:root{
  --primary:#2563eb; --primary-dark:#1d4ed8; --bg:#f1f5f9; --card:#ffffff;
  --text:#0f172a; --muted:#64748b; --border:#e2e8f0;
  --danger:#dc2626; --success:#16a34a; --warn:#d97706;
  --sidebar-bg:#0f172a; --sidebar-text:#cbd5e1;
  --radius:12px; --shadow:0 1px 3px rgba(0,0,0,.08);
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",Roboto,sans-serif;background:var(--bg);color:var(--text);font-size:14px;line-height:1.5}
.hidden{display:none!important}
button{font-family:inherit;cursor:pointer}
a{cursor:pointer}
input,select,textarea{font-family:inherit;font-size:14px;border:1px solid var(--border);border-radius:8px;padding:8px 10px;width:100%;background:#fff;color:var(--text)}
input:focus,select:focus,textarea:focus{outline:2px solid rgba(37,99,235,.25);border-color:var(--primary)}
textarea{resize:vertical;line-height:1.6}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:none;border-radius:8px;padding:9px 16px;font-size:14px;transition:.15s;background:#e2e8f0;color:#0f172a}
.btn:hover{filter:brightness(.96)}
.btn.primary{background:var(--primary);color:#fff}
.btn.danger{background:#fee2e2;color:var(--danger)}
.btn.success{background:var(--success);color:#fff}
.btn.warn{background:#fef3c7;color:var(--warn)}
.btn.ghost{background:transparent;color:var(--muted);border:1px solid var(--border)}
.btn.block{width:100%}
.btn.small{padding:5px 10px;font-size:12px}
.icon-btn{background:none;border:none;font-size:22px;padding:4px 8px;color:var(--text)}

/* ===== 登录页 ===== */
.login-page{min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#1e3a8a,#2563eb 50%,#3b82f6);padding:20px}
.login-box{background:#fff;border-radius:16px;padding:36px 32px;width:100%;max-width:400px;box-shadow:0 20px 60px rgba(0,0,0,.25)}
.login-logo{font-size:42px;text-align:center;margin-bottom:8px}
.login-box h1{font-size:22px;text-align:center;color:var(--text)}
.login-sub{text-align:center;color:var(--muted);margin:4px 0 20px;font-size:13px}
.login-box .field{margin-bottom:14px}
.login-box .field label{display:block;font-size:13px;color:var(--muted);margin-bottom:6px}
.login-error{color:var(--danger);font-size:13px;min-height:18px;text-align:center;margin-top:8px}
.login-tip{font-size:12px;color:var(--muted);text-align:center;margin-top:12px;line-height:1.7}

/* ===== 布局 ===== */
.app{display:flex;min-height:100vh}
.sidebar{width:210px;background:var(--sidebar-bg);color:var(--sidebar-text);display:flex;flex-direction:column;position:fixed;top:0;left:0;bottom:0;z-index:100;transition:transform .25s}
.sidebar-logo{font-size:16px;font-weight:700;color:#fff;padding:18px 16px;border-bottom:1px solid rgba(255,255,255,.08);letter-spacing:1px}
.nav{flex:1;overflow-y:auto;padding:10px 8px}
.nav-item{display:flex;align-items:center;gap:8px;padding:10px 12px;border-radius:8px;color:var(--sidebar-text);text-decoration:none;margin-bottom:2px;font-size:14px;cursor:pointer;user-select:none}
.nav-item:hover{background:rgba(255,255,255,.08);color:#fff}
.nav-item.active{background:var(--primary);color:#fff}
.nav-ico{width:22px;text-align:center;font-size:15px}
.sidebar-footer{padding:12px;border-top:1px solid rgba(255,255,255,.08)}
.user-badge{margin-bottom:8px;font-size:13px;color:#fff;word-break:break-all}
.sidebar-mask{display:none;position:fixed;inset:0;background:rgba(15,23,42,.4);z-index:90}
.main-wrap{flex:1;margin-left:210px;display:flex;flex-direction:column;min-height:100vh}
.topbar{height:54px;background:#fff;border-bottom:1px solid var(--border);display:flex;align-items:center;gap:10px;padding:0 16px;position:sticky;top:0;z-index:50}
.topbar h2{font-size:17px}
.topbar-right{margin-left:auto;font-size:13px;color:var(--muted)}
#content{padding:18px;flex:1}
.page{max-width:1200px;margin:0 auto}

/* ===== 通用卡片 ===== */
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin-bottom:16px}
.card h3{font-size:15px;margin-bottom:12px;display:flex;align-items:center;gap:8px}
.card-title-row{display:flex;align-items:center;justify-content:space-between;margin-bottom:12px;gap:8px;flex-wrap:wrap}
.card-title-row h3{margin-bottom:0}

/* ===== 统计卡 ===== */
.stat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px;margin-bottom:16px}
.stat-card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:16px;text-align:center;box-shadow:var(--shadow)}
.stat-num{font-size:30px;font-weight:700;color:var(--primary)}
.stat-label{font-size:13px;color:var(--muted);margin-top:4px}

/* ===== 快捷入口 ===== */
.quick-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:12px;margin-bottom:16px}
.quick-item{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:16px;text-align:center;cursor:pointer;transition:.15s;box-shadow:var(--shadow)}
.quick-item:hover{border-color:var(--primary);transform:translateY(-2px)}
.quick-ico{font-size:26px}
.quick-name{font-size:14px;font-weight:600;margin-top:6px}
.quick-desc{font-size:12px;color:var(--muted);margin-top:2px}

/* ===== 待办 ===== */
.todo-item{display:flex;align-items:center;justify-content:space-between;padding:10px 12px;border:1px solid var(--border);border-radius:10px;margin-bottom:8px;background:#f8fafc;gap:8px;flex-wrap:wrap}
.todo-item .todo-info{display:flex;align-items:center;gap:8px;flex-wrap:wrap;min-width:0}
.todo-names{color:var(--muted);font-size:12px;overflow:hidden;text-overflow:ellipsis}
.badge{display:inline-block;background:var(--primary);color:#fff;border-radius:10px;padding:1px 8px;font-size:12px;white-space:nowrap}
.badge.warn{background:var(--warn)}
.badge.success{background:var(--success)}
.badge.danger{background:var(--danger)}
.badge.gray{background:#e2e8f0;color:#475569}

/* ===== 表格 ===== */
.table-wrap{overflow-x:auto;background:#fff;border:1px solid var(--border);border-radius:var(--radius)}
table{width:100%;border-collapse:collapse;font-size:13px;min-width:640px}
th,td{padding:9px 10px;text-align:left;border-bottom:1px solid var(--border);white-space:nowrap}
th{background:#f8fafc;color:var(--muted);font-weight:600}
tbody tr:hover td{background:#f8fafc}

/* ===== 表单 ===== */
.form-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px}
.form-item{margin-bottom:12px}
.form-item label{display:block;font-size:13px;color:var(--muted);margin-bottom:6px}
.form-item label .req{color:var(--danger)}

/* ===== Tabs ===== */
.tabs{display:flex;gap:6px;border-bottom:1px solid var(--border);margin-bottom:16px;overflow-x:auto}
.tab{padding:9px 16px;cursor:pointer;border-radius:8px 8px 0 0;font-size:14px;color:var(--muted);border:1px solid transparent;border-bottom:none;white-space:nowrap;background:transparent}
.tab.active{background:#fff;color:var(--primary);font-weight:600;border-color:var(--border)}

/* ===== Chips 筛选 ===== */
.chips{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:12px}
.chip{padding:5px 12px;border-radius:14px;border:1px solid var(--border);background:#fff;font-size:13px;cursor:pointer;color:var(--muted)}
.chip.active{background:var(--primary);color:#fff;border-color:var(--primary)}

/* ===== 工具栏 ===== */
.toolbar{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:14px}
.toolbar .spacer{flex:1}
.toolbar input{width:auto;min-width:180px;flex:1;max-width:320px}

/* ===== 模态 ===== */
.modal-mask{position:fixed;inset:0;background:rgba(15,23,42,.5);z-index:200;display:flex;align-items:flex-start;justify-content:center;padding:30px 12px;overflow-y:auto}
.modal{background:#fff;border-radius:14px;width:100%;max-width:640px;padding:20px;animation:pop .15s;margin:auto}
.modal.wide{max-width:880px}
@keyframes pop{from{transform:scale(.96);opacity:.5}to{transform:scale(1);opacity:1}}
.modal h3{font-size:16px;margin-bottom:16px;display:flex;align-items:center;justify-content:space-between}
.modal-actions{display:flex;gap:8px;justify-content:flex-end;margin-top:16px;flex-wrap:wrap}

/* ===== Toast ===== */
.toast{position:fixed;top:70px;left:50%;transform:translateX(-50%);background:#0f172a;color:#fff;padding:10px 18px;border-radius:8px;z-index:300;font-size:14px;box-shadow:0 8px 24px rgba(0,0,0,.25);max-width:90vw}

/* ===== 公告 ===== */
.notice-item{border:1px solid var(--border);border-radius:10px;padding:12px 14px;margin-bottom:10px;background:#fff}
.notice-item.pinned{border-left:4px solid var(--warn);background:#fffbeb}
.notice-title{font-weight:600;font-size:14px;display:flex;align-items:center;gap:6px;flex-wrap:wrap}
.notice-meta{font-size:12px;color:var(--muted);margin-top:4px}
.notice-content{margin-top:8px;white-space:pre-wrap;font-size:13px}

/* ===== 错题 ===== */
.wrong-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:10px}
.wrong-card{border:1px solid var(--border);border-radius:10px;padding:12px;background:#fff;position:relative}
.wrong-card.selected{border-color:var(--primary);box-shadow:0 0 0 2px rgba(37,99,235,.15)}
.wrong-card .wc-head{display:flex;align-items:center;gap:8px;margin-bottom:6px}
.wrong-card .wc-sub{font-size:12px;color:var(--muted);margin-top:4px;white-space:pre-wrap}
.wrong-actions{margin-top:8px;display:flex;gap:6px;flex-wrap:wrap}

/* ===== 作业 ===== */
.hw-subject{background:#f8fafc;border:1px solid var(--border);border-radius:10px;padding:12px;margin-bottom:12px}
.hw-subject .head{display:flex;align-items:center;gap:8px;margin-bottom:8px;flex-wrap:wrap}
.img-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(90px,1fr));gap:8px;margin-top:8px}
.img-grid .img-item{position:relative}
.img-grid img{width:100%;height:90px;object-fit:cover;border-radius:8px;border:1px solid var(--border)}
.img-grid .img-del{position:absolute;top:2px;right:2px;background:rgba(0,0,0,.6);color:#fff;border:none;border-radius:50%;width:20px;height:20px;font-size:12px;line-height:20px;text-align:center}
.wrong-form-row{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-bottom:8px;align-items:start}
.wrong-form-row.full{grid-template-columns:1fr}

/* ===== 文档 ===== */
.doc-list{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:12px}
.doc-btn{padding:8px 14px;border:1px solid var(--border);border-radius:8px;background:#fff;cursor:pointer;font-size:13px}
.doc-btn.active{border-color:var(--primary);background:#eff6ff;color:var(--primary);font-weight:600}
textarea.doc-editor{min-height:52vh;line-height:1.8;font-size:14px}
.doc-view{white-space:pre-wrap;line-height:1.8;font-size:14px;min-height:52vh;border:1px solid var(--border);border-radius:8px;padding:14px;background:#f8fafc}

/* ===== 加练 ===== */
.radio-row{display:flex;gap:10px;flex-wrap:wrap}
.radio-row label{display:flex;align-items:center;gap:6px;font-size:14px;cursor:pointer;border:1px solid var(--border);padding:8px 14px;border-radius:8px;background:#fff}
.radio-row label.active{border-color:var(--primary);color:var(--primary);background:#eff6ff}
.exercise-output textarea{min-height:280px;font-size:14px;line-height:1.7}
.review-box{display:flex;align-items:flex-start;gap:8px;background:#fef3c7;border:1px solid #fde68a;border-radius:8px;padding:10px 12px;margin:10px 0;font-size:13px}

/* ===== 打印 ===== */
@media print{
  body *{visibility:hidden}
  .print-area,.print-area *{visibility:visible}
  .print-area{position:absolute;left:0;top:0;width:100%;padding:20px}
}

/* ===== 响应式 ===== */
@media (max-width:900px){
  .sidebar{transform:translateX(-100%);width:240px}
  .sidebar.open{transform:translateX(0);box-shadow:0 0 40px rgba(0,0,0,.3)}
  .sidebar-mask.show{display:block}
  .main-wrap{margin-left:0}
  #content{padding:12px}
  .form-grid{grid-template-columns:1fr}
  .wrong-form-row{grid-template-columns:1fr}
}

/* ===== 补充：文档卡片 ===== */
.docs-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:12px}
.doc-card{border:1px solid var(--border);border-radius:10px;padding:14px;background:#fff;display:flex;flex-direction:column;gap:8px}
.doc-title{font-weight:600;font-size:15px;color:var(--primary)}

/* ===== 补充：复选框行 ===== */
.chk{display:flex;align-items:center;gap:6px;font-size:13px;color:var(--text);cursor:pointer}
.chk input{width:16px;height:16px;accent-color:var(--primary)}

/* ===== 补充：待审核错题行高亮 ===== */
.row-pending td{background:#fffbeb}

/* ===== 补充：打印区兼容 id ===== */
@media print{
  #printArea,#printArea *{visibility:visible}
  #printArea{position:absolute;left:0;top:0;width:100%;padding:20px}
  .print-area,.print-area *{visibility:visible}
  .print-area{position:absolute;left:0;top:0;width:100%;padding:20px}
}
.wb-check{width:16px;height:16px;accent-color:#2f6fed;cursor:pointer}
.mastery-select{padding:4px 8px;font-size:12px;border:1px solid #ddd;border-radius:4px;background:#fff;cursor:pointer}
.exer-opt{display:flex;gap:10px;align-items:center;font-size:13px;color:#444;margin:6px 0}
.opt-radio{accent-color:#2f6fed}
.force-check{display:flex;gap:8px;align-items:flex-start;background:#fff8e1;border:1px solid #ffe082;padding:10px 12px;border-radius:8px;margin:10px 0;font-size:13px;color:#6d4c00}
.force-check input{width:18px;height:18px;accent-color:#f59e0b;margin-top:1px}
.print-btn{margin-top:10px}
.sel-bar{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:8px;font-size:13px;color:#555}
.sel-bar b{color:#333}