/* ============================================================
   教学资料网 · 后台管理样式
   ============================================================ */
:root{
  --paper:#F6F5F1;
  --surface:#FFFFFF;
  --ink:#232B2E;
  --ink-2:#3A4347;
  --muted:#6E7578;
  --line:#E2DED5;
  --primary:#3E9B6C;
  --danger:#C04A4A;
  --shadow:0 8px 24px rgba(35,43,46,.08);
}
*{box-sizing:border-box;}
body{
  margin:0;font-family:'Noto Sans SC',-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;
  background:var(--paper);color:var(--ink);line-height:1.6;-webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none;}
p{margin:0;}
h1,h2,h3,h4{margin:0;line-height:1.2;}
:focus-visible{outline:3px solid rgba(62,155,108,.4);outline-offset:2px;border-radius:4px;}

/* ===== 登录页 ===== */
.login-wrap{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px;}
.login-card{width:100%;max-width:400px;background:var(--surface);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:36px;}
.login-brand{display:flex;align-items:center;gap:10px;font-weight:900;font-size:20px;justify-content:center;}
.login-brand .logo-tab{
  display:flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:9px 9px 4px 4px;background:var(--ink);color:#fff;
}
.login-brand .logo-tab svg{width:20px;height:20px;}
.login-card h1{font-size:19px;font-weight:900;text-align:center;margin-top:18px;}
.login-tip{text-align:center;font-size:13px;color:var(--muted);margin-top:6px;}

/* ===== 表单 ===== */
.form{display:flex;flex-direction:column;gap:16px;margin-top:24px;}
.form-row{display:flex;flex-direction:column;gap:6px;}
.form-row label{font-size:13.5px;font-weight:600;color:var(--ink-2);}
.form-row input[type=text],
.form-row input[type=password],
.form-row input[type=search],
.form-row input[type=number],
.form-row input[type=color],
.form-row select,
.form-row textarea{
  border:1px solid var(--line);border-radius:10px;padding:10px 14px;font:inherit;font-size:14px;color:var(--ink);
  background:#fff;outline:0;width:100%;
}
.form-row input:focus,.form-row select:focus,.form-row textarea:focus{border-color:#b8b2a2;}
.form-row textarea{resize:vertical;min-height:90px;}
.form-row .hint{font-size:12px;color:var(--muted);}
.form-check{display:flex;align-items:center;gap:8px;}
.form-check input{width:17px;height:17px;accent-color:var(--primary);}
.form-check label{font-size:14px;color:var(--ink-2);}
.form-actions{display:flex;gap:12px;margin-top:6px;flex-wrap:wrap;}
.btn{
  display:inline-flex;align-items:center;gap:8px;font:inherit;font-size:14px;font-weight:600;cursor:pointer;
  padding:10px 20px;border-radius:999px;border:1px solid transparent;transition:all .2s;
}
.btn svg{width:16px;height:16px;}
.btn-primary{background:var(--ink);color:#fff;}
.btn-primary:hover{background:#101416;}
.btn-green{background:var(--primary);color:#fff;}
.btn-green:hover{background:#35865c;}
.btn-ghost{background:#fff;color:var(--ink);border-color:var(--line);}
.btn-ghost:hover{border-color:#b8b2a2;}
.btn-danger{background:#fff;color:var(--danger);border-color:#e3c0c0;}
.btn-danger:hover{background:var(--danger);color:#fff;}
.btn-sm{padding:6px 13px;font-size:13px;}

/* ===== 后台布局 ===== */
.admin-shell{display:flex;min-height:100vh;}
.admin-side{
  width:230px;flex:none;background:var(--ink);color:#fff;display:flex;flex-direction:column;position:sticky;top:0;height:100vh;
}
.admin-brand{padding:22px 20px;font-weight:900;font-size:17px;display:flex;flex-direction:column;gap:2px;border-bottom:1px solid rgba(255,255,255,.1);}
.admin-brand small{font-weight:400;font-size:12px;color:rgba(255,255,255,.55);}
.admin-nav{display:flex;flex-direction:column;padding:14px 12px;gap:4px;flex:1;}
.admin-nav a{
  padding:11px 14px;border-radius:9px;font-size:14.5px;color:rgba(255,255,255,.82);transition:all .2s;
}
.admin-nav a:hover{background:rgba(255,255,255,.08);}
.admin-nav a.active{background:rgba(62,155,108,.28);color:#fff;}
.admin-side-foot{padding:14px 12px;border-top:1px solid rgba(255,255,255,.1);display:flex;flex-direction:column;gap:4px;}
.admin-side-foot a{padding:9px 14px;border-radius:9px;font-size:13.5px;color:rgba(255,255,255,.7);}
.admin-side-foot a:hover{background:rgba(255,255,255,.08);color:#fff;}
.admin-main{flex:1;min-width:0;padding:26px 30px 60px;}
.admin-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:22px;}
.admin-top h1{font-size:22px;font-weight:900;}
.admin-user{font-size:13.5px;color:var(--muted);background:#fff;border:1px solid var(--line);padding:7px 14px;border-radius:999px;}

/* ===== 提示消息 ===== */
.flash{padding:12px 18px;border-radius:10px;margin-bottom:20px;font-size:14px;}
.flash--success{background:#e6f4ec;color:#2c7a52;border:1px solid #bfe3d0;}
.flash--error{background:#fbeaea;color:#b03a3a;border:1px solid #f0c9c9;}

/* ===== 仪表盘 ===== */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-bottom:26px;}
.stat-card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:20px;box-shadow:0 4px 14px rgba(35,43,46,.05);}
.stat-card .num{font-size:30px;font-weight:900;font-family:'Noto Serif SC',serif;}
.stat-card .label{font-size:13px;color:var(--muted);margin-top:4px;}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:22px;margin-bottom:22px;box-shadow:0 4px 14px rgba(35,43,46,.05);}
.panel h2{font-size:16px;font-weight:700;margin-bottom:16px;}
.panel h2 .more{float:right;font-size:13px;font-weight:500;color:var(--primary);}

/* ===== 表格 ===== */
.table-wrap{overflow-x:auto;}
table{width:100%;border-collapse:collapse;font-size:14px;}
th,td{text-align:left;padding:11px 12px;border-bottom:1px solid var(--line);vertical-align:middle;}
th{font-size:13px;color:var(--muted);font-weight:600;white-space:nowrap;}
td{color:var(--ink-2);}
tr:last-child td{border-bottom:0;}
.cat-dot{display:inline-block;width:9px;height:9px;border-radius:50%;margin-right:6px;vertical-align:1px;}
.badge{display:inline-block;font-size:12px;font-weight:600;padding:3px 10px;border-radius:999px;}
.badge--on{background:#e6f4ec;color:#2c7a52;}
.badge--off{background:#f0efea;color:#8a877e;}
.badge--top{background:#fdeee2;color:#c06a2f;}
.badge--vip{background:#fdeee2;color:#c06a2f;}
.row-actions{display:flex;gap:8px;white-space:nowrap;}
.row-actions form{display:inline;}
.link-btn{font-size:13px;color:var(--primary);font-weight:600;background:none;border:0;cursor:pointer;padding:0;font-family:inherit;}
.link-btn.danger{color:var(--danger);}

/* ===== 后台列表工具条 ===== */
.toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:12px;margin-bottom:18px;}
.toolbar form{display:flex;flex-wrap:wrap;gap:10px;align-items:center;}
.toolbar input[type=search],.toolbar select{
  border:1px solid var(--line);border-radius:10px;padding:8px 12px;font:inherit;font-size:13.5px;background:#fff;outline:0;
}
.toolbar input[type=search]:focus,.toolbar select:focus{border-color:#b8b2a2;}
.toolbar .spacer{flex:1;}
.pagination-sm{display:flex;gap:6px;align-items:center;font-size:13px;color:var(--muted);}
.pagination-sm a{
  min-width:30px;height:30px;display:inline-flex;align-items:center;justify-content:center;padding:0 8px;
  border:1px solid var(--line);border-radius:8px;background:#fff;font-size:13px;
}
.pagination-sm a.active{background:var(--ink);color:#fff;border-color:var(--ink);}

@media (max-width:899px){
  .admin-shell{flex-direction:column;}
  .admin-side{width:100%;height:auto;position:static;}
  .stats{grid-template-columns:repeat(2,1fr);}
  .admin-main{padding:20px;}
}