/* --- BỐ CỤC ĐẢO GIẤU VÀNG --- */
.island-arena {
    height: 220px;
    background: linear-gradient(180deg, #4fc3f7 0%, #0288d1 50%, #fff59d 50%, #fbc02d 100%);
    box-shadow: inset 0 0 20px rgba(0,0,0,0.4);
    position: relative; 
    overflow: hidden;
}

/* Biển lượn sóng */
.beach-bg {
    position: absolute;
    top: 35%; left: 0;
    width: 200%; height: 30px;
    background-image: radial-gradient(circle at 40px 10px, rgba(255,255,255,0.4) 20px, transparent 21px);
    background-repeat: repeat;
    animation: wave-beach 6s linear infinite;
    z-index: 1;
}
@keyframes wave-beach {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

/* Rương kho báu */
.treasure-chest {
    position: absolute;
    top: 55%; left: 50%;
    transform: translate(-50%, -50%);
    font-size: 4.5rem;
    z-index: 2;
    filter: drop-shadow(0 10px 5px rgba(0,0,0,0.3));
    transition: all 0.3s ease;
}

/* Hiệu ứng khi trả lời đúng (Mở rương) */
.glow-success {
    animation: pulse-glow 1s ease-out forwards;
    transform: translate(-50%, -60%) scale(1.2);
}
@keyframes pulse-glow {
    0% { filter: drop-shadow(0 0 10px #ffeb3b) brightness(1); }
    50% { filter: drop-shadow(0 0 40px #ffeb3b) brightness(1.5); }
    100% { filter: drop-shadow(0 10px 10px rgba(0,0,0,0.4)) brightness(1); }
}

/* Nhân vật Thám hiểm */
.explorer-char {
    position: absolute;
    bottom: 30px;
    left: 15%;
    font-size: 4rem;
    z-index: 5;
    filter: drop-shadow(3px 5px 4px rgba(0,0,0,0.4));
}

/* Nhảy mừng */
.happy-jump {
    animation: build-jump 0.8s ease-out forwards !important;
}
@keyframes build-jump {
    0% { transform: translateY(0); }
    50% { transform: translateY(-40px) scale(1.1); }
    100% { transform: translateY(0); }
}

/* Rung lắc khi sai */
.shake-error { animation: shake-char 0.4s !important; }
@keyframes shake-char {
    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); }
}

.min-h-75 { min-height: 85px; }