:root{
    --text-dark: #747474;
    --text-light: #FFFFFF;
    --cell-shadow: 0px 0px 1px #0000001a;

    --bg-color: #f1f1f1;
    --h1-color: #747474;;
    --border-bg: #bababa;
    --cell-bg: #d6d6d6;
    --msg-text: #707070;
    --msg-bg: rgba(231, 231, 231, 0.74);
}

[data-theme="dark"] {
    --bg-color: #3c3c3c;
    --h1-color: #d2d2d2;
    --border-bg: #626262;
    --cell-bg: #585858;
    --msg-text: #d2d2d2;
    --msg-bg: rgba(60, 60, 60, 0.74);
}

#theme-toggle {
    background: none;
    border: none;
    color: var(--h1-color);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background-color 0.3s ease;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#theme-icon {
    width: 100%;
    height: 100%;
}

#theme-icon svg {
    fill: currentColor;
}

[data-theme="dark"] #theme-icon svg {
    fill: currentColor;
}

#theme-toggle:hover {
    background-color: rgba(0, 0, 0, 0.1);
}

html, body{
    font-family: "Microsoft YaHei";
    background-color: var(--bg-color);
}

* {
    margin: 0;
    padding: 0;
}

h1 {
    color: var(--h1-color);
    font-size: 52px;
}

body{
    display: flex;
    justify-content: center;
    align-items: center;
}

#game-box{
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 450px;
    margin-top: 50px;
}

#game-border{
    position: relative;
    background-color: var(--border-bg);
    border-radius: 5px;
}

#game {
    position: relative;
    display: flex;
    flex-direction: column;
    width: 450px;
    height: 450px;
}

#game>div{
    display: flex;
    margin: 10px 0 0 10px;
}

#game b, #game i{
    margin-right: 10px;
    width: 100px;
    height: 100px;
    border-radius: 3px;
}

#game b{
    background-color: var(--cell-bg);
}

#game i{
    box-sizing: border-box;
    z-index: 5;
    position: absolute;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    font-size: 30px;
    font-style: normal;
    font-weight: bold;
}

#game-top{
    position: relative;
    font-size: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    height: 100px;
}

#game-footer{
    margin-top: 30px;
    display: flex;
    flex-direction: column;
    width: 100%;
    color: rgb(168, 168, 168);
    font-size: 14px;
    font-weight: bold;
}

#game-footer>div{
    margin: 4px 0;
}

#game-footer a{
    margin: 0 2px 0 0;
    color: rgb(168, 168, 168);
    text-decoration: none;
}

#game-top-info{
    display: flex;
    justify-content: flex-end;
    width: 280px;
    color: var(--text-dark);
    font-weight: bold;
}

#best-score-box{
    position: absolute;
    font-weight: bold;
    color: #b5b5b5;
    top: 0px;
    left: 250px;
}

#score-box {
    box-sizing: border-box;
    display: inline-block;
    padding-left: 10px;
    width: 115px;
    height: 36px;
    line-height: 36px;
    background-color: #d1d1d1;
    border-radius: 3px;
    white-space: nowrap;
}

#bt{
    margin: 0 5px 0 12px;
    color: var(--text-dark);
    font-size: 16px;
    border: none;
    outline: none;
    box-shadow: none;
    width: 80px;
    height: 36px;
    font-weight: bold;
    background-color: #d1d1d1;
    border-radius: 3px;
    cursor: pointer;
}

#bt:hover{
    background-color: #bababa;
}

#bt:active{
    background-color: #a0a0a0;
}

.cell-2 {
    color: var(--text-dark);
    background-color: #FFFFFF;
    box-shadow: var(--cell-shadow);
}
.cell-4 {
    color: var(--text-dark);
    background-color: #d9ffe1;
    box-shadow: var(--cell-shadow);
}
.cell-8 {
    color: var(--text-dark);
    background-color: #7CB802;
    box-shadow: var(--cell-shadow);
}
.cell-16 {
    color: var(--text-light);
    background-color: #009A2B;
    box-shadow: var(--cell-shadow);
}
.cell-32 {
    color: var(--text-dark);
    background-color: #F9E477;
    box-shadow: var(--cell-shadow);
}
.cell-64 {
    color: var(--text-light);
    background-color: #D5BB79;
    box-shadow: var(--cell-shadow);
}
.cell-128 {
    color: var(--text-dark);
    background-color: #FFB800;
    box-shadow: var(--cell-shadow);
}
.cell-256 {
    color: var(--text-light);
    background-color: #EEC906;
    box-shadow: var(--cell-shadow);
}
.cell-512 {
    color: var(--text-dark);
    background-color: #AADBFF;
    box-shadow: var(--cell-shadow);
}
.cell-1024 {
    color: var(--text-light);
    background-color: #4BC9FF;
    box-shadow: var(--cell-shadow);
}
.cell-2048 {
    color: var(--text-light);
    background-color: #0056FB;
    box-shadow: var(--cell-shadow);
}
.cell-4096 {
    color: var(--text-light);
    background-color: #00308F;
    box-shadow: var(--cell-shadow);
}
.cell-8192 {
    color: var(--text-dark);
    background-color: #FF9393;
    box-shadow: var(--cell-shadow);
}
.cell-16384 {
    color: var(--text-light);
    background-color: #FF3838;
    box-shadow: var(--cell-shadow);
}
.cell-32768 {
    color: var(--text-light);
    background-color: #A20101;
    box-shadow: var(--cell-shadow);
}
.cell-65536 {
    color: var(--text-light);
    background-color: #BD01FF;
    box-shadow: var(--cell-shadow);
}
.cell-infinite {
    color: var(--text-light);
    background-color: #3a3a3a;
    box-shadow: var(--cell-shadow);
}

@keyframes sudden-amt {

    0% {
        transform: scale(0);
    }

    50% {
        transform: scale(0.5);
    }

    100% {
        transform: scale(1);
    }
}

.sudden{
    animation: sudden-amt 100ms ease-in-out forwards;
}

@keyframes pop-amt {

    0% {
        transform: scale(0.8);
    }

    50% {
        transform: scale(1.1);
    }

    100% {
        transform: scale(1);
    }
}

.pop{
    animation: pop-amt 150ms ease-in-out forwards;
}

#msg-bg{
    visibility:hidden;
    z-index: 99999999999999;
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    top: 0;
    right: 0;
    left: 0;
    bottom: 0;
    background-color: var(--msg-bg);
}

#msg-bg>div{
    display: flex;
    flex-direction: column;
    align-content: space-between;
    align-items: center;
}

#msg-text{
    font-weight: bold;
    color: var(--msg-text);
    font-size: 56px;
}

#msg-button{
    color: #FFFFFF;
    margin-top: 18px;
    width: 180px;
    height: 50px;
    font-size: 34px;
    border: none;
    border-radius: 3px;
    background-color: var(--text-dark);
    cursor: pointer;
}

#msg-button:hover, #msg-ask-yes:hover, #msg-ask-no:hover
{
    background-color: #656565;
}

#msg-button:active, #msg-ask-yes:active, #msg-ask-yes:active{
    background-color: #494949;
}

#msg-ask{
    margin-top: 18px;
}

#msg-ask button{
    color: #FFFFFF;
    padding: 0 12px;
    font-size: 34px;
    border: none;
    border-radius: 3px;
    background-color: var(--text-dark);
    cursor: pointer;
}

#msg-ask button:first-child {
    margin-right: 28px;
}

@media (max-width: 470px) {
    #game-box {
        transform: scale(0.8);
    }
}

@media (max-width: 400px) {
    #game-box {
        transform: scale(0.7); 
    }
}

@media (max-width: 350px) {
    #game-box {
        transform: scale(0.6); 
    }
}

#bubble{
    display: inline-block;
    position: relative;
}

.bubble{
    display: none;
    position: absolute;
    top: 40px;
}

.bubble.bbamt{
    animation: bubble 300ms forwards;
}

.bubble.show{
    display: block;
}

@keyframes bubble {
    from{
        top: 40px;
        opacity: 0.2;
    }
    to{
        top: 0px;
        opacity: 1;
    }
}
.key_more:hover{
    color: #6a6a6a;
}