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

:root {
  --bg: #f0f2f5;
  --surface: #ffffff;
  --text: #1a1a2e;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
  --radius: 12px;
}

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

.app {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 20px 40px;
  /* padding-top: 8em; */
}

.header {
  text-align: center;
  margin-bottom: 28px;
}

.header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subtitle {
  margin-top: 6px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.main {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 24px;
  align-items: start;
}

.preview {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  position: relative;
}

.loading {
  position: absolute;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.loading.hidden {
  display: none;
}

.mockup {
  width: 100%;
  max-width: 480px;
  aspect-ratio: 1;
  position: relative;
  display: grid;
  place-items: center;
}

.mockup-layer {
  grid-area: 1 / 1;
  width: 100%;
  height: 100%;
  pointer-events: none;
  user-select: none;
}

.bag-color,
.bag-design,
.bag-shading {
  -webkit-mask-image: url("/static/assets/images/bag.png");
  mask-image: url("/static/assets/images/bag.png");
  -webkit-mask-size: contain;
  mask-size: contain;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-position: center;
  mask-position: center;
}

.bag-design {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18% 14% 16%;
  overflow: hidden;
  touch-action: none;
}

.bag-design.has-design {
  pointer-events: auto;
  cursor: grab;
}

.bag-design.is-dragging {
  cursor: grabbing;
}

.design-transform {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  transform-origin: center center;
  will-change: transform;
}

.design-transform img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  pointer-events: none;
}

.bag-shading {
  object-fit: contain;
  mix-blend-mode: multiply;
  opacity: 0.45;
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.panel {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
}

.panel h2 {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.palette {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-bottom: 16px;
}

.swatch {
  width: 100%;
  aspect-ratio: 1;
  border: 2px solid transparent;
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.15s, border-color 0.15s, box-shadow 0.15s;
}

.swatch:hover {
  transform: scale(1.08);
}

.swatch.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.25);
}

.color-picker-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.color-picker-label input[type="color"] {
  width: 48px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  padding: 2px;
  background: none;
}

.upload-btn {
  display: block;
  width: 100%;
  padding: 12px 16px;
  background: var(--accent);
  color: #fff;
  text-align: center;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
  margin-bottom: 10px;
}

.upload-btn:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  width: 100%;
  padding: 10px 16px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.btn-secondary:hover:not(:disabled) {
  background: var(--bg);
  color: var(--text);
}

.btn-secondary:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.hint {
  margin-top: 12px;
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.45;
}

.design-controls {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.range-label {
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.range-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.range-row input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
}

.range-row output {
  min-width: 42px;
  font-size: 0.85rem;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  text-align: right;
}

@media (max-width: 768px) {
  .main {
    grid-template-columns: 1fr;
  }

  .controls {
    order: 2;
  }

  .preview {
    min-height: 360px;
    padding: 20px;
  }
}