:root {
  --bg: #0b0c10;
  --card: #12141a;
  --text: #e9ecf1;
  --muted: #a7b0c0;
  --border: #252a35;
  --error: #ff6b6b;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  background: var(--bg);
  color: var(--text);
}

.wrap {
  max-width: 980px;
  margin: 0 auto;
  padding: 24px;
}

h1 { margin: 8px 0 18px; font-size: 28px; }
h2 { margin: 0 0 10px; font-size: 18px; color: var(--muted); font-weight: 600; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  margin: 14px 0;
}

label {
  display: block;
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

input, select, textarea, button {
  width: 100%;
  margin-top: 6px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #0f1117;
  color: var(--text);
  padding: 10px 12px;
  font-size: 14px;
}

textarea { resize: vertical; min-height: 120px; }

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  align-items: end;
  margin-bottom: 12px;
}

@media (max-width: 860px) {
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
  .grid { grid-template-columns: 1fr; }
}

.toggle {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: #0f1117;
}
.toggle input {
  width: auto;
  margin: 0;
}

.row {
  display: grid;
  gap: 12px;
  align-items: end;
}

.actions {
  grid-template-columns: 1fr 220px;
  align-items: end;
}

.grow { width: 100%; }

button {
  cursor: pointer;
  font-weight: 650;
  background: #1a2030;
}
button:hover { filter: brightness(1.08); }

.hint {
  margin: 10px 0 0;
  font-size: 13px;
  color: var(--muted);
}
.hint.error { color: var(--error); }

.preview {
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

iframe {
  width: 100%;
  height: 520px;
  border: 0;
  background: white;
}