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

:root {
  --page-bg: #f5f5f5;
  --panel-bg: #fff;
  --border: #ddd;
  --border-focus: #1677ff;
  --text: #333;
  --text-secondary: #666;
  --text-placeholder: #999;
  --preview-bg: #fafafa;
  --primary: #1677ff;
  --primary-hover: #4096ff;
  --radius: 4px;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 14px;
  line-height: 1.5;
  color: var(--text);
  background: var(--page-bg);
}

.page {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 16px 32px;
}

.page-header {
  margin-bottom: 16px;
}

.page-title {
  margin: 0 0 4px;
  font-size: 20px;
  font-weight: 600;
  color: var(--text);
}

.page-desc {
  margin: 0;
  font-size: 14px;
  color: var(--text-secondary);
}

.panel {
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

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

.block {
  margin-bottom: 16px;
}

.block-label {
  display: block;
  margin-bottom: 6px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
}

.input-text {
  width: 100%;
  padding: 8px 10px;
  font: inherit;
  font-size: 14px;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  resize: vertical;
  min-height: 100px;
}

.input-text::placeholder {
  color: var(--text-placeholder);
}

.input-text:focus {
  outline: none;
  border-color: var(--border-focus);
}

.params-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 16px;
}

.field--color,
.field--checkbox {
  grid-column: 1 / -1;
}

.checkbox-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--text);
  cursor: pointer;
  user-select: none;
}

.checkbox-label input {
  width: 14px;
  height: 14px;
  margin: 0;
  cursor: pointer;
}

.field-label {
  display: block;
  margin-bottom: 4px;
  font-size: 13px;
  font-weight: normal;
  color: var(--text-secondary);
}

.field-control {
  width: 100%;
  padding: 6px 8px;
  font: inherit;
  font-size: 14px;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.field-control:focus {
  outline: none;
  border-color: var(--border-focus);
}

.color-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.color-input {
  width: 40px;
  height: 32px;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
  cursor: pointer;
}

.color-text {
  flex: 1;
  padding: 6px 8px;
  font: inherit;
  font-size: 13px;
  font-family: ui-monospace, "Consolas", monospace;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.color-text:focus {
  outline: none;
  border-color: var(--border-focus);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 4px;
}

.btn {
  padding: 6px 14px;
  font: inherit;
  font-size: 14px;
  font-weight: normal;
  line-height: 1.5;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  background: #fff;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  color: #fff;
  background: var(--primary);
  border-color: var(--primary);
}

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

.btn-default {
  color: var(--text);
  background: #fff;
  border-color: var(--border);
}

.btn-default:hover:not(:disabled) {
  color: var(--primary);
  border-color: var(--primary);
}

.hint {
  margin: 12px 0 0;
  padding: 8px 10px;
  font-size: 13px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.hint--info {
  color: #0958d9;
  background: #e6f4ff;
  border-color: #91caff;
}

.hint--warn {
  color: #ad6800;
  background: #fffbe6;
  border-color: #ffe58f;
}

.hint--error {
  color: #cf1322;
  background: #fff2f0;
  border-color: #ffccc7;
}

.hint[hidden] {
  display: none;
}

.tool-preview .block-label {
  margin-bottom: 8px;
}

.preview-box {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 280px;
  padding: 16px;
  background: var(--preview-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.preview-empty {
  text-align: center;
  color: var(--text-placeholder);
}

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

.preview-result {
  display: flex;
  align-items: center;
  justify-content: center;
}

.preview-result[hidden],
.preview-empty[hidden] {
  display: none;
}

#qr-canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

@media (max-width: 720px) {
  .tool-layout {
    grid-template-columns: 1fr;
  }

  .preview-box {
    min-height: 220px;
  }

  .params-grid {
    grid-template-columns: 1fr;
  }

  .field--color {
    grid-column: auto;
  }
}