/* 通用樣式 */
body {
    font-family: Arial, sans-serif;
    text-align: center;
    background: linear-gradient(135deg, #c2a282, #F3D6B3);
    background-size: 400% 400%;
    animation: gradientAnimation 10s ease infinite;
    margin: 0;
    padding: 20px;
    color: #fff;
}

/* 背景漸變動畫 */
@keyframes gradientAnimation {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* 遊戲標題與描述 */
h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.5); /* 強化字陰影 */
}
p {
    font-size: 1.2rem;
    margin-bottom: 20px;
    text-shadow: 2px 2px 5px rgba(0, 0, 0, 0.5); /* 強化字陰影 */
}

/* 進度條樣式 */
.progress-bar-container {
    width: 80%;
    height: 20px;
    background: #fff;
    border-radius: 10px;
    margin: 20px auto;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}
.progress-bar {
    height: 100%;
    width: 0;
    background: #8A8A8A; /* 進度條顏色 */
    animation: progressBarAnimation 0.5s linear forwards;
}

/* 遊戲版面 */
#gameBoard {
    display: grid;
    grid-gap: 15px;
    margin: 20px auto; /* 置中 */
    width: fit-content;
}


/* 卡片樣式 */
.card {
    width: 100px;
    height: 100px;
    background: #4E5D6C; /* 自然柔和的青灰色卡牌背景 */
    color: rgb(148, 148, 148);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    cursor: pointer;
    user-select: none;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    transform-style: preserve-3d;
    transition: transform 0.6s, box-shadow 0.3s ease;
    position: relative;
}
.card:hover {
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.4);
}
.card.flipped {
    transform: rotateY(180deg);
}
.card .card-front, .card .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
}
.card .card-front {
    background: #fff;
    color: #333;
    transform: rotateY(180deg);
}
.card .card-back {
    background: #4E5D6C;
    color: white;
    font-size: 2.5rem; /* 調整星星大小 */
}

.card img.card-image {
    width: 80%;
    height: 80%;
    object-fit: contain;
    pointer-events: none;
}
.card.matched {
    visibility: hidden;
}

/* 重新開始按鈕樣式 */
button {
    padding: 15px 30px;
    font-size: 1.5rem;
    background-color: #FF9F43;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s;
    margin-top: 20px;
}

button:hover {
    background-color: #FF7F24; /* 鼠標懸停效果 */
}

button:disabled {
    background-color: #D1D1D1;
    cursor: not-allowed;
}

/* 讓重新開始按鈕居中 */
button {
    display: block;
    margin: 20px auto;
}