style.css

```css
/* Base Styles */
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
  background: linear-gradient(135deg, #1a1a2e, #16213e);
  color: #fff;
  min-height: 100vh;
}

.dashboard {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

/* Header Styles */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  padding-bottom: 15px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

header h1 {
  margin: 0;
  font-size: 28px;
}

nav a {
  color: #fff;
  text-decoration: none;
  margin-left: 20px;
  font-size: 16px;
  opacity: 0.7;
  transition: opacity 0.3s;
}

nav a:hover {
  opacity: 1;
}

nav a.active {
  opacity: 1;
  font-weight: bold;
}

/* Stat Cards */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.stat-card {
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.stat-label {
  font-size: 14px;
  opacity: 0.7;
  margin-bottom: 5px;
}

.stat-value {
  font-size: 24px;
  font-weight: bold;
  margin-bottom: 5px;
}

.stat-change {
  font-size: 12px;
}

.positive {
  color: #4ade80;
}

.negative {
  color: #f87171;
}

/* Content Sections */
.content-section {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 30px;
}

.content-section h2 {
  margin-top: 0;
  font-size: 20px;
  margin-bottom: 15px;
}

/* Tables */
.picks-table {
  width: 100%;
  border-collapse: collapse;
}

.picks-table th {
  text-align: left;
  padding: 10px;
  font-size: 14px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.picks-table td {
  padding: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.win {
  color: #4ade80;
}

.loss {
  color: #f87171;
}

/* Chart Container */
#performanceChart {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  padding: 20px;
}

/* Responsive Design */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  nav {
    margin-top: 15px;
  }
  
  nav a {
    margin-left: 0;
    margin-right: 15px;
  }
}
```