:root {
  --bg: #121214;
  --card: #1c1c21;
  --accent: #6366f1;
  --text: #f3f4f6;
  --border: #2e2e38;
  --input-bg: #09090b;
}

/* 1. Universal Box-Sizing Fix */
*, *::before, *::after {
  box-sizing: border-box;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  padding: 2rem;
  margin: 0;
  display: flex;
  justify-content: center;
}

/* Container Expansion */
.container {
  width: 100%;
  max-width: 1280px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 2rem;
}

h1 { 
  margin-top: 0; 
  font-size: 1.5rem; 
  text-align: center; 
}

/* Two-Column Grid Workspace */
.workspace {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 2rem;
  align-items: start;
}

/* Column Specific Styles */
.preview-column {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.controls-column {
  background: var(--input-bg);
  padding: 1.25rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  width: 100%;
  max-width: 100%;
  overflow: hidden; /* Hard boundary constraint */
}

.controls-form {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  width: 100%;
}

.full-width {
  grid-column: 1 / -1;
  width: 100%;
}

.input-subgroup {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  width: 100%;
}

.hidden { display: none !important; }

.field-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  width: 100%;
  min-width: 0; /* Prevents flex children from pushing grid boundaries */
}

label { 
  font-size: 0.875rem; 
  color: #a1a1aa; 
}

/* Inputs & Form Elements Containment */
input[type="number"], 
input[type="file"], 
input[type="color"],
select.param-input {
  background: var(--input-bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.6rem;
  border-radius: 6px;
  width: 100%;
  max-width: 100%;
}

input[type="file"] {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

input[type="color"] {
  height: 42px;
  cursor: pointer;
  padding: 0.2rem;
}

/* Segmented Control Fix */
.segmented-control {
  display: flex;
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px;
  width: 100%;
}

.segmented-control input[type="radio"] { display: none; }

.segmented-control label {
  flex: 1 1 0; /* Force equal shrinking and growing */
  min-width: 0;
  text-align: center;
  padding: 0.5rem 0.25rem;
  font-size: 0.8125rem;
  color: var(--text);
  cursor: pointer;
  border-radius: 4px;
  transition: background 0.2s;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.segmented-control input[type="radio"]:checked + label {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}

/* Radio Group Fix */
.radio-group {
  display: flex;
  gap: 1rem;
  background: var(--input-bg);
  padding: 0.6rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  width: 100%;
  flex-wrap: wrap; /* Allows wrap if panel is narrow */
}

.radio-group label {
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.875rem;
}

.checkbox-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Preview Header & Zoom Toolbar */
.preview-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--card);
  padding: 0.6rem 1rem;
  border: 1px solid var(--border);
  border-bottom: none;
  border-top-left-radius: 8px;
  border-top-right-radius: 8px;
  font-size: 0.875rem;
  font-weight: 600;
}

.zoom-toolbar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.zoom-toolbar button {
  width: auto;
  padding: 0.35rem 0.6rem;
  background: var(--input-bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
}

.zoom-toolbar button:hover {
  background: var(--accent);
}

#zoomLevel {
  font-size: 0.75rem;
  color: #a1a1aa;
  min-width: 42px;
  text-align: center;
}

button {
  width: 100%;
  padding: 0.8rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-weight: 600;
  cursor: pointer;
}

button:disabled { background: #3f3f46; cursor: not-allowed; }
button:hover:not(:disabled) { opacity: 0.9; }

#status {
  margin-top: 1rem;
  text-align: center;
  font-size: 0.9rem;
  color: #a1a1aa;
}

.preview-container {
  margin-top: 0 !important;
  border-top-left-radius: 0 !important;
  border-top-right-radius: 0 !important;
  min-height: 450px;
  max-height: 650px;
  overflow: auto;
  position: relative;
  background: #09090b;
  border: 1px dashed var(--border);
}

canvas {
  max-width: none !important;
  height: auto;
  display: block;
  margin: 0 auto;
  transform-origin: center top;
  transition: transform 0.15s ease-out;
}

/* Responsive Fallback for Smaller Screens */
@media (max-width: 900px) {
  .workspace {
    grid-template-columns: 1fr;
  }
}