:root {
  color-scheme: light;
  --panel: #ffffff;
  --canvas: #e7eaee;
  --text: #161616;
  --text-muted: #525252;
  --border: #c6c6c6;
  --soft: #f4f4f4;
  --accent: #0f62fe;
  --accent-hover: #0353e9;
  --danger: #da1e28;
  --shadow: 0 18px 60px rgba(15, 23, 42, .18);
  font-family: "IBM Plex Sans", "Noto Sans SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html,
body {
  height: 100%;
  margin: 0;
}

body {
  background: var(--canvas);
  color: var(--text);
}

button,
input {
  font: inherit;
}

button {
  border: 0;
}

.app-shell {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(340px, 420px) minmax(0, 1fr);
}

.tool-panel {
  background: var(--panel);
  border-right: 1px solid var(--border);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: auto;
}

.brand {
  display: flex;
  gap: 14px;
  align-items: center;
  padding: 22px 24px;
  border-bottom: 1px solid var(--border);
}

.brand-mark {
  width: 5px;
  height: 42px;
  background: var(--accent);
  flex: 0 0 auto;
}

.brand h1 {
  margin: 0;
  font-size: 25px;
  line-height: 1.1;
  font-weight: 300;
  letter-spacing: 0;
}

.brand p {
  margin: 5px 0 0;
  color: var(--text-muted);
  font-size: 12px;
}

.panel-section {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border);
}

.section-label {
  margin-bottom: 12px;
  color: var(--text-muted);
  font-size: 12px;
  font-weight: 600;
}

.drop-zone {
  display: grid;
  place-items: center;
  gap: 7px;
  min-height: 138px;
  padding: 22px;
  border: 1px dashed var(--border);
  background: var(--soft);
  text-align: center;
  cursor: pointer;
}

.drop-zone:hover,
.drop-zone.drag {
  border-color: var(--accent);
  background: #edf5ff;
}

.drop-zone strong {
  font-size: 15px;
}

.drop-zone span {
  color: var(--text-muted);
  font-size: 12px;
}

.drop-icon {
  width: 46px;
  height: 56px;
  border: 2px solid var(--text-muted);
  position: relative;
  background: #fff;
}

.drop-icon::before {
  content: "";
  position: absolute;
  right: -2px;
  top: -2px;
  width: 16px;
  height: 16px;
  background: linear-gradient(135deg, var(--soft) 0 50%, var(--text-muted) 51% 61%, #fff 62%);
  border-left: 2px solid var(--text-muted);
  border-bottom: 2px solid var(--text-muted);
}

.drop-icon::after {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 12px;
  height: 14px;
  border-top: 2px solid var(--accent);
  border-bottom: 2px solid var(--accent);
}

input[type="file"] {
  display: none;
}

.status,
.batch-meta {
  min-height: 19px;
  margin-top: 12px;
  color: var(--text-muted);
  font-size: 12px;
  line-height: 1.5;
}

.status.error {
  color: var(--danger);
}

.theme-grid {
  display: grid;
  gap: 8px;
}

.theme-card {
  width: 100%;
  padding: 13px 14px;
  border: 1px solid var(--border);
  border-left: 4px solid transparent;
  background: #fff;
  color: var(--text);
  text-align: left;
  cursor: pointer;
}

.theme-card:hover {
  background: var(--soft);
}

.theme-card.active {
  border-left-color: var(--accent);
  background: #edf5ff;
}

.theme-card span,
.theme-card small {
  display: block;
}

.theme-card span {
  font-size: 14px;
  font-weight: 600;
}

.theme-card small {
  margin-top: 3px;
  color: var(--text-muted);
  font-size: 11px;
}

.form-grid {
  display: grid;
  gap: 10px;
}

.form-grid .section-label {
  margin-bottom: 0;
}

.check-field {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 12px;
  cursor: pointer;
}

.check-field input[type="checkbox"] {
  width: 14px;
  height: 14px;
  margin: 0;
  accent-color: var(--accent);
}

.form-grid input[type="text"],
.style-grid input[type="number"] {
  width: 100%;
  min-width: 0;
  border: 0;
  border-bottom: 1px solid var(--border);
  background: var(--soft);
  color: var(--text);
  padding: 10px 11px;
  outline: none;
}

.form-grid input:disabled {
  color: var(--text-muted);
  opacity: .5;
}

.form-grid input:focus,
.style-grid input[type="number"]:focus {
  border-bottom-color: var(--accent);
  background: #edf5ff;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 4px;
}

.segmented button {
  height: 32px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 12px;
}

.segmented button.active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.adv summary {
  cursor: pointer;
  color: var(--text);
  font-size: 13px;
  font-weight: 600;
  list-style: none;
}

.adv summary::-webkit-details-marker {
  display: none;
}

.adv[open] summary {
  margin-bottom: 12px;
}

.style-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.style-grid label {
  display: grid;
  gap: 5px;
  color: var(--text-muted);
  font-size: 11px;
}

.style-grid input[type="color"] {
  width: 100%;
  height: 36px;
  border: 1px solid var(--border);
  background: #fff;
  padding: 2px;
  cursor: pointer;
}

.range-field {
  grid-column: 1 / -1;
  grid-template-columns: auto minmax(0, 1fr) 44px;
  align-items: center;
}

.range-field span {
  grid-column: 1 / -1;
}

.range-field input {
  grid-column: 1 / 3;
}

.range-field output {
  grid-column: 3;
  text-align: right;
  color: var(--text);
}

.compact {
  margin-top: 10px;
  min-height: 34px;
  font-size: 12px;
}

.batch-items {
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.batch-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  background: #fff;
}

.batch-item.active {
  background: #edf5ff;
}

.batch-item.error {
  border-left-color: var(--danger);
  background: #fff1f1;
}

.batch-item strong,
.batch-item small {
  display: block;
  min-width: 0;
}

.batch-item strong {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 13px;
}

.batch-item small {
  color: var(--text-muted);
  font-size: 11px;
}

.batch-item button {
  border: 1px solid var(--border);
  background: #fff;
  color: var(--accent);
  min-height: 30px;
  padding: 0 10px;
  cursor: pointer;
}

.bg-list {
  display: grid;
  gap: 8px;
}

.bg-slot {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr) 32px;
  gap: 10px;
  align-items: center;
  border: 1px dashed var(--border);
  background: var(--soft);
  padding: 10px;
  cursor: pointer;
}

.bg-slot.drag,
.bg-slot:hover {
  border-color: var(--accent);
  background: #edf5ff;
}

.bg-slot.has-img {
  border-style: solid;
  background: #fff;
}

.thumb {
  width: 48px;
  height: 48px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text-muted);
  display: grid;
  place-items: center;
  overflow: hidden;
  font-size: 10px;
}

.thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.bg-copy strong,
.bg-copy small {
  display: block;
}

.bg-copy strong {
  font-size: 13px;
}

.bg-copy small {
  margin-top: 3px;
  color: var(--text-muted);
  font-size: 11px;
}

.bg-remove {
  width: 30px;
  height: 30px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--danger);
  cursor: pointer;
}

.bg-remove:hover {
  background: #fff1f1;
}

.stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--border);
  border: 1px solid var(--border);
}

.stats div {
  min-width: 0;
  background: #fff;
  padding: 10px 12px;
}

.stats dt {
  color: var(--text-muted);
  font-size: 11px;
}

.stats dd {
  margin: 5px 0 0;
  font-size: 18px;
  font-weight: 600;
}

.actions {
  display: grid;
  gap: 10px;
  padding: 20px 24px 24px;
  margin-top: auto;
}

.primary-btn,
.secondary-btn,
.preview-toolbar button {
  min-height: 42px;
  padding: 0 14px;
  cursor: pointer;
  text-align: left;
}

.primary-btn {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}

.primary-btn:hover:not(:disabled) {
  background: var(--accent-hover);
}

.secondary-btn,
.preview-toolbar button {
  border: 1px solid var(--border);
  background: #fff;
  color: var(--accent);
}

.secondary-btn:hover:not(:disabled),
.preview-toolbar button:hover:not(:disabled) {
  background: var(--soft);
}

button:disabled {
  opacity: .45;
  cursor: not-allowed;
}

.preview-stage {
  min-width: 0;
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  position: relative;
}

.preview-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
  padding: 12px 20px;
  background: rgba(255, 255, 255, .92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
  z-index: 2;
}

.preview-toolbar strong,
.preview-toolbar span {
  display: block;
}

.preview-toolbar strong {
  font-size: 14px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: min(56vw, 760px);
}

.preview-toolbar span {
  margin-top: 2px;
  color: var(--text-muted);
  font-size: 12px;
}

#previewFrame {
  width: 100%;
  height: 100%;
  border: 0;
  background: #aeb5bf;
}

.empty-state {
  position: absolute;
  inset: 64px 0 0;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 28px;
  background:
    linear-gradient(90deg, rgba(255,255,255,.24) 1px, transparent 1px),
    linear-gradient(rgba(255,255,255,.24) 1px, transparent 1px),
    var(--canvas);
  background-size: 34px 34px;
  color: #384150;
}

.empty-state.hide {
  display: none;
}

.empty-state p {
  margin: 0;
  font-size: 14px;
}

.sheet-stack {
  width: 188px;
  height: 226px;
  position: relative;
}

.sheet-stack span {
  position: absolute;
  inset: 0;
  background: #fff;
  border: 1px solid #d0d5dd;
  box-shadow: var(--shadow);
}

.sheet-stack span:nth-child(1) {
  transform: rotate(-7deg) translate(-18px, 12px);
}

.sheet-stack span:nth-child(2) {
  transform: rotate(4deg) translate(18px, 8px);
}

.sheet-stack span:nth-child(3)::before {
  content: "";
  position: absolute;
  left: 24px;
  right: 24px;
  top: 36px;
  height: 122px;
  background:
    linear-gradient(var(--accent), var(--accent)) 0 0 / 72px 8px no-repeat,
    linear-gradient(#8b95a1, #8b95a1) 0 28px / 130px 7px no-repeat,
    linear-gradient(#c2c8d0, #c2c8d0) 0 52px / 118px 6px no-repeat,
    linear-gradient(#c2c8d0, #c2c8d0) 0 74px / 132px 6px no-repeat,
    linear-gradient(#c2c8d0, #c2c8d0) 0 96px / 98px 6px no-repeat;
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .tool-panel {
    min-height: auto;
    border-right: 0;
  }

  .preview-stage {
    min-height: 74vh;
  }

  .actions {
    position: sticky;
    bottom: 0;
    background: var(--panel);
    border-top: 1px solid var(--border);
  }
}