:root {
  --qa-primary: #0d6efd;
  --qa-primary-light: #f0f7ff;
  --qa-primary-dark: #0056b3;
  --qa-text: #1e293b;
  --qa-muted: #64748b;
  --qa-bg: #f8fafc;
  --qa-white: #ffffff;
  --qa-border: #e2e8f0;
  --qa-sidebar-width: 280px;
  --qa-header-height: 64px;
  --qa-radius-lg: 16px;
  --qa-radius-md: 12px;
  --qa-shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --qa-shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --qa-font: 'Inter', system-ui, -apple-system, sans-serif;
  --qa-glass: rgba(255, 255, 255, 0.8);
}

/* ── Global ──────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

.qa-body {
  background-color: var(--qa-bg);
  color: var(--qa-text);
  font-family: var(--qa-font);
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
}

.qa-app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* ── Header ──────────────────────────────────────── */
.qa-header {
  height: var(--qa-header-height);
  background: var(--qa-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--qa-border);
  position: sticky;
  top: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
}

.qa-header-container {
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.qa-header-left, .qa-header-right {
  display: flex;
  align-items: center;
  gap: 24px;
}

.qa-brand {
  display: flex;
  align-items: center;
  text-decoration: none;
  font-weight: 700;
  font-size: 20px;
  gap: 0;
}

.qa-brand-primary { color: var(--qa-primary); }
.qa-brand-divider { color: var(--qa-border); margin: 0 8px; font-weight: 300; }
.qa-brand-secondary { color: var(--qa-text); font-weight: 500; }

.qa-brand:hover { text-decoration: none; }

.qa-header-nav {
  display: flex;
  gap: 4px;
  margin-left: 12px;
}

.qa-nav-link {
  text-decoration: none;
  color: var(--qa-muted);
  font-size: 14px;
  font-weight: 500;
  padding: 8px 12px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

.qa-nav-link:hover, .qa-nav-link.active {
  color: var(--qa-primary);
  background: var(--qa-primary-light);
  text-decoration: none;
}

/* ── Layout Wrapper ──────────────────────────────── */
.qa-main-wrapper {
  display: flex;
  flex: 1;
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  align-items: flex-start;
}

/* ── Sidebar ─────────────────────────────────────── */
.qa-main-sidebar {
  width: var(--qa-sidebar-width);
  flex-shrink: 0;
  border-right: 1px solid var(--qa-border);
  padding: 24px;
  position: sticky;
  top: var(--qa-header-height);
  height: calc(100vh - var(--qa-header-height));
  overflow-y: auto;
}

.qa-sidebar-inner {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.qa-sidebar-header {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--qa-muted);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--qa-border);
}

.qa-tag-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.qa-tag-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s ease;
  color: var(--qa-text);
  font-size: 14px;
  font-weight: 500;
  user-select: none;
}

.qa-tag-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 6px;
  background: #f1f5f9;
  color: var(--qa-muted);
  flex-shrink: 0;
  transition: all 0.2s ease;
}

.qa-tag-item:hover {
  background: var(--qa-primary-light);
  color: var(--qa-primary);
}

.qa-tag-item:hover .qa-tag-icon {
  background: #fff;
  color: var(--qa-primary);
}

.qa-tag-item.active {
  background: var(--qa-primary);
  color: #fff;
}

.qa-tag-item.active .qa-tag-icon {
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
}

/* ── Main Content ────────────────────────────────── */
.qa-main-content {
  flex: 1;
  min-width: 0;
}

/* Index page content wrapper */
.qa-content {
  padding: 40px 32px;
  max-width: 900px;
  margin: 0 auto;
}

/* ── Search (in main content) ───────────────────── */
.qa-main-search {
  margin-bottom: 40px;
  background: var(--qa-white);
  padding: 8px;
  border-radius: 20px;
  box-shadow: var(--qa-shadow-md);
  border: 1px solid var(--qa-border);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.qa-main-search:focus-within {
  transform: translateY(-2px);
  box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  border-color: var(--qa-primary);
}

.qa-search-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 8px;
}

.qa-search-icon-inside {
  color: var(--qa-muted);
  font-size: 16px;
  flex-shrink: 0;
}

.qa-main-search-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  font-size: 16px;
  padding: 12px 0;
  color: var(--qa-text);
  font-family: var(--qa-font);
}

.qa-main-search-input::placeholder { color: var(--qa-muted); }

.qa-main-search-btn {
  background: var(--qa-primary);
  color: #fff;
  border: none;
  padding: 12px 24px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  font-family: var(--qa-font);
  transition: all 0.2s ease;
  white-space: nowrap;
}

.qa-main-search-btn:hover { background: var(--qa-primary-dark); }

/* ── Content Header ─────────────────────────────── */
.qa-content-header {
  margin-bottom: 32px;
}

.qa-content-title h1 {
  font-size: 28px;
  font-weight: 800;
  color: #0f172a;
  margin: 0 0 8px;
}

.qa-content-subtitle {
  color: var(--qa-muted);
  font-size: 15px;
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
}

.qa-search-badge {
  background: var(--qa-primary-light);
  color: var(--qa-primary);
  padding: 2px 10px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.qa-clear-search {
  color: var(--qa-primary);
  text-decoration: none;
  font-weight: bold;
  line-height: 1;
  display: flex;
  align-items: center;
}

/* ── Article Cards ──────────────────────────────── */
.qa-article-grid {
  display: flex;
  flex-direction: column;
}

.qa-article-card {
  display: flex;
  gap: 20px;
  padding: 24px;
  background: var(--qa-white);
  border: 1px solid var(--qa-border);
  border-radius: var(--qa-radius-lg);
  text-decoration: none;
  color: inherit;
  margin-bottom: 16px;
  transition: all 0.3s ease;
  box-shadow: var(--qa-shadow-sm);
}

.qa-article-card:hover {
  border-color: var(--qa-primary);
  box-shadow: var(--qa-shadow-md);
  transform: translateY(-2px);
  text-decoration: none;
  color: inherit;
}

.qa-card-icon {
  width: 48px;
  height: 48px;
  background: var(--qa-primary-light);
  color: var(--qa-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  font-size: 20px;
  flex-shrink: 0;
}

.qa-card-body { flex: 1; min-width: 0; }

.qa-card-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--qa-text);
  margin: 0 0 6px;
  line-height: 1.4;
  transition: color 0.2s ease;
}

.qa-article-card:hover .qa-card-title { color: var(--qa-primary); }

.qa-card-summary {
  font-size: 14px;
  color: var(--qa-muted);
  line-height: 1.6;
  margin: 0 0 12px;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.qa-card-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 12px;
  color: var(--qa-muted);
}

.qa-module-badge {
  background: #f1f5f9;
  color: #475569;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
  font-size: 11px;
}

.qa-date {
  display: flex;
  align-items: center;
  gap: 4px;
}

.qa-card-arrow {
  flex-shrink: 0;
  color: var(--qa-border);
  font-size: 16px;
  transition: color 0.2s, transform 0.2s;
  display: flex;
  align-items: center;
  margin-top: 4px;
}

.qa-article-card:hover .qa-card-arrow {
  color: var(--qa-primary);
  transform: translateX(4px);
}

/* ── States ─────────────────────────────────────── */
.qa-loading {
  text-align: center;
  padding: 60px 20px;
  color: var(--qa-muted);
}

.qa-spinner {
  width: 36px;
  height: 36px;
  border: 3px solid #e9ecef;
  border-top-color: var(--qa-primary);
  border-radius: 50%;
  animation: qa-spin 0.8s linear infinite;
  margin: 0 auto 12px;
}

@keyframes qa-spin { to { transform: rotate(360deg); } }

.qa-empty {
  text-align: center;
  padding: 70px 20px;
  color: var(--qa-muted);
}

.qa-empty i {
  font-size: 48px;
  margin-bottom: 16px;
  display: block;
  opacity: .4;
}

.qa-empty h3 {
  font-size: 18px;
  margin-bottom: 8px;
  color: var(--qa-text);
}

/* ── Pagination ──────────────────────────────────── */
.qa-pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  margin-top: 40px;
  padding-bottom: 20px;
}

.qa-page-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #fff;
  border: 1px solid var(--qa-border);
  border-radius: 10px;
  color: var(--qa-text);
  font-weight: 600;
  font-size: 14px;
  font-family: var(--qa-font);
  cursor: pointer;
  transition: all 0.2s ease;
  padding: 0;
}

.qa-page-btn:hover {
  border-color: var(--qa-primary);
  color: var(--qa-primary);
  background: var(--qa-primary-light);
  transform: translateY(-2px);
}

.qa-page-btn.active {
  background: var(--qa-primary);
  border-color: var(--qa-primary);
  color: #fff;
  box-shadow: 0 4px 12px rgba(13, 110, 253, 0.25);
}

.qa-page-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

.qa-page-ellipsis {
  color: var(--qa-muted);
  font-weight: 600;
  padding: 0 4px;
}

/* ── DETAIL PAGE ─────────────────────────────────── */
.qa-detail-article {
  background: #fff;
  border: 1px solid var(--qa-border);
  border-radius: 20px;
  box-shadow: var(--qa-shadow-sm);
  overflow: hidden;
  margin: 32px;
}

/* Breadcrumb */
.qa-breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 20px 40px 0;
  font-size: 13px;
  color: var(--qa-muted);
}

.qa-breadcrumb a {
  color: var(--qa-muted);
  text-decoration: none;
  transition: color 0.2s;
}

.qa-breadcrumb a:hover { color: var(--qa-primary); }

.qa-breadcrumb i { font-size: 10px; }

/* Detail Header */
.qa-detail-header {
  padding: 15px;
  border-bottom: 1px solid var(--qa-border);
  background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
}

.qa-detail-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.qa-detail-icon {
  width: 48px;
  height: 48px;
  background: var(--qa-primary-light);
  color: var(--qa-primary);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.qa-detail-title {
  font-size: 18px;
  font-weight: 800;
  color: #0f172a;
  margin: 0 0 20px;
  line-height: 1.3;
}

.qa-detail-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 24px;
  font-size: 14px;
  color: var(--qa-muted);
  flex-wrap: wrap;
}

.qa-detail-date, .qa-detail-id {
  display: flex;
  align-items: center;
  gap: 4px;
}

.qa-detail-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.qa-tag-badge {
  background: var(--qa-primary-light);
  color: var(--qa-primary);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all 0.2s;
}

.qa-tag-badge:hover {
  background: var(--qa-primary);
  color: #fff;
  transform: translateY(-1px);
  text-decoration: none;
}

/* Summary */
.qa-detail-summary {
  background: #f8fafc;
  border: 1px solid var(--qa-border);
  border-radius: 12px;
  padding: 20px;
  margin-top: 20px;
}

.qa-summary-label {
  font-weight: 700;
  color: #475569;
  font-size: 14px;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
}

.qa-summary-text {
  color: #64748b;
  font-size: 15px;
  line-height: 1.6;
}

/* Content body */
.qa-detail-content {
  padding: 40px;
  line-height: 1.8;
  font-size: 16px;
  color: #334155;
}

.qa-detail-content h1,
.qa-detail-content h2,
.qa-detail-content h3,
.qa-detail-content h4 {
  color: #0f172a;
  margin-top: 1.5em;
  margin-bottom: 0.6em;
  font-weight: 700;
}

.qa-detail-content h2 {
  font-size: 24px;
  border-left: 4px solid var(--qa-primary);
  padding-left: 16px;
  margin: 40px 0 20px;
}

.qa-detail-content p { margin-bottom: 1em; }

.qa-detail-content ul, .qa-detail-content ol {
  padding-left: 20px;
  margin-bottom: 1em;
}

.qa-detail-content li { margin-bottom: 6px; }

.qa-detail-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}

.qa-detail-content th,
.qa-detail-content td {
  border: 1px solid var(--qa-border);
  padding: 10px 14px;
}

.qa-detail-content th {
  background: var(--qa-bg);
  font-weight: 600;
}

.qa-detail-content img {
  max-width: 100%;
  border-radius: 8px;
  margin: 8px 0;
}

/* Footer */
.qa-detail-footer {
  padding: 30px 40px;
  background: #f8fafc;
  border-top: 1px solid var(--qa-border);
}

.qa-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  border: 1px solid var(--qa-border);
  padding: 10px 20px;
  border-radius: 10px;
  color: #475569;
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  font-family: var(--qa-font);
  transition: all 0.2s ease;
}

.qa-back-btn:hover {
  background: #f1f5f9;
  color: #0f172a;
  border-color: var(--qa-primary);
  text-decoration: none;
}

/* ── Scrollbar ───────────────────────────────────── */
.qa-main-sidebar::-webkit-scrollbar { width: 6px; }
.qa-main-sidebar::-webkit-scrollbar-track { background: transparent; }
.qa-main-sidebar::-webkit-scrollbar-thumb { background: #ced4da; border-radius: 6px; }

/* ── Responsive ──────────────────────────────────── */
@media (max-width: 1024px) {
  .qa-main-sidebar { width: 240px; }
}

@media (max-width: 768px) {
  .qa-main-wrapper { flex-direction: column; }

  .qa-main-sidebar {
    width: 100%;
    height: auto;
    position: static;
    border-right: none;
    border-bottom: 1px solid var(--qa-border);
    padding: 16px;
  }

  .qa-tag-list {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 6px;
  }

  .qa-tag-item {
    border-radius: 20px;
    padding: 6px 14px;
    font-size: 13px;
  }

  .qa-content { padding: 24px 16px; }

  .qa-detail-article { margin: 16px; }

  .qa-detail-header,
  .qa-detail-content,
  .qa-detail-footer { padding: 20px; }

  .qa-breadcrumb { padding: 16px 20px 0; }
}