:13px;color:#64748b;text-align:center;margin-top:6px}
.article-body blockquote{margin:1.2em 0;padding:10px 16px;border-left:4px solid var(--blue);background:var(--blue-soft);border-radius:0 12px 12px 0;color:#334155;font-style:italic}
.article-body blockquote p:last-child{margin-bottom:0}
.article-body code{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;font-size:.92em;background:rgba(15,23,42,.06);padding:1px 6px;border-radius:6px}
.article-body pre{background:#0f172a;color:#e2e8f0;padding:14px 16px;border-radius:14px;overflow:auto;font-size:13.5px;line-height:1.55;margin:1.2em 0;max-width:100%}
.article-body pre code{background:transparent;color:inherit;padding:0;border-radius:0;font-size:inherit}
.article-body table{width:100%;border-collapse:collapse;margin:1.2em 0;font-size:14px}
.article-body th,.article-body td{border:1px solid var(--line);padding:8px 12px;text-align:left}
.article-body th{background:#f8fafc;font-weight:500}
.article-body hr{border:none;border-top:1px solid var(--line);margin:2em 0}
.article-body .callout{border-left:4px solid var(--blue);background:#f1f7ff;padding:12px 16px;border-radius:0 12px 12px 0;margin:1.2em 0}
.article-body .callout.warn{border-left-color:#d97706;background:#fff7ed}
.article-body .callout.tip{border-left-color:#059669;background:#ecfdf5}
.article-footer{margin-top:30px;padding-top:16px;border-top:1px solid var(--line)}
.article-share{font-size:13px}
.article-share a{color:var(--blue);text-decoration:none;margin:0 2px}
.article-share a:hover{text-decoration:underline}
.article-nav{max-width:var(--main-max);margin:0 0 42px;display:grid;grid-template-columns:1fr 1fr;gap:14px}
.article-nav-link{display:flex;flex-direction:column;gap:4px;padding:15px 16px;background:#fff;border:1px solid var(--line);border-radius:16px;text-decoration:none;color:inherit;transition:border-color .15s ease,transform .15s ease,box-shadow .15s ease}
.article-nav-link:hover{border-color:rgba(10,102,194,.35);transform:translateY(-1px);box-shadow:var(--shadow-soft)}
.article-nav-link.newer{text-align:right;align-items:flex-end}
.article-nav-title{font-weight:500;font-size:14px;line-height:1.35}


/* ---------- Copy-code toolbar ---------- */
.code-copy-wrap{margin:1.2em 0;border-radius:14px;overflow:hidden;background:#0f172a;border:1px solid rgba(148,163,184,.22);box-shadow:0 10px 24px rgba(15,23,42,.10)}
.code-copy-toolbar{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:8px 10px;background:#111827;border-bottom:1px solid rgba(148,163,184,.20)}
.code-copy-label{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:#94a3b8}
.code-copy-btn{border:1px solid rgba(226,232,240,.18);background:rgba(255,255,255,.08);color:#e2e8f0;border-radius:999px;padding:5px 11px;font:inherit;font-size:12px;line-height:1.4;cursor:pointer;transition:background .15s ease,border-color .15s ease,color .15s ease,transform .15s ease}
.code-copy-btn:hover{background:rgba(255,255,255,.14);border-color:rgba(226,232,240,.30);transform:translateY(-1px)}
.code-copy-btn.copied{background:#dcfce7;border-color:#86efac;color:#166534}
.article-body .code-copy-wrap pre{margin:0;border-radius:0;box-shadow:none;border:0;max-height:none}

/* ---------- Empty states ---------- */
.card-empty{grid-column:1/-1}

/* ---------- Footer ---------- */
.site-footer{margin-top:34px;padding-top:14px;border-top:1px solid var(--line)}
.site-footer-inner{display:flex;align-items:center;justify-content:flex-start;gap:12px;color:#64748b;font-size:12.5px}
.site-footer a{color:var(--blue);text-decoration:none;font-weight:500}
.site-footer a:hover{text-decoration:underline}

/* ---------- Responsive ---------- */
@media (max-width:1500px){.grid{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media (max-width:1180px){.grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:900px){
  :root{--topbar:52px}
  .menu-toggle{display:flex}
  .blog-topbar-inner{display:flex;align-items:center;padding:0}
  .topbar-brand-zone{flex:1;border-right:none;padding:0 14px}
  .topbar-main-zone{flex:0 0 auto;padding:0 14px 0 0}
  .blog-toplinks a.main-tools-link{font-size:12px;padding:8px 10px}
  .brand-wordmark{font-size:17px}
  .blog-shell{grid-template-columns:1fr}
  .blog-sidebar{position:fixed;z-index:100;top:var(--topbar);left:0;width:min(86vw,var(--sidebar));height:calc(100vh - var(--topbar));max-height:none;transform:translateX(-105%);transition:transform .22s ease;box-shadow:var(--shadow)}
  .sidebar-open .blog-sidebar{transform:translateX(0)}
  .sidebar-scrim{display:block;position:fixed;z-index:90;inset:var(--topbar) 0 0 0;background:rgba(15,23,42,.35);opacity:0;pointer-events:none;transition:opacity .2s ease}
  .sidebar-open .sidebar-scrim{opacity:1;pointer-events:auto}
  .blog-main{padding:16px 16px 34px}
  .container{max-width:none}
  .article,.article-nav{max-width:none}
  .article-body{max-width:none}
}
@media (max-width:640px){
  .blog-toplinks{display:none}
  .blog-main{padding:14px 12px 32px}
  .breadcrumb{font-size:11px}
  .search-panel{border-radius:15px;padding:9px;margin-bottom:18px}
  .grid{grid-template-columns:1fr}
  .article{border-radius:16px;margin:6px 0 28px;padding:22px 18px 28px}
  .article-title{font-size:29px}
  .article-nav{grid-template-columns:1fr;margin-left:0;margin-right:0}
  .post-card-footer{flex-wrap:wrap;gap:7px}
  .post-author{text-align:left;flex-basis:100%}
}