:root {
  --bg-0: #0f1115;
  --bg-1: #151820;
  --bg-2: #1c2029;
  --bg-3: #242936;
  --border: #2a3040;
  --text: #e6e9ef;
  --text-dim: #8a92a6;
  --accent: #4f8cff;
  --accent-hover: #6fa0ff;
  --success: #4ade80;
  --warning: #fbbf24;
  --error: #f87171;
  --purple: #a78bfa;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg-0);
  color: var(--text);
  overflow: hidden;
}

body {
  display: flex;
  flex-direction: column;
}

/* ========= TOPBAR ========= */
.topbar {
  height: 52px;
  background: var(--bg-1);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 16px;
  gap: 24px;
  flex-shrink: 0;
}

.brand { display: flex; align-items: center; gap: 10px; }
.brand .logo {
  font-family: "Fira Code", "JetBrains Mono", monospace;
  font-weight: 700;
  color: var(--accent);
  font-size: 18px;
  padding: 4px 8px;
  background: var(--bg-3);
  border-radius: 6px;
}
.brand h1 { font-size: 16px; font-weight: 600; }

.modes { display: flex; gap: 4px; background: var(--bg-2); padding: 3px; border-radius: 8px; }
.mode-btn {
  background: transparent;
  border: none;
  color: var(--text-dim);
  padding: 6px 14px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.15s;
}
.mode-btn:hover { color: var(--text); }
.mode-btn.active { background: var(--accent); color: white; }

.level-selector { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--text-dim); }
#level-select {
  background: var(--bg-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
}

.run-controls { margin-left: auto; display: flex; gap: 6px; }

/* ========= BUTTONS ========= */
.btn {
  background: var(--bg-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 7px 14px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.15s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.btn:hover { background: var(--bg-3); border-color: #384056; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: white; }
.btn.primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn.primary.active { box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.25); }
.btn.ghost { background: transparent; border-color: transparent; color: var(--text-dim); }
.btn.ghost:hover { background: var(--bg-2); color: var(--text); }
.btn.small { padding: 4px 10px; font-size: 12px; }
.btn.small.active { background: var(--accent); border-color: var(--accent); color: white; }
.btn.small.active:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

/* Icona dels 3 eixos RGB dins del botó */
.axes-icon {
  position: relative;
  display: inline-block;
  width: 14px;
  height: 14px;
  margin-right: 2px;
}
.axes-icon span {
  position: absolute;
  left: 1px;
  top: 7px;
  width: 10px;
  height: 2px;
  border-radius: 1px;
  transform-origin: left center;
}
.axes-icon .axis-x { background: #ff3355; transform: rotate(0deg); }
.axes-icon .axis-y { background: #44dd55; transform: rotate(-90deg); }
.axes-icon .axis-z { background: #3388ff; transform: rotate(-35deg); }

.btn .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 6px var(--success);
  animation: pulse 1.5s infinite;
}
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }

/* ========= WORKSPACE ========= */
.workspace {
  flex: 1;
  display: grid;
  grid-template-columns: 280px 1fr 6px 1fr 260px;
  overflow: hidden;
  min-height: 0;
}

/* Mode sandbox */
body[data-mode="sandbox"] .workspace {
  grid-template-columns: 1.8fr 6px 1.3fr 200px;
}
body[data-mode="sandbox"] .lesson-panel {
  display: none;
}

/* API panel col·lapsat */
body[data-api="collapsed"] .workspace {
  grid-template-columns: 280px 1fr 6px 1fr 28px;
}
body[data-api="collapsed"][data-mode="sandbox"] .workspace {
  grid-template-columns: 1.8fr 6px 1.3fr 28px;
}

/* ========= RESIZERS ========= */
.resizer {
  background: var(--bg-1);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
  cursor: col-resize;
  position: relative;
  z-index: 10;
  transition: background 0.15s;
  user-select: none;
}
.resizer:hover,
.resizer.dragging {
  background: var(--accent);
}
.resizer::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 2px;
  height: 24px;
  background: var(--text-dim);
  border-radius: 1px;
  pointer-events: none;
  box-shadow: -3px 0 0 var(--text-dim), 3px 0 0 var(--text-dim);
}
.resizer:hover::after,
.resizer.dragging::after {
  background: white;
  box-shadow: -3px 0 0 white, 3px 0 0 white;
}

/* ========= LESSON PANEL ========= */
.lesson-panel {
  background: var(--bg-1);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.lesson-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.lesson-header h2 { font-size: 15px; font-weight: 600; }
.lesson-badge {
  background: var(--accent);
  color: white;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
}
.lesson-body {
  flex: 1;
  padding: 16px;
  overflow-y: auto;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-dim);
}
.lesson-body h3 { color: var(--text); font-size: 14px; margin: 12px 0 6px; }
.lesson-body h3:first-child { margin-top: 0; }
.lesson-body p { margin-bottom: 10px; }
.lesson-body code {
  background: var(--bg-3);
  color: var(--accent);
  padding: 1px 6px;
  border-radius: 4px;
  font-family: "Fira Code", "JetBrains Mono", monospace;
  font-size: 12px;
}
.lesson-body ul { margin-left: 20px; margin-bottom: 10px; }
.lesson-body li { margin-bottom: 4px; }
.lesson-body .challenge {
  background: var(--bg-2);
  border-left: 3px solid var(--purple);
  padding: 10px 12px;
  margin: 12px 0;
  border-radius: 4px;
}
.lesson-actions {
  padding: 12px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  gap: 8px;
}
.lesson-actions .btn { flex: 1; justify-content: center; }

/* ========= EDITOR PANEL ========= */
.editor-panel {
  background: var(--bg-0);
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border);
  overflow: hidden;
}
.panel-header {
  height: 36px;
  background: var(--bg-1);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  flex-shrink: 0;
}
.panel-title { font-size: 12px; font-weight: 600; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.5px; }
.panel-actions { display: flex; gap: 4px; }

#editor {
  flex: 1;
  min-height: 0;
  background: var(--bg-0);
}

.console {
  height: 140px;
  background: var(--bg-1);
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
}
.console-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 12px;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 600;
}
.console-output {
  flex: 1;
  overflow-y: auto;
  padding: 8px 12px;
  font-family: "Fira Code", "JetBrains Mono", monospace;
  font-size: 12px;
  line-height: 1.5;
}
.console-output .log-info { color: var(--text-dim); }
.console-output .log-success { color: var(--success); }
.console-output .log-warning { color: var(--warning); }
.console-output .log-error { color: var(--error); }
.console-output .log-line { margin-bottom: 3px; white-space: pre-wrap; word-break: break-word; }
.console-output .log-timestamp { color: var(--bg-3); margin-right: 8px; }

/* ========= RENDER PANEL ========= */
.render-panel {
  background: #000;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
#canvas-wrapper {
  flex: 1;
  position: relative;
  min-height: 0;
  overflow: hidden;
}
#render-canvas {
  display: block;
  width: 100%;
  height: 100%;
}
.fps-counter {
  position: absolute;
  top: 10px;
  right: 10px;
  background: rgba(0, 0, 0, 0.6);
  color: var(--success);
  padding: 4px 10px;
  border-radius: 4px;
  font-family: "Fira Code", monospace;
  font-size: 11px;
  pointer-events: none;
}

/* ========= API PANEL ========= */
.api-panel {
  background: var(--bg-1);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: row;
  overflow: hidden;
  position: relative;
}

/* Botó de col·lapsar — franja vertical a l'esquerra */
.api-collapse-btn {
  flex-shrink: 0;
  width: 28px;
  height: 100%;
  background: var(--bg-2);
  border: none;
  border-right: 1px solid var(--border);
  color: var(--text-dim);
  cursor: pointer;
  font-size: 11px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s;
  writing-mode: horizontal-tb;
}
.api-collapse-btn:hover { background: var(--bg-3); color: var(--text); }

/* Contingut del panell */
.api-panel-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  min-width: 0;
}

.api-panel .panel-header {
  flex-direction: column;
  align-items: stretch;
  height: auto;
  padding: 10px 12px;
  gap: 8px;
}
.api-panel .panel-header .panel-title { padding-bottom: 4px; }

/* Quan el panell està col·lapsat: amagar el contingut */
body[data-api="collapsed"] .api-panel-content {
  display: none;
}
body[data-api="collapsed"] .api-collapse-btn {
  border-right: none;
}

#api-search {
  background: var(--bg-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 12px;
  width: 100%;
  outline: none;
}
#api-search:focus { border-color: var(--accent); }
.api-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}
/* Acordió: capçalera de categoria */
.api-category {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-dim);
  font-weight: 600;
  padding: 8px 8px 8px 6px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  user-select: none;
  border-radius: 4px;
  transition: background 0.1s, color 0.1s;
  margin-top: 2px;
}
.api-category:hover { background: var(--bg-2); color: var(--text); }
.api-category.open { color: var(--text); }
.api-category .api-chevron {
  font-size: 10px;
  transition: transform 0.2s;
  display: inline-block;
}
.api-category.open .api-chevron { transform: rotate(90deg); }

/* Contenidor col·lapsable dels items */
.api-category-items {
  overflow: hidden;
  max-height: 0;
  transition: max-height 0.25s ease;
}
.api-category-items.open { max-height: 1000px; }

.api-item {
  padding: 6px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-family: "Fira Code", monospace;
  font-size: 12px;
  color: var(--text);
  transition: background 0.1s;
  margin-bottom: 2px;
}
.api-item:hover { background: var(--bg-2); }
.api-item .api-name { color: var(--accent); }
.api-item .api-signature { color: var(--text-dim); font-size: 11px; margin-top: 2px; }
.api-item .api-desc { color: var(--text-dim); font-size: 11px; margin-top: 3px; font-family: inherit; }

/* ========= POPUP ========= */
.popup {
  position: fixed;
  top: 100px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5);
  width: 400px;
  max-height: 500px;
  z-index: 100;
  display: flex;
  flex-direction: column;
}
.popup.hidden { display: none; }
.popup-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
}
.snippets-list {
  overflow-y: auto;
  padding: 8px;
}
.snippet-item {
  padding: 10px 12px;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.1s;
  margin-bottom: 4px;
}
.snippet-item:hover { background: var(--bg-3); }
.snippet-item .snippet-name { font-weight: 600; color: var(--text); font-size: 13px; }
.snippet-item .snippet-desc { color: var(--text-dim); font-size: 12px; margin-top: 3px; }

/* ========= RESPONSIVE ========= */
@media (max-width: 1200px) {
  .workspace { grid-template-columns: 240px 1fr 6px 1fr 220px; }
  body[data-mode="sandbox"] .workspace { grid-template-columns: 1.6fr 6px 1.2fr 180px; }
}
@media (max-width: 900px) {
  .workspace { grid-template-columns: 1fr 1fr; grid-template-rows: auto auto; }
  .lesson-panel, .api-panel { grid-column: 1 / -1; max-height: 200px; }
  .resizer { display: none; }
  body[data-mode="sandbox"] .workspace { grid-template-columns: 1fr 1fr; }
}