* {
  box-sizing: border-box;
}
body {
  margin: 0;
  font-family: system-ui, sans-serif;
  background: #0f1419;
  color: #e7e9ea;
  min-height: 100vh;
}
.top {
  padding: 12px 16px;
  border-bottom: 1px solid #2f3336;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}
.top h1 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 600;
}
.tools {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}
.tools input[type='search'] {
  min-width: 200px;
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid #38444d;
  background: #15202b;
  color: inherit;
}
button {
  padding: 6px 12px;
  border-radius: 6px;
  border: 1px solid #38444d;
  background: #1d9bf0;
  color: #fff;
  cursor: pointer;
  font-size: 0.85rem;
}
button:hover {
  filter: brightness(1.08);
}
.layout {
  display: grid;
  grid-template-columns: minmax(240px, 320px) 1fr;
  height: calc(100vh - 56px);
}
.list-panel {
  border-right: 1px solid #2f3336;
  overflow: auto;
}
.lesson-list {
  padding: 8px;
}
.lesson-item {
  padding: 8px 10px;
  border-radius: 8px;
  cursor: pointer;
  margin-bottom: 4px;
  font-size: 0.9rem;
}
.lesson-item:hover {
  background: #1e2732;
}
.lesson-item.active {
  background: #063a52;
  outline: 1px solid #1d9bf0;
}
.lesson-item .id {
  opacity: 0.55;
  font-size: 0.75rem;
}
.editor-panel {
  overflow: auto;
  padding: 16px;
}
.empty {
  opacity: 0.5;
  padding: 24px;
}
.editor.hidden {
  display: none;
}
.meta h2 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}
.sub {
  margin: 4px 0;
  font-size: 0.85rem;
  color: #8b98a5;
}
.tabs {
  display: flex;
  gap: 4px;
  margin: 16px 0 8px;
}
.tab {
  background: #15202b;
  border: 1px solid #38444d;
  color: #e7e9ea;
}
.tab.active {
  background: #1e2732;
  border-color: #1d9bf0;
}
textarea {
  width: 100%;
  padding: 10px;
  border-radius: 8px;
  border: 1px solid #38444d;
  background: #15202b;
  color: #e7e9ea;
  font-family: ui-monospace, monospace;
  font-size: 0.85rem;
  resize: vertical;
}
.actions {
  margin-top: 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.actions input[type='text'] {
  flex: 1;
  min-width: 200px;
  padding: 6px 10px;
  border-radius: 6px;
  border: 1px solid #38444d;
  background: #15202b;
  color: inherit;
}
.panel.hidden {
  display: none;
}
#previewFrame {
  width: 100%;
  min-height: 420px;
  border: 1px solid #38444d;
  border-radius: 8px;
  background: #fff;
}
.deploy {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid #2f3336;
}
#lessonJson {
  font-family: ui-monospace, 'Cascadia Code', monospace;
  font-size: 13px;
  line-height: 1.45;
}
#deployOut {
  margin-top: 8px;
  padding: 10px;
  background: #15202b;
  border-radius: 8px;
  font-size: 0.8rem;
  max-height: 200px;
  overflow: auto;
  white-space: pre-wrap;
}
.op-log-wrap {
  margin-top: 16px;
  border-top: 1px solid #2f3336;
  padding-top: 10px;
}
.op-log-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 6px;
}
.op-log-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: #8b98a5;
}
.op-log-clear {
  font-size: 0.75rem;
  padding: 4px 10px;
}
#opLog.op-log {
  margin: 0;
  padding: 10px 12px;
  background: #0a0f14;
  border: 1px solid #2f3336;
  border-radius: 8px;
  font-family: ui-monospace, monospace;
  font-size: 11px;
  line-height: 1.45;
  max-height: 320px;
  overflow: auto;
  white-space: pre-wrap;
  word-break: break-word;
  color: #c8d0d8;
}