/* =========================================================
   Skill-Lite — Tutorial Layout (sidebar + article styles)
   ========================================================= */

/* ── Layout ── */
.tutorial-layout {
  flex: 1;
  display: flex;
  align-items: stretch;
  min-height: 0;
}

/* ── Sidebar ── */
.side-nav {
  width: 272px;
  flex-shrink: 0;
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 24px 10px 64px;
  position: sticky;
  top: 94px;           /* header is sticky: 54px top bar + 40px nav = 94px */
  height: calc(100vh - 94px);
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.side-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.1px;
  padding: 4px 10px 16px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 8px;
  color: var(--text);
}

/* Logo icons shared base */
.side-title .k8s-logo,
.side-title .docker-logo,
.side-title .springboot-logo,
.side-title .langchain-logo,
.side-title .langgraph-logo,
.side-title .rag-logo,
.side-title .ml-logo,
.side-title .bestpractices-logo,
.side-title .kafka-logo {
  width: 28px; height: 28px;
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; flex-shrink: 0;
}

.side-title .k8s-logo         { background: rgba(50,108,229,.15);  border: 1px solid rgba(50,108,229,.3); }
.side-title .docker-logo       { background: rgba(13,183,237,.15);  border: 1px solid rgba(13,183,237,.3); }
.side-title .springboot-logo   { background: rgba(109,179,63,.15);  border: 1px solid rgba(109,179,63,.3); }
.side-title .langchain-logo    { background: rgba(124,58,237,.15);  border: 1px solid rgba(124,58,237,.3); }
.side-title .langgraph-logo    { background: rgba(234,88,12,.15);   border: 1px solid rgba(234,88,12,.3);  }
.side-title .rag-logo          { background: rgba(13,148,136,.15);  border: 1px solid rgba(13,148,136,.3); }
.side-title .ml-logo           { background: rgba(220,38,38,.15);   border: 1px solid rgba(220,38,38,.3);  }
.side-title .bestpractices-logo { background: rgba(245,158,11,.15); border: 1px solid rgba(245,158,11,.3); }
.side-title .kafka-logo         { background: rgba(225,29,72,.15);  border: 1px solid rgba(225,29,72,.3);  }

.side-section-label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin: 20px 10px 5px;
  opacity: 0.65;
}

.side-link {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 7px 10px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  transition: background 0.12s, color 0.12s;
  line-height: 1.4;
}
.side-link:hover {
  background: var(--surface2);
  color: var(--text);
}
.side-link.active {
  background: var(--accent-subtle);
  color: var(--accent);
  font-weight: 600;
}
.side-link .side-icon {
  font-size: 15px;
  width: 18px;
  text-align: center;
  flex-shrink: 0;
  opacity: 0.75;
}

/* ── Mobile sidebar ── */
.side-toggle {
  display: none;
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 700;
  align-items: center;
  gap: 7px;
  background: var(--accent);
  border: none;
  border-radius: 28px;
  color: #fff;
  cursor: pointer;
  font-family: inherit;
  font-size: 15px;
  font-weight: 600;
  padding: 12px 20px;
  box-shadow: 0 8px 28px rgba(0,164,239,.45);
  transition: transform 0.15s, box-shadow 0.15s;
}
.side-toggle:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(0,164,239,.55);
}

.side-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.65);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 599;
}
.side-backdrop.show { display: block; }

/* ── Content Area ── */
.tutorial-content {
  flex: 1;
  min-width: 0;
  padding: 44px 56px 88px;
  background: var(--bg);
}
.article { max-width: 800px; margin: 0 auto; }

/* ── Breadcrumb ── */
.crumb {
  display: flex;
  align-items: center;
  font-size: 14.5px;
  color: var(--text-muted);
  margin-bottom: 18px;
  gap: 2px;
}
.crumb a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
  padding: 2px 0;
}
.crumb a:hover { color: var(--accent); }
.crumb .sep {
  margin: 0 6px;
  opacity: 0.3;
  font-size: 13px;
  user-select: none;
}

/* ── Headings ── */
.article h1 {
  font-size: 34px;
  font-weight: 800;
  letter-spacing: -0.8px;
  line-height: 1.15;
  margin-bottom: 14px;
  color: var(--text);
}

.lead {
  font-size: 17.5px;
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 0;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 36px;
}

.article h2 {
  font-size: 23px;
  font-weight: 700;
  letter-spacing: -0.4px;
  margin: 48px 0 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}
.article h3 {
  font-size: 18.5px;
  font-weight: 700;
  margin: 28px 0 10px;
  color: var(--text);
  letter-spacing: -0.2px;
}

.article p {
  font-size: 16.5px;
  line-height: 1.8;
  margin-bottom: 16px;
  color: var(--text);
}

.article ul, .article ol {
  margin: 0 0 18px 24px;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--text);
}
.article li { margin-bottom: 6px; }

.article a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-ring);
  transition: border-color 0.15s, color 0.15s;
}
.article a:hover { border-bottom-color: var(--accent); }

/* ── Inline Code ── */
.article code {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-xs);
  color: #0369a1;
  font-family: 'Cascadia Code', 'Fira Code', Consolas, 'SF Mono', monospace;
  font-size: 14.5px;
  padding: 2px 6px;
  white-space: nowrap;
}

/* ── Code Blocks ── */
pre.code {
  background: #1a2035;
  border: 1px solid #2a3450;
  border-radius: var(--radius-md);
  margin: 16px 0 28px;
  padding: 0;
  overflow: hidden;
  position: relative;
}

/* Top bar — language label */
pre.code::before {
  content: attr(data-lang);
  display: block;
  height: 36px;
  background: #141d2e;
  border-bottom: 1px solid #2a3450;
  color: #64748b;
  font-family: inherit;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  padding: 0 16px;
  line-height: 36px;
}

pre.code code {
  background: none;
  border: none;
  border-radius: 0;
  color: #c8d0f0;
  display: block;
  font-family: 'Cascadia Code', 'Fira Code', Consolas, 'SF Mono', monospace;
  font-size: 15px;
  line-height: 1.7;
  padding: 18px 20px 18px;
  overflow-x: auto;
  white-space: pre;
}
pre.code code::-webkit-scrollbar { height: 4px; }
pre.code code::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

/* Copy button */
.copy-code-btn {
  position: absolute;
  top: 6px; right: 10px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-xs);
  color: var(--text-muted);
  cursor: pointer;
  font-family: inherit;
  font-size: 12.5px;
  font-weight: 600;
  padding: 3px 10px;
  transition: color 0.13s, border-color 0.13s, background 0.13s;
  z-index: 2;
  letter-spacing: 0.3px;
}
.copy-code-btn:hover {
  color: var(--text);
  border-color: var(--accent);
  background: var(--accent-subtle);
}

/* ── Callouts ── */
.callout {
  border-left: 3px solid var(--accent);
  background: var(--accent-subtle);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 16px;
  line-height: 1.72;
  margin: 18px 0 26px;
  padding: 14px 18px;
  color: var(--text-muted);
}
.callout strong { color: var(--text); }
.callout.tip  {
  border-left-color: var(--success);
  background: rgba(52,211,153,.07);
}
.callout.warn {
  border-left-color: var(--warn);
  background: rgba(251,191,36,.07);
}

/* ── Tables ── */
.article table {
  border-collapse: collapse;
  width: 100%;
  font-size: 15.5px;
  margin: 16px 0 28px;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border);
}
.article th {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-weight: 700;
  font-size: 13.5px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  padding: 10px 14px;
  text-align: left;
}
.article td {
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
  line-height: 1.65;
  padding: 10px 14px;
  vertical-align: top;
}
.article tr:last-child td { border-bottom: none; }
.article tr:nth-child(even) td { background: rgba(255,255,255,.015); }
.article td:first-child { color: var(--text); font-weight: 500; }

/* ── Diagram Boxes ── */
.diagram {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
  margin: 16px 0 28px;
  padding: 20px;
}
.diagram-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  flex: 1;
  min-width: 200px;
  padding: 16px 18px;
  transition: border-color 0.15s;
}
.diagram-box:hover { border-color: rgba(0,164,239,.4); }
.diagram-box.hl { border-color: var(--accent); }
.diagram-box h4 {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}
.diagram-box ul { list-style: none; margin: 0; }
.diagram-box li {
  font-size: 14.5px;
  color: var(--text-muted);
  padding: 4px 0;
  border-bottom: 1px dashed var(--border);
}
.diagram-box li:last-child { border-bottom: none; }
.diagram-box li b { color: var(--text); font-weight: 600; }

/* ── Prev / Next Pager ── */
.pager {
  display: flex;
  gap: 16px;
  max-width: 800px;
  margin: 64px auto 0;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}
.pager a {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  display: block;
  padding: 18px 22px;
  text-decoration: none;
  transition: border-color 0.15s, transform 0.15s, box-shadow 0.15s;
}
.pager a:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0,0,0,.25);
}
.pager a.next { text-align: right; }
.pager .pager-label {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text-muted);
  display: block;
  margin-bottom: 6px;
}
.pager .pager-title {
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
}
.pager a:hover .pager-title { color: var(--accent); }
.pager .pager-spacer { flex: 1; }

/* ── Responsive ── */
@media (max-width: 960px) {
  .side-nav {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    height: 100vh;
    z-index: 600;
    transform: translateX(-110%);
    transition: transform 0.25s cubic-bezier(.4,0,.2,1);
    box-shadow: 0 0 64px rgba(0,0,0,.65);
  }
  .side-nav.open { transform: translateX(0); }
  .side-toggle { display: flex; }
  .tutorial-content { padding: 30px 24px 80px; }
  .article h1 { font-size: 28px; }
  .pager { flex-direction: column; }
  .pager a.next { text-align: left; }
  .pager .pager-spacer { display: none; }
}

@media (max-width: 600px) {
  .tutorial-content { padding: 22px 16px 72px; }
  .article h1 { font-size: 24px; }
  .article h2 { font-size: 20px; }
  .lead { font-size: 16px; }
}