/* Vùng biển */
.ocean-container {
    height: 220px;
    background: linear-gradient(180deg, #4fc3f7 0%, #0288d1 50%, #01579b 100%);
    box-shadow: inset 0 0 20px rgba(0,0,0,0.3);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
}

/* Vỏ sò ở trên cùng */
.clam-shell {
    font-size: 3.5rem;
    margin-top: 10px;
    z-index: 3;
    filter: drop-shadow(0 4px 4px rgba(0,0,0,0.4));
    transition: transform 0.3s;
}

/* Ngọc trai rơi */
.pearl {
    position: absolute;
    top: 50px;
    font-size: 2rem;
    z-index: 2;
    filter: drop-shadow(0 0 10px rgba(255,255,255,0.8));
    animation: drop-pearl 0.8s cubic-bezier(0.55, 0.085, 0.68, 0.53) forwards;
}

@keyframes drop-pearl {
    0% { top: 50px; opacity: 1; transform: scale(0.5); }
    100% { top: 160px; opacity: 0; transform: scale(1); }
}

/* Bạch tuộc ở dưới đáy */
.octopus {
    font-size: 4.5rem;
    margin-bottom: 5px;
    z-index: 3;
    filter: drop-shadow(0 -4px 4px rgba(0,0,0,0.4));
    transition: transform 0.3s;
}

/* Hiệu ứng nảy lên bắt ngọc */
.jump-catch { animation: jump-up 0.5s ease-out; }
@keyframes jump-up {
    0% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-30px) scale(1.1); }
    100% { transform: translateY(0) scale(1); }
}

/* Rung lắc khi trả lời sai */
.shake-error { animation: shake-octopus 0.4s; }
@keyframes shake-octopus {
    0% { transform: translateX(0); }
    25% { transform: translateX(-10px) rotate(-10deg); }
    50% { transform: translateX(10px) rotate(10deg); }
    75% { transform: translateX(-10px) rotate(-10deg); }
    100% { transform: translateX(0); }
}

/* Bong bóng nước trang trí */
.bubbles {
    position: absolute;
    width: 100%; height: 100%;
    z-index: 1;
    overflow: hidden;
}
.bubble {
    position: absolute;
    bottom: -20px;
    width: 15px; height: 15px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: rise 4s infinite ease-in;
}
.bubble:nth-child(1) { left: 20%; animation-duration: 3s; width: 10px; height: 10px; }
.bubble:nth-child(2) { left: 40%; animation-duration: 5s; width: 20px; height: 20px; animation-delay: 1s; }
.bubble:nth-child(3) { left: 60%; animation-duration: 4s; width: 15px; height: 15px; animation-delay: 2s; }
.bubble:nth-child(4) { left: 80%; animation-duration: 3.5s; width: 12px; height: 12px; animation-delay: 0.5s; }

@keyframes rise {
    0% { bottom: -20px; transform: translateX(0); opacity: 0; }
    50% { opacity: 1; }
    100% { bottom: 250px; transform: translateX(-20px); opacity: 0; }
}

.min-h-75 { min-height: 85px; }
.hl-num { color: #0288d1; font-weight: 900; font-size: 1.2em; }