@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap');

body {
    font-family: 'Inter', sans-serif;
    background-color: #f9fafb;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
}

.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);
    }

.quiz-card {
    background: #ffffff;
    border-radius: 0.75rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    max-width: 700px;
    margin: auto;
    transition: transform 0.3s ease;
}

    .quiz-card:hover {
        transform: translateY(-5px);
    }

.progress-bar {
    height: 8px;
    background: #e5e7eb;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: #6366f1;
    transition: width 0.3s ease;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-bottom: 1rem;
}

.option {
    background: #f3f4f6;
    border-radius: 0.5rem;
    padding: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    overflow-wrap: break-word;
}

    .option:hover {
        background: #e5e7eb;
    }

    .option.correct {
        background: #dcfce7;
        border: 2px solid #22c55e;
    }

    .option.incorrect {
        background: #fee2e2;
        border: 2px solid #ef4444;
    }

.btn {
    border-radius: 0.5rem;
    padding: 0.75rem 1.5rem;
    transition: all 0.3s ease;
    color: white;
}

.btn-primary {
    background: #6366f1;
}

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

.btn-secondary {
    background: #6b7280;
}

    .btn-secondary:hover {
        background: #4b5563;
        transform: translateY(-2px);
    }

.btn:disabled {
    background: #d1d5db;
    cursor: not-allowed;
}

.result-item {
    border-radius: 0.5rem;
    padding: 1rem;
    margin-bottom: 0.75rem;
}

    .result-item.correct {
        background: #dcfce7;
    }

    .result-item.incorrect {
        background: #fee2e2;
    }

.ad-placeholder {
    background: linear-gradient(135deg, #e5e7eb, #d1d5db);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    color: #4b5563;
    transition: transform 0.3s ease;
    text-align: center;
    max-width: 100%;
    min-height: 200px;
    min-width: 300px;
    overflow: hidden;
    margin: 1.5rem auto;
}

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

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

footer a {
    color: #d1d5db;
    transition: color 0.3s ease;
}

    footer a:hover {
        color: #6366f1;
    }

@media (max-width: 640px) {
    .options-grid {
        grid-template-columns: 1fr;
    }

    .ad-placeholder {
        padding: 1rem;
        min-width: 100%;
    }
}