/* --- Base and Font Styles --- */
body {
    font-family: 'Inter', sans-serif;
    background-color: #f1f5f9; 
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 1rem;
    margin: 0;
}

/* --- Main Layout Containers --- */
.quiz-container {
    background-color: white;
    width: 100%;
    max-width: 42rem; 
    border-radius: 1rem; 
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05); /* shadow-lg */
    padding: 1.5rem;
    transition: all 0.3s ease-in-out;
}

@media (min-width: 768px) {
    .quiz-container {
        padding: 2rem;
    }
}

.score-section.hidden,
#question-section.hidden {
    display: none;
}

.score-section {
    text-align: center;
}

/* --- Typography and Text Elements --- */
.main-title {
    font-size: 1.5rem; 
    line-height: 2rem;
    font-weight: 700; 
    color: #1e293b; 
    margin-bottom: 0.5rem;
}

@media (min-width: 768px) {
    .main-title {
        font-size: 1.875rem; 
        line-height: 2.25rem;
    }
}

.title-underline {
    height: 4px;
    background-color: #6366f1; 
    border-radius: 9999px; 
    width: 25%;
    margin-bottom: 1.5rem;
}

.question-text {
    font-size: 1.25rem; 
    line-height: 1.75rem;
    font-weight: 600; 
    color: #334155; 
    margin-bottom: 1.5rem;
    min-height: 80px;
}

@media (min-width: 768px) {
    .question-text {
        font-size: 1.5rem; 
        line-height: 2rem;
    }
}

.progress-text {
    font-size: 0.875rem; 
    line-height: 1.25rem;
    font-weight: 500; 
    color: #64748b; 
}

.score-text {
    font-size: 1.5rem; 
    line-height: 2rem;
    font-weight: 700;
    color: #1e293b; 
    margin-bottom: 1rem;
}

@media (min-width: 768px) {
    .score-text {
        font-size: 1.875rem; 
        line-height: 2.25rem;
    }
}

.score-feedback {
    font-size: 1.125rem; 
    line-height: 1.75rem;
    color: #475569; 
    margin-bottom: 1.5rem;
}

/* --- Buttons and Interactive Elements --- */
.answer-buttons-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

@media (min-width: 768px) {
    .answer-buttons-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.answer-btn {
    width: 100%;
    padding: 1rem;
    border: 2px solid #cbd5e1; 
    border-radius: 0.5rem; 
    text-align: left;
    color: #334155; 
    font-weight: 500; 
    background-color: white;
    cursor: pointer;
    transition: background-color 0.2s, border-color 0.2s, transform 0.1s;
}

.answer-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    background-color: #f1f5f9; 
    border-color: #818cf8; 
}

.answer-btn.correct {
    background-color: #22c55e !important;
    color: white !important;
    border-color: #16a34a !important;
}

.answer-btn.incorrect {
    background-color: #ef4444 !important;
    color: white !important;
    border-color: #dc2626 !important;
}

.controls-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 2rem;
}

.next-btn, .restart-btn {
    color: white;
    font-weight: 700;
    padding: 0.5rem 1.5rem;
    border-radius: 0.5rem; 
    background-color: #6366f1; 
    border: none;
    cursor: pointer;
}

.restart-btn {
    padding: 0.75rem 2rem;
}

.next-btn:hover, .restart-btn:hover {
    background-color: #4f46e5; 
}

.next-btn:focus, .restart-btn:focus {
    outline: 2px solid transparent;
    outline-offset: 2px;
    box-shadow: 0 0 0 2px #a5b4fc; 
}

.next-btn:disabled {
    background-color: #e2e8f0; 
    cursor: not-allowed;
}