:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --panel: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #d9dee7;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #c62828;
  --danger-hover: #a61f1f;
  --shadow: 0 12px 35px rgba(15, 23, 42, .08);
}

body.dark {
  color-scheme: dark;
  --bg: #111827;
  --panel: #1f2937;
  --text: #f3f4f6;
  --muted: #9ca3af;
  --border: #374151;
  --primary: #3b82f6;
  --primary-hover: #60a5fa;
  --danger: #dc2626;
  --danger-hover: #ef4444;
  --shadow: 0 12px 35px rgba(0, 0, 0, .25);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
}

button, input, select { font: inherit; }

button, .button {
  appearance: none;
  border: 0;
  border-radius: 10px;
  background: var(--primary);
  color: white;
  padding: 10px 14px;
  cursor: pointer;
  font-weight: 700;
  transition: .2s ease;
}

button:hover, .button:hover { background: var(--primary-hover); }

button.secondary, .button.secondary {
  background: #4b5563;
}

button.ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

button.danger { background: var(--danger); }
button.danger:hover { background: var(--danger-hover); }

.app {
  width: min(1500px, calc(100% - 28px));
  margin: 20px auto 40px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 18px;
}

h1, h2, p { margin: 0; }
.topbar p { color: var(--muted); margin-top: 6px; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
}

.toolbar {
  padding: 16px;
  display: grid;
  gap: 14px;
}

.actions, .controls, .export-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: end;
}

.controls label, .export-row label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
}

input[type="number"], select {
  min-width: 110px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: var(--panel);
  color: var(--text);
  padding: 9px 10px;
}

input[type="color"] {
  width: 54px;
  height: 40px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: transparent;
  padding: 3px;
}

.drop-zone {
  margin-top: 16px;
  min-height: 110px;
  display: grid;
  place-content: center;
  text-align: center;
  gap: 6px;
  border-style: dashed;
  color: var(--muted);
}

.drop-zone.dragging {
  border-color: var(--primary);
  background: color-mix(in srgb, var(--primary) 8%, var(--panel));
}

.content-grid {
  margin-top: 16px;
  display: grid;
  grid-template-columns: minmax(330px, .8fr) minmax(0, 1.5fr);
  gap: 16px;
}

.panel { padding: 16px; min-height: 400px; }

.panel-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

.panel-head span { color: var(--muted); }

.image-list {
  display: grid;
  gap: 10px;
  max-height: 70vh;
  overflow: auto;
}

.image-item {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 12px;
}

.image-item img {
  width: 74px;
  height: 100px;
  object-fit: cover;
  border-radius: 8px;
  background: #ddd;
}

.item-meta {
  min-width: 0;
  display: grid;
  gap: 5px;
}

.item-name {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.item-size {
  color: var(--muted);
  font-size: 13px;
}

.item-actions {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  justify-content: end;
}

.item-actions button { padding: 8px 10px; }

.canvas-wrap {
  width: 100%;
  min-height: 360px;
  max-height: 75vh;
  overflow: auto;
  display: grid;
  place-items: start center;
  background:
    linear-gradient(45deg, #d6d6d6 25%, transparent 25%),
    linear-gradient(-45deg, #d6d6d6 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #d6d6d6 75%),
    linear-gradient(-45deg, transparent 75%, #d6d6d6 75%);
  background-size: 24px 24px;
  background-position: 0 0, 0 12px, 12px -12px, -12px 0;
  border-radius: 12px;
  padding: 12px;
}

canvas {
  max-width: 100%;
  height: auto;
  display: block;
  background: white;
  box-shadow: 0 8px 25px rgba(0,0,0,.18);
}

@media (max-width: 950px) {
  .content-grid { grid-template-columns: 1fr; }
  .image-list { max-height: none; }
}

@media (max-width: 620px) {
  .app { width: min(100% - 16px, 1500px); margin-top: 10px; }
  .topbar { align-items: flex-start; }
  .image-item { grid-template-columns: 62px 1fr; }
  .image-item img { width: 62px; height: 84px; }
  .item-actions { grid-column: 1 / -1; justify-content: start; }
}