body {
    background-color: #121212;
    color: #e0e0e0;
    font-family: 'Noto Sans Bengali', sans-serif;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px 10px;
    box-sizing: border-box;
}

.quiz-container {
    background-color: #1e1e1e;
    border-radius: 15px;
    padding: 25px;
    width: 100%;
    max-width: 600px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    margin-bottom: 20px;
}

.quiz-header {
    text-align: center;
    margin-bottom: 20px;
}

.quiz-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: #4CAF50;
    margin: 0;
}

.quiz-header .subtitle {
    font-size: 0.9rem;
    color: #b0b0b0;
}

.progress-container {
    width: 100%;
    background-color: #333;
    border-radius: 5px;
    margin-bottom: 10px;
}

.progress-bar {
    height: 8px;
    width: 0%;
    background-color: #4CAF50;
    border-radius: 5px;
    transition: width 0.4s ease;
}

.question-counter {
    text-align: center;
    margin-bottom: 20px;
    color: #aaa;
    background-color: #2a2a2a;
    padding: 8px;
    border-radius: 8px;
}

#question {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 25px;
    text-align: center;
    line-height: 1.6;
}

.btn-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.btn {
    background-color: #333;
    color: #e0e0e0;
    border: 1px solid #555;
    border-radius: 8px;
    padding: 15px;
    text-align: left;
    font-size: 1rem;
    font-family: 'Noto Sans Bengali', sans-serif;
    cursor: pointer;
    transition: background-color 0.2s, border-color 0.2s, transform 0.1s;
}

.btn:hover:not(:disabled) {
    background-color: #444;
    border-color: #777;
}

/* This is the highlight style for the selected answer */
.btn.selected {
    background-color: #4CAF50;
    border-color: #66bb6a;
    color: white;
    transform: scale(1.02);
    font-weight: bold;
}

.btn:disabled {
    cursor: not-allowed;
    opacity: 0.8;
}

.quiz-footer {
    display: flex;
    justify-content: flex-end;
    margin-top: 25px;
}

#next-btn, #restart-btn {
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 12px 30px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.2s;
}

#next-btn:disabled {
    background-color: #555;
    cursor: not-allowed;
}

#next-btn:hover:not(:disabled), #restart-btn:hover {
    background-color: #45a049;
}

.result-container { text-align: center; }
.result-container h3 { font-size: 1.5rem; }
.result-container .score {
    font-size: 2.8rem;
    font-weight: bold;
    color: #4CAF50;
    margin: 15px 0;
}
.result-container .comment { font-size: 1.1rem; color: #ccc; line-height: 1.7; }

.main-footer { text-align: center; color: #888; font-size: 0.9rem; padding: 10px; }
.main-footer a { color: #4CAF50; text-decoration: none; }
.main-footer a:hover { text-decoration: underline; }