:root{
    --bg-color:#f4f4f4;
    --text-color:#333;
    --article-bg:#fff;
    --border-color:#ccc;
    --shadow-color:rgba(0,0,0,0.1);
    --button-bg:#007bff;
    --button-text:white;
    --light-code-bg:#f8f9fa;
    --light-code-text:#333;
    --light-code-keyword:#d73a49;
    --light-code-tag:#22863a;
    --light-code-attr:#6f42c1;
    --light-code-string:#032f62;
    --light-code-comment:#6a737d;
    --transition-time:0.5s;
}
.dark-mode{
    --bg-color:#1a1a1a;
    --text-color:#e0e0e0;
    --article-bg:#2d2d2d;
    --border-color:#404040;
    --shadow-color:rgba(0,0,0,0.5);
    --button-bg:#4dabf7;
    --code-bg:#111;
    --code-text:#e0e0e0;
    --code-keyword:#569cd6;
    --code-tag:#4ec9b0;
    --code-attr:#9cdcfe;
    --code-string:#ce9178;
    --code-comment:#6A9955;
    --code-punctuation:#858585;
    --code-operator:#d4d4d4;
}
body,html{
    margin:0;
    padding:0;
    width:100%;
    min-height:100vh;
    background-color:var(--bg-color);
    font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;
    overflow-x:hidden;
    transition:background-color var(--transition-time) ease,color var(--transition-time) ease;
}
.container{
    width:80%;
    max-width:800px;
    margin:auto;
    overflow:hidden;
    background-color:var(--bg-color);
    padding:20px;
    box-sizing:border-box;
    transition:background-color var(--transition-time) ease,color var(--transition-time) ease;
}
header{
    padding:20px 0;
    text-align:center;
    position:relative;
    background-color:var(--bg-color);
    color:var(--text-color);
    transition:background-color var(--transition-time) ease,color var(--transition-time) ease;
}
.return-btn{
    display:inline-flex;
    align-items:center;
    gap:0.5rem;
    padding:0.8rem 1.2rem;
    background:var(--article-bg);
    border-radius:0.75rem;
    box-shadow:0 2px 8px rgba(0,0,0,0.05);
    color:var(--text-color);
    transition:transform 0.2s ease,background-color var(--transition-time) ease,color var(--transition-time) ease;
    text-decoration:none;
    position:absolute;
    left:20px;
    top:30px;
}
.return-btn:before{
    content:'\2190';
}
.return-btn:hover{
    transform:translateY(-2px);
    color:var(--text-color);
    box-shadow:0 4px 12px rgba(0,0,0,0.1);
}
.article-header{
    margin-top:20px;
    text-align:center;
    color:var(--text-color);
    background:var(--article-bg);
    padding:1.5rem;
    border-radius:1rem;
    box-shadow:0 2px 8px rgba(0,0,0,0.05);
    transition:background-color var(--transition-time) ease,color var(--transition-time) ease,box-shadow var(--transition-time) ease;
}
.article-header h1{
    margin:0;
    font-size:2.2em;
    transition:color var(--transition-time) ease;
}
.article-date{
    color:var(--text-color);
    font-size:0.9em;
    margin:10px 0 30px;
    opacity:0.8;
    transition:color var(--transition-time) ease;
}
.article{
    background-color:var(--article-bg);
    padding:30px;
    margin-top:50px;
    border-radius:10px;
    box-shadow:0 5px 15px var(--shadow-color);
    word-break:break-word;
    transition:background-color var(--transition-time) ease,box-shadow var(--transition-time) ease;
}
.article-content{
    margin-top:20px;
    line-height:1.8;
    text-align:left;
    color:var(--text-color);
    transition:color var(--transition-time) ease;
}
.link-button{
    padding:0.8rem 1.2rem;
    background:var(--article-bg);
    color:var(--button-bg);
    border:2px solid var(--border-color);
    text-decoration:none;
    border-radius:0.75rem;
    transition:transform 0.2s ease,box-shadow 0.2s ease,background-color var(--transition-time) ease,color var(--transition-time) ease,border-color var(--transition-time) ease;
    display:inline-block;
    margin:10px 0;
    box-shadow:0 2px 8px rgba(0,0,0,0.05);
}
.link-button:hover{
    transform:translateY(-2px);
    box-shadow:0 4px 12px rgba(0,0,0,0.1);
    background:var(--article-bg);
}
.code-block{
    background-color:var(--light-code-bg);
    color:var(--light-code-text);
    padding:1.5rem;
    border-radius:6px;
    margin:1.5rem 0;
    position:relative;
    overflow-x:auto;
    transition:background-color var(--transition-time) ease,color var(--transition-time) ease;
}
pre{
    margin:0 !important;
    padding-top:28px !important;
}
.code-block .code-header{
    position:absolute;
    top:0;
    left:0;
    padding:0.25rem 1rem;
    background:var(--border-color);
    color:var(--text-color);
    font-size:0.9em;
    border-radius:6px 0 6px 0;
    transition:background-color var(--transition-time) ease,color var(--transition-time) ease;
}
.token.keyword{
    color:var(--light-code-keyword);
    transition:color var(--transition-time) ease;
}
.token.tag{
    color:var(--light-code-tag);
    transition:color var(--transition-time) ease;
}
.token.attr-name{
    color:var(--light-code-attr);
    transition:color var(--transition-time) ease;
}
.token.string{
    color:var(--light-code-string);
    transition:color var(--transition-time) ease;
}
.token.comment{
    color:var(--light-code-comment);
    transition:color var(--transition-time) ease;
}
.article-content img{
    max-width:100%;
    height:auto;
    display:block;
    margin:20px auto;
    border-radius:4px;
}
@keyframes fadeIn{
    from{opacity:0;}
    to{opacity:1;}
}
.theme-toggle{
    position:fixed;
    top:20px;
    right:20px;
    width:40px;
    height:40px;
    border-radius:50%;
    background:var(--article-bg);
    color:var(--text-color);
    cursor:pointer;
    display:grid;
    place-items:center;
    box-shadow:0 2px 8px rgba(0,0,0,0.05);
    transition:transform 0.2s ease,background-color var(--transition-time) ease,color var(--transition-time) ease;
    font-size:1.2em;
    z-index:1000;
    border:none;
    outline:none;
}
.theme-toggle:hover{
    transform:scale(1.1);
    box-shadow:0 3px 15px var(--shadow-color);
}
pre[class*="language-"],code[class*="language-"]{
    background:var(--light-code-bg) !important;
    color:var(--light-code-text) !important;
    transition:background var(--transition-time) ease,color var(--transition-time) ease !important;
}
.token.keyword{
    color:var(--light-code-keyword) !important;
}
.token.tag{
    color:var(--light-code-tag) !important;
}
.token.attr-name{
    color:var(--light-code-attr) !important;
}
.token.string{
    color:var(--light-code-string) !important;
}
.token.comment{
    color:var(--light-code-comment) !important;
}
.dark-mode pre[class*="language-"],.dark-mode code[class*="language-"]{
    background:var(--code-bg) !important;
    color:var(--code-text) !important;
}
.dark-mode .token.keyword{
    color:var(--code-keyword) !important;
}
.dark-mode .token.tag{
    color:var(--code-tag) !important;
}
.dark-mode .token.attr-name{
    color:var(--code-attr) !important;
}
.dark-mode .token.string{
    color:var(--code-string) !important;
}
.dark-mode .token.comment{
    color:var(--code-comment) !important;
}
.dark-mode .token.punctuation{
    color:var(--code-punctuation);
}
.dark-mode .token.operator{
    color:var(--code-operator);
    background:transparent;
}
.dark-mode:not(pre)>code[class*="language-"]{
    background:var(--code-bg);
    padding:0.15em 0.4em;
    border:1px solid var(--border-color);
}
.outdated-warning{
    background-color:#fff3cd;
    color:#856404;
    padding:15px;
    border-left:5px solid #ffeeba;
    margin-bottom:20px;
    border-radius:4px;
    animation:fadeIn 0.5s;
    transition:background-color var(--transition-time) ease,color var(--transition-time) ease,border-color var(--transition-time) ease;
}
.dark-mode .outdated-warning{
    background-color:#343a40;
    color:#ffc107;
    border-left-color:#ffc107;
}
@media (max-width:768px){
    .container{
        width:100%;
        padding:0;
    }
    .article{
        padding:20px 15px;
        margin-top:30px;
        border-radius:0;
        box-shadow:none;
    }
    .article-header{
        padding:1rem 15px;
        border-radius:0;
        margin-top:10px;
    }
    .article-header h1{
        font-size:1.8em;
    }
    .return-btn{
        left:15px;
        top:15px;
        padding:8px 15px;
        border-radius:8px;
    }
    .theme-toggle{
        top:15px;
        right:15px;
        width:36px;
        height:36px;
        font-size:1em;
    }
    .code-block{
        padding:1rem 15px;
        margin:1rem -15px;
        border-radius:0;
    }
    .article-content{
        padding:0 5px;
    }
    .outdated-warning{
        padding:10px 15px;
        margin:0 -15px 15px;
        border-radius:0;
    }
}
.dark-mode{
    --code-bg:#111111;
    --code-text:#e0e0e0;
    --code-keyword:#569cd6;
    --code-tag:#4ec9b0;
    --code-attr:#9cdcfe;
    --code-string:#ce9178;
    --code-comment:#6A9955;
    --code-punctuation:#858585;
    --code-operator:#d4d4d4;
}
.dark-mode pre[class*="language-"],.dark-mode code[class*="language-"]{
    background:var(--code-bg);
    text-shadow:none;
    color:var(--code-text);
}
.dark-mode .token.comment,.dark-mode .token.prolog,.dark-mode .token.doctype,.dark-mode .token.cdata{
    color:var(--code-comment);
}
.dark-mode .token.punctuation{
    color:var(--code-punctuation);
}
.dark-mode .token.keyword{
    color:var(--code-keyword);
}
.dark-mode .token.tag:not(.script-punctuation),.dark-mode .token.boolean,.dark-mode .token.number{
    color:var(--code-tag);
}
.dark-mode .token.attr-name{
    color:var(--code-attr);
}
.dark-mode .token.string,.dark-mode .token.char{
    color:var(--code-string);
}
.dark-mode .token.operator{
    color:var(--code-operator);
    background:transparent;
}
.dark-mode .token.function{
    color:#dcdcaa;
}
.dark-mode:not(pre)>code[class*="language-"]{
    background:var(--code-bg);
    padding:0.15em 0.4em;
    border:1px solid var(--border-color);
}
.dark-mode .code-block{
    background-color:var(--code-bg);
    border:1px solid var(--border-color);
}
.dark-mode .code-block .code-header{
    background:var(--code-bg);
    border-right:1px solid var(--border-color);
    border-bottom:1px solid var(--border-color);
    color:var(--code-comment);
}
.dark-mode pre[class*="language-"]{
    border:none !important;
    background:var(--code-bg) !important;
}