:root{
  --navy:#1A3A5C;
  --navy-d:#12293F;
  --navy-l:#2C5480;
  --red:#C00000;
  --red-d:#A32D2D;
  --bg:#f4f6f8;
  --line:#e3e7ec;
  --txt:#22282f;
  --mut:#7a8699;
  --ok:#1f7a4d;
  --warn:#b26a00;
}
*{box-sizing:border-box;margin:0;padding:0}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei","PingFang SC",sans-serif;
  background:var(--bg);color:var(--txt);font-size:14px;line-height:1.65;-webkit-font-smoothing:antialiased;
}
a{color:var(--navy);text-decoration:none}
a:hover{color:var(--red)}

/* ---------- 顶栏 ---------- */
.topbar{background:var(--navy);color:#fff}
.topbar-in{max-width:1180px;margin:0 auto;padding:0 20px;height:58px;display:flex;align-items:center;gap:26px}
.brand{display:flex;align-items:center;gap:9px;color:#fff!important;font-weight:600;font-size:17px;letter-spacing:.5px}
.brand img{height:26px;display:block}
.brand .en{font-weight:400;font-size:12px;opacity:.62;letter-spacing:1.5px;margin-left:1px}
.nav{display:flex;gap:4px;margin-left:10px;flex:1}
.nav a{color:rgba(255,255,255,.8);padding:7px 13px;border-radius:2px;font-size:14px}
.nav a:hover{background:rgba(255,255,255,.1);color:#fff}
.nav a.on{background:rgba(255,255,255,.16);color:#fff;font-weight:500}
.who{font-size:13px;color:rgba(255,255,255,.72);white-space:nowrap}
.who b{color:#fff;font-weight:500}
.who a{color:rgba(255,255,255,.72)}
.who a:hover{color:#fff}

/* ---------- 布局 ---------- */
.wrap{max-width:1180px;margin:0 auto;padding:26px 20px 60px}
.page-title{font-size:21px;font-weight:600;color:var(--navy);letter-spacing:.3px}
.page-sub{color:var(--mut);font-size:13px;margin:5px 0 22px}
.row{display:flex;align-items:center;gap:10px}
.flex1{flex:1}
.right{margin-left:auto}

/* ---------- 卡片 ---------- */
.card{background:#fff;border:1px solid var(--line);border-radius:2px}
.pad{padding:20px}
.sec-h{font-size:15px;font-weight:600;color:var(--navy);margin:26px 0 12px;padding-left:10px;border-left:3px solid var(--red);line-height:1.2}
.sec-h small{font-weight:400;color:var(--mut);font-size:12px;margin-left:8px}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(288px,1fr));gap:12px}
.tool{background:#fff;border:1px solid var(--line);border-radius:2px;padding:15px 16px;display:block;transition:.15s}
.tool:hover{border-color:var(--navy-l);box-shadow:0 2px 10px rgba(26,58,92,.09);transform:translateY(-1px)}
.tool .cn{font-size:14.5px;font-weight:600;color:var(--txt);display:flex;align-items:center;gap:7px}
.tool .cd{font-size:12.5px;color:var(--mut);margin-top:5px;line-height:1.5}
.tag{font-size:11px;font-weight:500;padding:1.5px 7px;border-radius:2px;flex-shrink:0}
.t-free{background:#e8f3ec;color:#1f7a4d}
.t-teacher{background:#fdeceb;color:var(--red)}
.t-login{background:#eaeff6;color:var(--navy)}

/* ---------- 工具卡片：一功能一卡片 + 卡内多链接 ---------- */
.tcard{background:#fff;border:1px solid var(--line);border-radius:2px;display:flex;flex-direction:column;transition:.15s}
.tcard:hover{border-color:var(--navy-l);box-shadow:0 2px 10px rgba(26,58,92,.09)}
.tcard .hd{padding:14px 15px 0;display:flex;align-items:flex-start;gap:8px}
.tcard .hd .cn{font-size:14.5px;font-weight:600;color:var(--txt);flex:1;line-height:1.4}
.tcard .bd{padding:5px 15px 13px;font-size:12.5px;color:var(--mut);line-height:1.55;flex:1}
.tcard .acts{display:flex;flex-wrap:wrap;gap:6px;padding:10px 13px;border-top:1px solid var(--line);background:#fafbfc}
.chip{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;padding:4px 11px;
  border:1px solid #ccd4dd;border-radius:2px;background:#fff;color:var(--navy)!important;transition:.15s;white-space:nowrap}
.chip:hover{border-color:var(--navy-l);background:#f2f6fa;color:var(--red)!important}
.chip .dot{width:5px;height:5px;border-radius:50%;background:#1f7a4d;flex-shrink:0}
.chip.teacher .dot{background:var(--red)}
.chip.login .dot{background:var(--navy-l)}
.chip .lk{font-size:11px;color:var(--mut)}
.legend{display:flex;flex-wrap:wrap;gap:16px;font-size:12.5px;color:var(--mut);margin:2px 0 20px}
.legend i{display:inline-block;width:6px;height:6px;border-radius:50%;margin-right:5px;vertical-align:1px}

/* ---------- 统计 ---------- */
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-bottom:8px}
.stat{background:#fff;border:1px solid var(--line);border-radius:2px;padding:16px 18px}
.stat .n{font-size:25px;font-weight:600;color:var(--navy);line-height:1.2}
.stat .l{font-size:12.5px;color:var(--mut);margin-top:3px}

/* ---------- 表格 ---------- */
table{width:100%;border-collapse:collapse;background:#fff;font-size:13.5px}
th{background:var(--navy);color:#fff;font-weight:500;text-align:left;padding:10px 13px;font-size:13px;white-space:nowrap}
td{padding:10px 13px;border-bottom:1px solid var(--line);vertical-align:middle}
tr:last-child td{border-bottom:none}
tbody tr:hover{background:#f9fbfc}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12.5px}

/* ---------- 表单 ---------- */
label{display:block;font-size:12.5px;color:var(--mut);margin:0 0 5px}
input[type=text],input[type=password],input[type=number],input[type=date],select,textarea{
  width:100%;padding:8px 11px;border:1px solid #ccd4dd;border-radius:2px;font-size:14px;
  font-family:inherit;color:var(--txt);background:#fff;outline:none;transition:.15s}
input:focus,select:focus,textarea:focus{border-color:var(--navy-l);box-shadow:0 0 0 3px rgba(44,84,128,.1)}
textarea{min-height:96px;resize:vertical;line-height:1.6}
.f{margin-bottom:13px}
.f2{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.btn{display:inline-block;padding:8px 20px;background:var(--navy);color:#fff!important;border:none;
  border-radius:2px;font-size:14px;font-family:inherit;cursor:pointer;transition:.15s}
.btn:hover{background:var(--navy-d)}
.btn.red{background:var(--red)}
.btn.red:hover{background:var(--red-d)}
.btn.ghost{background:#fff;color:var(--navy)!important;border:1px solid #ccd4dd}
.btn.ghost:hover{border-color:var(--navy-l);background:#f7f9fb}
.btn.sm{padding:5px 12px;font-size:12.5px}
.btn.xs{padding:3px 9px;font-size:12px}
.btn.link{background:none;color:var(--mut)!important;padding:3px 6px}
.btn.link:hover{color:var(--red)!important;background:none}

/* ---------- 提示 ---------- */
.note{border-radius:2px;padding:12px 15px;font-size:13px;line-height:1.6;margin:14px 0}
.note.blue{background:#eef3f9;border-left:3px solid var(--navy);color:#2a4a6b}
.note.gold{background:#fdf6e8;border-left:3px solid var(--warn);color:#7a5200}
.note.green{background:#eaf5ef;border-left:3px solid var(--ok);color:#1a5f3c}
.note.red{background:#fdeceb;border-left:3px solid var(--red);color:#8a1f1f}

/* ---------- 登录页 ---------- */
.login-bg{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--navy) 0%,var(--navy-d) 55%,#0d1f30 100%);padding:24px;gap:26px}
.login-box{background:#fff;width:100%;max-width:396px;border-radius:2px;padding:42px 40px 36px;
  box-shadow:0 18px 50px rgba(0,0,0,.3)}
.login-logo{text-align:center;margin-bottom:8px}
.login-logo img{max-height:52px;max-width:100%;width:auto;height:auto}
.login-title{text-align:center;font-size:19px;font-weight:600;color:var(--navy);letter-spacing:1px}
.login-sub{text-align:center;font-size:12.5px;color:var(--mut);margin:6px 0 26px}
.login-box .btn{width:100%;padding:11px;font-size:15px;letter-spacing:2px}
.login-err{background:#fdeceb;color:#8a1f1f;font-size:13px;padding:9px 12px;border-radius:2px;margin-bottom:14px;text-align:center}
.login-foot{text-align:center;font-size:12px;color:#aab4c0;margin-top:20px;line-height:1.8}
.login-about{width:100%;max-width:396px;color:rgba(255,255,255,.78);font-size:12.5px;line-height:1.85}
.login-about h2{display:flex;align-items:center;gap:10px;font-size:14px;font-weight:600;color:#fff;
  letter-spacing:.5px;margin-bottom:10px}
.login-about h2::before,.login-about h2::after{content:"";height:1px;background:rgba(255,255,255,.22);flex:1}
.login-about h3{font-size:12.5px;font-weight:600;color:rgba(255,255,255,.92);margin:14px 0 4px;letter-spacing:.3px}
.login-about p{margin:0;text-align:justify}

/* ---------- 二维码 ---------- */
.qr-card{background:#fff;border:1px solid var(--line);border-radius:2px;padding:22px;text-align:center}
.qr-card svg{width:100%;max-width:260px;height:auto}

/* ---------- 其他 ---------- */
.empty{text-align:center;color:#aab4c0;padding:44px 0;font-size:14px}
.pill{display:inline-block;font-size:11.5px;padding:2px 9px;border-radius:10px;background:#eef2f6;color:var(--mut)}
.pill.on{background:#e8f3ec;color:var(--ok)}
.pill.off{background:#f1f3f5;color:#98a2b3}
.foot{text-align:center;color:#b6bec9;font-size:12.5px;padding:34px 0 10px}
.hr{height:1px;background:var(--line);margin:20px 0}
.copy{background:#f7f9fb;border:1px solid var(--line);border-radius:2px;padding:6px 10px;
  font-family:ui-monospace,Menlo,Consolas,monospace;font-size:12px;color:#3c4a5a;word-break:break-all}
@media(max-width:720px){
  .topbar-in{gap:12px;padding:0 12px}
  .nav{gap:0}
  .nav a{padding:6px 8px;font-size:13px}
  .who{display:none}
  .wrap{padding:18px 12px 50px}
  .f2{grid-template-columns:1fr}
}