.sb-exam {
            max-width: 640px;
            margin: 2rem auto;
            font-family: system-ui, sans-serif;
        }
        .sb-question {
            display: none;
            border: 1px solid #ddd;
            border-radius: 12px;
            padding: 1.5rem;
            box-shadow: 0 4px 10px rgba(0,0,0,0.05);
            margin-bottom: 1rem;
        }
        .sb-question-text {
            margin-bottom: 1rem;
            font-size: 1.05rem;
        }
        .sb-choices {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
            margin-bottom: 0.75rem;
        }
        .sb-choice {
            text-align: left;
            cursor: pointer;
            padding: 0.5rem 0.75rem;
            border-radius: 8px;
            border: 1px solid #ccc;
            background: #f7f7f7;
        }
        .sb-choice:hover {
            background: #eee;
        }
        .sb-choice.correct {
            border-color: #3c9a4b;
            background: #e4f6e7;
        }
        .sb-choice.incorrect {
            border-color: #c0392b;
            background: #f9e0de;
        }
        .sb-feedback {
            min-height: 1.2rem;
            font-size: 0.95rem;
        }
        .sb-feedback.ok {
            color: #2e7d32;
        }
        .sb-feedback.error {
            color: #c62828;
        }
        .sb-exam-controls {
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 0.75rem;
        }
        .sb-exam-progress {
            font-size: 0.9rem;
            opacity: 0.8;
        }
        .sb-exam-next {
            cursor: pointer;
            padding: 0.5rem 1rem;
            border-radius: 999px;
            border: 1px solid #ccc;
            background: #f7f7f7;
        }
        .sb-exam-next:disabled {
            opacity: 0.4;
            cursor: default;
        }
        .sb-exam-result {
            margin-top: 1rem;
            padding: 1rem;
            border-radius: 12px;
            background: #f1f1f1;
            text-align: center;
        }
        .sb-question-id {
            margin: 0 0 0.25rem;
            font-size: 0.8rem;
            opacity: 0.6;
        }