body {
    font-family: 'Inter', sans-serif;
    background-color: #f9fafb;
}

.navbar {
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
}

    .navbar.scrolled {
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    }

.ad-placeholder {
    background: linear-gradient(135deg, #e5e7eb, #d1d5db);
    border: none;
    border-radius: 0.75rem;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    color: #4b5563;
    transition: transform 0.3s ease;
    max-width: 100%;
}

    .ad-placeholder:hover {
        transform: translateY(-5px);
    }

    .ad-placeholder ins {
        width: 100% !important;
        max-height: 280px;
    }

.btn-primary {
    background: #6366f1;
    border: none;
    transition: all 0.3s ease;
}

    .btn-primary:hover {
        background: #4f46e5;
        transform: translateY(-2px);
        box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
    }

.btn-reset {
    background: #6b7280;
    border: none;
    transition: all 0.3s ease;
}

    .btn-reset:hover {
        background: #4b5563;
        transform: translateY(-2px);
        box-shadow: 0 4px 12px rgba(107, 114, 128, 0.4);
    }

.correct-answer {
    color: #10b981;
    font-weight: 600;
}

.incorrect-answer {
    color: #ef4444;
    font-weight: 600;
}

.answer-label.correct {
    background: #ecfdf5;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
}

.answer-label.incorrect {
    background: #fef2f2;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
}

.incorrect-answer-text {
    color: #ef4444;
    font-weight: 600;
    margin-top: 0.5rem;
}

.score-display {
    margin-top: 1rem;
    padding: 0.75rem;
    background: #f9fafb;
    border-radius: 0.5rem;
    text-align: center;
    font-weight: 600;
    color: #4b5563;
}

.timer {
    font-size: 1.5rem;
    font-weight: 600;
    color: #4b5563;
    text-align: center;
    padding: 1rem;
    background: #ffffff;
    border-radius: 0.5rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

@media (max-width: 1023px) {
    .exercises-section {
        position: static;
        max-height: none;
        overflow-y: visible;
        padding: 0 1rem;
    }
}
.breadcrumb {
    background: #ffffff;
    border-radius: 0.5rem;
    padding: 1rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

    .breadcrumb a {
        color: #6366f1;
        text-decoration: none;
    }

        .breadcrumb a:hover {
            text-decoration: underline;
        }

    .breadcrumb span {
        color: #4b5563;
    }