:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
}

.card {
    border: none;
    border-radius: 20px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1) !important;
}

.btn {
    border-radius: 12px;
    font-weight: 600;
    padding: 12px 24px;
    transition: all 0.3s ease;
}

.btn:hover {
    transform: translateY(-2px);
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
}

.exam-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

.question {
    margin-bottom: 20px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 15px;
    transition: all 0.3s ease;
}

.question:hover {
    background: #e9ecef;
    transform: scale(1.01);
}

.form-check-input:checked {
    background-color: #667eea;
    border-color: #667eea;
}

#timer {
    font-family: 'Courier New', monospace;
    font-weight: bold;
}

.question-nav {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 14px;
    font-weight: bold;
}

@media (max-width: 768px) {
    .exam-container .row > div {
        margin-bottom: 20px;
    }
    
    .question-nav {
        width: 35px;
        height: 35px;
        font-size: 12px;
    }
}

.sticky-top {
    position: sticky;
    top: 100px;
    z-index: 1020;
}

.badge {
    font-size: 0.75em;
}

.table-hover tbody tr:hover {
    background-color: rgba(0,123,255,.075);
}