/* ============================================================
   JSON to CSV Converter — Dark Theme Responsive Styles
   Freecvt.com
   ============================================================ */

/* --- CSS Variables / Theming --- */
:root {
  --color-primary: #6366f1;
  --color-primary-hover: #818cf8;
  --color-primary-light: rgba(99, 102, 241, 0.12);
  --color-primary-glow: rgba(99, 102, 241, 0.25);
  --color-success: #10b981;
  --color-success-bg: rgba(16, 185, 129, 0.1);
  --color-error: #ef4444;
  --color-error-bg: rgba(239, 68, 68, 0.1);
  --color-bg: #0f0f14;
  --color-surface: #1a1a24;
  --color-surface-hover: #22222e;
  --color-text: #e0e0e0;
  --color-text-muted: #8888a0;
  --color-border: #2a2a38;
  --color-border-hover: #3a3a4e;
  --color-dashed: #4a4a62;
  --font-stack: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
  --transition: 0.2s ease;
}

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

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

body {
  font-family: var(--font-stack);
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
}

.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;
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* --- Skip Link --- */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--color-primary);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 100;
  border-radius: 0 0 4px 0;
  text-decoration: none;
}
.skip-link:focus { top: 0; }

/* --- Header --- */
.header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: nowrap;
  gap: 0.75rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--color-primary);
  font-weight: 700;
  font-size: 1.1rem;
}

.logo:hover { opacity: 0.85; }

.logo svg { flex-shrink: 0; }

nav {
  display: flex;
  gap: 0.25rem;
  flex-wrap: wrap;
}

.nav-link {
  display: inline-block;
  padding: 0.35rem 0.7rem;
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: 0.8rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}

.nav-link:hover {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.nav-link.active {
  background: var(--color-primary);
  color: #fff;
}

/* --- Main Content --- */
main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.converter-section {
  width: 100%;
  max-width: 640px;
  padding: 2rem 1.25rem 3rem;
}

.page-title {
  font-size: clamp(1.5rem, 5vw, 2rem);
  font-weight: 700;
  text-align: center;
  margin-bottom: 0.5rem;
  line-height: 1.2;
}

.page-subtitle {
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin-bottom: 2rem;
  line-height: 1.5;
}

/* --- Upload Zone --- */
.upload-zone {
  border: 2px dashed var(--color-dashed);
  border-radius: var(--radius-lg);
  padding: 3rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition), box-shadow var(--transition);
  background: var(--color-surface);
  position: relative;
}

.upload-zone:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

.upload-zone.drag-over {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
  box-shadow: 0 0 0 4px var(--color-primary-glow);
}

.upload-zone:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.upload-icon {
  color: var(--color-primary);
  margin-bottom: 1rem;
  transition: transform var(--transition);
}

.upload-zone:hover .upload-icon {
  transform: translateY(-2px);
}

.upload-text {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.upload-hint {
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

/* --- Paste Section --- */
.paste-section { margin-top: 1rem; }

.toggle-paste-btn {
  display: block;
  width: 100%;
  padding: 0.65rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  font-size: 0.85rem;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: border-color var(--transition), color var(--transition);
}

.toggle-paste-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.paste-area { margin-top: 0.75rem; }

.paste-input {
  width: 100%;
  padding: 0.85rem 1rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
  font-size: 0.85rem;
  line-height: 1.5;
  resize: vertical;
  min-height: 120px;
  transition: border-color var(--transition);
}

.paste-input::placeholder {
  color: var(--color-text-muted);
  opacity: 0.6;
}

.paste-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-glow);
}

.convert-btn.small {
  margin-top: 0.75rem;
  padding: 0.6rem 1rem;
  font-size: 0.85rem;
  width: auto;
}

/* --- File Info --- */
.file-info { margin-top: 1rem; }

.file-info-inner {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.75rem 1rem;
  background: var(--color-primary-light);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
}

.file-icon { color: var(--color-primary); flex-shrink: 0; }

.file-name {
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
  min-width: 0;
}

.file-size {
  color: var(--color-text-muted);
  font-size: 0.8rem;
  flex-shrink: 0;
}

.remove-btn {
  background: none;
  border: none;
  font-size: 1.3rem;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 0 0.25rem;
  line-height: 1;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
  flex-shrink: 0;
}

.remove-btn:hover {
  color: var(--color-error);
  background: var(--color-error-bg);
}

/* --- Preview --- */
.preview-container { margin-top: 1rem; }

.preview-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

.preview-table-wrap {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
}

.preview-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
  white-space: nowrap;
}

.preview-table th {
  background: var(--color-surface-hover);
  color: var(--color-primary);
  font-weight: 600;
  padding: 0.5rem 0.75rem;
  text-align: left;
  border-bottom: 2px solid var(--color-border);
}

.preview-table td {
  padding: 0.4rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
  max-width: 200px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.preview-table tbody tr:last-child td { border-bottom: none; }

.preview-table tbody tr:hover { background: var(--color-primary-light); }

/* --- Convert Button --- */
.convert-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  width: 100%;
  margin-top: 1.25rem;
  padding: 0.9rem 1.5rem;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: background var(--transition), box-shadow var(--transition), transform 0.1s;
}

.convert-btn:hover:not(:disabled) {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-md);
}

.convert-btn:active:not(:disabled) { transform: scale(0.98); }

.convert-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-spinner {
  width: 18px;
  height: 18px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

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

/* --- Result --- */
.result { margin-top: 1.5rem; }

.result-success {
  text-align: center;
  padding: 2rem 1.5rem;
  background: var(--color-success-bg);
  border: 1px solid var(--color-success);
  border-radius: var(--radius-lg);
}

.success-icon { color: var(--color-success); margin-bottom: 0.75rem; }

.result-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
  color: var(--color-success);
}

.result-detail {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 1.25rem;
}

.result-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.65rem 1.25rem;
  background: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: background var(--transition), border-color var(--transition);
}

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

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  background: var(--color-success);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: background var(--transition), transform 0.1s;
}

.download-btn:hover {
  background: #059669;
  box-shadow: var(--shadow-md);
}

.download-btn:active { transform: scale(0.97); }

.convert-another-btn {
  display: block;
  margin: 1rem auto 0;
  padding: 0.5rem 1rem;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 0.85rem;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: border-color var(--transition), color var(--transition);
}

.convert-another-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* --- Error --- */
.error-msg {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-top: 1rem;
  padding: 0.85rem 1rem;
  background: var(--color-error-bg);
  border: 1px solid var(--color-error);
  border-radius: var(--radius-md);
  color: var(--color-error);
  font-size: 0.9rem;
  font-weight: 500;
}

.error-icon { flex-shrink: 0; }

/* --- Features Section --- */
.features {
  width: 100%;
  max-width: 900px;
  padding: 2rem 1.25rem 3rem;
}

.features-title {
  text-align: center;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-align: center;
}

.feature-icon { color: var(--color-primary); margin-bottom: 0.5rem; }

.feature-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.feature-card p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: 1.5rem 1rem;
  color: var(--color-text-muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--color-border);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    gap: 0.5rem;
  }
  .converter-section { padding: 1.5rem 1rem 2rem; }
  .features-grid { grid-template-columns: 1fr; }
  .result-actions { flex-direction: column; }
  .result-actions .copy-btn,
  .result-actions .download-btn { width: 100%; justify-content: center; }
}

@media (max-width: 480px) {
  .preview-table { font-size: 0.7rem; }
  .preview-table th,
  .preview-table td { padding: 0.3rem 0.5rem; }
}