:root {
  color-scheme: light dark;
  --bg: #f5f5f7;
  --card: #ffffff;
  --text: #1d1d1f;
  --muted: #6e6e73;
  --border: #d8d8dc;
  --accent: #0066ff;
  --accent-text: #ffffff;
  --error: #d92d20;
  --radius: 12px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17171a;
    --card: #232326;
    --text: #f2f2f3;
    --muted: #9a9aa1;
    --border: #37373c;
    --accent: #3d8bff;
    --accent-text: #0a0a0b;
  }
}

* { box-sizing: border-box; }

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

.page {
  max-width: 880px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 3rem;
}

header {
  margin-bottom: 1.75rem;
}

h1 {
  font-size: 1.75rem;
  margin: 0 0 0.35rem;
}

.subtitle {
  color: var(--muted);
  margin: 0;
}

.layout {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 1.25rem;
  align-items: start;
}

@media (max-width: 720px) {
  .layout { grid-template-columns: 1fr; }
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 1rem;
  font-size: 0.9rem;
}

.field > span {
  color: var(--muted);
  font-weight: 500;
}

.field.checkbox {
  flex-direction: row;
  align-items: center;
  gap: 0.6rem;
}

.field.checkbox input { width: 16px; height: 16px; }

input[type="text"],
input[type="number"],
textarea,
select {
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.55rem 0.7rem;
  width: 100%;
}

textarea { resize: vertical; }

input[type="color"] {
  width: 100%;
  height: 38px;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
}

input[type="range"] { width: 100%; }

.field-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
}

details.advanced {
  margin-top: 0.25rem;
  border-top: 1px solid var(--border);
  padding-top: 0.85rem;
}

details.advanced summary {
  cursor: pointer;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 0.85rem;
}

details.advanced .field-row { grid-template-columns: repeat(2, 1fr); }

.preview-card {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.preview-wrap {
  position: relative;
  min-height: 220px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  background: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.preview-wrap img {
  max-width: 100%;
  max-height: 320px;
  display: none;
}

.preview-wrap.has-image img { display: block; }
.preview-wrap.has-image .placeholder { display: none; }

.placeholder {
  color: #9a9aa1;
  font-size: 0.9rem;
  margin: 0;
}

.error {
  color: var(--error);
  font-size: 0.85rem;
  min-height: 1.1rem;
  margin: 0;
}

.actions {
  display: flex;
  gap: 0.6rem;
}

button {
  font: inherit;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  padding: 0.6rem 1rem;
  cursor: pointer;
  background: var(--accent);
  color: var(--accent-text);
}

button.secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

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

footer {
  margin-top: 2rem;
  color: var(--muted);
  font-size: 0.85rem;
}

footer a { color: var(--accent); }

code {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.1rem 0.4rem;
  font-size: 0.85em;
}