/* ==========================================================================
   IELTS Writing Grammar Studio Stylesheet
   Follows Taste Skill: Clean, Anti-Slop, High-Information-Density, 3-Tier Stepper
   ========================================================================== */

:root {
  --wg-font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --wg-mono: 'JetBrains Mono', monospace;
  
  /* Light Mode Colors */
  --wg-bg: #f8fafc;
  --wg-surface: #ffffff;
  --wg-surface-alt: #f1f5f9;
  --wg-border: #e2e8f0;
  --wg-border-hover: #cbd5e1;
  --wg-text: #0f172a;
  --wg-text-muted: #64748b;
  --wg-text-subtle: #94a3b8;
  
  --wg-primary: #3b82f6;
  --wg-primary-hover: #2563eb;
  --wg-primary-light: #eff6ff;
  
  --wg-t5-bg: #fff1f2;
  --wg-t5-border: #fecdd3;
  --wg-t5-text: #e11d48;
  
  --wg-t67-bg: #f8fafc;
  --wg-t67-border: #cbd5e1;
  --wg-t67-text: #334155;
  
  --wg-t75-bg: #f0fdf4;
  --wg-t75-border: #bbf7d0;
  --wg-t75-text: #16a34a;
  
  --wg-shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --wg-shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --wg-shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

/* Dark Mode Overrides */
html.dark, html[data-theme='dark'] {
  --wg-bg: #0b0f19;
  --wg-surface: #131b2e;
  --wg-surface-alt: #1e293b;
  --wg-border: #26334d;
  --wg-border-hover: #334155;
  --wg-text: #f8fafc;
  --wg-text-muted: #94a3b8;
  --wg-text-subtle: #64748b;
  
  --wg-primary: #60a5fa;
  --wg-primary-hover: #3b82f6;
  --wg-primary-light: rgba(59, 130, 246, 0.12);
  
  --wg-t5-bg: rgba(225, 29, 72, 0.08);
  --wg-t5-border: rgba(244, 63, 94, 0.25);
  --wg-t5-text: #fb7185;
  
  --wg-t67-bg: rgba(30, 41, 59, 0.6);
  --wg-t67-border: rgba(71, 85, 105, 0.4);
  --wg-t67-text: #cbd5e1;
  
  --wg-t75-bg: rgba(16, 185, 129, 0.08);
  --wg-t75-border: rgba(52, 211, 153, 0.25);
  --wg-t75-text: #34d399;
}

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

.mono {
  font-family: var(--wg-mono);
}

/* Layout Container */
.wg-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 1rem 4rem;
}

/* Navbar */
.wg-navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 1.75rem;
  background-color: var(--wg-surface);
  border-bottom: 1px solid var(--wg-border);
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(8px);
}

.wg-nav-brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--wg-text);
  text-decoration: none;
}

.wg-nav-brand i {
  color: var(--wg-primary);
  font-size: 1.2rem;
}

.wg-nav-links {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.wg-nav-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.85rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--wg-text-muted);
  text-decoration: none;
  border-radius: 0.5rem;
  transition: all 0.15s ease;
}

.wg-nav-link:hover {
  color: var(--wg-text);
  background-color: var(--wg-surface-alt);
}

.wg-nav-link.active {
  color: var(--wg-primary);
  background-color: var(--wg-primary-light);
  font-weight: 600;
}

.wg-theme-btn {
  background: transparent;
  border: 1px solid var(--wg-border);
  color: var(--wg-text-muted);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.wg-theme-btn:hover {
  color: var(--wg-text);
  border-color: var(--wg-border-hover);
  background-color: var(--wg-surface-alt);
}

/* Hero Section */
.wg-hero {
  text-align: center;
  padding: 2.5rem 1rem 2rem;
  max-width: 860px;
  margin: 0 auto;
}

.wg-hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: 9999px;
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  border: 1px solid rgba(59, 130, 246, 0.25);
  margin-bottom: 1rem;
}

.wg-hero-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  margin: 0 0 0.85rem;
  line-height: 1.2;
}

.wg-hero-title span {
  background: linear-gradient(135deg, #3b82f6, #06b6d4);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.wg-hero-desc {
  font-size: 1rem;
  color: var(--wg-text-muted);
  line-height: 1.6;
  margin: 0 0 1.5rem;
}

/* Mode Switcher Tabs */
.wg-tabs-wrapper {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
}

.wg-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.15rem;
  font-size: 0.88rem;
  font-weight: 600;
  border-radius: 0.65rem;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface);
  color: var(--wg-text-muted);
  cursor: pointer;
  transition: all 0.2s ease;
}

.wg-tab-btn:hover {
  color: var(--wg-text);
  border-color: var(--wg-border-hover);
  background-color: var(--wg-surface-alt);
}

.wg-tab-btn.active {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: #ffffff;
  border-color: #1d4ed8;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.wg-tab-badge {
  font-size: 0.72rem;
  padding: 0.15rem 0.45rem;
  border-radius: 9999px;
  background-color: rgba(255, 255, 255, 0.2);
  color: currentColor;
}

/* ==========================================================================
   Two-Tier Tab Bar: Main Parts (Tier 1) & Sub-Topic Tabs (Tier 2)
   Modeled on task 1 common paraphrases layout
   ========================================================================== */
.wg-two-tier-card {
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  border-radius: 16px;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
  box-shadow: var(--wg-shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.wg-tier1-section {
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--wg-border);
}

.wg-tier-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 0.15rem 0.35rem;
}

.wg-tier-label {
  font-size: 0.74rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--wg-text-muted);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--wg-mono);
}

.wg-tier-label i {
  color: var(--wg-primary);
  font-size: 0.82rem;
}

.wg-tier-counter {
  font-size: 0.72rem;
  font-family: var(--wg-mono);
  font-weight: 700;
  color: var(--wg-primary);
  background: var(--wg-primary-light);
  padding: 0.18rem 0.6rem;
  border-radius: 6px;
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.wg-tier1-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.5rem;
  margin-top: 0.25rem;
}

@media (min-width: 640px) {
  .wg-tier1-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1024px) {
  .wg-tier1-grid {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }
}

.wg-tier1-btn {
  padding: 0.65rem 0.75rem;
  border-radius: 12px;
  text-align: left;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface-alt);
  color: var(--wg-text);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 0.35rem;
  min-height: 64px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.wg-tier1-btn:hover {
  background-color: var(--wg-primary-light);
  border-color: var(--wg-primary);
  color: var(--wg-primary);
  transform: translateY(-1px);
}

.wg-tier1-btn.active {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  border-color: #1d4ed8;
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.wg-tier1-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.wg-tier1-icon {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.78rem;
  background-color: rgba(59, 130, 246, 0.12);
  color: var(--wg-primary);
  transition: all 0.2s ease;
}

.wg-tier1-btn.active .wg-tier1-icon {
  background-color: rgba(255, 255, 255, 0.22);
  color: #ffffff;
}

.wg-tier1-badge {
  font-size: 0.68rem;
  font-family: var(--wg-mono);
  font-weight: 700;
  padding: 0.1rem 0.38rem;
  border-radius: 4px;
  background-color: var(--wg-surface);
  color: var(--wg-text-muted);
  border: 1px solid var(--wg-border);
}

.wg-tier1-btn.active .wg-tier1-badge {
  background-color: rgba(255, 255, 255, 0.24);
  color: #ffffff;
  border-color: transparent;
}

.wg-tier1-title {
  font-size: 0.76rem;
  font-weight: 700;
  line-height: 1.25;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  width: 100%;
}

/* Tier 2: Sub-Topics Bar */
.wg-tier2-section {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.wg-subtab-scroll-wrap {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  width: 100%;
}

.wg-subtab-scroll-btn {
  width: 28px;
  height: 32px;
  border-radius: 8px;
  background-color: var(--wg-surface-alt);
  border: 1px solid var(--wg-border);
  color: var(--wg-text-muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  flex-shrink: 0;
  transition: all 0.15s ease;
  user-select: none;
}

.wg-subtab-scroll-btn:hover {
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  border-color: var(--wg-primary);
}

.wg-tier2-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0.25rem 0.1rem 0.45rem;
  scrollbar-width: none;
  cursor: grab;
  user-select: none;
  flex: 1;
}

.wg-tier2-row.is-dragging {
  cursor: grabbing;
}

.wg-tier2-row::-webkit-scrollbar {
  display: none;
}

.wg-subtab-btn {
  padding: 0.45rem 0.85rem;
  border-radius: 10px;
  font-size: 0.78rem;
  font-weight: 600;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface);
  color: var(--wg-text-muted);
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  transition: all 0.18s ease;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.wg-subtab-btn:hover {
  background-color: var(--wg-surface-alt);
  color: var(--wg-text);
  border-color: var(--wg-border-hover);
}

.wg-subtab-btn.active {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: #ffffff;
  border-color: #1d4ed8;
  box-shadow: 0 3px 10px rgba(37, 99, 235, 0.32);
}

.wg-subtab-num {
  width: 20px;
  height: 20px;
  border-radius: 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.65rem;
  font-family: var(--wg-mono);
  font-weight: 700;
  background-color: var(--wg-surface-alt);
  color: var(--wg-text);
  transition: all 0.2s ease;
}

.wg-subtab-btn.active .wg-subtab-num {
  background-color: rgba(255, 255, 255, 0.24);
  color: #ffffff;
}

.wg-subtab-count {
  font-size: 0.68rem;
  font-family: var(--wg-mono);
  opacity: 0.85;
}

/* ==========================================================================
   Interactive Slider Navigation Bar (Modeled on task 1 common paraphrases)
   ========================================================================== */
.wg-slider-card {
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  border-radius: 16px;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
  box-shadow: var(--wg-shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.wg-slider-header {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  border-bottom: 1px solid var(--wg-border);
  padding-bottom: 0.65rem;
}

@media (min-width: 640px) {
  .wg-slider-header {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.wg-slider-header-left {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.wg-slider-icon {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  flex-shrink: 0;
}

.wg-slider-title-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.wg-slider-title {
  font-size: 0.76rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--wg-text);
  font-family: var(--wg-mono);
}

.wg-slider-badge {
  font-size: 0.68rem;
  font-family: var(--wg-mono);
  font-weight: 700;
  padding: 0.12rem 0.5rem;
  border-radius: 9999px;
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.wg-slider-desc {
  font-size: 0.72rem;
  color: var(--wg-text-muted);
  margin-top: 0.1rem;
}

.wg-slider-active-preview {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--wg-mono);
  font-size: 0.76rem;
  flex-shrink: 0;
}

.wg-slider-active-label {
  color: var(--wg-text-subtle);
  font-size: 0.7rem;
}

.wg-slider-active-val {
  font-weight: 700;
  color: var(--wg-primary);
  background-color: var(--wg-primary-light);
  padding: 0.25rem 0.65rem;
  border-radius: 8px;
  border: 1px solid rgba(59, 130, 246, 0.25);
  max-width: 280px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Slider Track & Range Input */
.wg-slider-track-wrap {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.wg-slider-input {
  width: 100%;
  height: 8px;
  background-color: var(--wg-surface-alt);
  border: 1px solid var(--wg-border);
  border-radius: 8px;
  appearance: none;
  cursor: pointer;
  outline: none;
  accent-color: var(--wg-primary);
  transition: all 0.15s ease;
}

.wg-slider-input:focus {
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

/* Step labels beneath slider */
.wg-slider-steps-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 0.15rem;
  font-size: 0.68rem;
  font-family: var(--wg-mono);
  color: var(--wg-text-subtle);
  user-select: none;
  gap: 0.25rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.wg-slider-steps-row::-webkit-scrollbar {
  display: none;
}

.wg-step-label {
  cursor: pointer;
  padding: 0.15rem 0.25rem;
  border-radius: 4px;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.wg-step-label:hover {
  color: var(--wg-primary);
  background-color: var(--wg-primary-light);
}

.wg-step-label.active {
  color: var(--wg-primary);
  font-weight: 800;
  transform: scale(1.15);
}

/* Search & Filter Controls */
.wg-controls-card {
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  border-radius: 1rem;
  padding: 1.25rem;
  margin-bottom: 2rem;
  box-shadow: var(--wg-shadow-sm);
}

.wg-search-bar {
  position: relative;
  display: flex;
  align-items: center;
  margin-bottom: 1rem;
}

.wg-search-icon {
  position: absolute;
  left: 1rem;
  color: var(--wg-text-subtle);
  pointer-events: none;
}

.wg-search-input {
  width: 100%;
  padding: 0.75rem 2.5rem 0.75rem 2.6rem;
  font-size: 0.92rem;
  border-radius: 0.65rem;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface-alt);
  color: var(--wg-text);
  transition: all 0.2s ease;
}

.wg-search-input:focus {
  outline: none;
  border-color: var(--wg-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
  background-color: var(--wg-surface);
}

.wg-search-clear {
  position: absolute;
  right: 0.85rem;
  background: none;
  border: none;
  color: var(--wg-text-subtle);
  cursor: pointer;
  padding: 0.25rem;
}

.wg-filter-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.wg-filter-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--wg-text-muted);
}

.wg-filter-pills {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.wg-pill {
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: 9999px;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface);
  color: var(--wg-text-muted);
  cursor: pointer;
  transition: all 0.15s ease;
}

.wg-pill:hover {
  color: var(--wg-text);
  border-color: var(--wg-border-hover);
}

.wg-pill.active {
  background-color: var(--wg-text);
  color: var(--wg-bg);
  border-color: var(--wg-text);
}

/* ==========================================================================
   Results Status Bar & Focus Indicator
   ========================================================================== */
.wg-status-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 0.85rem;
  padding: 0.25rem 0.5rem;
  font-size: 0.825rem;
  color: var(--wg-text-muted);
}

.wg-status-counter {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.wg-focus-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.6rem;
  font-size: 0.725rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border-radius: 9999px;
  background: rgba(59, 130, 246, 0.12);
  color: #3b82f6;
  border: 1px solid rgba(59, 130, 246, 0.28);
}

.wg-all-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 6px;
  background: var(--wg-surface-alt);
  color: var(--wg-primary);
  font-size: 0.75rem;
  border: 1px solid var(--wg-border);
}

.wg-counter-text {
  font-weight: 500;
  color: var(--wg-text-muted);
}

.wg-counter-text strong {
  color: var(--wg-text);
  font-weight: 700;
}

.wg-filter-count {
  font-size: 0.775rem;
  color: var(--wg-text-muted);
  opacity: 0.85;
}

.wg-status-hint {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.8rem;
  color: var(--wg-text-muted);
}

.wg-status-hint i.fa-star {
  color: #f59e0b;
  filter: drop-shadow(0 0 4px rgba(245, 158, 11, 0.35));
}

@media (max-width: 640px) {
  .wg-status-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
    padding: 0;
  }
}

/* ==========================================================================
   Tier 3: Content-Level Sub Tabs & Focus Switcher (Better Single-Item Focus)
   ========================================================================== */
.wg-content-switcher-card {
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  border-radius: 1rem;
  padding: 0.9rem 1.15rem;
  margin-bottom: 1.25rem;
  box-shadow: var(--wg-shadow-sm);
  transition: all 0.2s ease;
}

.wg-content-switcher-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--wg-border);
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.wg-content-switcher-info {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.wg-content-switcher-icon {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  flex-shrink: 0;
}

.wg-content-switcher-meta {
  display: flex;
  flex-direction: column;
}

.wg-content-switcher-label {
  font-size: 0.74rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--wg-text);
  font-family: var(--wg-mono);
}

.wg-content-switcher-sub {
  font-size: 0.72rem;
  color: var(--wg-text-muted);
}

.wg-content-mode-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.wg-mode-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.75rem;
  font-size: 0.74rem;
  font-weight: 600;
  border-radius: 8px;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface-alt);
  color: var(--wg-text-muted);
  cursor: pointer;
  transition: all 0.2s ease;
}

.wg-mode-toggle-btn:hover {
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  border-color: rgba(59, 130, 246, 0.3);
}

.wg-mode-toggle-btn.active {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.15), rgba(6, 182, 212, 0.15));
  color: var(--wg-primary);
  border-color: var(--wg-primary);
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.15);
}

.wg-content-tabs-row {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  overflow-x: auto;
  scrollbar-width: none;
  padding: 0.2rem 0;
  scroll-behavior: smooth;
  width: 100%;
}

.wg-content-tabs-row::-webkit-scrollbar {
  display: none;
}

.wg-content-tabs-row.is-dragging {
  cursor: grabbing !important;
  cursor: -webkit-grabbing !important;
  user-select: none;
  scroll-behavior: auto;
}

.wg-content-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.75rem;
  border-radius: 8px;
  font-size: 0.76rem;
  font-weight: 500;
  white-space: nowrap;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface-alt);
  color: var(--wg-text-muted);
  cursor: pointer;
  transition: all 0.18s ease;
  user-select: none;
  flex-shrink: 0;
}

.wg-content-tab-btn:hover {
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  border-color: rgba(59, 130, 246, 0.35);
  transform: translateY(-1px);
}

.wg-content-tab-btn.active {
  background-color: var(--wg-primary);
  color: #ffffff;
  border-color: var(--wg-primary);
  box-shadow: 0 3px 10px rgba(59, 130, 246, 0.3);
  font-weight: 700;
}

.wg-content-tab-btn.all-btn.active {
  background-color: #0ea5e9;
  border-color: #0ea5e9;
  color: #ffffff;
}

.wg-content-tab-num {
  font-family: var(--wg-mono);
  font-size: 0.68rem;
  font-weight: 700;
  opacity: 0.85;
}

.wg-content-tab-btn.active .wg-content-tab-num {
  color: #ffffff;
  opacity: 1;
}

/* Focus Navigation Bar (Prev / Next bottom controls) */
.wg-focus-nav-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1.5rem;
  padding: 0.85rem 1.25rem;
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  border-radius: 1rem;
  box-shadow: var(--wg-shadow-sm);
  flex-wrap: wrap;
}

.wg-focus-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  border: 1px solid var(--wg-border);
  background-color: var(--wg-surface-alt);
  color: var(--wg-text);
  cursor: pointer;
  transition: all 0.2s ease;
}

.wg-focus-nav-btn:hover:not(:disabled) {
  background-color: var(--wg-primary-light);
  color: var(--wg-primary);
  border-color: var(--wg-primary);
  transform: translateY(-1px);
}

.wg-focus-nav-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

.wg-focus-nav-center {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.78rem;
}

/* Pattern Card Layout */
.wg-cards-grid {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.wg-pattern-card {
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  border-radius: 1.15rem;
  padding: 1.5rem;
  box-shadow: var(--wg-shadow-sm);
  transition: all 0.2s ease;
  position: relative;
}

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

.wg-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--wg-border);
}

.wg-badge-group {
  display: flex;
  gap: 0.45rem;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 0.45rem;
}

.wg-tag-task1 {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 0.4rem;
  background-color: rgba(6, 182, 212, 0.15);
  color: #06b6d4;
  border: 1px solid rgba(6, 182, 212, 0.3);
}

.wg-tag-task2 {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 0.4rem;
  background-color: rgba(168, 85, 247, 0.15);
  color: #a855f7;
  border: 1px solid rgba(168, 85, 247, 0.3);
}

.wg-tag-aspect {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.55rem;
  border-radius: 0.4rem;
  background-color: var(--wg-surface-alt);
  color: var(--wg-text-muted);
}

.wg-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 0 0 0.35rem;
  line-height: 1.4;
  color: var(--wg-text);
}

.wg-card-formula-banner {
  display: inline-block;
  font-family: var(--wg-mono);
  font-size: 0.85rem;
  background-color: var(--wg-surface-alt);
  border: 1px solid var(--wg-border);
  padding: 0.35rem 0.75rem;
  border-radius: 0.5rem;
  color: var(--wg-primary);
  margin-bottom: 0.5rem;
}

.wg-card-actions {
  display: flex;
  gap: 0.4rem;
  align-items: center;
}

.wg-action-btn {
  background: var(--wg-surface-alt);
  border: 1px solid var(--wg-border);
  color: var(--wg-text-muted);
  width: 2.2rem;
  height: 2.2rem;
  border-radius: 0.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.wg-action-btn:hover {
  color: var(--wg-text);
  border-color: var(--wg-border-hover);
}

.wg-action-btn.bookmarked {
  color: #f59e0b;
  background-color: rgba(245, 158, 11, 0.15);
  border-color: rgba(245, 158, 11, 0.35);
}

/* 3-Tier Stepper Vertical Layout */
.wg-stepper-wrap {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

/* Tier Step 1: Band 5.0 Trap */
.wg-tier-box-5 {
  border: 1px dashed var(--wg-t5-border);
  background-color: var(--wg-t5-bg);
  border-radius: 0.85rem;
  padding: 1rem 1.15rem;
}

.wg-tier-label-5 {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--wg-t5-text);
  display: flex;
  align-items: center;
  gap: 0.35rem;
  margin-bottom: 0.45rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.wg-tier-mistake-text {
  font-size: 0.92rem;
  color: var(--wg-t5-text);
  font-style: italic;
  text-decoration: line-through;
  margin-bottom: 0.4rem;
  line-height: 1.5;
}

.wg-tier-reason-text {
  font-size: 0.82rem;
  color: var(--wg-text-muted);
  line-height: 1.5;
}

/* Tier Step 2: Band 6.0–7.0 Baseline */
.wg-tier-box-67 {
  border: 1px solid var(--wg-t67-border);
  background-color: var(--wg-t67-bg);
  border-radius: 0.85rem;
  padding: 1rem 1.15rem;
}

.wg-tier-label-67 {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--wg-text-muted);
  display: flex;
  align-items: center;
  gap: 0.35rem;
  margin-bottom: 0.45rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.wg-tier-standard-text {
  font-size: 0.92rem;
  color: var(--wg-text);
  margin-bottom: 0.35rem;
  line-height: 1.5;
}

.wg-tier-assessment-text {
  font-size: 0.82rem;
  color: var(--wg-text-muted);
  line-height: 1.5;
}

/* Tier Step 3: Band 7.5+ High-Band Syntactic Polish */
.wg-tier-box-75 {
  border: 1.5px solid var(--wg-t75-border);
  background: var(--wg-t75-bg);
  border-radius: 0.85rem;
  padding: 1.15rem 1.25rem;
  position: relative;
}

.wg-tier-label-75 {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--wg-t75-text);
  display: flex;
  align-items: center;
  gap: 0.35rem;
  margin-bottom: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.wg-tier-pattern-text {
  font-size: 1rem;
  font-weight: 600;
  color: var(--wg-text);
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.wg-breakdown-tags {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  margin-bottom: 0.85rem;
}

.wg-breakdown-pill {
  font-family: var(--wg-mono);
  font-size: 0.72rem;
  padding: 0.2rem 0.5rem;
  border-radius: 0.35rem;
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  color: var(--wg-text-muted);
}

.wg-context-box {
  background-color: var(--wg-surface);
  border: 1px solid var(--wg-border);
  border-radius: 0.65rem;
  padding: 0.85rem;
  margin-top: 0.65rem;
}

.wg-context-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--wg-text-subtle);
  margin-bottom: 0.35rem;
}

.wg-context-model {
  font-size: 0.88rem;
  color: var(--wg-text);
  line-height: 1.55;
  margin-bottom: 0.5rem;
}

.wg-examiner-insight {
  font-size: 0.82rem;
  color: var(--wg-text-muted);
  border-left: 2px solid var(--wg-primary);
  padding-left: 0.65rem;
  font-style: italic;
  line-height: 1.5;
}

/* Toast Feedback */
.wg-toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background-color: #0f172a;
  color: #f8fafc;
  padding: 0.65rem 1.15rem;
  border-radius: 0.5rem;
  font-size: 0.85rem;
  font-weight: 500;
  box-shadow: var(--wg-shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  z-index: 50;
  transform: translateY(1rem);
  opacity: 0;
  transition: all 0.2s ease;
  pointer-events: none;
}

.wg-toast.show {
  transform: translateY(0);
  opacity: 1;
}

/* Empty State */
.wg-empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--wg-text-muted);
}

.wg-empty-state i {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  opacity: 0.4;
}

/* ==========================================================================
   Syntactic Structure Highlighting & Token Formatters (Task 1 & Task 2)
   ========================================================================== */

/* Formula Variable and Keyword Tokens */
.wg-token-var {
  display: inline-block;
  background: rgba(99, 102, 241, 0.12);
  color: #4338ca;
  border: 1px solid rgba(99, 102, 241, 0.28);
  padding: 1px 6px;
  border-radius: 4px;
  font-family: var(--wg-mono);
  font-size: 0.84em;
  font-weight: 600;
  margin: 0 1px;
  letter-spacing: -0.01em;
  transition: all 0.15s ease;
}

html.dark .wg-token-var,
html[data-theme='dark'] .wg-token-var {
  background: rgba(99, 102, 241, 0.24);
  color: #a5b4fc;
  border-color: rgba(99, 102, 241, 0.42);
}

.wg-token-kw {
  display: inline-block;
  color: #b45309;
  font-weight: 700;
  font-family: var(--wg-mono);
  margin: 0 2px;
}

html.dark .wg-token-kw,
html[data-theme='dark'] .wg-token-kw {
  color: #fbbf24;
}

.wg-token-op {
  color: var(--wg-primary);
  font-weight: 700;
  margin: 0 3px;
  opacity: 0.85;
}

/* Band 5.0 Trap Slip Highlight (Rose/Red dashed) */
.wg-hl-trap {
  display: inline;
  background: rgba(244, 63, 94, 0.14);
  color: #e11d48;
  border-bottom: 2px dashed #f43f5e;
  padding: 1px 5px;
  border-radius: 4px;
  font-weight: 600;
  cursor: help;
  transition: all 0.15s ease;
}

html.dark .wg-hl-trap,
html[data-theme='dark'] .wg-hl-trap {
  background: rgba(244, 63, 94, 0.24);
  color: #fda4af;
  border-bottom-color: #fb7185;
}

.wg-hl-trap:hover {
  background: rgba(244, 63, 94, 0.22);
}

/* Band 6.0–7.0 Baseline Structure Highlight (Amber/Honey solid) */
.wg-hl-band67 {
  display: inline;
  background: rgba(245, 158, 11, 0.15);
  color: #b45309;
  border-bottom: 2px solid #f59e0b;
  padding: 1px 5px;
  border-radius: 4px;
  font-weight: 600;
  cursor: help;
  transition: all 0.15s ease;
}

html.dark .wg-hl-band67,
html[data-theme='dark'] .wg-hl-band67 {
  background: rgba(245, 158, 11, 0.22);
  color: #fcd34d;
  border-bottom-color: #f59e0b;
}

.wg-hl-band67:hover {
  background: rgba(245, 158, 11, 0.24);
}

/* Band 7.5+ High-Band Syntactic Polish Highlight (Emerald/Teal solid + glow) */
.wg-hl-band75 {
  display: inline;
  background: rgba(16, 185, 129, 0.16);
  color: #047857;
  border-bottom: 2px solid #10b981;
  padding: 1px 5px;
  border-radius: 4px;
  font-weight: 700;
  box-shadow: 0 1px 3px rgba(16, 185, 129, 0.12);
  cursor: help;
  transition: all 0.15s ease;
}

html.dark .wg-hl-band75,
html[data-theme='dark'] .wg-hl-band75 {
  background: rgba(16, 185, 129, 0.24);
  color: #6ee7b7;
  border-bottom-color: #34d399;
  box-shadow: 0 1px 4px rgba(16, 185, 129, 0.2);
}

.wg-hl-band75:hover {
  background: rgba(16, 185, 129, 0.26);
}

/* Highlight Toggle Buttons in Toolbar & Sub-Header */
.wg-toggle-highlight-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.85rem;
  border-radius: 9999px;
  font-size: 0.78rem;
  font-weight: 600;
  border: 1px solid var(--wg-border);
  background: var(--wg-surface);
  color: var(--wg-text-muted);
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.wg-toggle-highlight-pill:hover {
  color: var(--wg-text);
  border-color: var(--wg-border-hover);
  background: var(--wg-surface-alt);
}

.wg-toggle-highlight-pill.active {
  background: rgba(245, 158, 11, 0.14);
  border-color: #f59e0b;
  color: #b45309;
}

html.dark .wg-toggle-highlight-pill.active,
html[data-theme='dark'] .wg-toggle-highlight-pill.active {
  background: rgba(245, 158, 11, 0.22);
  border-color: #f59e0b;
  color: #fcd34d;
}

/* Disabled Highlight Mode Overrides (When toggled OFF by student) */
.wg-hl-disabled .wg-hl-trap,
.wg-hl-disabled .wg-hl-band67,
.wg-hl-disabled .wg-hl-band75 {
  background: transparent !important;
  color: inherit !important;
  border: none !important;
  box-shadow: none !important;
  font-weight: inherit !important;
  padding: 0 !important;
  cursor: inherit !important;
}

.wg-hl-disabled .wg-token-var,
.wg-hl-disabled .wg-token-kw {
  background: transparent !important;
  border: none !important;
  color: inherit !important;
  padding: 0 !important;
  font-weight: inherit !important;
}

/* ==========================================================================
   Comprehensive Mobile & Tablet Responsive Architecture (< 768px & < 480px)
   ========================================================================== */

@media (max-width: 768px) {
  /* Container & Spacing */
  .wg-container {
    padding: 1rem 0.75rem 5rem;
  }

  /* Navbar */
  .wg-navbar {
    padding: 0.65rem 0.85rem;
  }

  .wg-brand-text {
    font-size: 0.95rem;
    max-width: 170px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .wg-nav-links {
    gap: 0.4rem;
  }

  .wg-nav-link {
    padding: 0.45rem 0.55rem;
    font-size: 0.8rem;
  }

  .wg-nav-link-text {
    display: none;
  }

  /* Hero Banner */
  .wg-hero {
    padding: 1.5rem 0.5rem 1rem;
  }

  .wg-hero-title {
    font-size: 1.65rem;
    line-height: 1.25;
    margin-bottom: 0.6rem;
  }

  .wg-hero-desc {
    font-size: 0.88rem;
    line-height: 1.55;
    margin-bottom: 1.25rem;
  }

  .wg-hero-badge {
    font-size: 0.68rem;
    padding: 0.25rem 0.65rem;
    white-space: normal;
    text-align: center;
    line-height: 1.4;
  }

  /* Two-Tier Card */
  .wg-two-tier-card {
    padding: 0.85rem 0.75rem;
    border-radius: 14px;
    margin-bottom: 1rem;
  }

  .wg-tier-header {
    flex-wrap: wrap;
    gap: 0.35rem;
  }

  .wg-tier-label {
    font-size: 0.7rem;
  }

  /* Slider Card */
  .wg-slider-card {
    padding: 0.85rem 0.75rem;
    border-radius: 14px;
    margin-bottom: 1rem;
  }

  .wg-slider-header {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
  }

  .wg-slider-title-row {
    flex-wrap: wrap;
    gap: 0.35rem;
  }

  .wg-slider-title {
    font-size: 0.82rem;
  }

  .wg-slider-active-preview {
    width: 100%;
    justify-content: space-between;
    background: var(--wg-surface-alt);
    padding: 0.45rem 0.65rem;
    border-radius: 8px;
    border: 1px solid var(--wg-border);
  }

  .wg-slider-active-val {
    max-width: 65%;
  }

  .wg-slider-steps-row {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 0.25rem;
    gap: 0.3rem;
  }

  .wg-slider-steps-row::-webkit-scrollbar {
    display: none;
  }

  .wg-slider-step-btn {
    min-width: 24px;
    height: 24px;
    font-size: 0.65rem;
    flex-shrink: 0;
  }

  /* Hide Desktop Chevron Buttons on Touch Devices */
  .wg-subtab-scroll-btn {
    display: none !important;
  }

  .wg-tier2-row,
  .wg-content-tabs-row {
    width: 100%;
    -webkit-overflow-scrolling: touch;
  }

  /* Controls Card & Filter Row */
  .wg-controls-card {
    padding: 0.85rem 0.75rem;
    border-radius: 14px;
    margin-bottom: 1rem;
  }

  .wg-search-bar {
    margin-bottom: 0.75rem;
  }

  .wg-filter-row {
    flex-direction: column;
    align-items: stretch;
    gap: 0.65rem;
  }

  .wg-filter-pills {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.35rem;
    width: 100%;
  }

  .wg-pill {
    text-align: center;
    padding: 0.4rem 0.5rem;
    font-size: 0.75rem;
  }

  .wg-controls-card .ml-auto {
    margin-left: 0 !important;
    width: 100%;
  }

  .wg-toggle-highlight-pill {
    width: 100%;
    justify-content: center;
    padding: 0.45rem;
  }

  /* Content Switcher Card */
  .wg-content-switcher-card {
    padding: 0.85rem 0.75rem;
    border-radius: 14px;
    margin-bottom: 1rem;
  }

  .wg-content-switcher-header {
    flex-direction: column;
    align-items: stretch;
    gap: 0.65rem;
  }

  .wg-content-mode-actions {
    display: flex;
    width: 100%;
    gap: 0.45rem;
  }

  .wg-mode-toggle-btn {
    flex: 1;
    justify-content: center;
    text-align: center;
    font-size: 0.72rem;
    padding: 0.45rem 0.4rem;
    white-space: nowrap;
  }

  /* Cards Grid & Pattern Card */
  .wg-pattern-card {
    padding: 1rem 0.85rem;
    border-radius: 14px;
    margin-bottom: 1rem;
  }

  .wg-card-header {
    margin-bottom: 0.85rem;
    padding-bottom: 0.75rem;
  }

  .wg-card-title {
    font-size: 1rem;
    line-height: 1.35;
  }

  .wg-card-formula-banner {
    display: block;
    max-width: 100%;
    overflow-x: auto;
    white-space: normal;
    word-break: break-word;
    font-size: 0.78rem;
    padding: 0.35rem 0.55rem;
    line-height: 1.45;
  }

  .wg-tier-box-5,
  .wg-tier-box-67,
  .wg-tier-box-75 {
    padding: 0.75rem 0.85rem;
    border-radius: 10px;
  }

  .wg-tier-label-5,
  .wg-tier-label-67,
  .wg-tier-label-75 {
    font-size: 0.68rem;
    flex-wrap: wrap;
    gap: 0.3rem;
  }

  .wg-tier-mistake-text,
  .wg-tier-standard-text {
    font-size: 0.86rem;
    line-height: 1.5;
  }

  .wg-tier-pattern-text {
    font-size: 0.92rem;
    line-height: 1.5;
  }

  .wg-context-box {
    padding: 0.65rem 0.75rem;
  }

  .wg-context-model {
    font-size: 0.84rem;
  }

  .wg-examiner-insight {
    font-size: 0.78rem;
  }

  /* Focus Navigation Bar (Bottom) */
  .wg-focus-nav-bar {
    position: sticky;
    bottom: 0.75rem;
    z-index: 35;
    padding: 0.65rem 0.75rem;
    border-radius: 12px;
    margin-top: 1rem;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.25);
  }

  .wg-focus-nav-btn {
    flex: 1;
    justify-content: center;
    padding: 0.45rem 0.65rem;
    font-size: 0.75rem;
  }

  .wg-focus-nav-center {
    font-size: 0.72rem;
  }

  /* Toast Notification */
  .wg-toast {
    bottom: 1rem;
    right: 1rem;
    left: 1rem;
    justify-content: center;
    padding: 0.55rem 0.85rem;
    font-size: 0.8rem;
  }
}

@media (max-width: 480px) {
  .wg-brand-text {
    max-width: 125px;
    font-size: 0.88rem;
  }

  .wg-hero-title {
    font-size: 1.45rem;
  }

  .wg-tier1-grid {
    grid-template-columns: 1fr 1fr;
    gap: 0.35rem;
  }

  .wg-tier1-btn {
    padding: 0.5rem 0.6rem;
    min-height: 52px;
  }

  .wg-tier1-title {
    font-size: 0.7rem;
  }

  .wg-content-mode-actions {
    flex-direction: row;
  }

  .wg-focus-nav-bar {
    flex-wrap: nowrap;
    gap: 0.4rem;
  }

  #prevGrammarPatternLabel,
  #nextGrammarPatternLabel {
    display: inline;
    font-size: 0.72rem;
  }
}