:root {
  --primary: #1677ff;
  --primary-hover: #0958d9;
  --primary-bg: #e6f4ff;
  --success: #52c41a;
  --bg-page: #f5f7fa;
  --bg-card: #ffffff;
  --text-main: #1f2329;
  --text-muted: #646a73;
  --border-color: #dee0e3;
  --code-bg: #f8f9fa;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --radius: 12px;
  --shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #2b85ff;
    --primary-hover: #1677ff;
    --primary-bg: rgba(43, 133, 255, 0.15);
    --bg-page: #121417;
    --bg-card: #1c1f24;
    --text-main: #f0f3f6;
    --text-muted: #8b949e;
    --border-color: #30363d;
    --code-bg: #16181d;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.35);
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.6;
  padding: 24px 16px;
  min-height: 100vh;
}

.container {
  max-width: 900px;
  margin: 0 auto;
}

header {
  text-align: center;
  margin-bottom: 24px;
}

.badge {
  display: inline-block;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 20px;
  background: var(--primary-bg);
  color: var(--primary);
  margin-bottom: 8px;
}

h1 {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 8px;
}

.subtitle {
  color: var(--text-muted);
  font-size: 14px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 20px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow);
}

.card-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.presets-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.btn-sm {
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 6px;
  border: 1px solid var(--border-color);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
}

.btn-sm:hover {
  color: var(--primary);
  border-color: var(--primary);
  background: var(--primary-bg);
}

.input-group {
  margin-bottom: 16px;
}

label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--text-muted);
}

textarea, input[type="text"], select {
  width: 100%;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-main);
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.2s;
}

textarea {
  resize: vertical;
  min-height: 80px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.4;
}

textarea:focus, input[type="text"]:focus, select:focus {
  outline: none;
  border-color: var(--primary);
}

.grid-params {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  padding-top: 12px;
  border-top: 1px dashed var(--border-color);
  margin-top: 12px;
}

.action-bar {
  display: flex;
  gap: 12px;
  margin-top: 16px;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s;
}

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

.btn-secondary {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 10px 16px;
  font-size: 14px;
  cursor: pointer;
}

.btn-secondary:hover {
  background: var(--code-bg);
}

/* Result Section */
.result-box {
  display: grid;
  grid-template-columns: 1fr 180px;
  gap: 20px;
  align-items: start;
}

@media (max-width: 680px) {
  .result-box {
    grid-template-columns: 1fr;
  }
}

.result-content {
  overflow: hidden;
}

.result-url-wrapper {
  background: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 12px;
  position: relative;
  margin-bottom: 12px;
}

.result-url {
  font-family: var(--font-mono);
  font-size: 13px;
  word-break: break-all;
  color: var(--primary);
  line-height: 1.5;
  user-select: all;
}

.qr-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: #ffffff;
  padding: 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

#qrcode-canvas {
  max-width: 156px;
  max-height: 156px;
  width: 100%;
  height: auto;
}

.qr-tip {
  font-size: 11px;
  color: #8c8c8c;
  margin-top: 6px;
  text-align: center;
}

/* Steps Breakdown */
.step-item {
  position: relative;
  padding-left: 36px;
  padding-bottom: 24px;
}

.step-item:last-child {
  padding-bottom: 0;
}

.step-item::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 24px;
  bottom: 0;
  width: 2px;
  background: var(--border-color);
}

.step-item:last-child::before {
  display: none;
}

.step-badge {
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
}

.step-header {
  margin-bottom: 6px;
}

.step-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-main);
}

.step-summary {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 2px;
}

.step-desc {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.detail-row {
  background: var(--code-bg);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 8px 12px;
  margin-top: 6px;
}

.detail-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.detail-value {
  font-family: var(--font-mono);
  font-size: 12px;
  word-break: break-all;
  color: var(--text-main);
  user-select: all;
}

.copy-link {
  font-size: 11px;
  color: var(--primary);
  cursor: pointer;
  border: none;
  background: none;
  padding: 0;
}

.copy-link:hover {
  text-decoration: underline;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: #333333;
  color: #ffffff;
  padding: 8px 18px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 500;
  opacity: 0;
  transition: transform 0.25s ease, opacity 0.25s ease;
  z-index: 1000;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}