:root {
  --ub-bg: #ffffff;
  --ub-bg-2: #f8fafc;
  --ub-bg-3: #f1f5f9;
  --ub-fg: #0f172a;
  --ub-fg-2: #475569;
  --ub-fg-3: #94a3b8;
  --ub-border: #e2e8f0;
  --ub-border-2: #cbd5e1;
  --ub-accent: #6366f1;
  --ub-accent-hover: #4f46e5;
  --ub-accent-soft: rgba(99, 102, 241, 0.1);
  --ub-source: #3b82f6;
  --ub-medium: #10b981;
  --ub-campaign: #a855f7;
  --ub-term: #f59e0b;
  --ub-content: #ec4899;
  --ub-error: #ef4444;
  --ub-warn: #f59e0b;
  --ub-success: #10b981;
  --ub-shadow: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
  --ub-shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  --ub-font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --ub-mono: 'JetBrains Mono', 'SF Mono', Menlo, Monaco, Consolas, monospace;
}

.dark {
  --ub-bg: #0f172a;
  --ub-bg-2: #1e293b;
  --ub-bg-3: #334155;
  --ub-fg: #e2e8f0;
  --ub-fg-2: #94a3b8;
  --ub-fg-3: #64748b;
  --ub-border: #1e293b;
  --ub-border-2: #334155;
  --ub-accent: #818cf8;
  --ub-accent-hover: #a5b4fc;
  --ub-accent-soft: rgba(129, 140, 248, 0.15);
  --ub-shadow: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
  --ub-shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.4), 0 4px 6px -2px rgba(0,0,0,0.2);
}

* { box-sizing: border-box; }

body {
  font-family: var(--ub-font);
  background: var(--ub-bg-2);
  color: var(--ub-fg);
  margin: 0;
  padding: 50px 0 0; /* room for toolzie toolbar */
  transition: background-color 0.2s ease, color 0.2s ease;
}

/* App layout */
.ub-app {
  max-width: 1280px;
  margin: 24px auto;
  padding: 0 16px;
}

/* Toolbar */
.ub-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--ub-bg);
  border: 1px solid var(--ub-border);
  border-radius: 14px;
  padding: 16px 20px;
  margin-bottom: 16px;
  box-shadow: var(--ub-shadow);
  gap: 12px;
  flex-wrap: wrap;
}

.ub-toolbar-left, .ub-toolbar-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.ub-logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.ub-logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--ub-accent), #8b5cf6);
  border-radius: 10px;
  font-size: 20px;
  box-shadow: 0 4px 12px rgba(99,102,241,0.3);
}

.ub-logo h1 {
  font-size: 18px;
  font-weight: 700;
  margin: 0;
  letter-spacing: -0.01em;
  color: var(--ub-fg);
}

.ub-logo p {
  font-size: 12.5px;
  color: var(--ub-fg-2);
  margin: 0;
}

/* Buttons */
.ub-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 32px;
  padding: 0 12px;
  border-radius: 8px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--ub-fg);
  font-family: var(--ub-font);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.ub-btn:hover {
  background: var(--ub-bg-3);
}

.ub-btn-ghost {
  color: var(--ub-fg-2);
}

.ub-btn-ghost:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.ub-btn-primary {
  background: var(--ub-accent);
  color: white;
  font-weight: 600;
}

.ub-btn-primary:hover {
  background: var(--ub-accent-hover);
  color: white;
}

.ub-kbd {
  display: inline-flex;
  align-items: center;
  height: 18px;
  padding: 0 5px;
  margin-left: 4px;
  background: rgba(0,0,0,0.08);
  border-radius: 3px;
  font-family: var(--ub-mono);
  font-size: 10px;
  font-weight: 600;
  color: var(--ub-fg-2);
  letter-spacing: 0.02em;
}

.dark .ub-kbd {
  background: rgba(255,255,255,0.1);
  color: var(--ub-fg-2);
}

.ub-icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: transparent;
  border: none;
  border-radius: 4px;
  color: var(--ub-fg-2);
  cursor: pointer;
  transition: all 0.15s ease;
}

.ub-icon-btn:hover {
  background: var(--ub-bg-3);
  color: var(--ub-fg);
}

/* Main split */
.ub-main {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 900px) {
  .ub-main {
    grid-template-columns: 1fr;
  }
}

/* Form pane */
.ub-form-pane {
  background: var(--ub-bg);
  border: 1px solid var(--ub-border);
  border-radius: 14px;
  padding: 20px;
  box-shadow: var(--ub-shadow);
}

.ub-presets {
  margin-bottom: 20px;
}

.ub-section-label {
  display: block;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ub-fg-3);
  margin-bottom: 8px;
}

.ub-preset-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
  gap: 6px;
}

.ub-preset {
  display: flex;
  align-items: center;
  gap: 6px;
  height: 32px;
  padding: 0 10px;
  background: var(--ub-bg-2);
  border: 1px solid var(--ub-border);
  border-radius: 8px;
  color: var(--ub-fg);
  font-family: var(--ub-font);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
}

.ub-preset:hover {
  border-color: var(--ub-accent);
  background: var(--ub-accent-soft);
  color: var(--ub-accent);
}

.ub-preset-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  background: var(--ub-bg);
  border: 1px solid var(--ub-border);
  border-radius: 4px;
  font-size: 10px;
  font-weight: 700;
  flex-shrink: 0;
}

.ub-preset-name {
  font-size: 12px;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Form fields */
.ub-field {
  margin-bottom: 14px;
}

.ub-field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 14px;
}

@media (max-width: 600px) {
  .ub-field-row {
    grid-template-columns: 1fr;
  }
}

.ub-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ub-fg);
  margin-bottom: 5px;
}

.ub-required {
  color: var(--ub-error);
  font-weight: 700;
}

.ub-optional {
  font-size: 10.5px;
  font-weight: 400;
  color: var(--ub-fg-3);
  font-style: italic;
}

.ub-counter {
  font-family: var(--ub-mono);
  font-size: 10.5px;
  color: var(--ub-fg-3);
  font-weight: 400;
}

.ub-counter.over {
  color: var(--ub-error);
}

.ub-input {
  display: block;
  width: 100%;
  height: 36px;
  padding: 0 10px;
  background: var(--ub-bg);
  border: 1px solid var(--ub-border);
  border-radius: 8px;
  color: var(--ub-fg);
  font-family: var(--ub-mono);
  font-size: 13px;
  transition: all 0.15s ease;
}

.ub-input:focus {
  outline: none;
  border-color: var(--ub-accent);
  box-shadow: 0 0 0 3px var(--ub-accent-soft);
}

.ub-input.invalid {
  border-color: var(--ub-error);
}

.ub-input::placeholder {
  color: var(--ub-fg-3);
  font-family: var(--ub-mono);
  font-size: 12.5px;
}

.ub-field-hint {
  font-size: 11.5px;
  color: var(--ub-fg-2);
  margin-top: 4px;
  line-height: 1.4;
}

.ub-field-hint.warn {
  color: var(--ub-warn);
}

.ub-field-hint.error {
  color: var(--ub-error);
}

.ub-field-hint.ok {
  color: var(--ub-success);
}

/* Validation summary */
.ub-validation {
  margin-top: 12px;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 12px;
  display: none;
}

.ub-validation.error {
  display: block;
  background: rgba(239, 68, 68, 0.08);
  color: var(--ub-error);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.ub-validation.warn {
  display: block;
  background: rgba(245, 158, 11, 0.08);
  color: var(--ub-warn);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

/* Preview pane */
.ub-preview-pane {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.ub-output-card {
  background: var(--ub-bg);
  border: 1px solid var(--ub-border);
  border-radius: 14px;
  padding: 16px;
  box-shadow: var(--ub-shadow);
}

.ub-output-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.ub-output-label {
  font-size: 11.5px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ub-fg-3);
}

.ub-output-meta {
  font-size: 11.5px;
  color: var(--ub-fg-2);
  font-family: var(--ub-mono);
}

.ub-output-url-wrap {
  position: relative;
  display: flex;
  gap: 6px;
  align-items: stretch;
}

.ub-output-url {
  flex: 1;
  min-height: 80px;
  max-height: 200px;
  overflow-y: auto;
  padding: 10px 12px;
  background: var(--ub-bg-2);
  border: 1px solid var(--ub-border);
  border-radius: 8px;
  font-family: var(--ub-mono);
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--ub-fg);
  word-break: break-all;
  white-space: pre-wrap;
  outline: none;
  user-select: all;
}

.ub-output-url:focus {
  border-color: var(--ub-accent);
  box-shadow: 0 0 0 3px var(--ub-accent-soft);
}

.ub-output-url.empty {
  color: var(--ub-fg-3);
  font-style: italic;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ub-copy-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  min-width: 64px;
  padding: 6px 10px;
  background: var(--ub-accent);
  color: white;
  border: none;
  border-radius: 8px;
  font-family: var(--ub-font);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  align-self: stretch;
}

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

.ub-copy-btn:disabled {
  background: var(--ub-bg-3);
  color: var(--ub-fg-3);
  cursor: not-allowed;
}

.ub-copy-btn.copied {
  background: var(--ub-success);
}

/* Param chips */
.ub-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin-top: 10px;
  min-height: 8px;
}

.ub-chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  height: 22px;
  padding: 0 8px;
  border-radius: 11px;
  font-family: var(--ub-mono);
  font-size: 10.5px;
  font-weight: 500;
  color: white;
  background: var(--ub-bg-3);
}

.ub-chip.source { background: var(--ub-source); }
.ub-chip.medium { background: var(--ub-medium); }
.ub-chip.campaign { background: var(--ub-campaign); }
.ub-chip.term { background: var(--ub-term); }
.ub-chip.content { background: var(--ub-content); }

.ub-chip-key {
  opacity: 0.7;
}

/* Action buttons row */
.ub-actions {
  display: flex;
  gap: 6px;
  margin-top: 10px;
  flex-wrap: wrap;
}

.ub-actions .ub-btn {
  flex: 1;
  min-width: 60px;
  justify-content: center;
  border: 1px solid var(--ub-border);
  background: var(--ub-bg-2);
}

.ub-actions .ub-btn:hover:not(:disabled) {
  border-color: var(--ub-accent);
  background: var(--ub-accent-soft);
  color: var(--ub-accent);
}

/* QR panel */
.ub-qr-panel,
.ub-history-panel {
  background: var(--ub-bg);
  border: 1px solid var(--ub-border);
  border-radius: 14px;
  padding: 14px 16px;
  box-shadow: var(--ub-shadow);
  animation: ub-slide-down 0.2s ease;
}

@keyframes ub-slide-down {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

.ub-qr-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  font-size: 13px;
  font-weight: 600;
  color: var(--ub-fg);
}

.ub-qr-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.ub-qr-body canvas {
  background: white;
  padding: 10px;
  border-radius: 8px;
  border: 1px solid var(--ub-border);
  max-width: 200px;
}

/* History panel */
.ub-history-body {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 280px;
  overflow-y: auto;
}

.ub-history-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 8px 10px;
  background: var(--ub-bg-2);
  border: 1px solid var(--ub-border);
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s ease;
  position: relative;
}

.ub-history-item:hover {
  border-color: var(--ub-accent);
  background: var(--ub-accent-soft);
}

.ub-history-item-url {
  font-family: var(--ub-mono);
  font-size: 11px;
  color: var(--ub-fg);
  word-break: break-all;
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.ub-history-item-time {
  font-size: 10px;
  color: var(--ub-fg-3);
}

.ub-history-empty {
  text-align: center;
  padding: 16px;
  color: var(--ub-fg-3);
  font-size: 12px;
  font-style: italic;
}

/* Social share preview */
.ub-share-preview {
  background: var(--ub-bg);
  border: 1px solid var(--ub-border);
  border-radius: 14px;
  padding: 14px 16px;
  box-shadow: var(--ub-shadow);
}

.ub-share-card {
  background: var(--ub-bg-2);
  border: 1px solid var(--ub-border);
  border-radius: 10px;
  padding: 12px;
  margin-top: 4px;
}

.ub-share-card-domain {
  font-size: 11px;
  color: var(--ub-fg-3);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 4px;
}

.ub-share-card-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--ub-fg);
  margin-bottom: 4px;
  line-height: 1.3;
  word-break: break-word;
}

.ub-share-card-desc {
  font-size: 12.5px;
  color: var(--ub-fg-2);
  line-height: 1.4;
}

/* Toast */
.ub-toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--ub-fg);
  color: var(--ub-bg);
  padding: 8px 16px;
  border-radius: 8px;
  font-family: var(--ub-font);
  font-size: 13px;
  font-weight: 500;
  box-shadow: var(--ub-shadow-lg);
  z-index: 10000;
  animation: ub-toast-in 0.2s ease, ub-toast-out 0.2s ease 1.6s forwards;
  pointer-events: none;
  display: flex;
  align-items: center;
  gap: 6px;
}

@keyframes ub-toast-in {
  from { opacity: 0; transform: translate(-50%, 10px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

@keyframes ub-toast-out {
  to { opacity: 0; transform: translate(-50%, -10px); }
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--ub-border-2);
  border-radius: 5px;
  border: 2px solid var(--ub-bg-2);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--ub-fg-3);
}