:root {
    --primary-blue: #2563eb;
    --dark-blue: #1e40af;
    --light-blue: #dbeafe;
    --success-green: #10b981;
    --warning-orange: #f59e0b;
    --text-dark: #1f2937;
    --text-light: #6b7280;
}

* {
    font-family: 'Inter', sans-serif;
}

body {
    line-height: 1.6;
    color: var(--text-dark);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-blue) !important;
}

.hero-section {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--dark-blue) 100%);
    color: white;
    padding: 100px 0;
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 2;
}

.btn-primary-custom {
    background-color: var(--success-green);
    border-color: var(--success-green);
    padding: 12px 30px;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-primary-custom:hover {
    background-color: #059669;
    border-color: #059669;
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.3);
}

.btn-outline-custom {
    border: 2px solid white;
    color: white;
    padding: 12px 30px;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-outline-custom:hover {
    background-color: white;
    color: var(--primary-blue);
    transform: translateY(-2px);
}

.feature-card {
    background: white;
    border-radius: 16px;
    padding: 40px 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: none;
    height: 100%;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    width: 70px;
    height: 70px;
    background: var(--light-blue);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 2rem;
    color: var(--primary-blue);
}

.quiz-preview {
    background: white;
    border-radius: 16px;
    padding: 40px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    margin: 60px 0;
}

.quiz-option {
    background: #f8fafc;
    color: var(--text-dark);
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    padding: 15px 20px;
    margin: 10px 0;
    cursor: pointer;
    transition: all 0.3s ease;
}

.quiz-option:hover {
    border-color: var(--primary-blue);
    background: var(--light-blue);
}

.quiz-option.selected {
    border-color: var(--primary-blue);
    background: var(--light-blue);
}

.quiz-option.correct {
    border-color: var(--success-green);
    background: #d1fae5;
    color: #065f46;
}

.quiz-option.incorrect {
    border-color: #ef4444;
    background: #fee2e2;
    color: #991b1b;
}

.stats-section {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    padding: 80px 0;
}

.stat-card {
    text-align: center;
    padding: 30px 20px;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-blue);
    display: block;
}

.stat-label {
    color: var(--text-light);
    font-weight: 500;
    margin-top: 10px;
}

.testimonial-card {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    margin: 20px 0;
}

.footer {
    background: var(--text-dark);
    color: white;
    padding: 60px 0 30px;
}

.footer-link {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-link:hover {
    color: white;
}

@media (max-width: 768px) {
    .hero-section {
        padding: 60px 0;
    }
    
    .hero-section h1 {
        font-size: 2.5rem;
    }
    
    .feature-card {
        margin-bottom: 30px;
    }
}