:root {
  --bg-color: #F9FAFB;
  --card-bg: #FFFFFF;
  --text-primary: #111827;
  --text-secondary: #6B7280;
  --accent: #2563EB;
  --accent-hover: #1D4ED8;
  --accent-disabled: #93C5FD;
  --border: #E5E7EB;
  --border-hover: #D1D5DB;
  --danger: #EF4444;
  --danger-hover: #FEE2E2;
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.04), 0 1px 3px rgba(0, 0, 0, 0.02);
  --shadow-hover: 0 14px 28px rgba(0, 0, 0, 0.06), 0 10px 10px rgba(0, 0, 0, 0.04);
  --shadow-inner: inset 0 -6px 0 0 rgba(0, 0, 0, 0.03);
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 24px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.5;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--accent-hover);
}

.hidden {
  display: none !important;
}

/* ============================
   Page Header (Logo Only)
=============================== */
.page-header {
  margin-bottom: 24px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.logo svg {
  color: var(--text-primary);
}

/* ============================
   Main Layouts
=============================== */
.main-container {
  flex: 1;
  max-width: 1000px;
  margin: 0 auto;
  width: 100%;
  padding: 48px 24px;
}

/* ============================
   Typography / Alignment
=============================== */
.hero,
.tool-header {
  text-align: left;
  margin-bottom: 48px;
}

.hero h1,
.tool-header h1 {
  font-size: 3.5rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  margin-bottom: 16px;
  color: var(--text-primary);
  line-height: 1.05;
}

.tool-header h1 {
  font-size: 2.75rem;
}

.hero p,
.tool-header p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
}

/* ============================
   Modern Overlapping Card UI
=============================== */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 1000px) {
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 650px) {
  .tools-grid {
    grid-template-columns: 1fr;
  }
}

.tool-card {
  background-color: var(--card-bg);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  transition: all 0.25s ease;
  box-shadow: var(--shadow-card);
  color: var(--text-primary);
  text-decoration: none;
  overflow: hidden;
  border: 1px solid rgba(0, 0, 0, 0.03);
  position: relative;
  top: 0;
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.tool-card.disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.tool-card.disabled:hover {
  transform: none;
  box-shadow: var(--shadow-card);
}

.card-content {
  padding: 32px;
  flex: 1;
}

.card-footer {
  padding: 16px 32px;
  background-color: var(--bg-color);
  border-top: 1px solid rgba(0, 0, 0, 0.04);
}

.icon-wrapper {
  width: 64px;
  height: 64px;
  border-radius: calc(var(--radius) + 4px);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 32px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

/* Color Themes for Cards */
.blue {
  background-color: #EFF6FF;
  color: #2563EB;
}

.blue-bg {
  background-color: #F8FAFC;
  border-top-color: #E2E8F0;
}

.blue-badge {
  background-color: #DBEAFE;
  color: #1E40AF;
}

.tool-card.border-blue {
  border: 2px solid #BFDBFE;
}

.green {
  background-color: #F0FDF4;
  color: #16A34A;
}

.green-bg {
  background-color: #F8FAFC;
  border-top-color: #DCFCE7;
}

.green-badge {
  background-color: #DCFCE7;
  color: #166534;
}

.tool-card.border-green {
  border: 2px solid #BBF7D0;
}

.purple {
  background-color: #FAF5FF;
  color: #9333EA;
}

.purple-bg {
  background-color: #F8FAFC;
  border-top-color: #F3E8FF;
}

.purple-badge {
  background-color: #F3E8FF;
  color: #6B21A8;
}

.tool-card.border-purple {
  border: 2px solid #E9D5FF;
}

.orange {
  background-color: #FFF7ED;
  color: #EA580C;
}

.orange-bg {
  background-color: #F8FAFC;
  border-top-color: #FFEDD5;
}

.orange-badge {
  background-color: #FFEDD5;
  color: #9A3412;
}

.tool-card.border-orange {
  border: 2px solid #FED7AA;
}

.gray {
  background-color: #F3F4F6;
  color: #4B5563;
}

.gray-bg {
  background-color: #F9FAFB;
  border-top-color: #E5E7EB;
}

.gray-badge {
  background-color: #E5E7EB;
  color: #374151;
}

.tool-card.border-gray {
  border: 2px solid #E5E7EB;
}

.tool-card h2 {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.tool-card p {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.badge {
  display: inline-block;
  padding: 6px 12px;
  font-size: 0.75rem;
  font-weight: 800;
  border-radius: 20px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}


/* ============================
   Workspace & Dropzone
=============================== */
.workspace {
  background: var(--card-bg);
  padding: 32px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  margin-bottom: 64px;
}

/* SEO Content Block */
.long-content {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 1.05rem;
}

.long-content p {
  margin-bottom: 16px;
}

.long-content h2,
.long-content h3 {
  color: var(--text-primary);
  margin: 24px 0 12px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.dropzone {
  border: 2px dashed var(--border-hover);
  border-radius: var(--radius);
  background-color: var(--bg-color);
  height: 280px;
  position: relative;
  transition: all 0.25s ease;
  cursor: pointer;
}

.dropzone:hover,
.dropzone.dragover {
  border-color: var(--accent);
  background-color: rgba(37, 99, 235, 0.04);
}

#file-input {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
  z-index: 10;
}

.dropzone-content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  pointer-events: none;
}

.upload-icon {
  width: 54px;
  height: 54px;
  color: var(--accent);
  margin-bottom: 16px;
  opacity: 0.9;
}

.green-stroke {
  color: #16A34A;
}

.purple-stroke {
  color: #9333EA;
}

.orange-stroke {
  color: #EA580C;
}

.drop-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.drop-subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* Dynamic Elements inside Workspace */
.file-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 24px;
}

.file-item {
  background-color: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.file-info {
  display: flex;
  align-items: center;
  gap: 16px;
  flex: 1;
  min-width: 0;
}

.file-name {
  font-weight: 600;
  font-size: 1rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-size {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin-left: auto;
  margin-right: 16px;
  white-space: nowrap;
}

.file-actions button {
  background: var(--bg-color);
  border: 1px solid var(--border);
  border-radius: 6px;
  width: 32px;
  height: 32px;
  cursor: pointer;
  color: var(--text-secondary);
  font-weight: 600;
}

.file-actions button:hover {
  background: #E5E7EB;
  color: var(--text-primary);
}

.file-actions .remove-btn {
  color: var(--danger);
  border-color: transparent;
  background: transparent;
}

.file-actions .remove-btn:hover {
  background: var(--danger-hover);
  color: #DC2626;
}

.action-bar {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 24px;
  padding: 24px;
  background: var(--bg-color);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.primary-btn {
  background-color: var(--accent);
  color: #FFFFFF;
  border: none;
  padding: 14px 28px;
  border-radius: var(--radius-sm);
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
}

.primary-btn:hover {
  background-color: var(--accent-hover);
}

.green-btn {
  background-color: #16A34A;
}

.green-btn:hover {
  background-color: #15803D;
}

.purple-btn {
  background-color: #9333EA;
}

.purple-btn:hover {
  background-color: #7E22CE;
}

.orange-btn {
  background-color: #EA580C;
}

.orange-btn:hover {
  background-color: #C2410C;
}

.primary-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.options-panel {
  margin-top: 24px;
}

.option-group label {
  font-weight: 700;
  color: var(--text-primary);
  display: block;
  margin-bottom: 8px;
}

.option-group input {
  padding: 14px 16px;
  border: 1px solid var(--border-hover);
  border-radius: var(--radius-sm);
  width: 100%;
  font-size: 1rem;
  background: var(--card-bg);
}

.option-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.progress {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
  font-weight: 600;
}

.spinner {
  width: 22px;
  height: 22px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.green-spin {
  border-top-color: #16A34A;
}

.purple-spin {
  border-top-color: #9333EA;
}

.orange-spin {
  border-top-color: #EA580C;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ============================
   Related Tools (Mini Cards)
=============================== */
.section-title {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 24px;
  letter-spacing: -0.02em;
}

.mini-grid {
  grid-template-columns: repeat(3, 1fr);
}

@media (max-width: 768px) {
  .mini-grid {
    grid-template-columns: 1fr;
  }
}

.mini-card .card-content {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 24px;
}

.mini-card .icon-wrapper {
  width: 48px;
  height: 48px;
  margin-bottom: 0;
  box-shadow: none;
  border-radius: 12px;
  flex-shrink: 0;
}

.mini-card h2 {
  font-size: 1.15rem;
  margin-bottom: 2px;
}

.mini-card p {
  font-size: 0.95rem;
}

/* Footers */
.site-footer {
  text-align: center;
  padding: 32px 24px;
  margin-top: auto;
  border-top: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.site-footer a {
  font-weight: 700;
}

/* ============================
   Category Filters
=============================== */
.category-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
  justify-content: center;
}

.filter-btn {
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: 24px;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02);
}

.filter-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  color: var(--text-primary);
  border-color: var(--border-hover);
}

.filter-btn.active-all,
.filter-btn.active-blue {
  background: #EFF6FF;
  color: #2563EB;
  border-color: #BFDBFE;
}

.filter-btn.active-purple {
  background: #FAF5FF;
  color: #9333EA;
  border-color: #E9D5FF;
}

.filter-btn.active-green {
  background: #F0FDF4;
  color: #16A34A;
  border-color: #BBF7D0;
}

.filter-btn.active-orange {
  background: #FFF7ED;
  color: #EA580C;
  border-color: #FED7AA;
}

.filter-btn.active-red {
  background: #FEF2F2;
  color: #DC2626;
  border-color: #FECACA;
}