*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;font-size:14px;line-height:1.6;color:#333;background:#f5f7fa;min-height:100vh}
a{color:#1a73e8;text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:60vw;margin:0 auto;padding:0 16px}
.page{padding:24px 0}
.header{background:#fff;border-bottom:1px solid #e8e8e8;padding:12px 0;position:sticky;top:0;z-index:100}
.header-inner{max-width:60vw;margin:0 auto;padding:0 16px;display:flex;justify-content:space-between;align-items:center}
.header-logo{font-size:20px;font-weight:bold;color:#1a73e8}
.header-nav a{margin-left:20px;color:#555;font-size:14px}
.header-nav a:hover{color:#1a73e8}
.header-user{display:flex;align-items:center;gap:12px}
.header-user span{color:#666}
.card{background:#fff;border-radius:8px;box-shadow:0 1px 3px rgba(0,0,0,0.08);padding:20px;margin-bottom:16px}
.card-title{font-size:18px;font-weight:600;margin-bottom:16px;padding-bottom:12px;border-bottom:1px solid #f0f0f0}
.table-wrap{overflow-x:auto}
table{width:100%;border-collapse:collapse;font-size:14px}
th,td{padding:12px 16px;text-align:left;border-bottom:1px solid #f0f0f0}
th{background:#fafafa;font-weight:600;color:#666}
tr:hover td{background:#fafafa}
.form-group{margin-bottom:16px}
.form-group label{display:block;margin-bottom:6px;font-weight:500;color:#555}
.form-group input,.form-group textarea,.form-group select,.form-group md-edit{width:100%;padding:10px 12px;border:1px solid #d9d9d9;border-radius:6px;font-size:14px;font-family:inherit;transition:border-color 0.2s}
.form-group input:focus,.form-group textarea:focus,.form-group select:focus{outline:none;border-color:#1a73e8}
.form-group textarea{resize:vertical;min-height:360px;line-height:1.5}
.form-error{color:#d93025;font-size:13px;margin-top:6px;display:none}
.form-error.show{display:block}
.btn{display:inline-block;padding:10px 24px;border:none;border-radius:6px;font-size:14px;font-weight:500;cursor:pointer;transition:all 0.2s;font-family:inherit}
.btn-primary{background:#1a73e8;color:#fff}
.btn-primary:hover{background:#1557b0}
.btn-secondary{background:#fff;color:#555;border:1px solid #d9d9d9}
.btn-secondary:hover{border-color:#1a73e8;color:#1a73e8}
.btn-danger{background:#d93025;color:#fff}
.btn-danger:hover{background:#b31412}
.btn-sm{padding:6px 14px;font-size:13px}
.tag{display:inline-block;padding:2px 10px;border-radius:4px;font-size:12px;font-weight:500}
.tag-diff-entry,.tag-diff-popm,.tag-diff-popp,.tag-diff-impvm,.tag-diff-impvp,.tag-diff-prov,.tag-diff-ctsc,.tag-diff-none{background:#f5f5f5;color:#555}
.tag-accepted{background:#e6f7e6;color:#2e7d32}
.tag-wrong_answer,.tag-time_limit_exceeded,.tag-memory_limit_exceeded,.tag-runtime_error{background:#ffebee;color:#c62828}
.tag-compilation_error,.tag-compile_error{background:#fff3e0;color:#ef6c00}
.tag-pending,.tag-compiling,.tag-running{background:#e3f2fd;color:#1565c0}
.pagination{display:flex;justify-content:center;align-items:center;gap:8px;margin-top:20px}
.pagination-btn{padding:8px 16px;border:1px solid #d9d9d9;border-radius:6px;background:#fff;color:#555;cursor:pointer;font-size:14px}
.pagination-btn:hover{border-color:#1a73e8;color:#1a73e8}
.pagination-btn:disabled{opacity:0.5;cursor:not-allowed}
.code-editor{width:100%;min-height:300px;padding:16px;border:1px solid #d9d9d9;border-radius:6px;font-family:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;font-size:14px;line-height:1.6;background:#fafafa;resize:vertical}
.code-editor:focus{outline:none;border-color:#1a73e8;background:#fff}
.code-block{background:#f6f8fa;border:1px solid #e1e4e8;border-radius:6px;padding:16px;overflow-x:auto;font-family:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;font-size:13px;line-height:1.6;white-space:pre-wrap;word-break:break-word}
.code-block-wrap{white-space:pre-wrap;word-break:break-word;overflow-x:hidden}
.katex-content pre,.card pre,.hw-desc pre{background:#f6f8fa;color:#24292e;border:1px solid #e1e4e8;border-radius:6px;padding:16px;overflow-x:auto;font-family:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;font-size:13px;line-height:1.6;margin:12px 0;white-space:pre;word-wrap:normal}
.katex-content pre code,.card pre code,.hw-desc pre code{background:none;color:inherit;padding:0;font-size:inherit;border:none}
.katex-content code,.card code,.hw-desc code{background:#f6f8fa;color:#24292e;padding:2px 6px;border-radius:4px;font-family:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;font-size:0.9em;border:1px solid #e1e4e8}
.token.comment,.token.prolog,.token.doctype,.token.cdata{color:#6a737d;font-style:italic}
.token.punctuation{color:#24292e}
.token.property,.token.tag,.token.boolean,.token.number,.token.constant,.token.symbol,.token.deleted{color:#005cc5}
.token.selector,.token.attr-name,.token.string,.token.char,.token.builtin,.token.inserted{color:#032f62}
.token.operator,.token.entity,.token.url{color:#d73a49}
.token.atrule,.token.attr-value,.token.keyword{color:#d73a49}
.token.function,.token.class-name{color:#6f42c1}
.token.regex,.token.important,.token.variable{color:#e36209}
.token.important,.token.bold{font-weight:bold}
.token.italic{font-style:italic}
.token.namespace{opacity:0.7}
.empty-state{text-align:center;padding:60px 20px;color:#999}
.empty-state p{font-size:16px}
.loading{text-align:center;padding:40px;color:#999}
.toast{position:fixed;top:20px;right:20px;padding:12px 20px;border-radius:6px;color:#fff;font-size:14px;z-index:1000;animation:slideIn 0.3s ease}
.toast-success{background:#2e7d32}
.toast-error{background:#c62828}
@keyframes slideIn{from{transform:translateX(100%);opacity:0}
to{transform:translateX(0);opacity:1}
}
.container.has-sidebar{position:relative}
.home-sidebar{position:absolute;left:calc(100% + 20px);top:0;width:220px;max-height:calc(100vh - 100px);overflow-y:auto}
.countdown-card{background:#fff;border-radius:8px;box-shadow:0 1px 3px rgba(0,0,0,0.08);overflow:hidden;margin-bottom:16px}
.countdown-header{padding:14px 16px;font-size:15px;font-weight:600;border-bottom:1px solid #f0f0f0;display:flex;align-items:center;gap:6px;color:#333}
.countdown-list{list-style:none}
.countdown-item{border-bottom:1px solid #f5f5f5;padding:10px 16px}
.countdown-item:last-child{border-bottom:none}
.countdown-title{font-size:13px;font-weight:500;color:#555;margin-bottom:2px}
.countdown-time{font-size:16px;font-weight:700;color:#1a73e8;font-family:"SFMono-Regular",Consolas,"Liberation Mono",Menlo,monospace;letter-spacing:1px}
.countdown-item.expired .countdown-time{color:#c62828}
.countdown-empty{padding:20px 16px;text-align:center;color:#ccc;font-size:13px}
.announcement-card{background:#fff;border-radius:8px;box-shadow:0 1px 3px rgba(0,0,0,0.08);overflow:hidden}
.announcement-header{padding:14px 16px;font-size:15px;font-weight:600;border-bottom:1px solid #f0f0f0;display:flex;align-items:center;gap:6px;color:#333}
.announcement-list{list-style:none}
.announcement-item{border-bottom:1px solid #f5f5f5}
.announcement-item:last-child{border-bottom:none}
.announcement-item-title{display:block;padding:10px 16px;font-size:13px;font-weight:500;color:#555;text-decoration:none;transition:background 0.15s,color 0.15s}
.announcement-item-title:hover{background:#f8f9fc;color:#1a73e8;text-decoration:none}
.announcement-body{padding:0 16px 20px;font-size:14px;color:#333;line-height:1.8;white-space:pre-wrap;word-break:break-word}
.announcement-empty{padding:20px 16px;text-align:center;color:#ccc;font-size:13px}
.split-container{display:flex;gap:16px;max-width:75vw;height:calc(100vh - 56px)}
.split-left,.split-right{flex:1 1 0;min-width:0;overflow-y:auto}
.split-left{padding-right:8px}
.split-right{padding-left:8px}
.split-left::-webkit-scrollbar,.split-right::-webkit-scrollbar{width:6px}
.split-left::-webkit-scrollbar-thumb,.split-right::-webkit-scrollbar-thumb{background:#ccc;border-radius:3px}
.split-left::-webkit-scrollbar-thumb:hover,.split-right::-webkit-scrollbar-thumb:hover{background:#aaa}
.split-right .code-editor{min-height:400px;resize:none;tab-size:4}
.user-info-card{padding:28px 24px}
.user-avatar-lg{width:72px;height:72px;border-radius:50%;object-fit:cover;flex-shrink:0}
.user-avatar-placeholder{width:72px;height:72px;border-radius:50%;background:#1a73e8;color:#fff;font-size:32px;font-weight:600;display:flex;align-items:center;justify-content:center;flex-shrink:0}
.user-nickname{font-size:20px;font-weight:600;color:#333}
.user-username{font-size:14px;color:#999}
.user-bio{margin-top:8px;color:#666;font-size:14px;line-height:1.6;white-space:pre-wrap;word-break:break-word}
.user-meta{margin-top:8px;color:#999;font-size:13px}
.tag-admin{background:#ffebee;color:#c62828}
.ac-status{font-size:16px;font-weight:bold;color:#2e7d32}
.tried-status{font-size:14px;font-weight:bold;color:#c62828;opacity:0.7}
.loading-state{text-align:center;padding:40px;color:#999}
.ac-problem-list{display:flex;flex-wrap:wrap;gap:8px}
.ac-tag{display:inline-flex;align-items:center;gap:6px;padding:6px 14px;background:#f0f7ff;border:1px solid #d0e3f7;border-radius:6px;font-size:14px;color:#333;text-decoration:none;transition:all 0.15s}
.ac-tag:hover{background:#dceeff;border-color:#1a73e8;color:#1a73e8;text-decoration:none}
@media (max-width:768px){.header-inner{flex-wrap:wrap}
.header-nav a{margin-left:12px;font-size:13px}
th,td{padding:10px 12px;font-size:13px}
.container{padding:0 12px}
.page{padding:0}
.split-container{flex-direction:column;height:auto}
.split-left{height:50vh}
.split-right{min-width:0}
}
.admin-sidebar{position:fixed;top:0;left:0;width:100px;height:100vh;background:#fff;border-right:1px solid #e8e8e8;display:flex;flex-direction:column;overflow-y:auto;z-index:200}
.sidebar-logo{padding:16px;font-size:20px;font-weight:bold;border-bottom:1px solid #e8e8e8}
.sidebar-logo a{color:#1a73e8;text-decoration:none}
.sidebar-nav{flex:1;padding:8px 0}
.sidebar-nav a{display:block;padding:8px 16px;color:#555;font-size:13px;text-decoration:none;transition:background 0.15s,color 0.15s}
.sidebar-nav a:hover{color:#1a73e8;background:#f0f4ff;text-decoration:none}
.sidebar-nav a.active{color:#1a73e8;background:#e8f0fe;font-weight:500}
.sidebar-footer{padding:10px 16px;border-top:1px solid #e8e8e8;font-size:12px}
.sidebar-footer a{color:#999;text-decoration:none}
.sidebar-footer a:hover{color:#1a73e8}
.admin-main{margin-left:100px;min-height:100vh}
@media (max-width:768px){.admin-sidebar{width:60px}
.admin-main{margin-left:60px}
}
.viewport-narrow .admin-main .container{max-width:none;padding:0 24px}
.viewport-narrow .admin-main .table-wrap{overflow-x:auto}