/* ==========================================================================
   PDFAxiom - Black & White Minimalist Compact Edition
   ========================================================================== */

:root, [data-theme="dark"] {
  /* Black & White Monochrome Palette (Dark Default) */
  --bg-primary: #000000;
  --bg-secondary: #09090b;
  --bg-card: #121215;
  --bg-card-hover: #1c1c21;
  --bg-input: #18181b;
  
  --border-color: #27272a;
  --border-color-hover: #ffffff;
  
  --text-primary: #ffffff;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  
  --accent-white: #ffffff;
  --accent-gray: #3f3f46;
  
  /* Compact Rectangular Radii & Spacing */
  --radius-lg: 10px;
  --radius-md: 8px;
  --radius-sm: 6px;
  --transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-input: #e2e8f0;
  
  --border-color: #94a3b8;
  --border-color-hover: #0f172a;
  
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  
  --accent-white: #0f172a;
}

/* Thicker High-Contrast Borders in Light Mode */
[data-theme="light"] .tool-card,
[data-theme="light"] .nav-btn,
[data-theme="light"] .mega-grid,
[data-theme="light"] .mini-dropdown-grid,
[data-theme="light"] .dropdown-single .mini-col,
[data-theme="light"] .header-container,
[data-theme="light"] .tool-workspace,
[data-theme="light"] .dropzone {
  border-width: 1.5px !important;
  border-color: #94a3b8 !important;
}

[data-theme="light"] .tool-card:hover,
[data-theme="light"] .nav-btn:hover {
  border-color: #0f172a !important;
}

/* Logo Color Inversion in Light Mode */
[data-theme="light"] .logo img {
  filter: invert(1) drop-shadow(0 1px 2px rgba(0, 0, 0, 0.15));
}

/* Theme Toggle Button Icons */
[data-theme="light"] .theme-toggle-btn .sun-icon {
  display: none !important;
}

[data-theme="light"] .theme-toggle-btn .moon-icon {
  display: block !important;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.5;
  letter-spacing: -0.01em;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  letter-spacing: -0.025em;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Header & Navbar */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
}

.header-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0.45rem 1.5rem;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
}

.logo-wrapper {
  justify-self: start;
  margin-left: 28px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.35rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.logo img, .brand-logo-img {
  height: 60px;
  width: auto;
  max-width: 350px;
  object-fit: contain;
  display: block;
}

/* 100% Mathematically Centered Navbar Category Dropdowns */
.header-nav {
  justify-self: center;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.header-actions {
  justify-self: end;
}

.dropdown-wrapper {
  position: relative;
}

.lang-dropdown-menu {
  right: 0;
  left: auto;
  min-width: 170px;
}

.lang-option.active {
  background: var(--bg-input);
  color: var(--text-primary);
  font-weight: 800;
}

.nav-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  font-weight: 700;
  transition: var(--transition);
}

.nav-btn:hover, .dropdown-wrapper:hover .nav-btn {
  background: var(--bg-input);
  border-color: var(--text-primary);
}

.nav-btn svg {
  transition: transform 0.25s ease;
}

.dropdown-wrapper.active .nav-btn svg {
  transform: rotate(180deg);
}

.nav-link-btn {
  text-decoration: none;
}

/* Mega Dropdown Sub-menu Panel */
.mega-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  padding-top: 0.6rem;
  display: none;
  z-index: 200;
  animation: fadeIn 0.2s ease-out;
}

/* Desktop: Support BOTH Hover AND Click on PC */
@media (min-width: 769px) {
  .dropdown-wrapper:hover .mega-dropdown,
  .dropdown-wrapper.active .mega-dropdown {
    display: block !important;
  }

  .dropdown-wrapper:hover .nav-btn svg,
  .dropdown-wrapper.active .nav-btn svg {
    transform: rotate(180deg);
  }
}

/* Mobile: Strict Active Toggle */
@media (max-width: 768px) {
  .dropdown-wrapper.active .mega-dropdown {
    display: block !important;
  }
  .dropdown-wrapper:not(.active) .mega-dropdown {
    display: none !important;
  }
}

.mega-grid {
  width: 780px;
  max-width: calc(100vw - 2rem);
  box-sizing: border-box;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.85);
}

.mini-dropdown-grid {
  width: 420px;
  max-width: calc(100vw - 2rem);
  box-sizing: border-box;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.85);
}

.dropdown-single .mini-col {
  width: 210px;
  max-width: calc(100vw - 2rem);
  box-sizing: border-box;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.85);
}

.mini-col, .mega-column {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.mega-title {
  font-size: 0.68rem;
  font-weight: 900;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 0.35rem;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid var(--border-color);
}

.mega-item {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-secondary);
  padding: 0.45rem 0.65rem;
  border-radius: 4px;
  transition: var(--transition);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.mega-item:hover {
  background: var(--bg-input);
  color: var(--text-primary);
  transform: translateX(3px);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.unified-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 700;
  white-space: nowrap;
}

/* Page Layout Containers */
.hero, .category-tabs, .tools-grid, .tool-workspace, .footer-container {
  max-width: 1240px;
  margin-left: auto;
  margin-right: auto;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-bottom: 3rem;
}

/* Hero Section (Compact) */
.hero {
  text-align: center;
  padding: 2.5rem 1.5rem 1.5rem 1.5rem;
  max-width: 800px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
}

.hero-badge span {
  color: #ffffff;
}

.hero h1 {
  font-size: 2.5rem;
  line-height: 1.15;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.hero p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

.hero-subtext {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  font-weight: 500;
}

/* Category Filter Tabs (Black & White Minimal) */
.category-tabs {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
}

.tab-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.45rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.tab-btn:hover, .tab-btn.active {
  background: var(--text-primary);
  color: var(--bg-primary);
  border-color: var(--text-primary);
}

/* Main Tools Grid - COMPACT RECTANGULAR CARDS */
.main-content {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem 1.5rem;
  flex: 1;
  width: 100%;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
}

/* Rectangular Tool Card (Fixed 64px Height - NEVER Increases in Height) */
.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.65rem 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  height: 64px;
  min-height: 64px;
  max-height: 64px;
  box-sizing: border-box;
  overflow: hidden;
}

.tool-card p {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin: 0;
  font-size: 0.8rem;
}

.tool-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-color-hover);
  transform: translateY(-2px);
}

/* Compact Monochromatic Icon */
.tool-icon-wrapper {
  width: 36px;
  height: 36px;
  min-width: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-input);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.tool-card-content {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  flex: 1;
  overflow: hidden;
}

.tool-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.tool-card h3 {
  font-size: 0.96rem;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tool-card p {
  font-size: 0.76rem;
  color: var(--text-secondary);
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Minimalist Monochrome Badges (Balanced Middle Ground Size) */
.tool-badge {
  font-size: 0.63rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.12rem 0.42rem;
  line-height: 1.1;
  border-radius: 4px;
  background: var(--bg-input);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
}

.tool-badge.hot, .tool-badge.popular {
  background: var(--text-primary);
  color: var(--bg-primary);
  border-color: var(--text-primary);
}

/* Tool Workspace Modal Interface */
.tool-workspace {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  max-width: 900px;
  margin: 0 auto;
  animation: fadeIn 0.25s ease-out;
}

.workspace-header {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1.25rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.workspace-title-box h2 {
  font-size: 1.75rem;
  color: var(--text-primary);
}

.workspace-title-box p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  margin-top: 4px;
}

.back-btn-lg {
  background: var(--text-primary);
  color: var(--bg-primary);
  border: 1px solid var(--text-primary);
  padding: 0.65rem 1.35rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 0.92rem;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(255, 255, 255, 0.15);
}

.back-btn-lg:hover {
  background: #e4e4e7;
  transform: translateX(-3px);
}

/* Rectangular Dropzone Area */
.dropzone {
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-md);
  padding: 3rem 1.5rem;
  text-align: center;
  background: var(--bg-secondary);
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.dropzone:hover, .dropzone.drag-over {
  border-color: var(--text-primary);
  background: var(--bg-card-hover);
}

.dropzone-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--text-primary);
  color: var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
}

.dropzone-text h3 {
  font-size: 1.15rem;
  color: var(--text-primary);
}

.dropzone-text p {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

/* Buttons */
.btn-primary {
  background: var(--text-primary);
  color: var(--bg-primary);
  border: 1px solid var(--text-primary);
  padding: 0.8rem 2rem;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.btn-primary:disabled {
  opacity: 0.3;
  cursor: not-allowed;
  transform: none;
}

/* File Previews */
.file-list-preview {
  margin-top: 1.5rem;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 1.25rem;
  max-height: 350px;
  overflow-y: auto;
  padding: 8px;
}

.file-preview-card {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.85rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  position: relative;
  gap: 0.5rem;
}

.file-preview-name {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  width: 100%;
}

.remove-file-btn {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #ffffff;
  color: #000000;
  border: 1px solid var(--border-color);
  font-size: 1.1rem;
  line-height: 1;
  font-weight: 900;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
  transition: var(--transition);
}

.remove-file-btn:hover {
  background: #ef4444;
  color: #ffffff;
  border-color: #ef4444;
  transform: scale(1.1);
}

/* Settings Form */
.tool-settings {
  margin-top: 1.5rem;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-control {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.65rem 1rem;
  color: var(--text-primary);
  font-size: 0.9rem;
  outline: none;
}

.form-control:focus {
  border-color: var(--text-primary);
}

/* Process & Result Section */
.process-actions {
  margin-top: 1.5rem;
  display: flex;
  justify-content: center;
}

.progress-container {
  display: none;
  margin-top: 1.5rem;
  text-align: center;
}

.progress-bar-bg {
  width: 100%;
  height: 6px;
  background: var(--bg-input);
  border-radius: 999px;
  overflow: hidden;
  margin-top: 0.5rem;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: var(--text-primary);
  transition: width 0.3s ease;
}

/* Download Box */
.download-box {
  display: none;
  margin-top: 1.75rem;
  padding: 2rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  text-align: center;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.download-box h3 {
  color: var(--text-primary);
}

.download-buttons-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.85rem;
  flex-wrap: wrap;
  margin-top: 0.5rem;
}

.btn-secondary {
  background: var(--bg-input);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 0.8rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-color-hover);
  transform: translateY(-1px);
}

/* Footer */
.app-footer {
  border-top: 1px solid var(--border-color);
  background: var(--bg-primary);
  padding: 2.5rem 1.5rem;
  margin-top: auto;
}

.footer-container {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  width: 100%;
}

.footer-row {
  position: relative;
  width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.copyright {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
}

.footer-about-right {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.82rem;
  font-weight: 500;
  white-space: nowrap;
  transition: var(--transition);
}

.footer-about-right:hover {
  color: var(--text-primary);
  text-decoration: underline;
}

@media (max-width: 600px) {
  .footer-row {
    flex-direction: column;
    gap: 0.5rem;
  }
  .footer-about-right {
    position: static;
    transform: none;
  }
}

/* About Us Floating Modal Overlay & Card */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(5px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s ease;
  padding: 1rem;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-card {
  background: var(--bg-card);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 520px;
  padding: 1.75rem;
  position: relative;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
  transform: translateY(12px) scale(0.98);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.active .modal-card {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: transparent;
  border: none;
  font-size: 1.5rem;
  color: var(--text-secondary);
  cursor: pointer;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: var(--transition);
}

.modal-close:hover {
  color: var(--text-primary);
  background: var(--bg-card-hover);
}

.modal-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.modal-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: var(--bg-input);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
}

.modal-header h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

.modal-body {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.modal-section h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
  color: var(--text-primary);
}

.modal-section p {
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--text-secondary);
}

.modal-link {
  color: var(--text-primary);
  text-decoration: underline;
  font-weight: 500;
}

/* Keyframes */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Mobile Menu Trigger Button */
.mobile-menu-btn {
  display: none;
  gap: 0.4rem;
  padding: 0.45rem 0.75rem;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Responsive Desktop Window Resize Adaptability (901px to 1200px) */
@media (max-width: 1200px) and (min-width: 901px) {
  .header-container {
    padding: 0.5rem 0.8rem;
  }
  .header-nav {
    gap: 0.3rem;
  }
  .nav-btn {
    padding: 0.36rem 0.5rem;
    font-size: 0.79rem;
  }
  .tools-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.8rem;
  }
}

/* Responsive Breakpoints & Mobile Device Mode Triggered ONLY at 900px */
@media (max-width: 900px) and (min-width: 521px) {
  .tools-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 0.75rem !important;
  }
}

@media (max-width: 900px) {
  .mobile-menu-btn {
    display: flex;
  }

  .lang-dropdown-wrapper {
    position: relative;
  }

  .lang-dropdown-wrapper .mega-dropdown {
    position: absolute !important;
    top: 100% !important;
    right: 0 !important;
    left: auto !important;
    width: 220px !important;
    min-width: 200px !important;
    background: var(--bg-secondary) !important;
    border: 1px solid var(--border-color) !important;
    border-radius: var(--radius-md) !important;
    padding: 0.5rem !important;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.95) !important;
    z-index: 1001 !important;
  }

  .lang-dropdown-wrapper.active .mega-dropdown {
    display: block !important;
  }

  .header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0.75rem;
    width: 100%;
  }

  .logo {
    font-size: 1.1rem;
    gap: 0.4rem;
  }

  .logo img, .brand-logo-img {
    height: 46px !important;
    width: auto !important;
    max-width: 220px !important;
  }

  .header-actions {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    flex-wrap: nowrap;
  }

  .header-actions .nav-btn {
    height: 34px !important;
    padding: 0 0.55rem !important;
    font-size: 0.76rem !important;
    gap: 0.3rem !important;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    box-sizing: border-box !important;
  }

  .theme-toggle-btn {
    width: 34px !important;
    height: 34px !important;
    padding: 0 !important;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    flex-shrink: 0 !important;
    box-sizing: border-box !important;
  }

  .header-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem;
    flex-direction: column;
    gap: 0.6rem;
    box-shadow: 0 12px 30px rgba(0,0,0,0.8);
    z-index: 999;
  }

  .header-nav.active {
    display: flex;
  }

  .header-nav .dropdown-wrapper {
    width: 100%;
  }

  .header-nav .nav-btn {
    width: 100%;
    justify-content: space-between;
    padding: 0.65rem 1rem;
  }

  .header-nav .mega-dropdown {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    display: none;
    width: 100%;
    margin-top: 0.5rem;
    box-shadow: none;
    border: 1px solid var(--border-color);
  }

  .header-nav .dropdown-wrapper.active .mega-dropdown {
    display: block;
  }

  .mini-dropdown-grid,
  .mega-grid,
  [data-theme="light"] .mini-dropdown-grid,
  [data-theme="light"] .mega-grid {
    width: 100% !important;
    max-width: 100% !important;
    box-sizing: border-box !important;
    grid-template-columns: repeat(2, 1fr) !important;
    padding: 0.65rem 0.75rem !important;
    gap: 0.75rem !important;
    box-shadow: none !important;
    border: none !important;
    background: transparent !important;
    overflow: hidden !important;
  }

  /* Fix Mobile Light Mode Sub-menu Double Card / Overlapping Box & Edge Alignment Bug */
  .dropdown-single .mini-col,
  .mini-col,
  [data-theme="light"] .mini-col,
  [data-theme="light"] .dropdown-single .mini-col {
    width: 100% !important;
    max-width: 100% !important;
    box-sizing: border-box !important;
    padding: 0.25rem 0.4rem !important;
    border: none !important;
    background: transparent !important;
    box-shadow: none !important;
  }

  .header-nav .mega-item {
    padding: 0.5rem 0.6rem !important;
    font-size: 0.78rem !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    border-radius: var(--radius-sm) !important;
  }

  .header-nav .mega-title {
    font-size: 0.65rem !important;
    margin-bottom: 0.45rem !important;
    padding-left: 0.35rem !important;
    letter-spacing: 0.05em !important;
  }

  .hero {
    padding: 1.5rem 1rem 1rem 1rem;
  }
  .hero h1 {
    font-size: 1.75rem;
  }
  .hero p {
    font-size: 0.9rem;
  }
  .hero-subtext {
    font-size: 0.8rem;
  }
  .category-tabs {
    display: none !important;
  }
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.65rem;
  }
  .tool-card {
    padding: 0.65rem 0.85rem;
    min-height: 64px;
  }
  .tool-card h3 {
    font-size: 0.88rem;
  }
  .tool-card p {
    font-size: 0.72rem;
  }
  .tool-workspace {
    padding: 1.25rem 1rem;
  }
  .dropzone {
    padding: 2rem 1rem;
  }
  .download-buttons-group {
    flex-direction: column;
    width: 100%;
  }
  .download-buttons-group .btn-primary,
  .download-buttons-group .btn-secondary {
    width: 100%;
    justify-content: center;
  }
}

@media (max-width: 520px) {
  .tools-grid {
    grid-template-columns: 1fr !important;
    gap: 0.6rem !important;
  }
  .tab-btn {
    padding: 0.35rem 0.65rem;
    font-size: 0.76rem;
  }
}

/* Touch Device & iOS Momentum Scrolling Optimization */
button, .tool-card, .tab-btn, .mega-item, .nav-btn {
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

body {
  -webkit-overflow-scrolling: touch;
}