:root {
  color-scheme: light;
  --bg: #eef3fb;
  --panel: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --border: #d7e0ef;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.06);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: linear-gradient(180deg, #f8fbff 0%, var(--bg) 100%);
  color: var(--text);
}

.layout {
  display: grid;
  grid-template-columns: minmax(360px, 460px) minmax(420px, 1fr);
  gap: 20px;
  min-height: 100vh;
  padding: 20px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.settings-panel {
  padding: 20px;
  overflow: auto;
  max-height: calc(100vh - 40px);
}

.preview-panel {
  padding: 16px;
  display: flex;
  flex-direction: column;
  min-height: calc(100vh - 40px);
}

.panel-header h1 {
  margin: 0 0 8px;
  font-size: 1.7rem;
}

.panel-header p {
  margin: 0 0 18px;
  color: var(--muted);
}

.card {
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  margin-bottom: 14px;
  background: #fbfdff;
}

.card h2 {
  margin: 0 0 12px;
  font-size: 1rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.92rem;
}

.field.compact {
  max-width: 140px;
}

.field span,
.checkbox span {
  color: var(--muted);
}

input[type="file"],
input[type="number"],
input[type="password"],
input[type="text"],
select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 11px;
  font-size: 0.92rem;
  background: #fff;
}

.options-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: end;
}

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

.actions {
  margin-top: 8px;
}

button {
  border: 0;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  padding: 11px 18px;
  font-size: 0.95rem;
  cursor: pointer;
}

button:hover:not(:disabled) {
  background: var(--primary-hover);
}

button:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

.status {
  min-height: 24px;
  margin-top: 14px;
  color: var(--muted);
}

.status.error {
  color: #b91c1c;
}

.status.success {
  color: #047857;
}

.preview-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-bottom: 10px;
}

.preview-toolbar input {
  width: 72px;
}

.preview-hint,
.preview-meta p {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 0.9rem;
}

.preview-stage {
  position: relative;
  flex: 1;
  min-height: 480px;
  border: 1px dashed var(--border);
  border-radius: 14px;
  background: #f8fafc;
  overflow: auto;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 12px;
}

.preview-canvas-wrap {
  position: relative;
  display: inline-block;
}

#pdf-canvas {
  display: block;
  max-width: 100%;
  cursor: crosshair;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
}

#stamp-overlay {
  position: absolute;
  pointer-events: none;
  opacity: 0.75;
  transform-origin: top left;
}

.preview-meta {
  margin-top: 12px;
}

@media (max-width: 1100px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .settings-panel,
  .preview-panel {
    max-height: none;
    min-height: auto;
  }
}

@media (max-width: 640px) {
  .layout {
    padding: 12px;
  }

  .grid-2 {
    grid-template-columns: 1fr;
  }
}