/* ================================================================
   KNOWLEDGE BASE — kb.css
   ================================================================ */

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --green-deep:  #1a3d2b;
  --green-mid:   #2d6a4f;
  --green-light: #52b788;
  --green-pale:  #95d5b2;
  --bamboo:      #8fbc5a;
  --bamboo-dark: #5a7a35;
  --paper:       #f8f6f2;
  --paper-dark:  #ede9e1;
  --ink:         #1a1209;
  --ink-light:   #3a3028;
  --ink-muted:   #7a7060;
  --border:      #d8d0c0;
  --card-bg:     #ffffff;
  --shadow:      rgba(26, 61, 43, 0.10);
  --shadow-deep: rgba(26, 61, 43, 0.18);
}

html, body {
  min-height: 100vh;
  background: var(--paper);
  font-family: 'Nunito', sans-serif;
  color: var(--ink);
}

/* ── Top Nav ─────────────────────────────────────────────── */
.kb-topnav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  height: 56px;
  background: var(--green-deep);
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.28);
}

.kb-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--green-pale);
  font-weight: 900;
  font-size: 15px;
  letter-spacing: 0.2px;
  transition: color 0.18s;
}
.kb-logo:hover { color: #fff; }
.kb-logo-panda { font-size: 22px; }

.kb-breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: rgba(149, 213, 178, 0.55);
}
.kb-breadcrumb a {
  color: var(--bamboo);
  text-decoration: none;
  font-weight: 700;
  transition: color 0.18s;
}
.kb-breadcrumb a:hover { color: #fff; }
.kb-breadcrumb-sep { color: rgba(149, 213, 178, 0.3); }

#kb-menu-toggle {
  display: none;
  background: none;
  border: 1.5px solid rgba(149, 213, 178, 0.3);
  border-radius: 7px;
  cursor: pointer;
  padding: 5px 9px;
  color: var(--green-pale);
  font-size: 16px;
  line-height: 1;
  transition: background 0.18s, border-color 0.18s;
}
#kb-menu-toggle:hover {
  background: rgba(149, 213, 178, 0.1);
  border-color: var(--bamboo);
}

/* ── Listing Page — Hero ─────────────────────────────────── */
.kb-hero {
  background: linear-gradient(150deg, #0e2a1a 0%, var(--green-deep) 50%, var(--green-mid) 100%);
  padding: 56px 28px 52px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.kb-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle, rgba(143,188,90,0.12) 1px, transparent 1px);
  background-size: 28px 28px;
  pointer-events: none;
}

.kb-hero::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 40px;
  background: linear-gradient(to top, var(--paper), transparent);
  pointer-events: none;
}

/* ── Reading Panda SVG ───────────────────────────────────── */
.kb-hero-panda-img {
  display: flex;
  justify-content: center;
  margin: 0 auto 20px;
  filter: drop-shadow(0 6px 18px rgba(0,0,0,0.28));
}


.kb-hero-title {
  font-size: 38px;
  font-weight: 900;
  color: #fff;
  margin-bottom: 8px;
  letter-spacing: -0.5px;
}

.kb-hero-sub {
  font-size: 14px;
  color: var(--green-pale);
  font-weight: 600;
  opacity: 0.82;
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ── Search ──────────────────────────────────────────────── */
.kb-search-wrap {
  max-width: 540px;
  margin: 32px auto 0;
  position: relative;
}

.kb-search-icon {
  position: absolute;
  left: 15px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 15px;
  pointer-events: none;
}

#kb-search {
  width: 100%;
  padding: 13px 18px 13px 44px;
  border-radius: 12px;
  border: 2px solid transparent;
  font-family: 'Nunito', sans-serif;
  font-size: 15px;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.95);
  color: var(--ink);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}
#kb-search:focus {
  border-color: var(--bamboo);
  box-shadow: 0 0 0 3px rgba(143, 188, 90, 0.22), 0 4px 16px rgba(0,0,0,0.15);
}
#kb-search::placeholder { color: var(--ink-muted); font-weight: 600; }

/* ── Filters (Category + Level) ─────────────────────────── */
.kb-filters {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 28px 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.kb-filter-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.kb-filter-label {
  font-size: 11px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--ink-muted);
  min-width: 64px;
  flex-shrink: 0;
}

.kb-filter-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.cat-filter,
.level-filter {
  padding: 4px 13px;
  border-radius: 20px;
  border: 1.5px solid var(--border);
  background: var(--card-bg);
  color: var(--ink-muted);
  font-family: 'Nunito', sans-serif;
  font-size: 12px;
  font-weight: 800;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  transition: all 0.18s;
}
.cat-filter:hover  { border-color: var(--bamboo); color: var(--bamboo-dark); background: rgba(143,188,90,0.07); }
.cat-filter.active { background: var(--green-deep); border-color: var(--green-deep); color: #fff; }

.level-filter:hover { border-color: var(--bamboo); color: var(--bamboo-dark); background: rgba(143,188,90,0.07); }

.level-filter[data-level="junior"].active  { background: #d4f0e4; border-color: #52b788; color: #1a5c3a; }
.level-filter[data-level="medior"].active  { background: #fef3cd; border-color: #c8960a; color: #7a5500; }
.level-filter[data-level="senior"].active  { background: #1a3d2b; border-color: #1a3d2b; color: #95d5b2; }
.level-filter[data-level="all"].active     { background: var(--green-deep); border-color: var(--green-deep); color: #fff; }

/* ── Articles Grid ───────────────────────────────────────── */
.kb-container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 36px 28px 72px;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 22px;
}

.article-card {
  display: block;
  text-decoration: none;
  background: var(--card-bg);
  border-radius: 12px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--bamboo);
  padding: 22px 20px 18px;
  color: inherit;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-left-color 0.18s ease;
  position: relative;
}
.article-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 28px var(--shadow-deep);
  border-left-color: var(--green-light);
}

.article-card[data-cat="languages"]       { border-left-color: #4ea8de; }
.article-card[data-cat="frameworks"]      { border-left-color: var(--bamboo); }
.article-card[data-cat="runtimes"]        { border-left-color: var(--green-light); }
.article-card[data-cat="tools"]           { border-left-color: #c084fc; }
.article-card[data-cat="troubleshooting"] { border-left-color: #fb923c; }

.article-card[data-cat="languages"]:hover       { border-left-color: #60b9f0; }
.article-card[data-cat="frameworks"]:hover      { border-left-color: #a4c65b; }
.article-card[data-cat="runtimes"]:hover        { border-left-color: var(--green-pale); }
.article-card[data-cat="tools"]:hover           { border-left-color: #d8aaff; }
.article-card[data-cat="troubleshooting"]:hover { border-left-color: #fca76c; }

.card-title {
  font-size: 17px;
  font-weight: 900;
  color: var(--green-deep);
  margin-bottom: 8px;
  line-height: 1.35;
}

.card-badges {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}

.card-category {
  display: inline-block;
  padding: 2px 9px;
  border-radius: 5px;
  background: rgba(26, 61, 43, 0.07);
  color: var(--green-deep);
  font-size: 10px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.card-level {
  display: inline-block;
  padding: 2px 9px;
  border-radius: 5px;
  font-size: 10px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin-bottom: 10px;
}

.card-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 5px;
  background: rgba(143, 188, 90, 0.12);
  color: var(--bamboo-dark);
  font-size: 10px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

.card-excerpt {
  font-size: 13px;
  color: var(--ink-muted);
  line-height: 1.65;
}

.kb-no-results {
  display: none;
  grid-column: 1 / -1;
  text-align: center;
  padding: 56px 20px;
  color: var(--ink-muted);
}
.no-results-icon { font-size: 42px; display: block; margin-bottom: 14px; }
.kb-no-results p { font-size: 15px; font-weight: 700; }

/* ── Level colours (shared: cards, sidebar, article header) */
.level-junior { background: #d4f0e4; color: #1a5c3a; }
.level-medior { background: #fef3cd; color: #7a5500; }
.level-senior { background: rgba(26,61,43,0.12); color: #1a3d2b; }

/* ── Article Page Layout ─────────────────────────────────── */
.kb-layout {
  display: flex;
  min-height: calc(100vh - 56px);
}

/* Sidebar */
#kb-sidebar {
  width: 262px;
  min-width: 262px;
  background: var(--card-bg);
  border-right: 1.5px solid var(--border);
  padding: 20px 0 40px;
  position: sticky;
  top: 56px;
  height: calc(100vh - 56px);
  overflow-y: auto;
  flex-shrink: 0;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.kb-sidebar-back {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 20px 18px;
  text-decoration: none;
  color: var(--bamboo-dark);
  font-size: 11px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.7px;
  border-bottom: 1.5px solid var(--border);
  margin-bottom: 14px;
  transition: color 0.18s;
}
.kb-sidebar-back:hover { color: var(--green-mid); }

.kb-sidebar-cat-label {
  padding: 14px 20px 5px;
  font-size: 10px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 1.1px;
  color: var(--ink-muted);
  border-top: 1px solid var(--border);
  margin-top: 4px;
}
.kb-sidebar-cat-label:first-of-type { border-top: none; margin-top: 0; }

.kb-sidebar-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 8px 16px 8px 17px;
  font-size: 13px;
  font-weight: 700;
  color: var(--ink-light);
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: all 0.18s;
  line-height: 1.4;
}
.kb-sidebar-link:hover {
  color: var(--green-mid);
  background: rgba(143, 188, 90, 0.06);
  border-left-color: var(--bamboo);
}
.kb-sidebar-link.active {
  color: var(--green-deep);
  font-weight: 900;
  background: rgba(82, 183, 136, 0.09);
  border-left-color: var(--green-mid);
}

.kb-sidebar-link-title { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.kb-sidebar-level {
  flex-shrink: 0;
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 9px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

/* Main content */
.kb-main {
  flex: 1;
  min-width: 0;
  padding: 48px 60px 72px;
  max-width: 800px;
}

.kb-article-header {
  margin-bottom: 36px;
  padding-bottom: 28px;
  border-bottom: 1.5px solid var(--border);
}

.kb-article-title {
  font-size: 34px;
  font-weight: 900;
  color: var(--green-deep);
  line-height: 1.22;
  margin-bottom: 16px;
  letter-spacing: -0.6px;
}

.kb-article-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.kb-article-category {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 6px;
  background: rgba(26, 61, 43, 0.07);
  color: var(--green-deep);
  font-size: 11px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.kb-article-level {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.kb-article-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 6px;
  background: rgba(143, 188, 90, 0.12);
  color: var(--bamboo-dark);
  font-size: 11px;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

/* ── Article Typography ──────────────────────────────────── */
.kb-content { line-height: 1.82; color: var(--ink-light); font-size: 15.5px; }

.kb-content > *:first-child { margin-top: 0; }

.kb-content h1,
.kb-content h2,
.kb-content h3,
.kb-content h4 {
  color: var(--green-deep);
  font-weight: 900;
  margin: 44px 0 14px;
  line-height: 1.3;
  letter-spacing: -0.3px;
}
.kb-content h1 { font-size: 26px; }
.kb-content h2 {
  font-size: 19px;
  margin-top: 52px;
  padding: 14px 18px;
  background: rgba(26, 61, 43, 0.04);
  border-left: 4px solid var(--green-mid);
  border-radius: 0 8px 8px 0;
  letter-spacing: -0.2px;
}
.kb-content h3 {
  font-size: 16px;
  color: var(--ink);
  margin-top: 32px;
  padding-bottom: 5px;
  border-bottom: 1px dashed var(--border);
}
.kb-content h4 { font-size: 15px; color: var(--ink); }

.kb-content p { margin-bottom: 16px; }

.kb-content ul,
.kb-content ol { padding-left: 22px; margin-bottom: 16px; }
.kb-content li { margin-bottom: 7px; }
.kb-content ul li::marker { color: var(--bamboo-dark); }
.kb-content ol li::marker { color: var(--bamboo-dark); font-weight: 800; }

.kb-content a {
  color: var(--green-mid);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.15s;
}
.kb-content a:hover { color: var(--green-deep); }

.kb-content code {
  background: rgba(26, 61, 43, 0.07);
  color: #1a3d2b;
  padding: 2px 7px;
  border-radius: 4px;
  font-size: 13.5px;
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Courier New', monospace;
  font-weight: 600;
  border: 1px solid rgba(26, 61, 43, 0.12);
}

.kb-content pre {
  background: #141c17;
  color: #d4e8da;
  border-radius: 10px;
  padding: 0;
  margin: 22px 0 28px;
  overflow: hidden;
  font-size: 13px;
  line-height: 1.7;
  box-shadow: 0 6px 24px rgba(0,0,0,0.22), inset 0 1px 0 rgba(255,255,255,0.06);
  position: relative;
}
.kb-content pre::before {
  content: '';
  display: block;
  height: 36px;
  background: rgba(255,255,255,0.04);
  border-bottom: 1px solid rgba(255,255,255,0.07);
  background-image: radial-gradient(circle, #ff6057 5px, transparent 5px),
                    radial-gradient(circle, #ffbd2e 5px, transparent 5px),
                    radial-gradient(circle, #27c93f 5px, transparent 5px);
  background-size: 12px 12px, 12px 12px, 12px 12px;
  background-position: 16px center, 36px center, 56px center;
  background-repeat: no-repeat;
}
.kb-content pre code {
  display: block;
  padding: 18px 22px 20px;
  background: none;
  color: inherit;
  border: none;
  border-radius: 0;
  font-size: inherit;
  font-weight: 400;
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Courier New', monospace;
  overflow-x: auto;
}

.kb-content blockquote {
  border-left: 3px solid var(--bamboo);
  margin: 24px 0;
  padding: 12px 20px;
  background: rgba(143, 188, 90, 0.05);
  border-radius: 0 8px 8px 0;
  color: var(--ink-muted);
  font-style: normal;
  font-size: 14.5px;
}

.kb-content hr {
  border: none;
  border-top: 1.5px solid var(--border);
  margin: 32px 0;
}

.kb-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 8px 0 24px;
  font-size: 13.5px;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 1px 8px var(--shadow);
}
.kb-content th {
  background: var(--green-deep);
  color: var(--green-pale);
  padding: 11px 14px;
  text-align: left;
  font-weight: 800;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.kb-content td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
}
.kb-content tr:last-child td { border-bottom: none; }
.kb-content tr:nth-child(even) td { background: rgba(143, 188, 90, 0.04); }

.kb-content img {
  max-width: 100%;
  border-radius: 10px;
  box-shadow: 0 4px 16px var(--shadow-deep);
  margin: 8px 0 16px;
}

/* ── Prev / Next ─────────────────────────────────────────── */
.kb-article-pagination {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  margin-top: 52px;
  padding-top: 28px;
  border-top: 1.5px solid var(--border);
  gap: 14px;
}

.kb-page-btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  border-radius: 12px;
  background: var(--card-bg);
  border: 1.5px solid var(--border);
  color: var(--green-deep);
  font-family: 'Nunito', sans-serif;
  text-decoration: none;
  transition: all 0.2s;
  max-width: 240px;
  flex: 1;
}
.kb-page-btn:hover {
  border-color: var(--bamboo);
  background: rgba(143, 188, 90, 0.06);
  box-shadow: 0 4px 14px var(--shadow);
}
.kb-page-btn.prev:hover { transform: translateX(-2px); }
.kb-page-btn.next { justify-content: flex-end; text-align: right; }
.kb-page-btn.next:hover { transform: translateX(2px); }

.kb-page-btn-arrow { font-size: 18px; color: var(--bamboo-dark); flex-shrink: 0; }

.kb-page-btn-label {
  font-size: 10px;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.7px;
  color: var(--ink-muted);
  display: block;
  margin-bottom: 3px;
}
.kb-page-btn-title {
  font-size: 13px;
  font-weight: 800;
  color: var(--green-deep);
  line-height: 1.35;
  display: block;
}

/* ── Mobile ──────────────────────────────────────────────── */
@media (max-width: 768px) {
  #kb-menu-toggle { display: block; }
  .kb-breadcrumb { display: none; }

  .kb-layout { display: block; }

  #kb-sidebar {
    position: fixed;
    top: 56px;
    left: 0;
    bottom: 0;
    width: 280px;
    z-index: 90;
    transform: translateX(-100%);
    transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 4px 0 28px rgba(0, 0, 0, 0.18);
    height: calc(100vh - 56px);
  }
  body.sidebar-open #kb-sidebar { transform: translateX(0); }

  .kb-sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    top: 56px;
    background: rgba(0, 0, 0, 0.38);
    z-index: 89;
    cursor: pointer;
  }
  body.sidebar-open .kb-sidebar-overlay { display: block; }

  .kb-main { padding: 28px 20px 52px; }
  .kb-article-title { font-size: 26px; }

  .kb-hero { padding: 40px 20px 36px; }
  .kb-hero-title { font-size: 28px; }
  .kb-container { padding: 24px 16px 56px; }
  .articles-grid { grid-template-columns: 1fr; }

  .kb-article-pagination { flex-direction: column; }
  .kb-page-btn { max-width: 100%; }
  .kb-page-btn.next { justify-content: flex-start; text-align: left; }
}

@media (min-width: 769px) and (max-width: 1100px) {
  .kb-main { padding: 40px 36px 60px; }
}

/* ── Table of Contents (right-rail) ─────────────────────── */
.kb-toc { display: none; }

@media (min-width: 1320px) {
  .kb-toc {
    display: flex;
    flex-direction: column;
    width: 210px;
    min-width: 210px;
    flex-shrink: 0;
    position: sticky;
    top: 56px;
    align-self: flex-start;
    max-height: calc(100vh - 56px);
    overflow-y: auto;
    padding: 36px 16px 36px 20px;
    border-left: 1px solid var(--border);
    scrollbar-width: thin;
    scrollbar-color: var(--border) transparent;
  }
}

.kb-toc-header {
  font-size: 10px;
  font-weight: 900;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 14px;
}

.kb-toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.toc-h2, .toc-h3 {
  display: block;
  padding: 4px 4px 4px 10px;
  font-size: 12px;
  font-family: 'Nunito', sans-serif;
  color: var(--ink-muted);
  text-decoration: none;
  line-height: 1.5;
  border-left: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
  border-radius: 0 4px 4px 0;
}
.toc-h3 {
  padding-left: 20px;
  font-size: 11px;
}
.toc-h2:hover, .toc-h3:hover { color: var(--green-mid); }
.toc-h2.active {
  color: var(--green-deep);
  font-weight: 800;
  border-left-color: var(--bamboo);
}
.toc-h3.active {
  color: var(--green-mid);
  font-weight: 700;
  border-left-color: var(--green-light);
}