:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --border: #e3e5ea;
  --text: #1a1f2b;
  --muted: #6b7280;
  --primary: #1a2e4a;
  --primary-ink: #ffffff;
  --accent: #c9a961;
  --error: #b91c1c;
  --ok: #166534;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
}

.muted { color: var(--muted); }

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
}

.brand strong { font-size: 16px; }
.brand span { margin-left: 10px; font-size: 13px; }

.status { font-size: 13px; color: var(--muted); }
.status.ok { color: var(--ok); }
.status.warn { color: #b45309; }
.status.err { color: var(--error); }

main {
  display: grid;
  grid-template-columns: minmax(360px, 420px) 1fr;
  gap: 16px;
  padding: 16px;
  height: calc(100vh - 53px);
  min-height: 0;
}

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

.form-pane, .preview-pane {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.form-pane {
  overflow-y: auto;
}

form { padding: 16px; }

fieldset {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px 14px;
  margin: 0 0 14px;
}

legend {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  padding: 0 6px;
}

label {
  display: block;
  font-size: 13px;
  margin-bottom: 10px;
}

label > span { display: block; }

.hint { font-size: 11px; color: var(--muted); margin-top: 4px; line-height: 1.35; }

input[type="text"], input[type="url"], input[type="number"], input:not([type]), textarea {
  width: 100%;
  margin-top: 4px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font: inherit;
  background: #fff;
}

textarea { resize: vertical; }

input:focus, textarea:focus {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
  border-color: var(--primary);
}

.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.req { color: var(--error); }

.palette { margin-top: 6px; }
.palette-label {
  display: block;
  font-size: 13px;
  margin-bottom: 6px;
}
.swatches {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
  margin-bottom: 8px;
}
.swatches label {
  display: flex;
  flex-direction: column;
  align-items: center;
  font-size: 11px;
  color: var(--muted);
  margin: 0;
}
.swatches input[type="color"] {
  width: 100%;
  height: 30px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  cursor: pointer;
}

.presets {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.presets button {
  font-size: 12px;
  padding: 4px 10px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
}
.presets button:hover { border-color: var(--primary); }

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

button {
  font: inherit;
  cursor: pointer;
  padding: 9px 14px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
}

button:disabled { opacity: 0.5; cursor: not-allowed; }

button.primary {
  background: var(--primary);
  color: var(--primary-ink);
  border-color: var(--primary);
}

button.primary:hover:not(:disabled) {
  background: #122339;
}

.messages {
  margin-top: 14px;
  font-size: 13px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.msg {
  padding: 8px 10px;
  border-radius: 6px;
  border: 1px solid var(--border);
}

.msg.error { background: #fef2f2; border-color: #fecaca; color: var(--error); }
.msg.warn { background: #fffbeb; border-color: #fde68a; color: #92400e; }
.msg.ok { background: #f0fdf4; border-color: #bbf7d0; color: var(--ok); }
.msg.info { background: #eff6ff; border-color: #bfdbfe; color: #1e40af; }

.msg ul { margin: 4px 0 0 18px; padding: 0; }

.preview-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  background: #fafbfc;
}

.device-toggle button {
  padding: 4px 10px;
  font-size: 12px;
  border-radius: 999px;
}
.device-toggle button.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.preview-frame-wrap {
  position: relative;
  flex: 1;
  min-height: 480px;
  background: #f0f1f3;
  display: flex;
  align-items: stretch;
  justify-content: center;
  overflow: auto;
}

#preview-frame {
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
  display: none;
}

#preview-frame.visible { display: block; }

.preview-frame-wrap.mobile #preview-frame {
  width: 390px;
  max-width: 100%;
  margin: 16px auto;
  height: calc(100% - 32px);
  border: 1px solid var(--border);
  border-radius: 12px;
}

.empty-state {
  align-self: center;
  margin: auto;
  text-align: center;
  padding: 24px;
  max-width: 360px;
}

.empty-state code {
  background: #e9ebef;
  padding: 1px 5px;
  border-radius: 3px;
  font-size: 12px;
}

.spinner {
  display: inline-block;
  width: 12px;
  height: 12px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  vertical-align: -2px;
  margin-right: 6px;
}
@keyframes spin { to { transform: rotate(360deg); } }