* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 20px;
  font-family: system-ui, sans-serif;
  background: #f4f6f9;
}

h1 {
  text-align: center;
  margin-bottom: 20px;
}

.matrix {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  max-width: 1100px;
  margin: auto;
}

@media (max-width: 768px) {
  .matrix {
    grid-template-columns: 1fr;
  }
}

.quadrant {
  background: white;
  border-radius: 16px;
  padding: 14px;
  box-shadow: 0 6px 16px rgba(0,0,0,0.08);
  display: flex;
  flex-direction: column;
  min-height: 260px;
}

h2 {
  margin: 0 0 10px;
  font-size: 16px;
}

.task-list {
  flex: 1;
  padding: 4px;
  overflow-y: auto;
}

.card {
  background: #e9eef5;
  padding: 10px;
  border-radius: 10px;
  margin-bottom: 8px;
  cursor: grab;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.card:hover {
  transform: scale(1.02);
  box-shadow: 0 6px 14px rgba(0,0,0,0.12);
}

button {
  margin-top: 8px;
  padding: 8px;
  border: none;
  border-radius: 10px;
  background: #2563eb;
  color: white;
  cursor: pointer;
  font-weight: 600;
}