:root{--primary:#1a73e8;--primary-hover:#1557b0;--primary-light:#e8f0fe;--success:#34a853;--danger:#ea4335;--warning:#fbbc04;--bg:#f5f5f5;--bg-white:#fff;--text:#1a1a1a;--text-secondary:#555;--text-muted:#999;--border:#e5e5e5;--border-light:#eee;--shadow:0 1px 4px rgba(0,0,0,.06);--shadow-hover:0 6px 20px rgba(0,0,0,.1);--radius:8px;--radius-lg:12px;--transition:all .25s ease}
*{margin:0;padding:0;box-sizing:border-box}html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;background:var(--bg);color:var(--text);line-height:1.6;font-size:14px}

.container{max-width:1200px;margin:0 auto;padding:0 24px}

/* 导航 */
.navbar{background:rgba(255,255,255,.92);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100;transition:box-shadow .3s}
.navbar.scrolled{box-shadow:0 2px 20px rgba(0,0,0,.08)}
.nav-container{display:flex;align-items:center;justify-content:space-between;height:56px}
.nav-logo{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);font-weight:700;font-size:16px}
.logo-icon{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;background:var(--primary);border-radius:8px;font-size:16px;font-weight:700;color:#fff;transition:transform .3s}
.nav-logo:hover .logo-icon{transform:rotate(-5deg) scale(1.1)}
.nav-menu{display:flex;align-items:center;gap:4px;list-style:none}
.nav-menu a{color:var(--text-secondary);text-decoration:none;padding:6px 14px;border-radius:var(--radius);transition:var(--transition);font-size:14px;position:relative}
.nav-menu a:hover{color:var(--primary);background:var(--primary-light)}
.nav-user{display:flex!important;align-items:center;gap:6px}
.user-level{background:var(--primary);color:#fff;padding:2px 8px;border-radius:4px;font-size:11px;font-weight:600}
.nav-login-btn{border:1px solid var(--border)!important}
.nav-register-btn{background:var(--primary)!important;color:#fff!important;font-weight:600;box-shadow:0 2px 8px rgba(26,115,232,.2)}
.nav-register-btn:hover{box-shadow:0 4px 16px rgba(26,115,232,.35);transform:translateY(-1px)}
.nav-admin-btn{color:var(--primary)!important;border:1px solid var(--primary)!important}
.nav-logout{color:var(--danger)!important}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:6px}
.nav-toggle span{display:block;width:20px;height:2px;background:var(--text);margin:4px 0;border-radius:1px;transition:.3s}

/* Hero */
.hero{padding:100px 0 80px;text-align:center;background:#e8e8e8;color:var(--text)}
.hero-badge{display:inline-flex;align-items:center;gap:6px;padding:6px 18px;background:rgba(255,255,255,.7);border:1px solid var(--border);border-radius:20px;font-size:13px;margin-bottom:28px;color:var(--text-secondary)}
.hero-badge::before{content:'';width:6px;height:6px;background:var(--success);border-radius:50%;animation:pulse 2s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:.4}}
.hero h1{font-size:56px;font-weight:800;margin-bottom:14px;letter-spacing:8px}
.hero-subtitle{font-size:17px;color:var(--text-secondary);margin-bottom:44px}
.hero-stats{display:flex;gap:60px;justify-content:center;margin-bottom:44px}
.stat-item{text-align:center}
.stat-num{display:block;font-size:36px;font-weight:700;color:var(--primary);font-variant-numeric:tabular-nums}
.stat-label{font-size:12px;color:var(--text-muted);margin-top:4px}

/* 按钮 */
.btn{display:inline-flex;align-items:center;gap:6px;padding:9px 22px;border-radius:var(--radius);font-size:14px;font-weight:500;text-decoration:none;cursor:pointer;border:none;transition:var(--transition);font-family:inherit;position:relative;overflow:hidden}
.btn::after{content:'';position:absolute;top:50%;left:50%;width:0;height:0;background:rgba(255,255,255,.2);border-radius:50%;transform:translate(-50%,-50%);transition:width .4s,height .4s}
.btn:active::after{width:200px;height:200px}
.btn-primary{background:var(--primary);color:#fff;box-shadow:0 2px 8px rgba(26,115,232,.2)}
.btn-primary:hover{background:var(--primary-hover);box-shadow:0 4px 16px rgba(26,115,232,.3);transform:translateY(-1px)}
.btn-secondary{background:#fff;border:1px solid var(--border);color:var(--text)}
.btn-secondary:hover{border-color:var(--primary);color:var(--primary);box-shadow:var(--shadow)}
.btn-danger{background:var(--danger);color:#fff}
.btn-success{background:var(--success);color:#fff}
.btn-lg{padding:12px 32px;font-size:15px;border-radius:var(--radius-lg)}
.btn-sm{padding:5px 12px;font-size:12px}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}

/* 表单 */
.form-group{margin-bottom:16px}
.form-group label{display:block;color:var(--text-secondary);margin-bottom:5px;font-size:13px}
.form-control{width:100%;padding:10px 14px;background:#fff;border:1px solid var(--border);border-radius:var(--radius);color:var(--text);font-size:14px;font-family:inherit;transition:var(--transition);outline:none}
.form-control:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(26,115,232,.08)}
.form-control::placeholder{color:var(--text-muted)}
textarea.form-control{min-height:80px;resize:vertical}
select.form-control{cursor:pointer}
.form-row{display:flex;gap:12px}
.form-row .form-group{flex:1}

/* 认证页 */
.auth-page{min-height:calc(100vh - 56px);display:flex;align-items:center;justify-content:center;padding:40px 20px}
.auth-card{width:100%;max-width:400px;background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);padding:36px;box-shadow:var(--shadow-hover);position:relative;overflow:hidden}
.auth-card::before{content:'';position:absolute;top:0;left:0;width:100%;height:3px;background:var(--primary)}
.auth-card h2{text-align:center;margin-bottom:4px;font-size:1.3em}
.auth-card .auth-subtitle{text-align:center;color:var(--text-muted);margin-bottom:24px;font-size:13px}
.auth-tabs{display:flex;margin-bottom:22px;border-bottom:1px solid var(--border)}
.auth-tab{flex:1;padding:10px;text-align:center;cursor:pointer;color:var(--text-muted);border:none;border-bottom:2px solid transparent;background:none;font-family:inherit;font-size:14px;transition:var(--transition)}
.auth-tab.active{color:var(--primary);border-bottom-color:var(--primary);font-weight:600}
.auth-link{text-align:center;margin-top:18px;font-size:13px;color:var(--text-muted)}
.auth-link a{color:var(--primary);text-decoration:none;font-weight:500}
.code-group{display:flex;gap:8px}
.code-group .form-control{flex:1}
.code-btn{padding:10px 16px;white-space:nowrap;font-size:13px;background:#f5f5f5;border:1px solid var(--border);color:var(--text-secondary);border-radius:var(--radius);cursor:pointer;transition:var(--transition);font-family:inherit}
.code-btn:hover{border-color:var(--primary);color:var(--primary)}
.code-btn:disabled{opacity:.4;cursor:not-allowed}

/* 页面头部 */
.page-header{padding:88px 0 36px;text-align:center;background:var(--bg-white);border-bottom:1px solid var(--border)}
.page-header h1{font-size:26px;margin-bottom:6px}
.page-header p{color:var(--text-muted);font-size:14px}

/* 筛选栏 */
.filter-bar{display:flex;gap:10px;margin-bottom:22px;flex-wrap:wrap;align-items:center;padding:14px 18px;background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow)}
.filter-bar .form-control{width:auto;min-width:130px;font-size:13px}
.filter-bar .search-input{flex:1;min-width:180px}

/* 靶场卡片 */
.challenge-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:18px}
.challenge-card{background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);padding:22px;transition:var(--transition);cursor:pointer;box-shadow:var(--shadow);position:relative;overflow:hidden}
.challenge-card::before{content:'';position:absolute;top:0;left:0;width:100%;height:3px;background:var(--primary);transform:scaleX(0);transition:transform .3s;transform-origin:left}
.challenge-card:hover{box-shadow:var(--shadow-hover);transform:translateY(-3px);border-color:rgba(26,115,232,.2)}
.challenge-card:hover::before{transform:scaleX(1)}
.challenge-card .card-top{display:flex;justify-content:space-between;align-items:start;margin-bottom:10px}
.challenge-card h3{font-size:15px;margin-bottom:6px;font-weight:600}
.challenge-card p{color:var(--text-muted);font-size:13px;line-height:1.5;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.tag{padding:3px 9px;border-radius:4px;font-size:11px;font-weight:600}
.tag-web{background:#e8f0fe;color:#1967d2}
.tag-pwn{background:#fce8e6;color:#c5221f}
.tag-reverse{background:#f3e8fd;color:#8430ce}
.tag-crypto{background:#e6f4ea;color:#137333}
.tag-misc{background:#fef7e0;color:#b06000}
.difficulty{padding:3px 9px;border-radius:4px;font-size:11px;font-weight:600}
.diff-easy{background:#e6f4ea;color:#137333}
.diff-medium{background:#fef7e0;color:#b06000}
.diff-hard{background:#fce8e6;color:#c5221f}
.challenge-meta{display:flex;justify-content:space-between;align-items:center;margin-top:14px;padding-top:14px;border-top:1px solid var(--border-light);color:var(--text-muted);font-size:13px}
.points{color:var(--primary);font-weight:600}

/* 靶场详情 */
.challenge-detail{padding:88px 0 40px}
.challenge-main{display:grid;grid-template-columns:1fr 340px;gap:26px}
.challenge-info h1{font-size:22px;margin-bottom:16px}
.challenge-desc{color:var(--text-secondary);line-height:1.8;margin-bottom:22px;padding:18px;background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);white-space:pre-line;font-size:14px}
.challenge-hint{background:#fffde7;border:1px solid #fff9c4;border-radius:var(--radius-lg);padding:16px;margin-bottom:18px}
.challenge-hint h4{color:#f9a825;margin-bottom:6px;font-size:13px}
.challenge-hint p{color:var(--text-secondary);font-size:13px}
.challenge-sidebar{position:sticky;top:76px;align-self:start}
.sidebar-card{background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);padding:20px;margin-bottom:16px;box-shadow:var(--shadow)}
.sidebar-card h3{margin-bottom:14px;font-size:13px;color:var(--text-muted);font-weight:600}
.timer{font-size:2em;color:var(--primary);text-align:center;font-weight:700;padding:16px;background:var(--primary-light);border-radius:var(--radius);font-variant-numeric:tabular-nums;transition:color .3s,background .3s}
.timer.warning{color:var(--warning);background:#fff8e1}
.timer.danger{color:var(--danger);background:#fce8e6;animation:timerPulse 1s infinite}
@keyframes timerPulse{0%,100%{opacity:1}50%{opacity:.7}}
.container-info .info-row{display:flex;justify-content:space-between;padding:8px 0;border-bottom:1px solid var(--border-light);font-size:13px}
.container-info .info-row:last-child{border-bottom:none}
.container-info .info-label{color:var(--text-muted)}
.container-info .info-value{color:var(--primary);word-break:break-all;font-weight:500}
.flag-input{display:flex;gap:8px;margin-top:12px}
.flag-input input{flex:1}

/* 排行榜 */
.leaderboard{padding:88px 0 40px}
.lb-table{width:100%;border-collapse:separate;border-spacing:0;background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden;box-shadow:var(--shadow)}
.lb-table th{padding:14px 18px;text-align:left;color:var(--text-muted);font-size:12px;border-bottom:2px solid var(--border);font-weight:600;background:#fafafa;text-transform:uppercase;letter-spacing:.5px}
.lb-table td{padding:14px 18px;border-bottom:1px solid var(--border-light);font-size:14px;transition:background .2s}
.lb-table tr:last-child td{border-bottom:none}
.lb-table tr:hover td{background:#f8f9fa}
.lb-rank{font-weight:700;width:52px;color:var(--text-muted)}
.lb-rank-1{color:#f9a825}
.lb-rank-2{color:#90a4ae}
.lb-rank-3{color:#8d6e63}
.lb-user{display:flex;align-items:center;gap:10px}
.lb-avatar{width:36px;height:36px;border-radius:8px;background:var(--primary);display:flex;align-items:center;justify-content:center;font-size:14px;color:#fff;font-weight:600;transition:transform .2s}
.lb-table tr:hover .lb-avatar{transform:scale(1.1)}
.lb-name{font-weight:500}
.lb-title{color:var(--text-muted);font-size:12px}
.lb-points{color:var(--primary);font-weight:600}
.lb-level{color:var(--success);font-weight:600;font-size:13px}

/* 个人中心 */
.profile{padding:88px 0 40px}
.profile-header{display:flex;gap:28px;align-items:start;margin-bottom:28px;background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);padding:28px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.profile-header::before{content:'';position:absolute;top:0;left:0;width:100%;height:3px;background:linear-gradient(90deg,var(--primary),var(--success))}
.profile-avatar{width:88px;height:88px;border-radius:12px;background:var(--primary);display:flex;align-items:center;justify-content:center;font-size:2.2em;font-weight:700;color:#fff;flex-shrink:0;box-shadow:0 4px 12px rgba(26,115,232,.2);transition:transform .3s}
.profile-header:hover .profile-avatar{transform:rotate(-3deg)}
.profile-info h2{margin-bottom:4px;font-size:1.4em}
.profile-info .profile-title{color:var(--primary);font-size:13px;margin-bottom:12px;background:var(--primary-light);padding:3px 10px;border-radius:4px;display:inline-block}
.profile-stats{display:flex;gap:24px}
.profile-stat{text-align:center}
.profile-stat .num{display:block;font-size:1.3em;font-weight:700;color:var(--primary)}
.profile-stat .label{color:var(--text-muted);font-size:11px}
.profile-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.profile-section{background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);padding:22px;box-shadow:var(--shadow)}
.profile-section h3{margin-bottom:16px;font-size:14px;color:var(--text-secondary);font-weight:600}
.badge-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(100px,1fr));gap:10px}
.badge-item{text-align:center;padding:14px 6px;background:#f8f9fa;border:1px solid var(--border-light);border-radius:var(--radius);transition:var(--transition)}
.badge-item:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.badge-item .badge-icon{font-size:1.6em;margin-bottom:6px}
.badge-item .badge-name{font-size:11px;color:var(--text-muted)}
.badge-item.earned{border-color:var(--primary);background:var(--primary-light)}
.badge-item.earned .badge-name{color:var(--primary);font-weight:500}

/* 分页 */
.pagination{display:flex;justify-content:center;gap:4px;margin-top:24px}
.pagination a,.pagination span{display:inline-flex;align-items:center;justify-content:center;min-width:36px;height:36px;border-radius:var(--radius);background:var(--bg-white);border:1px solid var(--border);color:var(--text-secondary);text-decoration:none;font-size:13px;transition:var(--transition)}
.pagination a:hover{border-color:var(--primary);color:var(--primary);transform:translateY(-1px)}
.pagination .active{background:var(--primary);color:#fff;border-color:var(--primary)}

/* 提示框 */
.alert{padding:12px 16px;border-radius:var(--radius);margin-bottom:12px;font-size:13px}
.alert-success{background:#e6f4ea;border:1px solid #ceead6;color:#137333}
.alert-danger{background:#fce8e6;border:1px solid #f5c6cb;color:#c5221f}
.alert-info{background:var(--primary-light);border:1px solid #c2d7f2;color:#1967d2}

/* 弹窗 */
.modal-overlay{display:none;position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.45);z-index:2000;align-items:center;justify-content:center;backdrop-filter:blur(4px)}
.modal-overlay.active{display:flex}
.modal{background:var(--bg-white);border:1px solid var(--border);border-radius:var(--radius-lg);padding:28px;width:90%;max-width:500px;max-height:80vh;overflow-y:auto;box-shadow:0 20px 60px rgba(0,0,0,.15);animation:modalSlide .3s ease}
@keyframes modalSlide{from{opacity:0;transform:translateY(-20px)}to{opacity:1;transform:translateY(0)}}
.modal h3{margin-bottom:20px}
.modal-close{float:right;background:none;border:none;color:var(--text-muted);font-size:20px;cursor:pointer;padding:4px;transition:color .2s}
.modal-close:hover{color:var(--danger)}

/* 加载 */
.loading{display:inline-block;width:22px;height:22px;border:2.5px solid var(--border);border-top-color:var(--primary);border-radius:50%;animation:spin .7s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.loading-overlay{display:none;position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(255,255,255,.75);z-index:3000;align-items:center;justify-content:center;backdrop-filter:blur(2px)}
.loading-overlay.active{display:flex}

/* Toast */
.toast-container{position:fixed;top:72px;right:20px;z-index:5000}
.toast{padding:12px 20px;border-radius:var(--radius);margin-bottom:8px;background:var(--bg-white);border:1px solid var(--border);color:var(--text);font-size:13px;box-shadow:var(--shadow-hover);animation:toastIn .4s cubic-bezier(.34,1.56,.64,1);min-width:260px;display:flex;align-items:center;gap:8px}
.toast.success{border-left:3px solid var(--success)}
.toast.error{border-left:3px solid var(--danger)}
@keyframes toastIn{from{transform:translateX(120%);opacity:0}to{transform:translateX(0);opacity:1}}

/* Tabs */
.tabs{display:flex;gap:0;margin-bottom:20px;border-bottom:2px solid var(--border)}
.tab{padding:10px 20px;cursor:pointer;color:var(--text-muted);border:none;background:none;border-bottom:2px solid transparent;margin-bottom:-2px;transition:var(--transition);font-family:inherit;font-size:14px}
.tab.active{color:var(--primary);border-bottom-color:var(--primary);font-weight:600}
.tab-content{display:none}
.tab-content.active{display:block;animation:fadeIn .3s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

/* 公告 */
.announcement-bar{background:var(--primary-light);border-bottom:1px solid #c2d7f2;padding:10px 0;position:relative;overflow:hidden}
.announcement-bar::after{content:'';position:absolute;top:0;left:-100%;width:50%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.3),transparent);animation:announceShine 4s infinite}
@keyframes announceShine{0%{left:-100%}100%{left:200%}}
.announcement-content{display:flex;align-items:center;gap:10px}
.announcement-tag{background:var(--primary);color:#fff;padding:3px 12px;border-radius:4px;font-size:11px;font-weight:600}
.announcement-text{color:var(--text-secondary);font-size:13px}

/* 页脚 */
.footer{background:var(--bg-white);border-top:1px solid var(--border);padding:40px 0 20px;margin-top:40px;position:relative;z-index:1}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.5fr;gap:36px;margin-bottom:28px}
.footer-brand h3{display:flex;align-items:center;gap:8px;margin-bottom:10px;font-size:16px}
.footer-brand p{color:var(--text-muted);font-size:13px;line-height:1.7}
.footer-links h4{color:var(--text-secondary);margin-bottom:14px;font-size:13px;font-weight:600}
.footer-links ul{list-style:none}
.footer-links li{margin-bottom:8px}
.footer-links a{color:var(--text-muted);text-decoration:none;font-size:13px;transition:var(--transition)}
.footer-links a:hover{color:var(--primary)}
.footer-partners h4{color:var(--text-secondary);margin-bottom:14px;font-size:13px;font-weight:600}
.partner-list{display:flex;flex-wrap:wrap;gap:8px}
.partner-item{padding:6px 14px;background:#f5f5f5;border:1px solid var(--border-light);border-radius:var(--radius);color:var(--text-secondary);text-decoration:none;font-size:12px;transition:var(--transition)}
.partner-item:hover{border-color:var(--primary);color:var(--primary);transform:translateY(-1px)}
.footer-bottom{text-align:center;padding-top:18px;border-top:1px solid var(--border-light);color:var(--text-muted);font-size:12px}

/* 滚动动画 */
.scroll-animate{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.scroll-animate.visible{opacity:1;transform:translateY(0)}

/* 响应式 */
@media(max-width:768px){
.nav-toggle{display:block}
.nav-menu{display:none;position:absolute;top:56px;left:0;width:100%;background:rgba(255,255,255,.98);backdrop-filter:blur(16px);border-bottom:1px solid var(--border);flex-direction:column;padding:12px 20px;box-shadow:var(--shadow-hover)}
.nav-menu.active{display:flex}
.hero h1{font-size:32px;letter-spacing:4px}
.hero-stats{gap:28px}
.stat-num{font-size:24px}
.stat-item::after{display:none}
.challenge-main{grid-template-columns:1fr}
.profile-header{flex-direction:column;align-items:center;text-align:center}
.profile-stats{justify-content:center}
.profile-grid{grid-template-columns:1fr}
.challenge-grid{grid-template-columns:1fr}
.form-row{flex-direction:column}
.filter-bar{flex-direction:column}
.filter-bar .form-control{width:100%;min-width:0}
.footer-grid{grid-template-columns:1fr;gap:24px}
}

/* 滚动动画 */
.scroll-animate{opacity:0;transform:translateY(20px);transition:opacity .5s ease,transform .5s ease}
.scroll-animate.visible{opacity:1;transform:translateY(0)}