/* ===== SYNTHESIZE PAGE STYLES ===== */
:root {
  --primary-900: #042f2e;
  --primary-700: #0f5554;
  --primary-600: #0d7377;
  --primary-500: #0d9488;
  --primary-400: #2dd4bf;
  --primary-300: #5eead4;
  --primary-200: #99f6e4;
  --accent-500: #06b6d4;
  --accent-400: #22d3ee;
  --emerald-500: #10b981;
  --emerald-400: #34d399;
  --bg-dark: #0a1628;
  --bg-card: #0f2137;
  --bg-card-hover: #132b45;
  --bg-surface: #111d32;
  --text-primary: #f0fdfa;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --gradient-primary: linear-gradient(135deg, var(--primary-500), var(--accent-500));
  --glass-bg: rgba(15, 33, 55, 0.7);
  --glass-border: rgba(13, 148, 136, 0.15);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --transition-fast: 0.2s ease;
  --transition-base: 0.3s ease;
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-display: 'Outfit', 'Inter', sans-serif;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-sans);
  background: var(--bg-dark);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.container { max-width: 960px; margin: 0 auto; padding: 0 24px; }

/* ===== NAVBAR ===== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  padding: 10px 0;
  background: rgba(10, 22, 40, 0.92);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
}
.navbar .container { display: flex; align-items: center; justify-content: space-between; }
.nav-logo {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--font-display); font-size: 1.3rem; font-weight: 700;
}
.nav-logo-icon {
  width: 36px; height: 36px; border-radius: var(--radius-sm);
  background: var(--gradient-primary);
  display: flex; align-items: center; justify-content: center; font-size: 1rem;
}
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a {
  font-size: 0.88rem; font-weight: 500; color: var(--text-secondary);
  transition: color var(--transition-fast); position: relative;
}
.nav-links a.active { color: var(--primary-400); }
.nav-links a:hover { color: var(--primary-300); }
.nav-cta {
  padding: 8px 20px; border-radius: var(--radius-full);
  background: var(--gradient-primary); color: var(--primary-900) !important;
  font-weight: 600 !important; cursor: pointer; border: none;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast) !important;
}
.nav-cta:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(13, 148, 136, 0.3); }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; }
.nav-toggle span { width: 24px; height: 2px; background: var(--text-primary); border-radius: 2px; transition: all var(--transition-base); }

/* ===== LANGUAGE TOGGLE ===== */
.lang-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--glass-border);
  background: rgba(13, 148, 136, 0.06);
  color: var(--text-primary);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  z-index: 1001;
}

.lang-toggle:hover {
  border-color: var(--primary-400);
  background: rgba(13, 148, 136, 0.12);
  color: var(--primary-300);
}

.lang-flag { font-size: 1rem; }
.lang-text { font-family: var(--font-display); letter-spacing: 1px; }

.lang-toggle.lang-switching {
  animation: lang-pop 0.4s ease;
}

@keyframes lang-pop {
  0%   { transform: scale(1); }
  50%  { transform: scale(0.88); opacity: 0.5; }
  100% { transform: scale(1); opacity: 1; }
}

/* ===== MAIN ===== */
.tool-main { flex: 1; padding-top: 100px; padding-bottom: 60px; }

.tool-header { text-align: center; margin-bottom: 40px; }
.section-label {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.78rem; font-weight: 600; letter-spacing: 2px; text-transform: uppercase;
  color: var(--primary-400); margin-bottom: 12px;
  padding: 5px 14px; border: 1px solid rgba(13, 148, 136, 0.25);
  border-radius: var(--radius-full); background: rgba(13, 148, 136, 0.06);
}
.dot { width: 6px; height: 6px; border-radius: 50%; background: var(--primary-400); display: inline-block; animation: pulse-dot 2s ease-in-out infinite; }
@keyframes pulse-dot { 0%, 100% { opacity: 1; } 50% { opacity: 0.4; } }
.tool-title {
  font-family: var(--font-display); font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800; line-height: 1.2; margin-bottom: 12px;
}
.gradient-text {
  background: linear-gradient(135deg, var(--primary-400), var(--accent-400), var(--emerald-400));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.tool-subtitle { font-size: 1rem; color: var(--text-secondary); max-width: 560px; margin: 0 auto; }

/* ===== STEPPER ===== */
.stepper {
  display: flex; align-items: center; justify-content: center; gap: 0;
  margin-bottom: 40px; padding: 0 20px;
}
.step {
  display: flex; align-items: center; gap: 8px;
  font-size: 0.82rem; font-weight: 500; color: var(--text-muted);
  transition: all var(--transition-base);
}
.step.active { color: var(--primary-400); }
.step.done { color: var(--emerald-400); }
.step-dot {
  width: 32px; height: 32px; border-radius: 50%;
  border: 2px solid var(--text-muted); display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 0.82rem; transition: all var(--transition-base);
}
.step.active .step-dot {
  border-color: var(--primary-400); background: rgba(13, 148, 136, 0.15); color: var(--primary-400);
}
.step.done .step-dot {
  border-color: var(--emerald-400); background: var(--emerald-400); color: var(--primary-900);
}
.step-line {
  width: 48px; height: 2px; background: var(--text-muted); margin: 0 8px; opacity: 0.3;
  transition: all var(--transition-base);
}
.step-line.done { background: var(--emerald-400); opacity: 1; }

/* ===== CARD ===== */
.card {
  background: var(--glass-bg); border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg); padding: 36px; box-shadow: var(--glass-shadow);
}
.card-title { font-family: var(--font-display); font-size: 1.4rem; font-weight: 700; margin-bottom: 8px; }
.card-desc { font-size: 0.92rem; color: var(--text-secondary); margin-bottom: 28px; }

/* ===== UPLOAD ZONE ===== */
.upload-zone {
  border: 2px dashed rgba(13, 148, 136, 0.3); border-radius: var(--radius-lg);
  padding: 48px 24px; text-align: center; cursor: pointer;
  transition: all var(--transition-base); background: rgba(13, 148, 136, 0.03);
}
.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--primary-400); background: rgba(13, 148, 136, 0.08);
  transform: translateY(-2px);
}
.upload-icon { font-size: 2.5rem; margin-bottom: 12px; }
.upload-zone h3 { font-family: var(--font-display); font-size: 1.1rem; margin-bottom: 4px; }
.upload-zone p { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 16px; }
.btn-upload {
  padding: 10px 24px; border-radius: var(--radius-full);
  background: rgba(13, 148, 136, 0.12); border: 1px solid var(--glass-border);
  color: var(--primary-300); font-weight: 600; font-size: 0.88rem; cursor: pointer;
  transition: all var(--transition-fast);
}
.btn-upload:hover { background: rgba(13, 148, 136, 0.2); border-color: var(--primary-400); }

/* Sample Data */
.sample-divider {
  text-align: center; margin: 20px 0 14px; position: relative;
}
.sample-divider::before {
  content: ''; position: absolute; left: 0; right: 0; top: 50%;
  height: 1px; background: var(--glass-border);
}
.sample-divider span {
  position: relative; background: var(--glass-bg); padding: 0 16px;
  font-size: 0.82rem; color: var(--text-muted);
}
.btn-sample {
  width: 100%; padding: 14px 24px; border-radius: var(--radius-md);
  background: rgba(16, 185, 129, 0.06); border: 1px dashed rgba(16, 185, 129, 0.3);
  color: var(--emerald-400); font-weight: 600; font-size: 0.9rem; cursor: pointer;
  transition: all var(--transition-fast);
}
.btn-sample:hover {
  background: rgba(16, 185, 129, 0.12); border-color: var(--emerald-400);
  transform: translateY(-1px);
}

/* File Info */
.file-info {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px; margin-top: 16px;
  background: rgba(13, 148, 136, 0.08); border: 1px solid rgba(13, 148, 136, 0.2);
  border-radius: var(--radius-md);
}
.file-meta { display: flex; align-items: center; gap: 12px; }
.file-icon { font-size: 1.6rem; }
.file-name { font-weight: 600; font-size: 0.92rem; }
.file-size { font-size: 0.78rem; color: var(--text-muted); }
.btn-remove {
  width: 32px; height: 32px; border-radius: 50%; border: 1px solid rgba(239, 68, 68, 0.3);
  background: rgba(239, 68, 68, 0.1); color: #ef4444; cursor: pointer; font-size: 0.9rem;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition-fast);
}
.btn-remove:hover { background: rgba(239, 68, 68, 0.2); border-color: #ef4444; }

/* Data Preview */
.data-preview { margin-top: 24px; }
.preview-title { font-family: var(--font-display); font-size: 1rem; font-weight: 600; margin-bottom: 12px; }
.table-wrapper { overflow-x: auto; border-radius: var(--radius-md); border: 1px solid var(--glass-border); }
table {
  width: 100%; border-collapse: collapse; font-size: 0.82rem;
  font-family: 'Fira Code', monospace;
}
thead th {
  background: rgba(13, 148, 136, 0.12); padding: 10px 14px; text-align: left;
  font-weight: 600; color: var(--primary-300); white-space: nowrap;
  border-bottom: 1px solid var(--glass-border); position: sticky; top: 0;
}
tbody td {
  padding: 8px 14px; border-bottom: 1px solid rgba(148, 163, 184, 0.06);
  white-space: nowrap; color: var(--text-secondary);
}
tbody tr:hover td { background: rgba(13, 148, 136, 0.04); }
.data-summary {
  display: flex; gap: 20px; flex-wrap: wrap; margin-top: 16px;
  padding: 14px 18px; background: rgba(13, 148, 136, 0.05); border-radius: var(--radius-md);
  font-size: 0.85rem; color: var(--text-secondary);
}
.data-summary strong { color: var(--primary-300); }

/* ===== CONFIG GRID ===== */
.config-grid { 
  display: grid; 
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); 
  gap: 24px; 
}
.config-item {
  padding: 24px; 
  border-radius: var(--radius-md);
  background: rgba(13, 148, 136, 0.04); 
  border: 1px solid rgba(13, 148, 136, 0.1);
  display: flex;
  flex-direction: column;
}
.full-width { grid-column: 1 / -1; }

.config-label { font-weight: 700; font-size: 0.95rem; margin-bottom: 4px; display: flex; align-items: center; gap: 8px; }
.config-help { font-size: 0.82rem; color: var(--text-muted); margin-bottom: 16px; }

/* AI Model Selection */
.model-select { display: flex; flex-direction: column; gap: 10px; }
.model-radio { 
  display: flex; align-items: center; gap: 12px; 
  font-size: 0.9rem; cursor: pointer; color: var(--text-secondary); 
  padding: 12px 16px; background: rgba(13, 148, 136, 0.03); 
  border-radius: var(--radius-md); border: 1px solid var(--glass-border); 
  transition: all var(--transition-base); 
}
.model-radio:hover { background: rgba(13, 148, 136, 0.08); border-color: rgba(13, 148, 136, 0.3); }
.model-radio:has(input:checked) { 
  border-color: var(--primary-400); 
  background: rgba(13, 148, 136, 0.15); 
  color: var(--primary-300); 
  box-shadow: 0 0 15px rgba(13, 148, 136, 0.1);
}
.model-radio input { accent-color: var(--primary-400); width: 18px; height: 18px; }
.adv-help { font-size: 0.75rem; color: var(--text-muted); font-style: italic; margin-top: 10px; line-height: 1.4; }

/* Multiplier */
.multiplier-control {
  display: flex; align-items: center; gap: 20px; justify-content: center; margin: 10px 0;
}
.mult-btn {
  width: 48px; height: 48px; border-radius: 50%; border: 1px solid var(--glass-border);
  background: rgba(13, 148, 136, 0.08); color: var(--primary-300);
  font-size: 1.5rem; cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: all var(--transition-fast);
}
.mult-btn:hover { background: var(--gradient-primary); color: var(--primary-900); border-color: transparent; transform: scale(1.05); }
.mult-value {
  font-family: var(--font-display); font-size: 3.2rem; font-weight: 800;
  background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}

/* Slider Style Update */
.noise-slider {
  width: 100%; height: 6px; border-radius: 3px; outline: none; cursor: pointer;
  -webkit-appearance: none; appearance: none;
  background: rgba(148, 163, 184, 0.1);
}
.noise-slider::-webkit-slider-thumb {
  -webkit-appearance: none; width: 22px; height: 22px; border-radius: 50%;
  background: var(--primary-400); border: 4px solid var(--bg-card); cursor: pointer;
  box-shadow: 0 0 10px rgba(13, 148, 136, 0.5);
}

/* ===== GENERATION PROGRESS ===== */
.generation-section { margin-top: 28px; }

.run-summary {
  padding: 16px 18px;
  border-radius: var(--radius-md);
  background: rgba(13, 148, 136, 0.04);
  border: 1px solid rgba(13, 148, 136, 0.1);
  margin-bottom: 20px;
}
.run-summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 10px 14px;
}
.run-summary-item {
  padding: 10px 12px;
  border-radius: var(--radius-md);
  background: rgba(148, 163, 184, 0.04);
  border: 1px solid rgba(148, 163, 184, 0.06);
}
.run-summary-label {
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1.4px;
  font-weight: 700;
  margin-bottom: 2px;
}
.run-summary-value {
  font-size: 0.92rem;
  color: var(--text-primary);
  font-weight: 700;
  word-break: break-word;
}
.run-summary-hint {
  margin-top: 10px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.notice {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--glass-border);
  background: rgba(13, 148, 136, 0.06);
  margin-bottom: 18px;
}
.notice-body { flex: 1; min-width: 0; }
.notice-title { font-weight: 800; margin-bottom: 2px; }
.notice-text { font-size: 0.86rem; color: var(--text-secondary); }
.notice-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.notice-error { border-color: rgba(239, 68, 68, 0.25); background: rgba(239, 68, 68, 0.07); }
.notice-error .notice-title { color: #ef4444; }

.btn-icon {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--glass-border);
  background: rgba(148, 163, 184, 0.06);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}
.btn-icon:hover {
  background: rgba(13, 148, 136, 0.12);
  border-color: rgba(13, 148, 136, 0.25);
  color: var(--primary-300);
}

.is-running .navbar { pointer-events: none; opacity: 0.8; }
.is-running #generationSection {
  margin-top: 0 !important;
  padding-top: 0 !important;
  border-top: none !important;
}

.generation-progress { display: grid; gap: 16px; margin-bottom: 28px; }
.gen-step {
  display: flex; align-items: center; gap: 14px;
  padding: 16px 18px; border-radius: var(--radius-md);
  background: rgba(148, 163, 184, 0.04); border: 1px solid rgba(148, 163, 184, 0.06);
  opacity: 0.4; transition: all var(--transition-base);
}
.gen-step.active { opacity: 1; border-color: var(--glass-border); background: rgba(13, 148, 136, 0.06); }
.gen-step.done { opacity: 1; border-color: rgba(16, 185, 129, 0.2); }
.gen-icon { font-size: 1.3rem; flex-shrink: 0; }
.gen-info { flex: 1; }
.gen-label { font-size: 0.88rem; font-weight: 500; margin-bottom: 6px; }
.gen-bar { height: 4px; border-radius: 2px; background: rgba(148, 163, 184, 0.1); overflow: hidden; }
.gen-fill {
  height: 100%; width: 0; border-radius: 2px;
  background: var(--gradient-primary); transition: width 0.3s ease;
}
.gen-status { font-size: 1rem; flex-shrink: 0; }

.gen-overall { text-align: center; }
.gen-overall-bar {
  height: 8px; border-radius: 4px; background: rgba(148, 163, 184, 0.1);
  overflow: hidden; margin-bottom: 8px;
}
.gen-overall-fill {
  height: 100%; width: 0; border-radius: 4px;
  background: var(--gradient-primary); transition: width 0.5s ease;
}
.gen-overall-text { font-size: 0.88rem; color: var(--text-secondary); font-weight: 600; }

/* ===== RESULTS & QUALITY ===== */
.quality-report { margin-bottom: 28px; }
.report-title { font-family: var(--font-display); font-size: 1.05rem; font-weight: 600; margin-bottom: 14px; }
.quality-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; }
.quality-item {
  padding: 16px; border-radius: var(--radius-md); text-align: center;
  background: rgba(13, 148, 136, 0.05); border: 1px solid rgba(13, 148, 136, 0.1);
}
.quality-score {
  font-family: var(--font-display); font-size: 1.8rem; font-weight: 800;
  margin-bottom: 4px;
}
.quality-score.good { color: var(--emerald-400); }
.quality-score.ok { color: #f59e0b; }
.quality-label { font-size: 0.78rem; color: var(--text-muted); }

/* Result Tabs */
.result-tabs { display: flex; gap: 4px; margin-bottom: 16px; }
.result-tab {
  padding: 8px 20px; border-radius: var(--radius-full); border: 1px solid var(--glass-border);
  background: transparent; color: var(--text-secondary); font-size: 0.85rem; font-weight: 500;
  cursor: pointer; transition: all var(--transition-fast);
}
.result-tab.active { background: rgba(13, 148, 136, 0.15); border-color: var(--primary-400); color: var(--primary-300); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* Comparison Tables */
.comparison-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 16px; }
.comp-card {
  padding: 18px; border-radius: var(--radius-md);
  background: rgba(13, 148, 136, 0.04); border: 1px solid rgba(13, 148, 136, 0.1);
}
.comp-col-name { font-weight: 700; font-size: 0.92rem; margin-bottom: 10px; color: var(--primary-300); }
.comp-row { display: flex; justify-content: space-between; padding: 4px 0; font-size: 0.82rem; }
.comp-row span:first-child { color: var(--text-muted); }
.comp-row span:last-child { font-weight: 600; color: var(--text-secondary); }

/* ===== BUTTONS ===== */
.step-actions { 
  display: flex; 
  justify-content: flex-end; 
  gap: 16px; 
  margin-top: 32px; 
  padding-top: 24px;
  border-top: 1px solid var(--glass-border);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 32px;
  border-radius: var(--radius-full);
  background: var(--gradient-primary);
  color: var(--primary-900);
  font-weight: 700;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: 0 4px 15px rgba(13, 148, 136, 0.2);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(13, 148, 136, 0.4);
}

.btn-primary.disabled, .btn-primary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 32px;
  border-radius: var(--radius-full);
  background: transparent;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 1rem;
  border: 1px solid var(--glass-border);
  cursor: pointer;
  transition: all var(--transition-base);
}

.btn-secondary:hover {
  border-color: var(--primary-400);
  background: rgba(13, 148, 136, 0.08);
}

/* Column List / Chips */
.column-list { display: flex; flex-wrap: wrap; gap: 8px; }
.col-chip {
  display: flex; align-items: center; gap: 6px;
  padding: 6px 14px; border-radius: var(--radius-full);
  font-size: 0.8rem; font-weight: 500; cursor: pointer;
  border: 1px solid var(--glass-border); background: rgba(13, 148, 136, 0.04);
  color: var(--text-secondary); transition: all var(--transition-fast);
  user-select: none;
}
.col-chip.selected {
  border-color: var(--primary-400); background: rgba(13, 148, 136, 0.15);
  color: var(--primary-300);
}
.col-chip .col-type {
  font-size: 0.68rem; padding: 1px 6px; border-radius: 4px;
  background: rgba(148, 163, 184, 0.1);
}
.col-chip.selected .col-type { background: rgba(13, 148, 136, 0.2); }

/* Multiplier extras */
.mult-display { text-align: center; }
.mult-suffix { display: block; font-size: 0.85rem; color: var(--text-muted); margin-top: -4px; }
.output-estimate {
  text-align: center; margin-top: 12px; font-size: 0.88rem; color: var(--text-secondary);
  padding: 8px 16px; background: rgba(13, 148, 136, 0.06); border-radius: var(--radius-full);
  display: inline-block; width: 100%;
}

/* Epoch slider labels */
.epoch-labels { display: flex; justify-content: space-between; margin-top: 8px; font-size: 0.72rem; color: var(--text-muted); }
.epoch-value { font-weight: 700; color: var(--primary-400); }

/* Noise slider labels */
.noise-labels {
  display: flex; justify-content: space-between; margin-top: 8px;
  font-size: 0.78rem; color: var(--text-muted);
}
.noise-value { font-weight: 700; color: var(--primary-300); }

/* Table note */
.table-note { font-size: 0.82rem; color: var(--text-muted); margin-top: 10px; text-align: center; }

/* ===== UTILITIES ===== */
.hidden { display: none !important; }

/* Footer */
.tool-footer {
  padding: 40px 0; text-align: center;
  border-top: 1px solid var(--glass-border);
  font-size: 0.85rem; color: var(--text-muted);
}
.footer-nav { display: flex; justify-content: center; gap: 20px; margin-top: 10px; }
.footer-nav a:hover { color: var(--primary-400); }

/* Custom Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: linear-gradient(var(--primary-700), var(--primary-500)); border-radius: 4px; }

@media (max-width: 768px) {
  .nav-links {
    display: none; position: fixed; inset: 0;
    background: rgba(10, 22, 40, 0.97); backdrop-filter: blur(20px);
    flex-direction: column; justify-content: center; align-items: center;
    gap: 24px; z-index: 999;
  }
  .nav-links.active { display: flex; }
  .nav-toggle { display: flex; z-index: 1001; }
  .stepper { flex-wrap: wrap; gap: 8px; }
  .step span { display: none; }
  .step-line { width: 24px; }
  .config-grid { grid-template-columns: 1fr; }
  .card { padding: 24px 16px; }
  .mult-value { font-size: 2.5rem; }
  .comparison-grid { grid-template-columns: 1fr; }
  .quality-grid { grid-template-columns: 1fr 1fr; }
  .step-actions { flex-direction: column; }
  .btn-primary, .btn-secondary { width: 100%; justify-content: center; }
}