:root {
  --cell-size: 20px;
  --gap: 4px;
  --color-scale-0: #ebedf0;
  --color-scale-1: #9be9a8;
  --color-scale-2: #40c463;
  --color-scale-3: #30a14e;
  --color-scale-4: #216e39;
}

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

body {
  font-family: 'Inter', sans-serif;
  background: #f6f8fa;
  color: #1f2328;
  padding: 2rem;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

h1 {
  margin-bottom: 2rem;
  text-align: center;
}

.calendar-grid {
  display: grid;
  grid-template-columns: repeat(26, var(--cell-size));
  grid-auto-rows: var(--cell-size);
  gap: var(--gap);
  margin-bottom: 2rem;
}

.day-cell {
  background: var(--color-scale-0);
  border-radius: 3px;
  cursor: pointer;
  transition: transform 0.1s ease;
}

.day-cell:hover {
  transform: scale(1.1);
  z-index: 1;
}

.contributions-container {
  border: 1px solid #e1e4e8;
  border-radius: 6px;
  padding: 1rem;
  background: white;
}

.contribution-item {
  padding: 1rem;
  border-bottom: 1px solid #eaecef;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.contribution-item:last-child {
  border-bottom: none;
}

.contribution-type {
  width: 80px;
  font-weight: 600;
  text-transform: capitalize;
}

.contribution-date {
  color: #656d76;
  font-size: 0.9em;
}

.loading {
  text-align: center;
  padding: 2rem;
  color: #656d76;
}

.tooltip {
  position: absolute;
  background: rgba(0,0,0,0.8);
  color: white;
  padding: 8px;
  border-radius: 4px;
  font-size: 12px;
  pointer-events: none;
  white-space: nowrap;
}