:root{
    --primary:#2563eb;
    --primary-dark:#1d4ed8;
    --bg:#f5f7fa;
    --card:#fff;
    --border:#e2e8f0;
    --text:#1e293b;
    --text-muted:#64748b;
    --success:#16a34a;
    --error:#dc2626;
    --warning:#d97706;
    --gray:#94a3b8;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;font-size:14px;color:var(--text);background:var(--bg);line-height:1.6}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
h2,h3{margin:0 0 16px;font-weight:600}
.container{max-width:1280px;margin:0 auto;padding:24px 20px}
.topbar{background:#1e293b;color:#fff;box-shadow:0 1px 3px rgba(0,0,0,.08)}
.topbar-inner{max-width:1280px;margin:0 auto;padding:0 20px;height:56px;display:flex;align-items:center;gap:24px}
.brand{color:#fff;font-size:18px;font-weight:700}
.brand:hover{text-decoration:none}
.topmenu{display:flex;gap:18px;flex:1}
.topmenu a{color:#cbd5e1;font-size:14px}
.topmenu a:hover{color:#fff;text-decoration:none}
.topuser{display:flex;align-items:center;gap:14px;color:#cbd5e1;font-size:13px}
.topuser a{color:#cbd5e1}
.topuser a:hover{color:#fff}
.footer{text-align:center;color:var(--text-muted);padding:30px 20px;font-size:12px}

/* card */
.card{background:var(--card);border:1px solid var(--border);border-radius:8px;padding:20px;margin-bottom:20px}
.card h3{font-size:16px;color:var(--text)}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:20px}
@media(max-width:768px){.grid-2{grid-template-columns:1fr}}

/* form */
.form-label{display:block;margin-bottom:14px;font-size:13px;color:var(--text-muted)}
.form-label input,.form-label select,.form-label textarea{
    display:block;width:100%;margin-top:4px;padding:8px 10px;border:1px solid var(--border);
    border-radius:6px;font-size:14px;background:#fff;color:var(--text)}
.form-label input:focus,.form-label select:focus,.form-label textarea:focus{
    outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.12)}
textarea{min-height:80px;resize:vertical}
input[required]+.req::before,input.required+::before{content:"*";color:var(--error)}
label.required::after{content:" *";color:var(--error)}

/* button */
.btn{display:inline-block;padding:8px 16px;border:1px solid var(--border);background:#fff;color:var(--text);
    border-radius:6px;cursor:pointer;font-size:14px;transition:all .15s;text-decoration:none}
.btn:hover{background:#f1f5f9;text-decoration:none}
.btn-primary{background:var(--primary);color:#fff;border-color:var(--primary)}
.btn-primary:hover{background:var(--primary-dark)}
.btn-danger{background:var(--error);color:#fff;border-color:var(--error)}
.btn-danger:hover{opacity:.9}
.btn-sm{padding:4px 10px;font-size:12px}
.btn-block{display:block;width:100%;text-align:center}

/* table */
.data-table{width:100%;border-collapse:collapse;font-size:13px}
.data-table th,.data-table td{padding:10px 12px;border-bottom:1px solid var(--border);text-align:left}
.data-table th{background:#f8fafc;color:var(--text-muted);font-weight:600;white-space:nowrap}
.data-table tbody tr:hover{background:#f8fafc}
.data-table td.empty,.data-table td.empty{text-align:center;color:var(--text-muted);padding:24px}
.info-table th{background:transparent;color:var(--text-muted);font-weight:500;width:120px;padding:8px 0;text-align:right}
.info-table td{padding:8px 16px}

/* tag */
.tag{display:inline-block;padding:2px 8px;border-radius:10px;font-size:12px;background:#f1f5f9;color:var(--text-muted)}
.tag-green{background:#dcfce7;color:var(--success)}
.tag-red{background:#fee2e2;color:var(--error)}
.tag-gray{background:#e2e8f0;color:var(--text-muted)}
.tag-yellow{background:#fef3c7;color:var(--warning)}

/* alert */
.alert{padding:10px 14px;border-radius:6px;margin-bottom:16px;font-size:13px}
.alert-success{background:#dcfce7;color:var(--success)}
.alert-error{background:#fee2e2;color:var(--error)}
.alert-info{background:#dbeafe;color:var(--primary-dark)}

/* auth */
.auth-box{max-width:380px;margin:60px auto;padding:32px;background:#fff;border:1px solid var(--border);border-radius:10px;box-shadow:0 4px 12px rgba(0,0,0,.04)}
.auth-box h2{margin-bottom:20px;text-align:center}
.auth-foot{text-align:center;margin-top:14px;font-size:13px}

/* stat cards */
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:14px;margin-bottom:20px}
.stat-card{background:#fff;border:1px solid var(--border);border-radius:8px;padding:16px}
.stat-card .label{font-size:12px;color:var(--text-muted)}
.stat-card .value{font-size:24px;font-weight:700;margin-top:4px;color:var(--text)}
.stat-card .delta{font-size:11px;margin-top:4px}
.stat-card .delta.up{color:var(--success)}
.stat-card .delta.down{color:var(--error)}

/* charts */
.chart-box{background:#fff;border:1px solid var(--border);border-radius:8px;padding:18px;margin-bottom:20px}
.chart-box h3{margin-bottom:12px}
.chart{width:100%;height:300px}
.chart-row{display:grid;grid-template-columns:1.6fr 1fr;gap:20px}
@media(max-width:900px){.chart-row{grid-template-columns:1fr}}

/* toolbar */
.toolbar{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:16px}
.toolbar select,.toolbar input,.toolbar .btn{margin:0}
.toolbar .right{margin-left:auto}

/* modal */
.modal-mask{position:fixed;inset:0;background:rgba(0,0,0,.4);display:none;align-items:center;justify-content:center;z-index:1000}
.modal-mask.active{display:flex}
.modal{background:#fff;border-radius:10px;padding:24px;width:90%;max-width:520px;max-height:90vh;overflow:auto}
.modal h3{margin-top:0}
.modal-foot{display:flex;gap:10px;justify-content:flex-end;margin-top:20px}

.code-block{background:#1e293b;color:#e2e8f0;padding:14px;border-radius:6px;font-family:Consolas,Monaco,monospace;font-size:12px;word-break:break-all;white-space:pre-wrap}

/* ============ 三期：UI polish ============ */
/* 主题切换按钮 */
.theme-toggle{cursor:pointer;padding:6px 10px;border-radius:6px;background:#f1f5f9;border:1px solid var(--border);font-size:14px;line-height:1}
.theme-toggle:hover{background:#e2e8f0}

/* 深色模式 */
html[data-theme="dark"]{--bg:#0f172a;--card:#1e293b;--border:#334155;--text:#e2e8f0;--text-muted:#94a3b8}
html[data-theme="dark"] body{background:var(--bg)}
html[data-theme="dark"] .data-table th{background:#0f172a}
html[data-theme="dark"] .data-table tbody tr:hover{background:#0f172a}
html[data-theme="dark"] .form-label input,
html[data-theme="dark"] .form-label select,
html[data-theme="dark"] .form-label textarea{background:#0f172a;color:var(--text)}
html[data-theme="dark"] .btn{background:#334155;color:var(--text);border-color:#475569}
html[data-theme="dark"] .btn:hover{background:#475569}
html[data-theme="dark"] .btn-primary{background:var(--primary);color:#fff;border-color:var(--primary)}
html[data-theme="dark"] .btn-primary:hover{background:var(--primary-dark)}
html[data-theme="dark"] .tag{background:#334155;color:#cbd5e1}
html[data-theme="dark"] .stat-card{background:var(--card)}
html[data-theme="dark"] .modal{background:var(--card);color:var(--text)}
html[data-theme="dark"] .topbar{background:#020617}
html[data-theme="dark"] .toolbar select,
html[data-theme="dark"] .toolbar input{background:#0f172a;color:var(--text);border-color:#334155}
html[data-theme="dark"] input[type=date],html[data-theme="dark"] input[type=text],html[data-theme="dark"] input[type=password],html[data-theme="dark"] input[type=email]{background:#0f172a;color:var(--text);border-color:#334155}

/* 加载态骨架屏 */
.skeleton{background:linear-gradient(90deg,#e2e8f0 25%,#f1f5f9 37%,#e2e8f0 63%);background-size:400% 100%;animation:skeleton-loading 1.4s ease infinite;border-radius:6px}
html[data-theme="dark"] .skeleton{background:linear-gradient(90deg,#1e293b 25%,#334155 37%,#1e293b 63%);background-size:400% 100%}
@keyframes skeleton-loading{0%{background-position:100% 50%}100%{background-position:0 50%}}
.skeleton-line{height:14px;margin-bottom:6px;width:100%}
.skeleton-chart{height:300px;width:100%}
.chart.loading{position:relative}
.chart.loading::after{content:"加载中…";position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);color:var(--text-muted);font-size:14px}

/* 空状态 */
.empty-state{text-align:center;padding:60px 20px;color:var(--text-muted)}
.empty-state .empty-icon{font-size:36px;margin-bottom:12px;opacity:.6}
.empty-state .empty-text{font-size:14px;margin-bottom:16px}

/* 响应式：移动端折叠菜单 */
.menu-toggle{display:none;background:transparent;border:0;color:#fff;font-size:22px;padding:6px 10px;cursor:pointer;border-radius:6px}
.menu-toggle:hover{background:rgba(255,255,255,.1)}
@media(max-width:768px){
    .topbar-inner{flex-wrap:wrap;height:auto;padding:8px 12px;gap:8px}
    .topmenu{order:3;width:100%;flex-direction:column;gap:0;display:none;background:#0f172a;border-radius:6px;overflow:hidden}
    .topmenu.open{display:flex}
    .topmenu a{padding:10px 14px;border-bottom:1px solid #1e293b}
    .topmenu a:last-child{border-bottom:0}
    .menu-toggle{display:block;margin-left:auto}
    .topuser{font-size:12px;gap:10px}
    .stat-grid{grid-template-columns:repeat(2,1fr)}
    .chart{height:240px}
    .data-table{font-size:12px}
    .data-table th,.data-table td{padding:6px 8px}
    .container{padding:14px 12px}
    .toolbar{gap:6px}
    .toolbar .right{margin-left:0;width:100%}
}

/* 切换登录提示横幅 */
.switched-banner{background:#fef3c7;color:#92400e;padding:8px 16px;text-align:center;font-size:13px;border-bottom:1px solid #fde68a}
html[data-theme="dark"] .switched-banner{background:#422006;color:#fde68a;border-color:#92400e}