/* ============================================================
   AI TEXT HUMANIZER — DESIGN SYSTEM & STYLES
   ============================================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Core Palette — Dark Mode (default) */
  --bg-base:        #09090f;
  --bg-surface:     #0f0f1a;
  --bg-card:        #13131f;
  --bg-card-hover:  #17172a;
  --bg-input:       #0c0c18;

  /* Glass Effect */
  --glass-bg:       rgba(255,255,255,0.04);
  --glass-border:   rgba(255,255,255,0.08);
  --glass-hover:    rgba(255,255,255,0.07);

  /* Brand Colors */
  --violet:         #8b5cf6;
  --violet-light:   #a78bfa;
  --violet-dark:    #7c3aed;
  --cyan:           #22d3ee;
  --cyan-light:     #67e8f9;
  --pink:           #ec4899;
  --pink-light:     #f472b6;
  --amber:          #f59e0b;
  --green:          #10b981;
  --red:            #ef4444;

  /* Gradients */
  --grad-brand:     linear-gradient(135deg, #8b5cf6 0%, #22d3ee 100%);
  --grad-card:      linear-gradient(135deg, rgba(139,92,246,0.15) 0%, rgba(34,211,238,0.05) 100%);
  --grad-hero:      linear-gradient(180deg, #09090f 0%, #0f0a1e 50%, #09090f 100%);
  --grad-btn:       linear-gradient(135deg, #7c3aed 0%, #2563eb 100%);
  --grad-btn-hover: linear-gradient(135deg, #8b5cf6 0%, #3b82f6 100%);

  /* Text */
  --text-primary:   #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted:     #475569;
  --text-accent:    #a78bfa;

  /* Typography */
  --font-ui:        'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display:   'Outfit', 'Inter', sans-serif;

  /* Spacing */
  --radius-sm:      8px;
  --radius-md:      14px;
  --radius-lg:      20px;
  --radius-xl:      28px;

  /* Shadows */
  --shadow-glow:    0 0 40px rgba(139,92,246,0.2);
  --shadow-card:    0 4px 24px rgba(0,0,0,0.4), 0 1px 4px rgba(0,0,0,0.3);
  --shadow-btn:     0 4px 20px rgba(139,92,246,0.4);

  /* Transitions */
  --ease-smooth:    cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring:    cubic-bezier(0.34, 1.56, 0.64, 1);
  --dur-fast:       150ms;
  --dur-normal:     250ms;
  --dur-slow:       400ms;
}

/* ---------- Light Mode ---------- */
[data-theme="light"] {
  --bg-base:        #f8f7ff;
  --bg-surface:     #ffffff;
  --bg-card:        #ffffff;
  --bg-card-hover:  #f1f0fe;
  --bg-input:       #fafafe;
  --glass-bg:       rgba(139,92,246,0.04);
  --glass-border:   rgba(139,92,246,0.12);
  --glass-hover:    rgba(139,92,246,0.08);
  --text-primary:   #1e1b4b;
  --text-secondary: #4338ca;
  --text-muted:     #6b7280;
  --text-accent:    #7c3aed;
  --shadow-card:    0 4px 24px rgba(139,92,246,0.1), 0 1px 4px rgba(0,0,0,0.06);
  --shadow-glow:    0 0 40px rgba(139,92,246,0.12);
  --bg-surface:     #f8f7ff;
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-ui);
  background: var(--bg-base);
  color: var(--text-primary);
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
  transition: background var(--dur-slow) var(--ease-smooth), color var(--dur-slow) var(--ease-smooth);
}

a {
  color: var(--violet-light);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-smooth);
}
a:hover { color: var(--cyan-light); }

button { cursor: pointer; border: none; background: none; font-family: var(--font-ui); }

/* ============================================================
   ANIMATED BACKGROUND ORBS
   ============================================================ */
.bg-orbs {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.18;
  animation: orb-float 12s ease-in-out infinite;
}

.orb-1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, #7c3aed, transparent 70%);
  top: -200px; left: -150px;
  animation-delay: 0s;
}
.orb-2 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, #0891b2, transparent 70%);
  top: 30%; right: -150px;
  animation-delay: -4s;
  animation-duration: 15s;
}
.orb-3 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, #db2777, transparent 70%);
  bottom: 5%; left: 30%;
  animation-delay: -8s;
  animation-duration: 18s;
}

@keyframes orb-float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -40px) scale(1.05); }
  66% { transform: translate(-20px, 30px) scale(0.97); }
}

[data-theme="light"] .orb { opacity: 0.07; }

/* ============================================================
   HEADER
   ============================================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9,9,15,0.8);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--glass-border);
  transition: background var(--dur-slow) var(--ease-smooth);
}

[data-theme="light"] .header {
  background: rgba(248,247,255,0.85);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 68px;
  display: flex;
  align-items: center;
  gap: 24px;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.logo-icon {
  width: 36px; height: 36px;
  display: flex; align-items: center; justify-content: center;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 10px;
  transition: transform var(--dur-normal) var(--ease-spring), box-shadow var(--dur-normal) var(--ease-smooth);
}
.logo:hover .logo-icon {
  transform: rotate(-8deg) scale(1.1);
  box-shadow: var(--shadow-btn);
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-badge {
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 2px 6px;
  background: var(--grad-brand);
  color: #fff;
  border-radius: 4px;
  margin-top: -8px;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.nav-link {
  padding: 6px 14px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: color var(--dur-fast) var(--ease-smooth), background var(--dur-fast) var(--ease-smooth);
}
.nav-link:hover {
  color: var(--text-primary);
  background: var(--glass-hover);
}

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

.btn-icon {
  width: 36px; height: 36px;
  display: flex; align-items: center; justify-content: center;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: all var(--dur-fast) var(--ease-smooth);
}
.btn-icon:hover {
  color: var(--text-primary);
  background: var(--glass-hover);
  border-color: var(--violet-light);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 72px 24px 56px;
  max-width: 800px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(139,92,246,0.12);
  border: 1px solid rgba(139,92,246,0.3);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--violet-light);
  margin-bottom: 24px;
  animation: fade-in-up 0.6s var(--ease-smooth) both;
}

.pulse-dot {
  width: 7px; height: 7px;
  background: var(--green);
  border-radius: 50%;
  animation: pulse-anim 2s ease-in-out infinite;
}

@keyframes pulse-anim {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.7); }
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.4rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 20px;
  animation: fade-in-up 0.7s var(--ease-smooth) 0.1s both;
}

.gradient-text {
  background: var(--grad-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
  animation: fade-in-up 0.8s var(--ease-smooth) 0.2s both;
}

@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   EDITOR SECTION
   ============================================================ */
.editor-section {
  position: relative;
  z-index: 1;
  max-width: 1300px;
  margin: 0 auto;
  padding: 0 24px 48px;
}

/* Controls Bar */
.controls-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 24px;
  padding: 20px 24px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  margin-bottom: 20px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.control-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.style-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.style-pill {
  padding: 6px 14px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 100px;
  transition: all var(--dur-normal) var(--ease-spring);
  white-space: nowrap;
}
.style-pill:hover {
  color: var(--text-primary);
  border-color: var(--violet-light);
  background: rgba(139,92,246,0.1);
  transform: translateY(-1px);
}
.style-pill.active {
  background: rgba(139,92,246,0.2);
  border-color: var(--violet);
  color: var(--violet-light);
  box-shadow: 0 0 12px rgba(139,92,246,0.25);
  transform: translateY(-1px);
}

/* Slider */
.slider {
  -webkit-appearance: none;
  appearance: none;
  width: 200px;
  height: 4px;
  background: var(--glass-border);
  border-radius: 100px;
  outline: none;
  cursor: pointer;
}
.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px; height: 18px;
  background: var(--grad-brand);
  border-radius: 50%;
  cursor: pointer;
  transition: transform var(--dur-fast) var(--ease-spring), box-shadow var(--dur-fast) var(--ease-smooth);
  box-shadow: 0 2px 8px rgba(139,92,246,0.5);
}
.slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  box-shadow: 0 4px 16px rgba(139,92,246,0.7);
}
.slider::-moz-range-thumb {
  width: 18px; height: 18px;
  background: var(--grad-brand);
  border-radius: 50%;
  border: none;
  cursor: pointer;
}

/* Editor Panels */
.editor-panels {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 0;
  align-items: stretch;
  min-height: 420px;
}

.panel {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: border-color var(--dur-normal) var(--ease-smooth), box-shadow var(--dur-normal) var(--ease-smooth);
}
.panel:focus-within {
  border-color: rgba(139,92,246,0.4);
  box-shadow: 0 0 24px rgba(139,92,246,0.12);
}

.panel-input { border-radius: var(--radius-lg) 0 0 var(--radius-lg); }
.panel-output { border-radius: 0 var(--radius-lg) var(--radius-lg) 0; border-left: none; }

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  border-bottom: 1px solid var(--glass-border);
  flex-shrink: 0;
}

.panel-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.panel-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
}
.dot-input { background: var(--pink); box-shadow: 0 0 8px var(--pink); }
.dot-output { background: var(--green); box-shadow: 0 0 8px var(--green); }

.panel-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-sm {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 5px 10px;
  font-size: 0.76rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  transition: all var(--dur-fast) var(--ease-smooth);
  white-space: nowrap;
}
.btn-sm:hover {
  color: var(--text-primary);
  background: var(--glass-hover);
  border-color: rgba(255,255,255,0.15);
  transform: translateY(-1px);
}
.btn-sm.btn-primary {
  background: rgba(139,92,246,0.15);
  border-color: rgba(139,92,246,0.3);
  color: var(--violet-light);
}
.btn-sm.btn-primary:hover {
  background: rgba(139,92,246,0.25);
  border-color: var(--violet);
  box-shadow: 0 4px 16px rgba(139,92,246,0.3);
}
.btn-sm.btn-danger {
  color: #f87171;
  border-color: rgba(239,68,68,0.2);
}
.btn-sm.btn-danger:hover {
  background: rgba(239,68,68,0.1);
  border-color: rgba(239,68,68,0.4);
}

/* Textarea */
.panel-textarea {
  flex: 1;
  width: 100%;
  min-height: 320px;
  padding: 18px;
  background: transparent;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 0.95rem;
  line-height: 1.75;
  resize: none;
  caret-color: var(--violet-light);
}
.panel-textarea::placeholder { color: var(--text-muted); }
.panel-textarea::-webkit-scrollbar { width: 4px; }
.panel-textarea::-webkit-scrollbar-track { background: transparent; }
.panel-textarea::-webkit-scrollbar-thumb { background: var(--glass-border); border-radius: 100px; }

/* Output */
.panel-output-content {
  flex: 1;
  padding: 18px;
  overflow-y: auto;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--text-primary);
  white-space: pre-wrap;
  word-break: break-word;
}
.panel-output-content::-webkit-scrollbar { width: 4px; }
.panel-output-content::-webkit-scrollbar-thumb { background: var(--glass-border); border-radius: 100px; }

.output-placeholder {
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--text-muted);
  text-align: center;
  padding: 40px;
}
.placeholder-icon {
  opacity: 0.25;
  animation: gentle-bounce 3s ease-in-out infinite;
}
@keyframes gentle-bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}
.output-placeholder p { font-size: 0.95rem; font-weight: 500; }
.output-placeholder small { font-size: 0.82rem; opacity: 0.7; }

/* Panel Footer */
.panel-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 18px;
  border-top: 1px solid var(--glass-border);
  flex-shrink: 0;
}

.word-count {
  font-size: 0.76rem;
  color: var(--text-muted);
}

.ai-score-badge, .readability-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.74rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 100px;
  background: rgba(239,68,68,0.12);
  border: 1px solid rgba(239,68,68,0.25);
  color: #f87171;
}
.readability-badge {
  background: rgba(16,185,129,0.12);
  border-color: rgba(16,185,129,0.25);
  color: #34d399;
}
.badge-dot {
  width: 6px; height: 6px;
  background: var(--green);
  border-radius: 50%;
  animation: pulse-anim 2s ease-in-out infinite;
}

/* Center Column (Humanize Button) */
.center-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 0 16px;
}

.btn-humanize {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 80px; height: 80px;
  border-radius: 50%;
  background: var(--grad-btn);
  border: 2px solid rgba(139,92,246,0.4);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  transition: all var(--dur-normal) var(--ease-spring);
  box-shadow: var(--shadow-btn), 0 0 0 0 rgba(139,92,246,0.4);
  overflow: hidden;
}
.btn-humanize::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--grad-btn-hover);
  opacity: 0;
  transition: opacity var(--dur-normal) var(--ease-smooth);
  border-radius: inherit;
}
.btn-humanize:hover::before { opacity: 1; }
.btn-humanize:hover {
  transform: scale(1.08);
  box-shadow: var(--shadow-btn), 0 0 0 8px rgba(139,92,246,0.15);
}
.btn-humanize:active { transform: scale(0.96); }
.btn-humanize.loading {
  pointer-events: none;
  opacity: 0.8;
}
.btn-humanize.success {
  background: linear-gradient(135deg, #059669, #10b981);
}

.humanize-icon { transition: transform var(--dur-normal) var(--ease-spring); }
.btn-humanize:hover .humanize-icon { transform: scale(1.15); }
.humanize-label { position: relative; z-index: 1; }

/* Spinner */
.spinner {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: inherit;
  border-radius: inherit;
}
.spin-ring {
  width: 28px; height: 28px;
  border: 3px solid rgba(255,255,255,0.2);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.swap-arrows {
  color: var(--text-muted);
  opacity: 0.5;
  transition: opacity var(--dur-fast) var(--ease-smooth), transform var(--dur-normal) var(--ease-spring);
}
.center-col:hover .swap-arrows {
  opacity: 1;
  transform: rotate(180deg);
}

/* Mobile Humanize Button */
.mobile-humanize { display: none; margin-top: 16px; }
.btn-humanize-full {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 16px;
  background: var(--grad-btn);
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  border: none;
  transition: all var(--dur-normal) var(--ease-spring);
  box-shadow: var(--shadow-btn);
}
.btn-humanize-full:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(139,92,246,0.5); }
.btn-humanize-full:active { transform: translateY(0); }

/* ============================================================
   PROGRESS BAR
   ============================================================ */
.progress-bar-container {
  margin-top: 16px;
  position: relative;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: 100px;
  height: 8px;
  overflow: visible;
}
.progress-bar {
  height: 100%;
  border-radius: 100px;
  background: var(--grad-brand);
  width: 0%;
  transition: width 0.3s var(--ease-smooth);
  position: relative;
}
.progress-bar::after {
  content: '';
  position: absolute;
  right: -2px;
  top: 50%;
  transform: translateY(-50%);
  width: 14px; height: 14px;
  background: #fff;
  border-radius: 50%;
  box-shadow: 0 0 8px rgba(139,92,246,0.8);
}
.progress-label {
  position: absolute;
  right: 0;
  top: 16px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ============================================================
   STATS STRIP
   ============================================================ */
.stats-strip {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  max-width: 700px;
  margin: 0 auto 48px;
  padding: 0 24px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  animation: fade-in-up 0.5s var(--ease-smooth) both;
}

.stat-card {
  flex: 1;
  text-align: center;
  padding: 20px;
}
.stat-number {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 800;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 4px;
}
.stat-label {
  font-size: 0.74rem;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--glass-border);
  flex-shrink: 0;
}

/* ============================================================
   HISTORY SECTION
   ============================================================ */
.history-section {
  position: relative;
  z-index: 1;
  max-width: 1300px;
  margin: 0 auto 56px;
  padding: 0 24px;
}

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

.section-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}
.section-title.centered {
  justify-content: center;
  display: block;
  text-align: center;
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 48px;
  font-size: 1rem;
}

.history-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.history-item {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  transition: all var(--dur-normal) var(--ease-smooth);
  cursor: pointer;
  animation: fade-in-up 0.3s var(--ease-smooth) both;
}
.history-item:hover {
  border-color: rgba(139,92,246,0.3);
  background: var(--glass-hover);
  transform: translateX(4px);
}

.history-meta {
  flex: 1;
  min-width: 0;
}
.history-preview {
  font-size: 0.875rem;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-bottom: 4px;
}
.history-info {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.history-badge {
  padding: 3px 8px;
  font-size: 0.72rem;
  font-weight: 600;
  background: rgba(139,92,246,0.12);
  border: 1px solid rgba(139,92,246,0.25);
  color: var(--violet-light);
  border-radius: 100px;
  flex-shrink: 0;
}

.history-restore {
  padding: 6px 12px;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  transition: all var(--dur-fast) var(--ease-smooth);
  flex-shrink: 0;
}
.history-restore:hover {
  color: var(--violet-light);
  border-color: rgba(139,92,246,0.4);
}

/* ============================================================
   FEATURES SECTION
   ============================================================ */
.features-section {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto 80px;
  padding: 0 24px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.feature-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all var(--dur-normal) var(--ease-smooth);
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: var(--grad-brand);
  opacity: 0;
  transition: opacity var(--dur-normal) var(--ease-smooth);
}
.feature-card:hover {
  border-color: rgba(139,92,246,0.25);
  background: var(--glass-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}
.feature-card:hover::before { opacity: 1; }

.feature-icon {
  font-size: 2rem;
  margin-bottom: 16px;
  display: block;
  filter: drop-shadow(0 2px 8px rgba(0,0,0,0.3));
}
.feature-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
}
.feature-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ============================================================
   HOW IT WORKS
   ============================================================ */
.how-section {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto 100px;
  padding: 0 24px;
}

.steps-grid {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.step-card {
  flex: 1;
  min-width: 200px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: center;
  transition: all var(--dur-normal) var(--ease-smooth);
}
.step-card:hover {
  border-color: rgba(139,92,246,0.3);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}

.step-number {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--grad-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0.3;
  line-height: 1;
  margin-bottom: 12px;
}
.step-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}
.step-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.step-arrow {
  color: var(--text-muted);
  font-size: 1.5rem;
  font-weight: 300;
  flex-shrink: 0;
}

/* ============================================================
   TOAST
   ============================================================ */
.toast {
  position: fixed;
  bottom: 32px;
  right: 32px;
  z-index: 9999;
  padding: 12px 20px;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.3s var(--ease-spring);
  max-width: 320px;
  pointer-events: none;
}
.toast.show {
  transform: translateY(0);
  opacity: 1;
}
.toast.success { border-color: rgba(16,185,129,0.4); }
.toast.error { border-color: rgba(239,68,68,0.4); }
.toast.info { border-color: rgba(139,92,246,0.4); }

/* ============================================================
   MODAL
   ============================================================ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  animation: fade-in 0.2s var(--ease-smooth);
}
@keyframes fade-in { from { opacity: 0; } to { opacity: 1; } }

.modal-box {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: 32px;
  max-width: 460px;
  width: 100%;
  box-shadow: var(--shadow-glow), var(--shadow-card);
  animation: scale-in 0.25s var(--ease-spring);
}
@keyframes scale-in { from { opacity: 0; transform: scale(0.9); } to { opacity: 1; transform: scale(1); } }

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}
.modal-title {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 700;
}
.modal-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
}
.modal-field { margin-bottom: 8px; display: flex; flex-direction: column; gap: 8px; }
.modal-hint {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}
.modal-actions {
  display: flex;
  gap: 12px;
  justify-content: flex-end;
}

.text-input {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-input);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 0.9rem;
  outline: none;
  transition: border-color var(--dur-fast) var(--ease-smooth);
}
.text-input:focus {
  border-color: var(--violet);
  box-shadow: 0 0 0 3px rgba(139,92,246,0.15);
}

.input-with-toggle {
  position: relative;
  display: flex;
  align-items: center;
}
.input-with-toggle .text-input { padding-right: 44px; }
.input-with-toggle .btn-icon {
  position: absolute;
  right: 4px;
  background: transparent;
  border: none;
}

.btn-secondary {
  padding: 10px 20px;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--dur-fast) var(--ease-smooth);
}
.btn-secondary:hover {
  color: var(--text-primary);
  background: var(--glass-hover);
}
.btn-primary-full {
  padding: 10px 20px;
  background: var(--grad-btn);
  border: none;
  border-radius: var(--radius-md);
  color: #fff;
  font-size: 0.9rem;
  font-weight: 600;
  transition: all var(--dur-normal) var(--ease-spring);
  box-shadow: var(--shadow-btn);
}
.btn-primary-full:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(139,92,246,0.5);
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--glass-border);
  padding: 48px 24px;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.footer-brand { display: flex; flex-direction: column; gap: 6px; }
.footer-tagline { font-size: 0.82rem; color: var(--text-muted); }
.footer-links { display: flex; flex-wrap: wrap; gap: 4px; }
.footer-link {
  padding: 6px 12px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: all var(--dur-fast) var(--ease-smooth);
}
.footer-link:hover {
  color: var(--violet-light);
  background: rgba(139,92,246,0.08);
}
.footer-link-btn {
  background: none;
  border: none;
  font-family: var(--font-ui);
  cursor: pointer;
}
.footer-copy {
  width: 100%;
  font-size: 0.78rem;
  color: var(--text-muted);
  text-align: center;
}

/* ============================================================
   HIGHLIGHTED DIFF OUTPUT
   ============================================================ */
.diff-changed {
  background: rgba(139,92,246,0.18);
  border-radius: 3px;
  padding: 0 2px;
  color: var(--violet-light);
  border-bottom: 1px solid rgba(139,92,246,0.4);
  transition: background 0.3s ease;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .editor-panels {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
  }
  .panel-input { border-radius: var(--radius-lg); }
  .panel-output { border-radius: var(--radius-lg); border-left: 1px solid var(--glass-border); }

  .center-col { display: none; }
  .mobile-humanize { display: block; }

  .header-nav { display: none; }
  .hero { padding: 48px 24px 40px; }
  .hero-title { font-size: 2.2rem; }

  .steps-grid { flex-direction: column; }
  .step-arrow { transform: rotate(90deg); }

  .stats-strip { flex-direction: column; }
  .stat-divider { width: 80px; height: 1px; }
}

@media (max-width: 600px) {
  .controls-bar { flex-direction: column; align-items: stretch; gap: 16px; }
  .style-pills { justify-content: flex-start; }
  .slider { width: 100%; }

  .header-inner { padding: 0 16px; }
  .editor-section { padding: 0 16px 40px; }

  .toast { bottom: 16px; right: 16px; left: 16px; }

  .features-grid { grid-template-columns: 1fr; }
}