/* ═══════════════════════════════════════════════════════════════
   DocConverter Pro — Stylesheet
   Design: Industrial/Utilitarian × Acid Neon accent
   Palette: Volcanic Glass (#1A1A1A, #333, #FF6B2B, #CCFF00)
   Fonts: Plus Jakarta Sans + Space Mono
═══════════════════════════════════════════════════════════════ */

/* ─── CSS Custom Properties ──────────────────────────────────── */
:root {
  /* Colors */
  --bg-base:        #0D0D0D;
  --bg-surface:     #141414;
  --bg-elevated:    #1C1C1C;
  --bg-card:        #1E1E1E;
  --bg-hover:       #252525;
  --border:         #2A2A2A;
  --border-light:   #333333;

  --text-primary:   #F0EDE8;
  --text-secondary: #9A9A9A;
  --text-muted:     #555555;

  --accent-lime:    #CCFF00;
  --accent-orange:  #FF6B2B;
  --accent-blue:    #3B82F6;
  --accent-purple:  #8B5CF6;
  --accent-green:   #22C55E;
  --accent-red:     #EF4444;

  /* Typography */
  --font-body:    'Plus Jakarta Sans', sans-serif;
  --font-mono:    'Space Mono', monospace;

  /* Spacing */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  40px;
  --space-2xl: 64px;
  --space-3xl: 96px;

  /* Radii */
  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-xl:  28px;

  /* Shadows */
  --shadow-sm:  0 1px 3px rgba(0,0,0,0.4);
  --shadow-md:  0 4px 16px rgba(0,0,0,0.5);
  --shadow-lg:  0 8px 32px rgba(0,0,0,0.6);
  --shadow-lime: 0 0 24px rgba(204,255,0,0.15);
  --shadow-orange: 0 0 24px rgba(255,107,43,0.15);

  /* Transitions */
  --transition-fast:   150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow:   400ms ease;

  /* Layout */
  --container-max: 1200px;
  --nav-height:    64px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }
ul, ol { list-style: none; }
details > summary { list-style: none; }
details > summary::-webkit-details-marker { display: none; }

/* Focus styles for accessibility */
:focus-visible {
  outline: 2px solid var(--accent-lime);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ─── Container ──────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ─── Buttons ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: all var(--transition-normal);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0.05);
  opacity: 0;
  transition: opacity var(--transition-fast);
}
.btn:hover::before { opacity: 1; }

.btn--primary {
  background: var(--accent-lime);
  color: #0D0D0D;
  box-shadow: 0 0 0 0 rgba(204,255,0,0);
}
.btn--primary:hover {
  background: #D9FF1A;
  box-shadow: var(--shadow-lime);
  transform: translateY(-1px);
}
.btn--primary:active { transform: translateY(0); }

.btn--secondary {
  background: var(--accent-orange);
  color: #fff;
  box-shadow: 0 0 0 0 rgba(255,107,43,0);
}
.btn--secondary:hover {
  background: #FF7D45;
  box-shadow: var(--shadow-orange);
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}
.btn--ghost:hover {
  border-color: var(--accent-lime);
  color: var(--accent-lime);
}

.btn--outline {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}
.btn--outline:hover {
  border-color: var(--text-primary);
  background: var(--bg-elevated);
}

.btn--sm { padding: 8px 16px; font-size: 0.8rem; }
.btn--full { width: 100%; }

.btn--convert {
  width: 100%;
  padding: 14px 24px;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-top: var(--space-md);
}
.btn--convert:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

/* ─── Advertisement Styles ───────────────────────────────────── */
.ad-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  display: block;
  text-align: center;
  margin-bottom: var(--space-xs);
}

.ad-banner {
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  padding: var(--space-sm) 0;
}
.ad-banner--footer {
  border-bottom: none;
  border-top: 1px solid var(--border);
}
.ad-banner__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.ad-slot--leaderboard {
  width: 100%;
  max-width: 728px;
  height: 90px;
}
.ad-slot--sidebar {
  width: 300px;
  height: 600px;
}
.ad-slot--rectangle {
  width: 336px;
  height: 280px;
}

.ad-placeholder {
  width: 100%;
  height: 100%;
  background: var(--bg-elevated);
  border: 1px dashed var(--border-light);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}
.ad-placeholder--vertical {
  flex-direction: column;
  gap: var(--space-md);
}
.ad-placeholder--rectangle {
  flex-direction: column;
  gap: var(--space-sm);
}
.ad-placeholder__content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  text-align: center;
}
.ad-placeholder__icon { font-size: 1.5rem; }
.ad-placeholder__text {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  line-height: 1.4;
}
.ad-placeholder__cta {
  font-size: 0.75rem;
  color: var(--accent-lime);
  border: 1px solid var(--accent-lime);
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}
.ad-placeholder__cta:hover {
  background: var(--accent-lime);
  color: #0D0D0D;
}

.ad-mid-page {
  padding: var(--space-xl) 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.ad-mid-page__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
}

/* ─── Navigation ─────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13,13,13,0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  gap: var(--space-lg);
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-shrink: 0;
}
.nav__logo { flex-shrink: 0; }
.nav__name {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}
.nav__pro {
  color: var(--accent-lime);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  background: rgba(204,255,0,0.1);
  padding: 1px 6px;
  border-radius: 4px;
  margin-left: 2px;
  vertical-align: middle;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  flex: 1;
  justify-content: center;
}
.nav__link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  position: relative;
}
.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent-lime);
  transition: width var(--transition-normal);
}
.nav__link:hover { color: var(--text-primary); }
.nav__link:hover::after { width: 100%; }

.nav__actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  flex-shrink: 0;
}

.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
}
.nav__hamburger:hover { background: var(--bg-elevated); }
.nav__hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition-normal);
}
.nav__hamburger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__hamburger.is-open span:nth-child(2) { opacity: 0; }
.nav__hamburger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.nav__mobile {
  display: none;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  padding: var(--space-md) var(--space-lg);
}
.nav__mobile.is-open { display: block; }
.nav__mobile ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}
.nav__mobile a {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}
.nav__mobile a:hover { color: var(--text-primary); }

/* ─── Hero Section ───────────────────────────────────────────── */
.hero {
  position: relative;
  padding: var(--space-3xl) 0 var(--space-2xl);
  overflow: hidden;
}

.hero__bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(204,255,0,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(204,255,0,0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}

.hero__orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}
.hero__orb--1 {
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(204,255,0,0.08) 0%, transparent 70%);
  top: -100px;
  right: -100px;
}
.hero__orb--2 {
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255,107,43,0.06) 0%, transparent 70%);
  bottom: -50px;
  left: -50px;
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 680px;
  animation: heroFadeUp 0.7s ease both;
}

@keyframes heroFadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  background: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: 100px;
  padding: 6px 14px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  font-family: var(--font-mono);
}
.hero__badge-dot {
  width: 7px;
  height: 7px;
  background: var(--accent-lime);
  border-radius: 50%;
  animation: pulse 2s ease infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.6; transform: scale(0.85); }
}

.hero__title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-lg);
  color: var(--text-primary);
}
.hero__title-accent {
  color: var(--accent-lime);
  font-family: var(--font-mono);
  display: block;
}

.hero__subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 520px;
  margin-bottom: var(--space-xl);
}

.hero__stats {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  flex-wrap: wrap;
}
.hero__stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.hero__stat-num {
  font-size: 1.5rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--text-primary);
  letter-spacing: -0.02em;
}
.hero__stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.hero__stat-divider {
  width: 1px;
  height: 36px;
  background: var(--border-light);
}

/* ─── Converter Section ──────────────────────────────────────── */
.converter-section {
  padding: var(--space-2xl) 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.converter-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-xl);
  align-items: start;
}

/* Converter Card */
.converter-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-lg);
  animation: cardSlideIn 0.5s ease both;
}
@keyframes cardSlideIn {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Tabs */
.converter-tabs {
  display: flex;
  gap: var(--space-sm);
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  padding: 4px;
  margin-bottom: var(--space-xl);
}
.converter-tab {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: all var(--transition-normal);
  font-family: var(--font-body);
}
.converter-tab:hover { color: var(--text-secondary); }
.converter-tab--active {
  background: var(--bg-card);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
}

/* Drop Zone */
.drop-zone {
  border: 2px dashed var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl) var(--space-xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  text-align: center;
  background: var(--bg-elevated);
}
.drop-zone:hover,
.drop-zone.is-dragover {
  border-color: var(--accent-lime);
  background: rgba(204,255,0,0.03);
  box-shadow: inset 0 0 0 1px rgba(204,255,0,0.1);
}
.drop-zone.is-dragover {
  transform: scale(1.01);
}
.drop-zone__input {
  position: absolute;
  inset: 0;
  opacity: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
}
.drop-zone__icon { margin-bottom: var(--space-sm); }
.drop-zone__primary {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}
.drop-zone__secondary {
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.drop-zone__browse {
  color: var(--accent-lime);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.drop-zone__hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* File Preview */
.file-preview {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  background: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin-top: var(--space-md);
  animation: fadeIn 0.3s ease;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}
.file-preview__info {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.file-preview__name {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.file-preview__size {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.file-preview__remove {
  color: var(--text-muted);
  padding: 6px;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  flex-shrink: 0;
}
.file-preview__remove:hover {
  color: var(--accent-red);
  background: rgba(239,68,68,0.1);
}

/* Status Area */
.status-area {
  margin-top: var(--space-md);
  min-height: 0;
  transition: all var(--transition-normal);
}
.status-message {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  animation: fadeIn 0.3s ease;
}
.status-message--loading {
  background: rgba(59,130,246,0.1);
  border: 1px solid rgba(59,130,246,0.2);
  color: #93C5FD;
}
.status-message--success {
  background: rgba(34,197,94,0.1);
  border: 1px solid rgba(34,197,94,0.2);
  color: #86EFAC;
}
.status-message--error {
  background: rgba(239,68,68,0.1);
  border: 1px solid rgba(239,68,68,0.2);
  color: #FCA5A5;
}

/* Progress Bar */
.progress-bar {
  width: 100%;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
  margin-top: var(--space-sm);
}
.progress-bar__fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-lime), var(--accent-orange));
  border-radius: 2px;
  transition: width 0.4s ease;
  animation: progressShimmer 1.5s ease infinite;
}
@keyframes progressShimmer {
  0%   { background-position: -200% center; }
  100% { background-position: 200% center; }
}

/* Download Button */
.download-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  width: 100%;
  padding: 14px 24px;
  background: linear-gradient(135deg, var(--accent-lime), #A8E600);
  color: #0D0D0D;
  border-radius: var(--radius-md);
  font-weight: 700;
  font-size: 1rem;
  margin-top: var(--space-md);
  transition: all var(--transition-normal);
  animation: fadeIn 0.4s ease;
  box-shadow: var(--shadow-lime);
}
.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 32px rgba(204,255,0,0.25);
}

/* Spinner */
.spinner {
  width: 18px;
  height: 18px;
  border: 2px solid rgba(147,197,253,0.3);
  border-top-color: #93C5FD;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex-shrink: 0;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Security Note */
.security-note {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-top: var(--space-lg);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ─── Converter Sidebar ──────────────────────────────────────── */
.converter-sidebar {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  position: sticky;
  top: calc(var(--nav-height) + var(--space-lg));
}

/* Pro Card */
.pro-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  position: relative;
  overflow: hidden;
}
.pro-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-lime), var(--accent-orange));
}
.pro-card__badge {
  display: inline-block;
  background: rgba(204,255,0,0.1);
  color: var(--accent-lime);
  font-size: 0.65rem;
  font-weight: 700;
  font-family: var(--font-mono);
  letter-spacing: 0.1em;
  padding: 3px 8px;
  border-radius: 4px;
  margin-bottom: var(--space-sm);
}
.pro-card__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
  color: var(--text-primary);
}
.pro-card__features {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}
.pro-card__features li {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* ─── Section Shared Styles ──────────────────────────────────── */
.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}
.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-lime);
  background: rgba(204,255,0,0.08);
  padding: 4px 12px;
  border-radius: 100px;
  margin-bottom: var(--space-md);
}
.section-title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.1;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
}
.section-subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ─── Features Section ───────────────────────────────────────── */
.features-section {
  padding: var(--space-3xl) 0;
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}
.feature-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(204,255,0,0.02), transparent);
  opacity: 0;
  transition: opacity var(--transition-normal);
}
.feature-card:hover {
  border-color: var(--border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.feature-card:hover::after { opacity: 1; }

.feature-card__icon {
  width: 48px;
  height: 48px;
  background: rgba(204,255,0,0.1);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-lime);
  margin-bottom: var(--space-lg);
}
.feature-card__icon--orange { background: rgba(255,107,43,0.1); color: var(--accent-orange); }
.feature-card__icon--blue   { background: rgba(59,130,246,0.1); color: var(--accent-blue); }
.feature-card__icon--purple { background: rgba(139,92,246,0.1); color: var(--accent-purple); }
.feature-card__icon--green  { background: rgba(34,197,94,0.1);  color: var(--accent-green); }
.feature-card__icon--red    { background: rgba(239,68,68,0.1);  color: var(--accent-red); }

.feature-card__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--text-primary);
}
.feature-card__desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ─── How It Works ───────────────────────────────────────────── */
.how-section {
  padding: var(--space-3xl) 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.steps-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  flex-wrap: wrap;
}
.step {
  flex: 1;
  min-width: 200px;
  max-width: 280px;
  text-align: center;
  padding: var(--space-xl);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: all var(--transition-normal);
}
.step:hover {
  border-color: var(--accent-lime);
  box-shadow: var(--shadow-lime);
  transform: translateY(-4px);
}
.step__number {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--accent-lime);
  letter-spacing: 0.1em;
  margin-bottom: var(--space-md);
}
.step__icon {
  width: 56px;
  height: 56px;
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  margin: 0 auto var(--space-md);
}
.step__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--text-primary);
}
.step__desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.6;
}
.step__arrow {
  font-size: 1.5rem;
  color: var(--text-muted);
  flex-shrink: 0;
}

/* ─── Pricing Section ────────────────────────────────────────── */
.pricing-section {
  padding: var(--space-3xl) 0;
}
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  align-items: start;
}
.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  position: relative;
  transition: all var(--transition-normal);
}
.pricing-card:hover {
  border-color: var(--border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.pricing-card--featured {
  border-color: var(--accent-lime);
  background: linear-gradient(135deg, var(--bg-card), rgba(204,255,0,0.03));
  box-shadow: var(--shadow-lime);
  transform: scale(1.02);
}
.pricing-card--featured:hover {
  transform: scale(1.02) translateY(-4px);
}
.pricing-card__badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-lime);
  color: #0D0D0D;
  font-size: 0.7rem;
  font-weight: 700;
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
  padding: 4px 14px;
  border-radius: 100px;
  white-space: nowrap;
}
.pricing-card__header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--border);
}
.pricing-card__name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}
.pricing-card__price {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: var(--space-sm);
}
.pricing-card__amount {
  font-size: 2.5rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--text-primary);
  letter-spacing: -0.03em;
}
.pricing-card__period {
  font-size: 0.875rem;
  color: var(--text-muted);
}
.pricing-card__tagline {
  font-size: 0.8rem;
  color: var(--text-secondary);
}
.pricing-card__features {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}
.pricing-card__features li {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.pricing-card__feature--muted {
  color: var(--text-muted) !important;
}

/* ─── FAQ Section ────────────────────────────────────────────── */
.faq-section {
  padding: var(--space-3xl) 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
}
.faq-list {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}
.faq-item[open] { border-color: var(--border-light); }
.faq-item__question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  transition: color var(--transition-fast);
  user-select: none;
}
.faq-item__question:hover { color: var(--accent-lime); }
.faq-item__question::after {
  content: '+';
  font-size: 1.25rem;
  font-weight: 300;
  color: var(--text-muted);
  transition: transform var(--transition-normal);
  flex-shrink: 0;
  margin-left: var(--space-md);
}
.faq-item[open] .faq-item__question::after {
  transform: rotate(45deg);
  color: var(--accent-lime);
}
.faq-item__answer {
  padding: 0 var(--space-lg) var(--space-lg);
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.7;
  border-top: 1px solid var(--border);
  padding-top: var(--space-md);
}

/* ─── Advertise Section ──────────────────────────────────────── */
.advertise-section {
  padding: var(--space-3xl) 0;
  border-top: 1px solid var(--border);
}
.advertise-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-2xl);
  align-items: center;
  position: relative;
  overflow: hidden;
}
.advertise-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-lime), var(--accent-orange), var(--accent-blue));
}
.advertise-card__title {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  margin: var(--space-sm) 0 var(--space-md);
  color: var(--text-primary);
}
.advertise-card__desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 520px;
  margin-bottom: var(--space-xl);
}
.advertise-stats {
  display: flex;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
}
.advertise-stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.advertise-stat__num {
  font-size: 1.5rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--accent-lime);
}
.advertise-stat__label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.advertise-formats {
  margin-bottom: var(--space-xl);
}
.advertise-formats h3 {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
  font-family: var(--font-mono);
}
.advertise-formats ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}
.advertise-formats li {
  font-size: 0.875rem;
  color: var(--text-secondary);
  padding-left: var(--space-md);
  position: relative;
}
.advertise-formats li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent-lime);
}

/* Ad Mockup Visual */
.ad-mockup {
  width: 200px;
  flex-shrink: 0;
}
.ad-mockup__screen {
  background: var(--bg-elevated);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.ad-mockup__bar {
  height: 28px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 var(--space-sm);
  gap: 5px;
}
.ad-mockup__bar::before {
  content: '';
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent-red);
  box-shadow: 13px 0 0 var(--accent-orange), 26px 0 0 var(--accent-green);
}
.ad-mockup__content {
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.ad-mockup__ad {
  background: linear-gradient(135deg, rgba(204,255,0,0.15), rgba(255,107,43,0.1));
  border: 1px dashed rgba(204,255,0,0.3);
  border-radius: var(--radius-sm);
  padding: var(--space-lg);
  text-align: center;
  font-size: 0.7rem;
  color: var(--accent-lime);
  font-family: var(--font-mono);
  font-weight: 700;
}

/* ─── Footer ─────────────────────────────────────────────────── */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: var(--space-2xl);
  padding: var(--space-2xl) 0;
}
.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}
.footer-brand__desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 280px;
}
.footer-brand__legal {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: auto;
}
.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}
.footer-nav__col h4 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-bottom: var(--space-md);
}
.footer-nav__col ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.footer-nav__col a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}
.footer-nav__col a:hover { color: var(--text-primary); }

/* ─── Responsive ─────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .converter-layout {
    grid-template-columns: 1fr;
  }
  .converter-sidebar {
    position: static;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-lg);
  }
  .ad-slot--sidebar {
    width: 100%;
    height: 250px;
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 420px;
    margin: 0 auto;
  }
  .pricing-card--featured {
    transform: none;
  }
  .pricing-card--featured:hover {
    transform: translateY(-4px);
  }
  .advertise-card {
    grid-template-columns: 1fr;
  }
  .ad-mockup { display: none; }
}

@media (max-width: 768px) {
  :root {
    --space-2xl: 48px;
    --space-3xl: 64px;
  }

  .nav__links { display: none; }
  .nav__hamburger { display: flex; }
  .nav__actions .btn--ghost { display: none; }

  .hero { padding: var(--space-2xl) 0; }
  .hero__stats { gap: var(--space-lg); }

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

  .steps-row { flex-direction: column; }
  .step__arrow { transform: rotate(90deg); }

  .converter-sidebar {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }
  .footer-nav {
    grid-template-columns: repeat(2, 1fr);
  }

  .advertise-stats { gap: var(--space-lg); }

  .ad-slot--leaderboard { height: 60px; }
}

@media (max-width: 480px) {
  .container { padding: 0 var(--space-md); }
  .converter-card { padding: var(--space-lg); }
  .converter-tab { font-size: 0.8rem; padding: 8px 10px; }
  .drop-zone { padding: var(--space-xl) var(--space-md); }
  .hero__stats { flex-direction: column; gap: var(--space-md); }
  .hero__stat-divider { display: none; }
  .footer-nav { grid-template-columns: 1fr; }
  .advertise-card { padding: var(--space-lg); }
}

/* ─── Utility Classes ────────────────────────────────────────── */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* Scroll reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}