/* 全局重置：确保全屏无滚动条溢出，卡片区域完整展示 */
* {
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    box-sizing: border-box;
}
html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;  /* 防止整体页面滚动，所有内容都在视口内 */
}

body {
    background: url('../assets/images/background.svg') no-repeat center center fixed;
    background-size: cover;
    image-rendering: crisp-edges; /* 优化SVG渲染清晰度 */
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 游戏盘面网格布局 - 卡片宽度自适应且完整展示，不滚动 */
.board {
    display: grid;
    grid-template-columns: repeat(4, minmax(70px, 90px)); /* 固定宽度范围，确保卡片大小适中 */
    gap: 12px;
    justify-content: center;
    align-items: center;
    margin: 0 auto;
}

/* 卡片3D核心样式 */
.card {
    aspect-ratio: 3 / 4;
    width: 100%;
    perspective: 1000px;
    cursor: pointer;
}

.card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 0.55s cubic-bezier(0.23, 1, 0.32, 1);
    border-radius: 16px;
    box-shadow: 0 12px 18px -8px rgba(0, 0, 0, 0.4);
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.2rem;
    font-weight: bold;
    box-sizing: border-box;
}

/* 背面花纹 */
.card-back {
    background: repeating-linear-gradient(45deg, #2b2d42, #2b2d42 12px, #1e1f2c 12px, #1e1f2c 24px);
    border: 1px solid #ffffff; 
    transform: rotateY(0deg);
    box-shadow: inset 0 0 0 1px #ffffff;
}
.card-back::after {
    content: "?";
    font-size: 2.5rem;
    font-weight: bold;
    color: #ffd966;
    text-shadow: 2px 2px 0 #b45309;
    opacity: 0.9;
}

/* 正面水果图案 */
.card-front {
    background: linear-gradient(145deg, #fff9e8, #ffefcf);
    transform: rotateY(180deg);
    border: 1px solid #ffffff;
    color: #c2410c;
    font-family: 'Apple Color Emoji', 'Segoe UI Emoji', 'Noto Color Emoji', sans-serif;
    box-shadow: inset 0 0 0 1px #ffffff, 0 4px 10px rgba(0,0,0,0.2);
}

/* 翻转状态 */
.card.flipped .card-inner {
    transform: rotateY(180deg);
}

/* 配对成功 → 透明消除 (完全不可见但占位，保留网格) */
.card.eliminated {
    cursor: default;
    pointer-events: none;
}
.card.eliminated .card-inner {
    opacity: 0;
    transform: rotateY(0deg);
    transition: opacity 0.25s ease;
    box-shadow: none;
}
.card.eliminated .card-front,
.card.eliminated .card-back {
    display: none;
}

/* 排行榜滚动条 */
.rank-scroll::-webkit-scrollbar {
    width: 5px;
}
.rank-scroll::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}
.rank-scroll::-webkit-scrollbar-thumb {
    background: #f59e0b;
    border-radius: 10px;
}

/* 响应式: 小屏幕进一步缩小卡片和间隙 */
@media (max-width: 550px) {
    .board {
        gap: 8px;
        grid-template-columns: repeat(4, minmax(60px, 75px));
    }
    .card-front, .card-back {
        font-size: 1.6rem;
    }
    .card-back::after {
        font-size: 2rem;
    }
}
@media (max-width: 420px) {
    .board {
        gap: 6px;
        grid-template-columns: repeat(4, minmax(55px, 68px));
    }
    .card-front, .card-back {
        font-size: 1.4rem;
    }
    .card-back::after {
        font-size: 1.6rem;
    }
}

/* 确保游戏界面内部紧凑，卡片区域不滚动且完整显示 */
.game-inner {
    display: flex;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
    backdrop-filter: blur(10px);    /*毛玻璃效果*/
}
.card-area {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 0;  /* flex限制溢出 */
    padding: 8px 0;
}

/* 音量滑条：更清晰的可用性 */
.volume-range {
    accent-color: #4f46e5; /* indigo-600 */
}