* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: #f3f4f6;
  color: #111827;
}

.app {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
}

.app-header h1 {
  margin: 0 0 4px;
  font-size: 24px;
}

.subtitle {
  margin: 0 0 24px;
  color: #6b7280;
}

.layout {
  display: grid;
  grid-template-columns: minmax(280px, 380px) 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 800px) {
  .layout {
    grid-template-columns: 1fr;
  }
}

.form-panel,
.preview-panel {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  padding: 20px;
}

fieldset {
  border: none;
  padding: 0;
  margin: 0 0 20px;
}

legend {
  font-weight: 600;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: #6b7280;
  margin-bottom: 8px;
  padding: 0;
}

label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  margin: 10px 0 4px;
}

input[type="text"],
input[type="email"],
input[type="url"] {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  font-size: 14px;
}

input[type="color"] {
  width: 60px;
  height: 32px;
  padding: 0;
  border: 1px solid #d1d5db;
  border-radius: 6px;
}

.layout-switch {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}

.layout-option {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin: 0;
  padding: 10px 8px;
  font-size: 13px;
  font-weight: 500;
  text-align: center;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  cursor: pointer;
}

.layout-option input {
  margin: 0;
}

.layout-option:has(input:checked) {
  border-color: #2563eb;
  background: #eff6ff;
  color: #2563eb;
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 400;
}

.checkbox-row input {
  margin: 0;
}

.advanced-fieldset {
  margin: 16px 0;
}

.advanced-fieldset summary {
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  color: #6b7280;
}

.advanced-fieldset fieldset {
  margin-top: 10px;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.92em;
  background: #f3f4f6;
  padding: 1px 4px;
  border-radius: 4px;
}

.warning-banner {
  margin: 12px 0 0;
  padding: 10px 12px;
  font-size: 13px;
  line-height: 1.5;
  color: #92400e;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 8px;
}

.warning-banner code {
  background: #fef3c7;
}

.hint {
  font-size: 12px;
  color: #6b7280;
  line-height: 1.4;
  margin: 8px 0;
}

.hint.error {
  color: #b91c1c;
}

.hint.success {
  color: #16a34a;
}

.generate-photo-gif {
  margin: 12px 0 16px;
  padding: 12px;
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
}

.generate-photo-gif input[type="file"] {
  display: block;
  width: 100%;
  font-size: 13px;
  margin: 6px 0 10px;
}

.generated-preview-img {
  max-width: 140px;
  display: block;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  margin: 10px 0 6px;
}

.preview-panel h2 {
  margin-top: 0;
  font-size: 16px;
}

.preview-frame-wrap {
  border: 1px dashed #d1d5db;
  border-radius: 8px;
  padding: 16px;
  background: #fafafa;
}

#preview {
  width: 100%;
  height: 260px;
  border: none;
  background: #fff;
}

.actions {
  display: flex;
  gap: 10px;
  margin-top: 16px;
  flex-wrap: wrap;
}

button {
  cursor: pointer;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 500;
  border-radius: 6px;
  border: 1px solid transparent;
  background: #2563eb;
  color: #fff;
}

button#copy-source {
  background: #fff;
  color: #2563eb;
  border-color: #2563eb;
}

.copy-status {
  min-height: 18px;
  font-size: 13px;
  color: #16a34a;
  margin: 8px 0 0;
}

details {
  margin-top: 16px;
}

summary {
  cursor: pointer;
  font-size: 13px;
  color: #6b7280;
}

#html-source {
  width: 100%;
  height: 200px;
  margin-top: 8px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
  padding: 10px;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  resize: vertical;
}