:root {
  --bg: #0b0d12;
  --panel: #11151c;
  --panel-2: #151a22;
  --text: #e6e8eb;
  --muted: #94a3b8;
  --primary: #4f46e5;
  --primary-2: #6366f1;
  --border: #273043;
}

* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Helvetica,
    Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
  background: linear-gradient(180deg, var(--bg), #0d1117 60%, #0f131a);
  color: var(--text);
}

.app-header {
  padding: 24px 28px;
  border-bottom: 1px solid var(--border);
  background: rgba(21, 26, 34, 0.8);
  backdrop-filter: saturate(140%) blur(6px);
  display: flex;
  align-items: baseline;
  gap: 16px;
}
.brand {
  font-weight: 700;
  font-size: 20px;
}
.subtitle {
  color: var(--muted);
  font-size: 14px;
}

.app-main {
  display: grid;
  grid-template-columns: 480px 1fr;
  gap: 20px;
  padding: 20px;
}

.controls {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 12px;
}
label {
  font-size: 12px;
  color: var(--muted);
}
input[type="text"],
input[type="number"],
select,
textarea {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  padding: 10px 12px;
  outline: none;
}
textarea {
  min-height: 72px;
  resize: vertical;
}

.two-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.grid-3 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 12px;
}

.actions {
  display: flex;
  gap: 10px;
  padding-top: 8px;
}
button {
  cursor: pointer;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  color: var(--text);
  background: var(--panel-2);
}
.primary {
  background: var(--primary);
  border-color: var(--primary-2);
}
.secondary {
  background: #1f2430;
}
button:active {
  transform: translateY(1px);
}

.preview {
  display: grid;
}
.preview-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px;
  display: grid;
  place-items: center;
  min-height: 520px;
}

#result-canvas {
  max-width: 100%;
  height: auto;
}

.app-footer {
  padding: 16px 20px;
  color: var(--muted);
}

@media (max-width: 980px) {
  .app-main {
    grid-template-columns: 1fr;
  }
}