* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: #f7f8fa;
  color: #1a1a1a;
}
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: #fff;
  border-bottom: 1px solid #e3e6eb;
}
header h1 { font-size: 18px; margin: 0; }
.hdr-right { display: flex; gap: 12px; align-items: center; font-size: 14px; }
button {
  font: inherit;
  padding: 6px 12px;
  border: 1px solid #c3c6cb;
  background: #fff;
  border-radius: 4px;
  cursor: pointer;
}
button:hover { background: #f0f1f4; }
main { max-width: 1200px; margin: 0 auto; padding: 24px; }

#signin-pane, #error-pane { text-align: center; padding: 48px 0; }
#error-msg { color: #b00020; margin-bottom: 16px; }

.bubbles {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}
.bubble {
  background: #fff;
  border: 1px solid #e3e6eb;
  border-radius: 12px;
  padding: 20px;
  text-align: center;
}
.bubble-value { font-size: 28px; font-weight: 600; line-height: 1.2; }
.bubble-label { font-size: 12px; color: #5a6068; text-transform: uppercase; letter-spacing: 0.5px; margin-top: 4px; }

.charts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 32px;
}
.chart-card {
  background: #fff;
  border: 1px solid #e3e6eb;
  border-radius: 12px;
  padding: 16px;
}
.chart-card h2 { font-size: 14px; margin: 0 0 12px; color: #5a6068; }
.chart-card canvas { max-height: 240px; }

h2 { font-size: 14px; margin: 0 0 12px; color: #5a6068; text-transform: uppercase; letter-spacing: 0.5px; }

#leaderboard {
  width: 100%;
  background: #fff;
  border: 1px solid #e3e6eb;
  border-radius: 12px;
  border-collapse: separate;
  border-spacing: 0;
  overflow: hidden;
}
#leaderboard th, #leaderboard td {
  text-align: left;
  padding: 10px 16px;
  border-bottom: 1px solid #f0f1f4;
  font-size: 14px;
}
#leaderboard th {
  background: #fafbfc;
  font-weight: 600;
  color: #5a6068;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
#leaderboard tbody tr:last-child td { border-bottom: none; }

@media (max-width: 800px) {
  .bubbles { grid-template-columns: repeat(2, 1fr); }
  .charts { grid-template-columns: 1fr; }
}