:root {
  --bg: #f5f7fa;
  --surface: #ffffff;
  --border: #d9dee5;
  --border-strong: #b9c2cc;
  --text: #1f2933;
  --text-muted: #5b6776;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: #eaf0ff;
  --danger: #c0392b;
  --danger-hover: #a3291c;
  --success: #16a34a;
  --warn: #d97706;
  --row-hover: #f3f6fb;
  --row-edit: #fff7d6;
  --header-bg: #1f2933;
  --header-text: #f5f7fa;
  --shadow-sm: 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,.08);
  --radius: 6px;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
body {
  font: 14px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.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;
}

/* ---------- Header ---------- */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--header-bg);
  color: var(--header-text);
  gap: 16px;
  flex-wrap: wrap;
}
.brand { display: flex; align-items: baseline; gap: 12px; }
.brand-link {
  color: var(--header-text);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.02em;
  text-decoration: none;
}
.brand-link:hover { text-decoration: none; opacity: 0.9; }
.tag { color: #9aa6b2; font-size: 12px; }

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}
.header-link {
  color: #9aa6b2;
  font-size: 13px;
  padding: 6px 4px;
}
.header-link:hover { color: var(--header-text); text-decoration: none; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  background: var(--surface);
  color: var(--text);
  transition: background .12s, border-color .12s, transform .04s;
  text-decoration: none;
}
.btn:hover { background: #f0f3f8; text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-secondary { border-color: var(--border-strong); }
.btn-primary {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}
.btn-primary:hover:not(:disabled) { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn-primary:disabled { background: #6b7785; border-color: #6b7785; }

.btn-download {
  font-size: 14px;
  padding: 8px 16px;
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}
.btn-download:not(:disabled) {
  animation: subtle-pulse 2.4s ease-in-out infinite;
}
@keyframes subtle-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(37,99,235,.45); }
  50%      { box-shadow: 0 0 0 6px rgba(37,99,235,0); }
}
.dl-icon { font-size: 14px; }

.btn-danger {
  background: var(--danger);
  color: white;
  border-color: var(--danger);
}
.btn-danger:hover:not(:disabled) { background: var(--danger-hover); border-color: var(--danger-hover); }

.btn-link {
  background: transparent;
  border: none;
  color: var(--accent);
  cursor: pointer;
  padding: 4px 6px;
  font-size: 13px;
}
.btn-link:hover { text-decoration: underline; }

.btn-nav {
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 6px 12px;
  cursor: pointer;
  font-size: 16px;
  min-width: 36px;
}
.btn-nav:hover:not(:disabled) { background: #f0f3f8; }
.btn-nav:disabled { opacity: .35; cursor: not-allowed; }

/* ---------- Empty state ---------- */
main { flex: 1; padding: 24px 20px; }
.empty-state {
  max-width: 640px;
  margin: 60px auto;
  text-align: center;
}
.empty-state h1 { font-size: 24px; margin: 0 0 12px; font-weight: 600; }
.empty-state p { color: var(--text-muted); margin-bottom: 24px; }

.drop-zone {
  border: 2px dashed var(--border-strong);
  border-radius: 10px;
  padding: 60px 20px;
  color: var(--text-muted);
  background: var(--surface);
  transition: background .15s, border-color .15s;
}
.drop-zone.dragover {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
}

/* ---------- Workspace ---------- */
.workspace {
  max-width: 1280px;
  margin: 0 auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.toolbar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.view-toggle {
  display: inline-flex;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  overflow: hidden;
}
.toggle-btn {
  background: var(--surface);
  border: none;
  padding: 6px 14px;
  cursor: pointer;
  font-size: 13px;
  color: var(--text-muted);
}
.toggle-btn + .toggle-btn { border-left: 1px solid var(--border-strong); }
.toggle-btn.active {
  background: var(--accent);
  color: white;
}

.search-group {
  display: flex;
  align-items: center;
  gap: 6px;
  flex: 1;
  min-width: 280px;
}
.search-group select,
.search-group input {
  padding: 6px 8px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  font-size: 13px;
  background: var(--surface);
}
.search-group select { min-width: 140px; }
.search-group input { flex: 1; min-width: 100px; }

.file-info { color: var(--text-muted); font-size: 12px; }
.filename { font-family: var(--mono); }

/* ---------- Stats bar ---------- */
.stats-bar {
  padding: 8px 14px;
  background: #f9fafc;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}
.stats-bar strong { color: var(--text); font-weight: 600; }
.stats-bar .stat-divider { color: var(--border-strong); }

/* ---------- Grid ---------- */
.grid-view { padding: 0; }
.grid-scroll {
  overflow: auto;
  max-height: calc(100vh - 320px);
  min-height: 280px;
}
.data-grid {
  border-collapse: separate;
  border-spacing: 0;
  width: 100%;
  font-size: 13px;
}
.data-grid th, .data-grid td {
  border-bottom: 1px solid var(--border);
  border-right: 1px solid var(--border);
  padding: 6px 10px;
  text-align: left;
  vertical-align: top;
  white-space: nowrap;
  max-width: 360px;
  overflow: hidden;
  text-overflow: ellipsis;
}
.data-grid th {
  background: #eef1f6;
  position: sticky;
  top: 0;
  z-index: 2;
  font-weight: 600;
  user-select: none;
}
.data-grid th.col-header {
  cursor: pointer;
}
.data-grid th.col-header:hover { background: #e3e8ef; }
.data-grid th .col-name { display: inline-block; }
.data-grid th .col-type {
  display: inline-block;
  font-weight: 400;
  font-size: 10px;
  color: var(--text-muted);
  margin-left: 4px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.data-grid th .col-remove {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  margin-left: 6px;
  font-size: 14px;
  padding: 0 4px;
  border-radius: 3px;
}
.data-grid th .col-remove:hover { background: var(--danger); color: white; }
.data-grid th .sort-arrow { margin-left: 4px; color: var(--accent); }

.data-grid tr:hover td { background: var(--row-hover); }
.data-grid td[contenteditable="true"]:focus {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
  background: var(--row-edit);
  white-space: normal;
}
.data-grid td.row-actions {
  width: 36px;
  text-align: center;
  color: var(--text-muted);
  padding: 4px;
}
.data-grid th.row-actions-header { width: 36px; }
.row-delete-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 14px;
}
.row-delete-btn:hover { background: var(--danger); color: white; }

.grid-actions {
  padding: 10px 14px;
  display: flex;
  gap: 10px;
  border-top: 1px solid var(--border);
  background: #fbfcfd;
}

/* ---------- Form ---------- */
.form-view { padding: 16px; }
.form-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 14px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--border);
}
.form-position {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--text-muted);
  padding: 0 10px;
  min-width: 110px;
  text-align: center;
}
.spacer { flex: 1; }

.form-fields {
  display: grid;
  grid-template-columns: minmax(160px, 220px) 1fr;
  gap: 10px 16px;
  max-width: 720px;
}
.form-fields label {
  align-self: center;
  font-weight: 500;
  color: var(--text);
}
.form-fields .col-type-hint {
  font-weight: 400;
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-left: 6px;
}
.form-fields input,
.form-fields textarea,
.form-fields select {
  padding: 7px 9px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  font-size: 14px;
  font-family: inherit;
  background: var(--surface);
}
.form-fields input:focus,
.form-fields textarea:focus,
.form-fields select:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
  border-color: var(--accent);
}
.form-empty {
  grid-column: 1 / -1;
  text-align: center;
  color: var(--text-muted);
  padding: 40px 20px;
}

/* ---------- Footer ---------- */
.app-footer {
  padding: 14px 20px;
  font-size: 12px;
  color: var(--text-muted);
  text-align: center;
  border-top: 1px solid var(--border);
  background: var(--surface);
}

/* ---------- FAQ / Examples shared ---------- */
.page-wrap {
  max-width: 820px;
  margin: 30px auto;
  padding: 0 20px;
}
.page-wrap h1 { font-size: 28px; margin-top: 0; }
.page-wrap h2 { font-size: 18px; margin-top: 28px; }
.page-wrap p { color: var(--text); }

.examples-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
  margin-top: 18px;
}
.example-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  box-shadow: var(--shadow-sm);
}
.example-card h3 { margin: 0; font-size: 15px; }
.example-card p { margin: 0; color: var(--text-muted); font-size: 13px; flex: 1; }
.example-card .ex-actions { display: flex; gap: 8px; margin-top: 8px; }

/* ---------- Modal ---------- */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 32, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}
.modal {
  background: var(--surface);
  border-radius: 8px;
  box-shadow: var(--shadow-md);
  padding: 20px;
  min-width: 320px;
  max-width: 90vw;
}
.modal h3 { margin: 0 0 14px; font-size: 16px; }
.modal .field { display: flex; flex-direction: column; gap: 4px; margin-bottom: 12px; }
.modal label { font-size: 12px; color: var(--text-muted); font-weight: 500; }
.modal input, .modal select {
  padding: 7px 9px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  font-size: 14px;
}
.modal .modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  margin-top: 14px;
}