@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800;900&display=swap');

body { font-family: 'Plus Jakarta Sans', sans-serif; }

/* Nút bấm trắc nghiệm 3D - Bấm lún cực đã */
.option-btn {
    background-color: #ffffff;
    border: 2px solid #e2e8f0;
    box-shadow: 0 4px 0 0 #cbd5e1;
    transition: all 0.08s ease;
}
.option-btn:hover:not(:disabled) {
    border-color: #3b82f6;
    background-color: #f8fafc;
}
.option-btn:active:not(:disabled) {
    transform: translateY(4px);
    box-shadow: 0 0 0 0 #cbd5e1;
}

/* Khi đã chọn đúng */
.opt-correct {
    background-color: #ecfdf5 !important;
    border-color: #10b981 !important;
    box-shadow: 0 2px 0 0 #059669 !important;
    color: #065f46 !important;
}
/* Khi chọn sai */
.opt-wrong {
    background-color: #fff1f2 !important;
    border-color: #f43f5e !important;
    box-shadow: 0 2px 0 0 #e11d48 !important;
    color: #9f1239 !important;
}

/* Các viên gạch xếp từ Kéo Thả */
.drag-item {
    cursor: grab; touch-action: none;
    box-shadow: 0 3px 0 0 #cbd5e1;
    transition: transform 0.05s;
}
.drag-item:active { cursor: grabbing; transform: scale(1.05); }
.sortable-ghost { opacity: 0.3; background: #e2e8f0; border: 2px dashed #64748b; }