/* ==========================================================================
   科技情報閱讀室 (Tech Intelligence Reading Room) - Site V1 Stylesheet
   ========================================================================== */

:root {
  /* Dark Theme Palette (Default) */
  --bg-main: #0B0F17;
  --bg-card: #111827;
  --bg-card-hover: #162032;
  --bg-header: rgba(11, 15, 23, 0.88);
  --bg-nav: rgba(15, 23, 42, 0.92);
  --bg-subtle: #1E293B;
  --bg-pill: #1E293B;
  --bg-expanded: #0F172A;
  
  --text-primary: #F8FAFC;
  --text-secondary: #CBD5E1;
  --text-muted: #94A3B8;
  --text-dim: #64748B;
  
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-card: rgba(255, 255, 255, 0.12);
  --border-highlight: rgba(56, 189, 248, 0.4);
  
  --accent-blue: #38BDF8;
  --accent-cyan: #06B6D4;
  --accent-emerald: #10B981;
  --accent-amber: #F59E0B;
  --accent-rose: #F43F5E;
  
  --badge-top-bg: rgba(56, 189, 248, 0.12);
  --badge-top-text: #38BDF8;
  --badge-fresh-bg: rgba(16, 185, 129, 0.12);
  --badge-fresh-text: #34D399;
  --badge-stale-bg: rgba(245, 158, 11, 0.12);
  --badge-stale-text: #FBBF24;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-full: 9999px;
  
  --font-sans: "Geist", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans TC", sans-serif;
  --font-mono: "JetBrains Mono", Menlo, Consolas, monospace;
}

html.light {
  /* Light Theme Palette - Calibrated to WCAG AAA/AA */
  --bg-main: #F8FAFC;
  --bg-card: #FFFFFF;
  --bg-card-hover: #F1F5F9;
  --bg-header: rgba(248, 250, 252, 0.92);
  --bg-nav: rgba(255, 255, 255, 0.92);
  --bg-subtle: #E2E8F0;
  --bg-pill: #F1F5F9;
  --bg-expanded: #F8FAFC;
  
  --text-primary: #0F172A;
  --text-secondary: #334155;
  --text-muted: #475569;
  --text-dim: #64748B;
  
  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-card: rgba(0, 0, 0, 0.12);
  --border-highlight: rgba(2, 132, 199, 0.5);
  
  --accent-blue: #0284C7;
  --accent-cyan: #0891B2;
  --accent-emerald: #059669;
  --accent-amber: #D97706;
  --accent-rose: #E11D48;
  
  --badge-top-bg: rgba(2, 132, 199, 0.12);
  --badge-top-text: #0369A1;
  --badge-fresh-bg: rgba(5, 150, 105, 0.12);
  --badge-fresh-text: #047857;
  --badge-stale-bg: rgba(217, 119, 6, 0.12);
  --badge-stale-text: #B45309;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
}

/* Accessible Focus States */
:focus-visible {
  outline: 2px solid var(--accent-blue);
  outline-offset: 2px;
}

/* Reduced Motion Override */
@media (prefers-reduced-motion: reduce) {
  *, ::before, ::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .live-dot {
    animation: none !important;
  }
}

/* ==========================================================================
   Base & Reset
   ========================================================================== */

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

body {
  background-color: var(--bg-main);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.25s ease, color 0.25s ease;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ==========================================================================
   Layout Containers
   ========================================================================== */

.site-wrapper {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.main-content {
  flex: 1;
  max-width: 1120px;
  width: 100%;
  margin: 0 auto;
  padding: 24px 20px 60px 20px;
}

/* ==========================================================================
   Header (Hero Bar)
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-header);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 16px 20px;
}

.header-container {
  max-width: 1120px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.brand-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
}

.brand-info {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.brand-badge-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.live-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-emerald);
  box-shadow: 0 0 8px var(--accent-emerald);
  animation: pulse-glow 2s infinite ease-in-out;
}

@keyframes pulse-glow {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

.brand-tag {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--accent-blue);
  text-transform: uppercase;
}

.date-badge {
  font-family: var(--font-mono);
  font-size: 12px;
  background: var(--bg-subtle);
  color: var(--text-secondary);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.brand-title {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  line-height: 1.2;
}

.meta-strip {
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.meta-strip span.sep {
  opacity: 0.4;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.control-select {
  background: var(--bg-subtle);
  color: var(--text-primary);
  border: 1px solid var(--border-card);
  padding: 7px 12px;
  font-size: 13px;
  font-family: var(--font-mono);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color 0.2s ease;
}

.control-select:focus {
  border-color: var(--accent-blue);
}

.control-btn {
  background: var(--bg-subtle);
  color: var(--text-primary);
  border: 1px solid var(--border-card);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.control-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-blue);
}

.light .light-icon { display: none; }
.light .dark-icon { display: inline-block; }
.dark .light-icon { display: inline-block; }
.dark .dark-icon { display: none; }

/* 搜尋與操作 */
.search-bar-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.search-input-wrapper {
  position: relative;
  flex: 1;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 12px;
  font-size: 14px;
  color: var(--text-muted);
  pointer-events: none;
}

#search-input {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 9px 36px 9px 36px;
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  transition: all 0.2s ease;
}

#search-input:focus {
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

#search-input::placeholder {
  color: var(--text-dim);
}

.search-clear-btn {
  position: absolute;
  right: 10px;
  color: var(--text-muted);
  font-size: 12px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--bg-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
}

.action-btn {
  background: var(--bg-subtle);
  color: var(--text-secondary);
  border: 1px solid var(--border-card);
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 500;
  border-radius: var(--radius-md);
  white-space: nowrap;
  transition: all 0.2s ease;
}

.action-btn:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--accent-blue);
}

/* ==========================================================================
   Section Headers
   ========================================================================== */

.section-header {
  margin-bottom: 18px;
}

.section-title-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
}

.section-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  background: var(--badge-top-bg);
  color: var(--badge-top-text);
  padding: 3px 8px;
  border-radius: var(--radius-full);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.section-badge.deep-badge {
  background: rgba(244, 63, 94, 0.12);
  color: var(--accent-rose);
}

.section-title {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.section-desc {
  font-size: 13px;
  color: var(--text-muted);
  display: block;
  margin-top: 2px;
}

/* ==========================================================================
   1. Highlights (Top 5 焦點)
   ========================================================================== */

.highlights-section {
  margin-bottom: 32px;
}

.highlights-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.highlight-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-left: 4px solid var(--accent-blue);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  display: flex;
  gap: 16px;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.highlight-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-highlight);
  border-left-color: var(--accent-blue);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.highlight-rank {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--accent-blue);
  line-height: 1;
  padding-top: 2px;
  min-width: 28px;
}

.highlight-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

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

.card-category-tag {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent-cyan);
  background: var(--bg-pill);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

.card-source-tag {
  font-size: 12px;
  color: var(--text-muted);
}

.badge-freshness {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 1px 6px;
  border-radius: var(--radius-sm);
}

.badge-freshness.fresh {
  background: var(--badge-fresh-bg);
  color: var(--badge-fresh-text);
}

.badge-freshness.background {
  background: var(--badge-stale-bg);
  color: var(--badge-stale-text);
}

.highlight-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.35;
}

.highlight-title a {
  transition: color 0.15s ease;
}

.highlight-title a:hover {
  color: var(--accent-blue);
  text-decoration: underline;
}

.highlight-summary {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.highlight-why {
  background: var(--bg-subtle);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 13px;
  color: var(--text-secondary);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.why-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: var(--accent-blue);
  background: var(--badge-top-bg);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.divergent-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  color: var(--accent-amber);
  background: var(--badge-stale-bg);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  letter-spacing: 0.03em;
  margin-right: 6px;
}

.deep-read-tag {
  color: var(--accent-rose);
  background: rgba(244, 63, 94, 0.12);
  margin-right: 6px;
}

.cat-svg {
  display: inline-block;
  vertical-align: middle;
  stroke: currentColor;
}

.action-btn:active,
.control-btn:active,
.cat-tab:active,
.toggle-details-btn:active {
  transform: scale(0.97);
}

/* ==========================================================================
   2. Category Filter Navigation (Sticky)
   ========================================================================== */

.category-nav {
  position: sticky;
  top: 138px;
  z-index: 90;
  background: var(--bg-nav);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 24px;
  padding: 8px 0;
}

.category-nav-inner {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 0 4px;
}

.category-nav-inner::-webkit-scrollbar {
  display: none;
}

.cat-tab {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  background: transparent;
  border-radius: var(--radius-full);
  border: 1px solid transparent;
  white-space: nowrap;
  transition: all 0.2s ease;
}

.cat-tab:hover {
  color: var(--text-primary);
  background: var(--bg-subtle);
}

.cat-tab.active {
  color: var(--accent-blue);
  background: var(--badge-top-bg);
  border-color: rgba(56, 189, 248, 0.3);
  font-weight: 600;
}

.cat-count {
  font-family: var(--font-mono);
  font-size: 11px;
  background: var(--bg-subtle);
  color: var(--text-muted);
  padding: 1px 6px;
  border-radius: var(--radius-full);
}

.cat-tab.active .cat-count {
  background: var(--accent-blue);
  color: #0B0F17;
  font-weight: 700;
}

/* ==========================================================================
   3. Event Cards Stream (先看結論，再決定要不要展開)
   ========================================================================== */

.events-stream {
  margin-bottom: 40px;
}

.events-container {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.event-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.event-card:hover {
  border-color: var(--border-highlight);
  box-shadow: var(--shadow-md);
}

.event-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.event-tags-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.badge-quality {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  background: var(--bg-pill);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.event-importance {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--accent-blue);
}

.event-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 8px;
}

.event-core-summary {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 10px;
}

.event-why-box {
  background: var(--bg-subtle);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 13px;
  color: var(--text-secondary);
  display: flex;
  gap: 6px;
  margin-bottom: 12px;
}

.event-why-box strong {
  color: var(--text-primary);
  white-space: nowrap;
}

.event-actions-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 10px;
  border-top: 1px solid var(--border-subtle);
}

.toggle-details-btn {
  font-size: 13px;
  font-weight: 500;
  color: var(--accent-blue);
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: background-color 0.15s ease;
}

.toggle-details-btn:hover {
  background: var(--bg-subtle);
}

.source-link-btn {
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
  transition: color 0.15s ease;
}

.source-link-btn:hover {
  color: var(--accent-blue);
  text-decoration: underline;
}

/* 展開詳細內容 (Expanded Content Drawer) */
.event-details-drawer {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px dashed var(--border-card);
  background: var(--bg-expanded);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

.details-subtitle {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.bullets-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.bullets-list li {
  font-size: 13.5px;
  color: var(--text-secondary);
  line-height: 1.5;
  position: relative;
  padding-left: 16px;
}

.bullets-list li::before {
  content: "•";
  position: absolute;
  left: 4px;
  color: var(--accent-blue);
  font-weight: bold;
}

.orig-title-text {
  font-size: 12px;
  font-style: italic;
  color: var(--text-muted);
}

.divergent-box {
  background: rgba(245, 158, 11, 0.08);
  border-left: 3px solid var(--accent-amber);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 13px;
  color: var(--text-secondary);
}

.sources-list-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 12px;
}

.source-badge-link {
  font-family: var(--font-mono);
  background: var(--bg-subtle);
  border: 1px solid var(--border-card);
  color: var(--text-secondary);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.source-badge-link:hover {
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* ==========================================================================
   4. Deep Reads (值得深入閱讀)
   ========================================================================== */

.deep-reads-section {
  margin-bottom: 40px;
}

.deep-reads-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
}

.deep-read-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-top: 3px solid var(--accent-rose);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 12px;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-sm);
}

.deep-read-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-rose);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.deep-read-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.deep-read-source {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent-rose);
}

.deep-read-words {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
}

.deep-read-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.35;
}

.deep-read-why {
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--bg-subtle);
  border-radius: var(--radius-sm);
  padding: 8px 10px;
  line-height: 1.45;
}

.deep-read-why strong {
  color: var(--text-primary);
}

.deep-read-footer {
  display: flex;
  justify-content: flex-end;
}

.deep-read-btn {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-rose);
  display: flex;
  align-items: center;
  gap: 4px;
  transition: transform 0.15s ease;
}

.deep-read-btn:hover {
  transform: translateX(2px);
  text-decoration: underline;
}

/* ==========================================================================
   5. System Quality & Status Footer
   ========================================================================== */

.quality-section {
  margin-top: 20px;
  margin-bottom: 20px;
}

.quality-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 18px 20px;
}

.quality-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}

.quality-title-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.quality-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
}

.transparency-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
}

.quality-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 14px;
}

.quality-item {
  background: var(--bg-subtle);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.quality-label {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.quality-value {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.quality-footer {
  border-top: 1px solid var(--border-subtle);
  padding-top: 10px;
}

.inv-note {
  font-size: 12px;
  color: var(--accent-emerald);
  display: block;
}

/* ==========================================================================
   Footer & Empty States
   ========================================================================== */

.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 24px 20px;
  background: var(--bg-card);
}

.footer-container {
  max-width: 1120px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 10px;
}

kbd {
  font-family: var(--font-mono);
  background: var(--bg-subtle);
  border: 1px solid var(--border-card);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 11px;
}

.empty-results {
  text-align: center;
  padding: 48px 20px;
  background: var(--bg-card);
  border: 1px dashed var(--border-card);
  border-radius: var(--radius-md);
}

.empty-icon {
  font-size: 32px;
  margin-bottom: 8px;
}

.empty-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.empty-subtitle {
  font-size: 13px;
  color: var(--text-muted);
}

.loading-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
}

/* ==========================================================================
   Mobile Responsiveness (768px Breakpoint)
   ========================================================================== */

@media (max-width: 768px) {
  .site-header {
    padding: 12px 16px;
  }

  .brand-title {
    font-size: 20px;
  }

  .category-nav {
    top: 146px;
  }

  .main-content {
    padding: 16px 14px 40px 14px;
  }

  .highlight-card {
    flex-direction: column;
    gap: 8px;
  }

  .highlight-rank {
    font-size: 18px;
  }

  .footer-container {
    flex-direction: column;
    align-items: flex-start;
  }
}