/**
 * PicDriver Photo Comparison Tools - Master Stylesheet
 * Obsidian Dark Theme with Cyan, Emerald, Gold, Indigo & Rose Accents
 * Strict Decoupled Architecture: Zero inline styles
 * (c) 2026 PicDriver - 100% Client-Side In-Browser Diff & Heatmap Engine
 */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
  --bg-main: #0c0e14;
  --surface: #141822;
  --surface-raised: #1c2230;
  --surface-hover: #242c3e;
  --border: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(56, 189, 248, 0.5);

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;

  --accent-cyan: #38bdf8;     /* Split Slider / Diff */
  --accent-emerald: #10b981;  /* Match / Byte Savings */
  --accent-gold: #f59e0b;     /* Quality / PSNR */
  --accent-indigo: #6366f1;   /* Codecs / Formats */
  --accent-rose: #f43f5e;     /* Diff Heatmap / Errors */
  --accent-purple: #a855f7;   /* Presets & Color Grade */

  --font-main: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 25px rgba(56, 189, 248, 0.35);
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Site Header */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 32px;
  background: rgba(20, 24, 34, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo-badge {
  background: linear-gradient(135deg, var(--accent-cyan), #0284c7);
  color: #0c0e14;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
}

.logo-text {
  font-weight: 700;
  font-size: 1.15rem;
  color: #fff;
}

.logo-text span {
  color: var(--accent-cyan);
}

/* Hero Section */
.hero {
  padding: 40px 24px 24px;
  text-align: center;
  background: radial-gradient(circle at 50% 0%, rgba(56, 189, 248, 0.08) 0%, transparent 70%);
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  border-radius: 9999px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent-cyan);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
  background: linear-gradient(180deg, #ffffff 30%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  color: var(--text-muted);
  max-width: 780px;
  margin: 0 auto;
  font-size: 1rem;
}

/* 12 Tool Chips Navigation Bar */
.tool-chips-bar {
  padding: 0 24px 24px;
  max-width: 1440px;
  margin: 0 auto;
  width: 100%;
}

.chips-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
  font-weight: 700;
}

.tool-chips-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tool-chip {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 8px 14px;
  border-radius: 9999px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
}

.tool-chip:hover {
  background: var(--surface-hover);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-1px);
}

.tool-chip.active {
  background: var(--accent-cyan);
  color: #0c0e14;
  border-color: var(--accent-cyan);
  font-weight: 700;
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.4);
}

.tool-chip.fire {
  border-color: rgba(245, 158, 11, 0.3);
}

.tool-chip.fire.active {
  background: var(--accent-gold);
  color: #0c0e14;
  border-color: var(--accent-gold);
  box-shadow: 0 0 16px rgba(245, 158, 11, 0.4);
}

/* Workspace Layout */
.workspace {
  max-width: 1440px;
  margin: 0 auto 48px;
  padding: 0 24px;
  width: 100%;
  display: grid;
  grid-template-columns: 390px 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 1080px) {
  .workspace {
    grid-template-columns: 1fr;
  }
}

/* Control Panel Card */
.panel-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 90px;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.panel-title {
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
  color: #fff;
}

.panel-badge {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 8px;
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent-cyan);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(56, 189, 248, 0.25);
  text-transform: uppercase;
}

/* Active Tool Banner */
.active-tool-banner {
  background: var(--surface-raised);
  border-left: 3px solid var(--accent-cyan);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 14px 16px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
  transition: all 0.25s ease;
}

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

.banner-tag {
  font-size: 0.7rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-cyan);
  text-transform: uppercase;
  font-family: var(--font-mono);
}

.banner-title {
  font-size: 0.95rem;
  font-weight: 800;
  color: #fff;
}

.banner-pill {
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 9999px;
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  font-weight: 700;
}

.banner-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.45;
  margin: 0;
}

/* Mode Navigation Tabs */
.mode-tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
  background: var(--surface-raised);
  padding: 4px;
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

.mode-tab-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-family: var(--font-main);
  font-size: 0.76rem;
  font-weight: 600;
  padding: 8px 4px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  text-align: center;
}

.mode-tab-btn:hover {
  color: #fff;
}

.mode-tab-btn.active {
  background: var(--surface);
  color: #fff;
  font-weight: 700;
  box-shadow: var(--shadow-sm);
}

/* Tab Views */
.tab-view {
  display: none;
}

.tab-view.active {
  display: block;
}

/* Dual Dropzone Grid */
.dual-dropzone-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 18px;
}

.dual-drop-card {
  background: rgba(28, 34, 48, 0.4);
  border: 2px dashed rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  padding: 14px 10px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
}

.dual-drop-card:hover {
  border-color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.04);
}

.drop-card-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-cyan);
  text-transform: uppercase;
  margin-bottom: 6px;
}

.drop-card-badge.after {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
}

.drop-card-title {
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 2px;
}

.drop-card-hint {
  font-size: 0.7rem;
  color: var(--text-dim);
}

.file-input-hidden {
  display: none;
}

/* Form Controls */
.form-group {
  margin-bottom: 18px;
}

.form-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  font-weight: 600;
  color: #cbd5e1;
  margin-bottom: 8px;
}

.form-hint {
  font-size: 0.74rem;
  color: var(--text-dim);
  font-weight: 500;
  font-family: var(--font-mono);
}

.range-slider {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--surface-raised);
  outline: none;
  -webkit-appearance: none;
  appearance: none;
  cursor: pointer;
}

.range-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-cyan);
  cursor: pointer;
  border: 2px solid #0c0e14;
  box-shadow: 0 0 10px rgba(56, 189, 248, 0.5);
  transition: transform 0.15s ease;
}

.range-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.form-select, .form-control {
  width: 100%;
  padding: 10px 14px;
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: #fff;
  font-family: var(--font-main);
  font-size: 0.84rem;
  outline: none;
  transition: all 0.2s ease;
}

.form-select:focus, .form-control:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

.overlay-checkbox-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  font-size: 0.8rem;
}

.overlay-checkbox-label {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

/* Heatmap Legend Bar */
.heatmap-legend {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--surface-raised);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  margin-top: 10px;
}

.heatmap-bar {
  flex: 1;
  height: 10px;
  border-radius: 5px;
  background: linear-gradient(90deg, #10b981 0%, #f59e0b 50%, #f43f5e 100%);
}

.heatmap-legend-label {
  font-size: 0.72rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* Buttons */
.btn-group {
  display: flex;
  gap: 10px;
  margin-top: 20px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-family: var(--font-main);
  font-size: 0.84rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--accent-cyan);
  color: #0c0e14;
  font-weight: 700;
  box-shadow: 0 4px 14px rgba(56, 189, 248, 0.3);
}

.btn-primary:hover {
  background: #0284c7;
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.45);
}

.btn-secondary {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  color: #fff;
}

.btn-secondary:hover {
  background: var(--surface-hover);
  border-color: rgba(255, 255, 255, 0.2);
}

.btn-flex-2 { flex: 2; }
.btn-flex-1 { flex: 1; }
.btn-full-width { width: 100%; }

/* Quick Export Chips */
.export-quick-chips {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.quick-chip {
  flex: 1;
  background: var(--surface-raised);
  border: 1px solid var(--border);
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-size: 0.76rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  text-align: center;
}

.quick-chip:hover {
  background: var(--surface-hover);
  color: #fff;
  border-color: var(--accent-cyan);
}

/* Results Area */
.results-area {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* 6 Featured Metric Cards Grid */
.metrics-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

@media (max-width: 768px) {
  .metrics-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .metrics-grid {
    grid-template-columns: 1fr;
  }
}

.metric-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  transition: all 0.2s ease;
  position: relative;
  overflow: hidden;
}

.metric-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
}

.metric-card.cyan::before { background: var(--accent-cyan); }
.metric-card.green::before { background: var(--accent-emerald); }
.metric-card.gold::before { background: var(--accent-gold); }
.metric-card.indigo::before { background: var(--accent-indigo); }
.metric-card.rose::before { background: var(--accent-rose); }
.metric-card.purple::before { background: var(--accent-purple); }

.metric-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 6px;
}

.metric-val {
  font-size: 1.15rem;
  font-weight: 800;
  color: #fff;
  font-family: var(--font-mono);
  margin-bottom: 2px;
}

.metric-val span {
  font-size: 0.74rem;
  color: var(--text-dim);
  font-weight: 500;
  margin-left: 4px;
}

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

/* Visual Stage Switcher Tabs */
.vis-stage-tabs {
  display: flex;
  gap: 8px;
  background: var(--surface);
  padding: 6px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  flex-wrap: wrap;
}

.vis-stage-tab-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-family: var(--font-main);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.vis-stage-tab-btn:hover {
  color: #fff;
}

.vis-stage-tab-btn.active {
  background: var(--surface-raised);
  color: #fff;
  font-weight: 700;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

/* Visual Stage Cards */
.vis-stage-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-md);
}

.vis-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.vis-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Canvas Viewport */
.canvas-wrapper {
  background: #08090d;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  min-height: 480px;
  user-select: none;
}

.canvas-container {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  overflow: hidden;
  position: relative;
}

#comparison-canvas {
  max-width: 100%;
  max-height: 540px;
  object-fit: contain;
  box-shadow: var(--shadow-lg);
  border-radius: 4px;
  cursor: default;
}

/* Viewport Toolbar */
.viewport-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 10px 16px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
  gap: 8px;
}

.viewport-btn-group {
  display: flex;
  gap: 6px;
  align-items: center;
}

.vp-btn {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-family: var(--font-main);
  font-size: 0.76rem;
  font-weight: 600;
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
}

.vp-btn:hover {
  background: var(--surface-hover);
  color: #fff;
}

.zoom-level-text {
  cursor: default;
  min-width: 48px;
  text-align: center;
}

/* Sample Images Bar */
.sample-images-bar {
  margin-top: 16px;
}

.sample-strip {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 6px;
}

.sample-thumb-card {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 6px;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.sample-thumb-card:hover {
  border-color: #fff;
}

.sample-thumb-card.active {
  border-color: var(--accent-cyan);
  background: rgba(56, 189, 248, 0.1);
}

.sample-thumb-img {
  width: 48px;
  height: 36px;
  border-radius: 4px;
  object-fit: cover;
}

.sample-thumb-text {
  font-size: 0.76rem;
  font-weight: 600;
  color: #fff;
}

/* Showcase Grid */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}

.showcase-card {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px;
}

.showcase-card-title {
  color: #fff;
  display: block;
  margin-bottom: 4px;
  font-size: 0.88rem;
}

.showcase-card-desc {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin: 0;
}

/* Specs Box Grid */
.specs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 14px;
  font-size: 0.82rem;
}

.spec-box {
  background: var(--surface-raised);
  padding: 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.spec-box-label {
  color: var(--text-dim);
  display: block;
  font-size: 0.72rem;
  text-transform: uppercase;
}

.spec-box-val-white { color: #fff; font-size: 1.05rem; }
.spec-box-val-green { color: var(--accent-emerald); font-size: 1.05rem; }
.spec-box-val-cyan { color: var(--accent-cyan); font-size: 1.05rem; }
.spec-box-val-gold { color: var(--accent-gold); font-size: 1.05rem; }

/* Article & Matrix Section */
.content-section {
  max-width: 1440px;
  margin: 0 auto 48px;
  padding: 0 24px;
  width: 100%;
}

.article-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-md);
}

.article-card h2 {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: #fff;
}

.article-card p {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
  margin-bottom: 16px;
}

/* Matrix Table */
.table-responsive {
  overflow-x: auto;
  margin-top: 20px;
}

.matrix-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.84rem;
  text-align: left;
}

.matrix-table th {
  background: var(--surface-raised);
  padding: 12px 14px;
  color: #fff;
  font-weight: 700;
  border-bottom: 2px solid var(--border);
  white-space: nowrap;
}

.matrix-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
}

.matrix-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.table-cell-gold { color: var(--accent-gold); font-weight: bold; }
.table-cell-white { color: #fff; font-weight: bold; }
.table-cell-cyan { color: var(--accent-cyan); }
.table-badge-sm { font-size: 0.72rem; }

/* Educational Guide Grid */
.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 18px;
  margin-top: 20px;
}

.guide-card {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px;
}

.guide-card-title-cyan { font-size: 1rem; color: var(--accent-cyan); margin-bottom: 8px; }
.guide-card-title-gold { font-size: 1rem; color: var(--accent-gold); margin-bottom: 8px; }
.guide-card-title-green { font-size: 1rem; color: var(--accent-emerald); margin-bottom: 8px; }
.guide-card-title-indigo { font-size: 1rem; color: var(--accent-indigo); margin-bottom: 8px; }
.guide-card-text { font-size: 0.84rem; color: var(--text-muted); margin: 0; }

/* FAQ Accordion */
.faq-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 20px;
}

.faq-item {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all 0.2s ease;
}

.faq-q {
  width: 100%;
  padding: 18px 20px;
  background: transparent;
  border: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #fff;
  font-family: var(--font-main);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
}

.faq-q svg {
  width: 18px;
  height: 18px;
  stroke: var(--text-muted);
  transition: transform 0.25s ease;
  flex-shrink: 0;
}

.faq-item.active .faq-q svg, .faq-item.open .faq-q svg {
  transform: rotate(45deg);
  stroke: var(--accent-cyan);
}

.faq-a {
  padding: 0 20px 18px;
  color: var(--text-muted);
  font-size: 0.88rem;
  line-height: 1.6;
  display: none;
}

.faq-item.active .faq-a, .faq-item.open .faq-a {
  display: block;
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: var(--surface-raised);
  border: 1px solid var(--accent-cyan);
  padding: 12px 20px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 0.84rem;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateY(16px);
  pointer-events: none;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  z-index: 1000;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

/* Site Footer */
.site-footer {
  margin-top: auto;
  padding: 32px 24px;
  border-top: 1px solid var(--border);
  background: var(--surface);
  text-align: center;
  color: var(--text-dim);
  font-size: 0.82rem;
}

.footer-note {
  margin-top: 6px;
  font-size: 0.74rem;
}


/* ==========================================================================
   Universal Mobile & Tablet Responsiveness Suite (320px - 1040px)
   ========================================================================== */

/* 1. Fluid Media & Canvas Scaling */
img, canvas, svg, video {
  max-width: 100% !important;
  height: auto !important;
}

/* 2. Responsive Touch-Scroll Tables */
table {
  width: 100%;
  max-width: 100%;
  border-collapse: collapse;
}

.table-responsive,
.table-container,
.table-wrap,
.table-wrapper,
.matrix-container,
.data-table-wrap {
  width: 100%;
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* 3. Tablet Breakpoint (<= 1040px) */
@media (max-width: 1040px) {
  .workspace,
  .studio-layout,
  .finder-workspace,
  .simulator-grid,
  .layout-grid,
  .remover-workspace {
    grid-template-columns: 1fr !important;
    gap: 20px !important;
  }

  .sidebar-panel,
  .controls-sidebar {
    border-left: none !important;
    border-top: 1px solid var(--border, rgba(255,255,255,0.1));
  }
}

/* 4. Mobile Portrait & Landscape (<= 768px) */
@media (max-width: 768px) {
  .site-header {
    height: auto !important;
    padding: 10px 16px !important;
  }

  .header-inner,
  .header-container {
    flex-wrap: wrap;
    gap: 10px;
    justify-content: space-between;
    width: 100%;
  }

  .logo,
  .brand-logo,
  .logo-wrap {
    font-size: 1.15rem !important;
  }

  .menu-toggle {
    display: block !important;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: #0a0d14;
    flex-direction: column;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border, rgba(255,255,255,0.1));
    z-index: 1000;
  }

  .nav-links.open {
    display: flex !important;
  }

  .hero {
    padding: 28px 16px 20px !important;
  }

  .hero h1 {
    font-size: clamp(1.6rem, 5.5vw, 2.3rem) !important;
    line-height: 1.2 !important;
  }

  .hero p {
    font-size: 0.92rem !important;
  }

  .page-wrapper,
  .portal-main,
  .container {
    padding: 16px 12px 40px !important;
  }

  .workspace,
  .studio-layout,
  .finder-workspace,
  .remover-workspace {
    padding: 0 !important;
    gap: 16px !important;
  }

  .panel-card,
  .results-card,
  .sidebar-panel,
  .stage-area,
  .card {
    padding: 16px 14px !important;
    border-radius: 12px !important;
  }

  .metrics-grid,
  .data-grid,
  .grid-2,
  .grid-3,
  .grid-4,
  .calc-grid,
  .features-grid,
  .steps-grid {
    grid-template-columns: 1fr !important;
    gap: 12px !important;
  }

  .tool-chips-grid,
  .chips-bar,
  .preset-chip-group,
  .mode-tabs {
    flex-wrap: wrap !important;
    gap: 6px !important;
  }

  .tool-chip,
  .preset-btn,
  .mode-tab-btn {
    padding: 6px 12px !important;
    font-size: 0.78rem !important;
  }

  .btn-primary,
  .btn-secondary,
  .action-btn,
  .btn-action {
    min-height: 44px;
    width: 100%;
    justify-content: center;
  }

  .btn-group,
  .action-btns,
  .download-row {
    flex-direction: column !important;
    width: 100% !important;
    gap: 8px !important;
  }

  table {
    display: block !important;
    width: 100% !important;
    overflow-x: auto !important;
    -webkit-overflow-scrolling: touch !important;
    white-space: nowrap !important;
  }

  th, td {
    padding: 8px 10px !important;
    font-size: 0.8rem !important;
  }
}

/* 5. Small Handsets (<= 480px) */
@media (max-width: 480px) {
  .hero-pill,
  .hero-badge {
    font-size: 0.72rem !important;
    padding: 3px 10px !important;
  }

  .form-group {
    margin-bottom: 14px !important;
  }

  .form-control,
  .form-select,
  .control-input,
  .control-select,
  input[type="text"],
  input[type="number"],
  select {
    font-size: 16px !important; /* Prevents auto-zoom in iOS Safari */
    min-height: 42px;
  }

  .info-section,
  .guide-section,
  .faq-section {
    padding: 24px 12px !important;
  }
}