/* ============================================
   WebFont Subsetter — Typography-focused Design
   Theme: Monochrome + green reduction accents
   ============================================ */

:root {
  --bg-primary: #0a0a0c;
  --bg-secondary: #111114;
  --bg-tertiary: #18181c;
  --bg-card: rgba(24, 24, 30, 0.85);
  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.15);
  --text-primary: #f0f0f2;
  --text-secondary: #8a8a96;
  --text-muted: #55555f;
  --accent-green: #22c55e;
  --accent-green-dim: rgba(34, 197, 94, 0.15);
  --accent-green-glow: rgba(34, 197, 94, 0.25);
  --accent-blue: #6366f1;
  --accent-blue-dim: rgba(99, 102, 241, 0.12);
  --danger: #ef4444;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition: 0.2s ease;
}

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

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

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

/* Screen reader only utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* App Container */
.app-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px 20px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.app-header {
  margin-bottom: 32px;
}

.logo-section {
  display: flex;
  align-items: center;
  gap: 16px;
}

.logo-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--accent-green);
}

.app-header h1 {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.tagline {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Upload Section */
.upload-section {
  margin-bottom: 32px;
}

.upload-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: 64px 32px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  background: var(--bg-secondary);
}

.upload-zone:hover,
.upload-zone:focus-visible,
.upload-zone.drag-over {
  border-color: var(--accent-green);
  background: var(--accent-green-dim);
  outline: none;
}

.upload-icon {
  color: var(--text-muted);
  margin-bottom: 16px;
  transition: color var(--transition);
}

.upload-zone:hover .upload-icon,
.upload-zone.drag-over .upload-icon {
  color: var(--accent-green);
}

.upload-text {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.upload-link {
  color: var(--accent-green);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.upload-hint {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Font Info Bar */
.font-info-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  padding: 16px 20px;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin-bottom: 24px;
}

.font-name {
  font-size: 1.1rem;
  font-weight: 600;
}

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

.size-badge-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.size-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
}

.size-badge.original {
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
}

.size-badge.subset {
  background: var(--accent-green-dim);
  border: 1px solid rgba(34, 197, 94, 0.2);
}

.size-badge.savings {
  background: var(--accent-green);
  color: #000;
  font-weight: 700;
  border-radius: 100px;
  padding: 4px 12px;
}

.size-label {
  color: var(--text-muted);
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.size-value {
  font-weight: 600;
  font-size: 0.85rem;
}

.size-arrow {
  color: var(--text-muted);
  font-size: 1.2rem;
}

/* Editor Grid */
.editor-grid {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 24px;
  flex: 1;
}

/* Panels */
.panel {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.panel-title {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.panel-subtitle {
  display: block;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* Selection Panel */
.selection-panel {
  display: flex;
  flex-direction: column;
  gap: 20px;
  height: fit-content;
  position: sticky;
  top: 24px;
}

/* Preset Buttons */
.preset-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.preset-btn {
  font-family: var(--font);
  font-size: 0.78rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 100px;
  border: 1px solid var(--border);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
}

.preset-btn:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
}

.preset-btn.active {
  background: var(--accent-green-dim);
  border-color: var(--accent-green);
  color: var(--accent-green);
}

/* Custom Characters */
.custom-input {
  width: 100%;
  font-family: var(--font);
  font-size: 0.85rem;
  padding: 10px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  resize: vertical;
  transition: border-color var(--transition);
}

.custom-input:focus {
  outline: none;
  border-color: var(--accent-green);
}

/* Unicode Range */
.unicode-range-box {
  padding: 0;
}

.unicode-range {
  display: block;
  font-size: 0.75rem;
  color: var(--accent-green);
  background: var(--bg-primary);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  word-break: break-all;
  max-height: 80px;
  overflow-y: auto;
}

/* Output Format */
.format-select {
  width: 100%;
  font-family: var(--font);
  font-size: 0.85rem;
  padding: 8px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1L5 5L9 1' stroke='%238a8a96' stroke-width='1.5' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
}

.format-select:focus {
  outline: none;
  border-color: var(--accent-green);
}

/* Action Buttons */
.action-buttons {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.btn {
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 12px 20px;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all var(--transition);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--accent-green);
  color: #000;
}

.btn-primary:hover:not(:disabled) {
  background: #16a34a;
  box-shadow: 0 0 20px var(--accent-green-glow);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--border-hover);
  background: rgba(255, 255, 255, 0.05);
}

/* Preview Section */
.preview-panel {
  display: flex;
  flex-direction: column;
  gap: 24px;
  overflow: hidden;
}

.preview-text-area {
  min-height: 100px;
  padding: 20px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 32px;
  line-height: 1.4;
  color: var(--text-primary);
  outline: none;
  transition: border-color var(--transition);
  word-break: break-word;
}

.preview-text-area:focus {
  border-color: var(--accent-blue);
}

.preview-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

.preview-controls input[type="range"] {
  flex: 1;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg-tertiary);
  border-radius: 100px;
  outline: none;
}

.preview-controls input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-green);
  cursor: pointer;
  border: 2px solid var(--bg-primary);
}

.preview-size-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  min-width: 40px;
}

/* Glyph Section */
.glyph-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 0;
}

.glyph-header .panel-title {
  margin-bottom: 0;
}

.glyph-count {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.glyph-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(44px, 1fr));
  gap: 4px;
  max-height: 320px;
  overflow-y: auto;
  padding: 4px;
  margin-top: 12px;
}

.glyph-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1;
  background: var(--bg-tertiary);
  border: 1px solid transparent;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition);
  color: var(--text-secondary);
  position: relative;
}

.glyph-cell:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
  transform: scale(1.08);
  z-index: 1;
}

.glyph-cell.selected {
  background: var(--accent-green-dim);
  border-color: var(--accent-green);
  color: var(--accent-green);
}

.glyph-cell[title]::after {
  content: attr(title);
  position: absolute;
  bottom: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-primary);
  color: var(--text-secondary);
  font-size: 0.6rem;
  padding: 2px 6px;
  border-radius: 4px;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.15s;
}

.glyph-cell:hover[title]::after {
  opacity: 1;
}

/* CSS Snippet */
.css-snippet-box {
  position: relative;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.css-snippet-box pre {
  padding: 16px;
  margin: 0;
  overflow-x: auto;
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--accent-green);
}

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  font-family: var(--font);
  font-size: 0.7rem;
  padding: 4px 10px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
}

.copy-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-hover);
}

/* Footer */
.app-footer {
  margin-top: 48px;
  padding: 24px 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.app-footer p {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Loading state */
.loading {
  pointer-events: none;
  opacity: 0.6;
}

.loading .btn-primary::after {
  content: '';
  width: 14px;
  height: 14px;
  border: 2px solid transparent;
  border-top-color: #000;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

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

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 100px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* Responsive */
@media (max-width: 900px) {
  .editor-grid {
    grid-template-columns: 1fr;
  }

  .selection-panel {
    position: static;
  }

  .font-info-bar {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 600px) {
  .app-container {
    padding: 16px 12px;
  }

  .upload-zone {
    padding: 40px 20px;
  }

  .panel {
    padding: 16px;
  }

  .glyph-grid {
    grid-template-columns: repeat(auto-fill, minmax(36px, 1fr));
  }
}