* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  height: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: #f6f8fa;
  color: #1f2328;
  display: flex;
  flex-direction: column;
  height: 100vh;
}

.topbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 16px;
  background: #ffffff;
  border-bottom: 1px solid #d0d7de;
}

.brand {
  font-weight: 600;
  font-size: 15px;
}

.actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.hint {
  font-size: 12px;
  color: #656d76;
}

#addBtn {
  border: 1px solid #2da44e;
  background: #2da44e;
  color: #fff;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
}

#addBtn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#columns {
  flex: 1 1 auto;
  display: flex;
  gap: 12px;
  padding: 12px;
  align-items: stretch;
  min-height: 0;
  overflow: auto;
}

.column {
  flex: 1 1 0;
  min-width: 0;
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid #d0d7de;
  border-radius: 8px;
  overflow: hidden;
}

.column-head {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 10px;
  background: #f6f8fa;
  border-bottom: 1px solid #eaeef2;
}

.col-title {
  font-size: 13px;
  font-weight: 600;
}

.col-del {
  border: none;
  background: transparent;
  color: #cf222e;
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  padding: 2px 6px;
  border-radius: 4px;
}

.col-del:hover {
  background: #ffebe9;
}

.col-del:disabled {
  color: #d0d7de;
  cursor: not-allowed;
  background: transparent;
}

.column .editor {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.ql-toolbar {
  flex: 0 0 auto;
  border: none !important;
  border-bottom: 1px solid #eaeef2 !important;
}

.ql-container {
  flex: 1 1 auto;
  min-height: 0;
  overflow: auto;
  font-size: 14px;
}

.col-foot {
  flex: 0 0 auto;
  padding: 5px 10px;
  font-size: 12px;
  color: #656d76;
  border-top: 1px solid #eaeef2;
  background: #f6f8fa;
}

@media (max-width: 800px) {
  #columns {
    flex-wrap: wrap;
  }
  .column {
    flex: 1 1 100%;
    min-height: 360px;
  }
}