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

body {
  margin: 0;
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(160deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  min-height: 100vh;
  color: #e8e8e8;
}

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

.header {
  text-align: center;
  margin-bottom: 2rem;
}

.header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0;
  font-size: 0.95rem;
  opacity: 0.85;
  line-height: 1.4;
}

.upload {
  border: 2px dashed rgba(255, 255, 255, 0.25);
  border-radius: 12px;
  padding: 2.5rem;
  text-align: center;
  transition: border-color 0.2s, background 0.2s;
  cursor: pointer;
  margin-bottom: 1.5rem;
}

.upload:hover,
.upload.dragover {
  border-color: rgba(255, 255, 255, 0.5);
  background: rgba(255, 255, 255, 0.04);
}

.upload-inner {
  pointer-events: none;
}

.upload-icon {
  font-size: 2.5rem;
  display: block;
  margin-bottom: 0.75rem;
}

.upload p {
  margin: 0;
  font-size: 0.95rem;
  opacity: 0.9;
}

.controls {
  background: rgba(255, 255, 255, 0.06);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.control-group {
  margin-bottom: 1.25rem;
}

.control-group:last-of-type {
  margin-bottom: 1rem;
}

.control-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.control-group input[type="range"] {
  width: 100%;
  max-width: 280px;
  margin-right: 0.75rem;
  vertical-align: middle;
}

.control-group .hint {
  font-size: 0.8rem;
  opacity: 0.75;
  margin: 0.5rem 0 0;
}

.page-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-list label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: normal;
  cursor: pointer;
}

.page-list input {
  margin: 0;
}

.checkbox-label {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-weight: normal;
  cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
  margin: 0.25rem 0 0;
  flex-shrink: 0;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.btn-primary {
  background: linear-gradient(135deg, #e94560, #c73e54);
  color: #fff;
}

.btn-primary:hover:not(:disabled) {
  box-shadow: 0 4px 14px rgba(233, 69, 96, 0.4);
}

.preview {
  margin-top: 1.5rem;
}

.preview h2 {
  font-size: 1.1rem;
  margin: 0 0 0.75rem;
}

.preview-container {
  background: #2a2a3e;
  border-radius: 12px;
  padding: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: flex-start;
}

.preview-item {
  background: repeating-conic-gradient(#555 0% 25%, #444 0% 50%) 50% / 16px 16px;
  border-radius: 8px;
  padding: 8px;
  max-width: 100%;
}

.preview-item img {
  display: block;
  max-width: 280px;
  height: auto;
}

.status {
  min-height: 1.5rem;
  margin-top: 1rem;
  font-size: 0.9rem;
  opacity: 0.9;
}

.status.error {
  color: #f08080;
}

.status.success {
  color: #90ee90;
}