:root{
  --pri:#4f46e5; --pri-d:#4338ca; --pri-s:#eef2ff;
  --bg:#f4f5f7; --card:#fff; --text:#1f2328; --sub:#6b7280;
  --line:#e5e7eb; --line2:#f1f2f4;
  --ok:#16a34a; --ok-s:#e8f6ed; --no:#dc2626; --no-s:#fdeceb;
  --warn:#d97706; --warn-s:#fef6e7;
  --r:12px; --shadow:0 1px 3px rgba(16,24,40,.06),0 1px 2px rgba(16,24,40,.04);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{background:var(--bg);color:var(--text);font:14px/1.6 -apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;-webkit-font-smoothing:antialiased}
button{font:inherit;color:inherit;background:none;border:none;padding:0;cursor:pointer}
a{color:var(--pri);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{margin:0;font-weight:600}
code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}

/* ============ 登录 ============ */
.login-wrap{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px;
  background:linear-gradient(135deg,#4f46e5 0%,#7c3aed 55%,#4338ca 100%)}
.login-card{width:100%;max-width:400px;background:#fff;border-radius:16px;padding:28px 26px;box-shadow:0 20px 45px rgba(30,27,75,.25)}
.login-card .brand{text-align:center;margin-bottom:22px}
.login-card .logo{width:52px;height:52px;border-radius:14px;background:var(--pri-s);color:var(--pri);
  display:flex;align-items:center;justify-content:center;font-size:22px;font-weight:700;margin:0 auto 10px}
.login-card h1{font-size:19px}
.login-card .tip{margin-top:6px;font-size:12.5px;color:var(--sub)}

/* ============ 布局 ============ */
.topbar{position:sticky;top:0;z-index:40;height:56px;background:#fff;border-bottom:1px solid var(--line);
  display:flex;align-items:center;gap:12px;padding:0 18px}
.topbar .logo{width:30px;height:30px;border-radius:8px;background:var(--pri);color:#fff;display:flex;
  align-items:center;justify-content:center;font-size:14px;font-weight:700;flex:none}
.topbar .tt{font-size:16px;font-weight:600}
.topbar .tt span{font-size:12px;color:var(--sub);font-weight:400;margin-left:8px}
.topbar .right{margin-left:auto;display:flex;align-items:center;gap:12px;font-size:13px;color:var(--sub)}
.layout{display:flex;align-items:flex-start;max-width:1560px;margin:0 auto}
.side{width:196px;flex:none;position:sticky;top:56px;height:calc(100vh - 56px);overflow-y:auto;
  background:#fff;border-right:1px solid var(--line);padding:12px 10px}
.side button{display:flex;align-items:center;gap:9px;width:100%;padding:9px 11px;border-radius:9px;
  font-size:14px;color:var(--sub);text-align:left;margin-bottom:2px}
.side button:hover{background:var(--line2);color:var(--text)}
.side button.on{background:var(--pri-s);color:var(--pri);font-weight:600}
.side .ico{width:18px;text-align:center;font-size:13px;opacity:.9}
.main{flex:1;min-width:0;padding:18px}
.page-title{display:flex;align-items:center;gap:10px;margin-bottom:14px;flex-wrap:wrap}
.page-title h2{font-size:18px}
.page-title .desc{font-size:12.5px;color:var(--sub)}

/* ============ 通用组件 ============ */
.card{background:var(--card);border-radius:var(--r);box-shadow:var(--shadow);padding:16px;margin-bottom:14px}
.card h3{font-size:15px;margin-bottom:4px}
.card h4{font-size:13.5px;margin-bottom:8px;color:var(--sub)}
.muted{color:var(--sub)}
.note{font-size:12.5px;color:var(--sub);line-height:1.75}
.hr{height:1px;background:var(--line);margin:14px 0}
.empty{text-align:center;padding:44px 16px;color:var(--sub);font-size:13.5px}
.loading{text-align:center;padding:30px 16px;color:var(--sub);font-size:13.5px}
.err-box{background:var(--no-s);color:var(--no);border-radius:10px;padding:10px 13px;font-size:13px;margin-bottom:12px;line-height:1.6}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:5px;padding:7px 14px;border-radius:9px;
  border:1px solid var(--line);background:#fff;font-size:13.5px;white-space:nowrap}
.btn:hover{border-color:#cfd3da;background:#fafafa}
.btn.pri{background:var(--pri);border-color:var(--pri);color:#fff}
.btn.pri:hover{background:var(--pri-d);border-color:var(--pri-d)}
.btn.danger{color:var(--no);border-color:#f3c9c5}
.btn.danger:hover{background:var(--no-s)}
.btn.sm{padding:4px 9px;font-size:12.5px;border-radius:7px}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn-block{width:100%;padding:11px;font-size:15px;font-weight:600}

.inp{width:100%;padding:8px 11px;border:1px solid var(--line);border-radius:9px;background:#fff;color:var(--text);
  font:inherit;font-size:13.5px;outline:none}
.inp:focus{border-color:var(--pri);box-shadow:0 0 0 3px rgba(79,70,229,.12)}
textarea.inp{min-height:78px;resize:vertical;line-height:1.6}
select.inp{padding:8px 9px}
.inp.w-auto{width:auto}
.field{margin-bottom:13px}
.field>label{display:block;font-size:12.5px;color:var(--sub);margin-bottom:5px}
.field-row{display:flex;gap:10px;flex-wrap:wrap}
.field-row>*{flex:1;min-width:150px}
.toolbar{display:flex;gap:9px;align-items:center;flex-wrap:wrap;margin-bottom:13px}
.toolbar .grow{flex:1;min-width:180px}

.stat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(158px,1fr));gap:12px}
.stat{background:var(--pri-s);border-radius:12px;padding:14px}
.stat b{display:block;font-size:24px;color:var(--pri);line-height:1.25;font-weight:700}
.stat span{font-size:12.5px;color:var(--sub)}
.stat.g{background:var(--ok-s)} .stat.g b{color:var(--ok)}
.stat.o{background:var(--warn-s)} .stat.o b{color:var(--warn)}

.tbl-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;border:1px solid var(--line);border-radius:10px}
.tbl{width:100%;border-collapse:collapse;font-size:13px;min-width:640px}
.tbl th{background:#fafbfc;text-align:left;padding:9px 11px;font-weight:600;color:var(--sub);
  font-size:12.5px;white-space:nowrap;border-bottom:1px solid var(--line)}
.tbl td{padding:9px 11px;border-bottom:1px solid var(--line2);vertical-align:middle}
.tbl tr:last-child td{border-bottom:none}
.tbl tbody tr:hover{background:#fafbfc}
.tbl .act{white-space:nowrap;text-align:right}
.ell{max-width:190px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ell2{max-width:300px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12.5px}

.chip{display:inline-block;background:var(--pri-s);color:var(--pri);border-radius:6px;padding:1px 8px;font-size:11.5px;font-weight:600;white-space:nowrap}
.chip.g{background:var(--ok-s);color:var(--ok)}
.chip.r{background:var(--no-s);color:var(--no)}
.chip.n{background:var(--line2);color:var(--sub)}

.pager{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-top:13px;flex-wrap:wrap;font-size:13px}
.pg-btns{display:flex;align-items:center;gap:6px}
.pg{padding:4px 10px;border:1px solid var(--line);border-radius:7px;font-size:12.5px;background:#fff}
.pg:hover{background:#fafbfc}
.pg.dis{opacity:.45;cursor:not-allowed}
.pg-cur{font-size:12.5px;color:var(--sub);padding:0 4px}

.subtabs{display:flex;gap:8px;margin-bottom:14px}
.subtab{padding:7px 16px;border:1px solid var(--line);border-radius:9px;font-size:13.5px;color:var(--sub);background:#fff}
.subtab.on{background:var(--pri-s);border-color:var(--pri);color:var(--pri);font-weight:600}

/* 开关 */
.switch{position:relative;display:inline-block;width:42px;height:23px;flex:none}
.switch input{opacity:0;width:0;height:0;position:absolute}
.switch i{position:absolute;inset:0;background:#cbd5e1;border-radius:23px;transition:.18s}
.switch i::before{content:"";position:absolute;width:17px;height:17px;left:3px;top:3px;background:#fff;border-radius:50%;transition:.18s}
.switch input:checked+i{background:var(--pri)}
.switch input:checked+i::before{transform:translateX(19px)}

/* 密码展示 */
.pwd-box{background:var(--ok-s);border:1px solid #bfe6cd;border-radius:12px;padding:14px;margin-top:13px}
.pwd-box .lb{font-size:13px;color:#15803d;margin-bottom:4px;font-weight:600}
.pwd-box .sub2{font-size:12.5px;color:#15803d;opacity:.85;margin-bottom:9px}
.pwd-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.pwd-row code{font-size:22px;font-weight:700;letter-spacing:2px;color:#14532d;background:#fff;
  border:1px dashed #86cfa4;border-radius:9px;padding:6px 14px}

/* 弹窗 */
.modal{position:fixed;inset:0;z-index:80;background:rgba(17,20,28,.5);display:none;
  padding:24px 16px;overflow:auto}
.modal.show{display:flex;align-items:flex-start;justify-content:center}
.modal-box{background:#fff;border-radius:14px;width:100%;max-width:720px;box-shadow:0 24px 60px rgba(16,24,40,.28);
  display:flex;flex-direction:column;max-height:calc(100vh - 48px)}
.modal-box.wide{max-width:900px}
.modal-box.narrow{max-width:460px}
.modal-hd{display:flex;align-items:center;padding:15px 18px;border-bottom:1px solid var(--line)}
.modal-hd h3{font-size:16px;flex:1}
.modal-hd .x{font-size:20px;color:var(--sub);line-height:1;padding:2px 6px;border-radius:6px}
.modal-hd .x:hover{background:var(--line2)}
.modal-bd{padding:16px 18px;overflow:auto;flex:1}
.modal-ft{padding:12px 18px;border-top:1px solid var(--line);display:flex;justify-content:flex-end;gap:9px}

.toast{position:fixed;left:50%;bottom:34px;transform:translateX(-50%) translateY(8px);background:#1f2328;
  color:#fff;padding:9px 18px;border-radius:20px;font-size:13.5px;z-index:99;opacity:0;pointer-events:none;
  transition:.2s;max-width:82%;text-align:center}
.toast.on{opacity:1;transform:translateX(-50%) translateY(0)}
.toast.ok{background:#15803d}
.toast.no{background:#b91c1c}

/* 无权限 */
.noperm{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px;background:var(--bg)}
.noperm .box{background:#fff;border-radius:14px;padding:34px 30px;text-align:center;box-shadow:var(--shadow);max-width:380px;width:100%}
.noperm .ic{font-size:40px;margin-bottom:10px}
.noperm h2{font-size:18px;margin-bottom:8px}
.noperm p{color:var(--sub);font-size:13.5px;margin:0 0 18px}

@media (max-width:1000px){
  .layout{display:block}
  .side{width:auto;height:auto;position:static;border-right:none;border-bottom:1px solid var(--line);
    display:flex;gap:6px;overflow-x:auto;padding:9px 10px;-webkit-overflow-scrolling:touch}
  .side button{width:auto;flex:none;margin-bottom:0;white-space:nowrap}
  .main{padding:14px}
  .stat-grid{grid-template-columns:repeat(auto-fill,minmax(140px,1fr))}
  .modal{padding:12px 8px}
  .ell,.ell2{max-width:200px}
}
/* 学习笔记管理补充 */
.tag{display:inline-block;padding:2px 8px;border-radius:99px;font-size:12px;background:#f1f2f4;color:#6b7280;white-space:nowrap}
.tag.ok{background:#e8f6ed;color:#16a34a}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:0 14px}
@media (max-width:640px){.grid2{grid-template-columns:1fr}}

/* v5.5 讨论管理 */
.mini{font-size:11.5px;color:var(--sub);margin-top:3px;line-height:1.45}