:root {
    --primary: #4e73df;
    --secondary: #858796;
    --success: #1cc88a;
    --dark: #2e2e2e;
}
body {
    background-color: #f8f9fc;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
.card {
    border: none;
    border-radius: 15px;
    box-shadow: 0 0.15rem 1.75rem 0 rgba(58, 59, 69, 0.15);
    transition: transform 0.2s;
}
.card:hover {
    transform: translateY(-3px);
}
.navbar {
    background: linear-gradient(90deg, var(--primary) 0%, #224abe 100%);
}
.stat-card {
    border-left: 4px solid var(--primary);
}
.quiz-timer {
    position: fixed;
    top: 70px;
    right: 20px;
    z-index: 1000;
    background: #fff;
    padding: 10px 20px;
    border-radius: 50px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    font-weight: bold;
    color: #e74a3b;
}