:root{
  --primary:#3b82f6; --primary-d:#2563eb; --primary-l:#eff6ff;
  --blue:#3b82f6; --blue-l:#eff6ff;
  --green:#22c55e; --green-l:#f0fdf4; --green-d:#16a34a;
  --amber:#f59e0b; --amber-l:#fffbeb;
  --red:#ef4444; --red-l:#fef2f2;
  --purple:#8b5cf6; --purple-l:#f5f3ff;
  --ink:#1e293b; --ink2:#475569; --ink3:#94a3b8;
  --line:#e2e8f0; --bg:#f1f5f9; --card:#ffffff;
  --radius:14px; --shadow:0 1px 3px rgba(15,23,42,.06),0 4px 16px rgba(15,23,42,.05);
  --topbar-h:52px; --bottomnav-h:62px;
  --border:var(--line);
}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:"PingFang SC","Microsoft YaHei","Hiragino Sans GB",system-ui,sans-serif;background:var(--bg);color:var(--ink);line-height:1.65;padding-bottom:0}
button{font-family:inherit;cursor:pointer;border:none;background:none}
input,textarea,select{font-family:inherit;font-size:15px;color:var(--ink)}
textarea{width:100%;min-height:84px;border:1.5px solid var(--line);border-radius:10px;padding:10px 12px;resize:vertical;outline:none;background:#fafbfc}
textarea:focus{border-color:var(--primary);background:#fff}
.fill-in{width:100%;max-width:340px;border:1.5px solid var(--line);border-radius:10px;padding:9px 12px;outline:none;background:#fafbfc}
.fill-in:focus{border-color:var(--primary);background:#fff}
.fld{display:block;width:100%;border:1.5px solid var(--line);border-radius:10px;padding:9px 12px;outline:none;background:#fafbfc;margin-top:6px}
.fld:focus{border-color:var(--primary);background:#fff}
label.lbl-t{font-size:13px;color:var(--ink2);font-weight:600;display:block;margin-top:12px}

header{position:sticky;top:0;z-index:50;background:linear-gradient(135deg,#2563eb,#3b82f6 55%,#60a5fa);color:#fff;box-shadow:0 2px 12px rgba(37,99,235,.25)}
.hd-in{max-width:1080px;margin:0 auto;padding:14px 20px;display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px;letter-spacing:.5px}
.logo{width:36px;height:36px;border-radius:10px;background:rgba(255,255,255,.2);display:flex;align-items:center;justify-content:center;font-size:17px;font-weight:900}
.hd-sub{font-size:12px;opacity:.85;font-weight:400;margin-left:2px}
.hd-date{margin-left:auto;font-size:13px;background:rgba(255,255,255,.16);padding:5px 12px;border-radius:999px;white-space:nowrap}
.hd-ver{font-size:11.5px;font-weight:600;color:rgba(255,255,255,.92);background:rgba(255,255,255,.18);padding:3px 9px;border-radius:999px;white-space:nowrap}
.hd-out{font-size:12.5px;color:#fff;background:rgba(255,255,255,.18);padding:5px 12px;border-radius:999px}
.hd-out:hover{background:rgba(255,255,255,.3)}
nav.topnav{display:flex;gap:4px;flex-wrap:wrap;width:100%}
nav.topnav button{color:rgba(255,255,255,.82);padding:7px 14px;border-radius:999px;font-size:14px;transition:.2s}
nav.topnav button:hover{background:rgba(255,255,255,.15);color:#fff}
nav.topnav button.on{background:#fff;color:var(--primary-d);font-weight:700}

/* ===== 左右结构：左侧导航栏 + 右侧内容区 ===== */
.layout{display:flex;min-height:100vh}
.sidebar{width:230px;flex-shrink:0;background:linear-gradient(165deg,#1e3a8a,#2563eb);color:#fff;display:flex;flex-direction:column;position:sticky;top:0;height:100vh;box-shadow:2px 0 14px rgba(15,23,42,.14)}
.side-brand{display:flex;align-items:center;gap:11px;padding:18px 18px 12px}
.side-brand .logo{width:38px;height:38px;flex-shrink:0;background:rgba(255,255,255,.2);color:#fff;display:flex;align-items:center;justify-content:center;font-size:17px;font-weight:900;border-radius:10px}
.side-brand .b-text{display:flex;flex-direction:column;gap:5px;min-width:0}
.side-brand .b-title{font-weight:800;font-size:18px;color:#fff;white-space:nowrap;line-height:1.2;letter-spacing:.5px}
.side-role{font-size:11px;font-weight:600;background:rgba(255,255,255,.18);padding:2px 9px;border-radius:999px;align-self:flex-start;white-space:nowrap}
.side-role:empty{display:none}
.side-account{display:flex;align-items:center;gap:10px;margin:6px 12px 8px;padding:10px 12px;border-radius:12px;background:rgba(255,255,255,.1);cursor:pointer;transition:.2s}
.side-account:hover{background:rgba(255,255,255,.18)}
.side-account .av{width:38px;height:38px;border-radius:10px;background:rgba(255,255,255,.24);display:flex;align-items:center;justify-content:center;font-weight:800;font-size:17px;flex-shrink:0}
.acc-info{flex:1;min-width:0}
.acc-name{font-weight:700;font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.acc-role{font-size:11.5px;opacity:.82;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.acc-caret{font-size:12px;opacity:.8;flex-shrink:0}
.sidenav{display:flex;flex-direction:column;gap:4px;padding:6px 12px;flex:1;overflow-y:auto}
.sidenav button{display:flex;align-items:center;gap:10px;color:rgba(255,255,255,.82);padding:10px 12px;border-radius:10px;font-size:14.5px;text-align:left;transition:.2s}
.sidenav button .icn{width:22px;text-align:center;font-size:16px;flex-shrink:0}
.sidenav button:hover{background:rgba(255,255,255,.14);color:#fff}
.sidenav button.on{background:#fff;color:var(--primary-d);font-weight:700}
.side-foot{display:flex;flex-direction:column;gap:5px;padding:12px 16px 16px;border-top:1px solid rgba(255,255,255,.12)}
.side-foot .hd-ver{background:rgba(255,255,255,.16);color:rgba(255,255,255,.92);align-self:flex-start}
.side-date{font-size:11.5px;opacity:.8}
.content{flex:1;min-width:0}

/* 移动端精简顶栏（仅手机显示，承载品牌/日期/直接退出） */
.topbar{display:none;position:sticky;top:0;z-index:50;background:linear-gradient(135deg,#2563eb,#3b82f6);color:#fff;box-shadow:0 2px 12px rgba(37,99,235,.25)}
.tb-in{display:flex;align-items:center;gap:10px;padding:10px 14px;flex-wrap:wrap}
.tb-date{font-size:12px;background:rgba(255,255,255,.16);padding:4px 10px;border-radius:999px;white-space:nowrap}
.tb-acc{display:flex;flex-direction:column;line-height:1.25;margin-left:auto;cursor:pointer;padding:3px 8px;border-radius:8px}
.tb-acc:hover{background:rgba(255,255,255,.15)}
.tb-acc-name{font-size:13px;font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:120px}
.tb-acc-role{font-size:10.5px;opacity:.85}

/* 账户下拉菜单：区分不同账户，点击弹出「退回（退出登录）」选项 */
.account-menu{position:fixed;z-index:300;min-width:224px;background:#fff;border-radius:14px;box-shadow:0 12px 40px rgba(15,23,42,.22);padding:8px;display:none}
.account-menu.open{display:block;animation:fade .15s ease}
.am-head{padding:8px 10px;border-bottom:1px solid var(--line);margin-bottom:6px}
.am-name{font-weight:700;font-size:14px}
.am-role{font-size:11.5px;color:var(--ink3);margin-top:1px}
.am-item{width:100%;text-align:left;padding:10px;font-size:14px;color:var(--red);border-radius:10px;transition:.15s}
.am-item:hover{background:var(--red-l)}
.aset-tabs{display:flex;gap:8px;margin-bottom:14px;flex-wrap:wrap}
.aset-tabs button{padding:8px 16px;border-radius:999px;border:1px solid var(--line);background:#fff;color:var(--ink2);font-size:14px;cursor:pointer;transition:.2s}
.aset-tabs button:hover{background:#eef2f7}
.aset-tabs button.on{background:var(--primary);color:#fff;border-color:var(--primary);font-weight:700}

main{max-width:1080px;margin:0 auto;padding:18px 16px 30px}
.grid{display:grid;gap:14px}
.g2{grid-template-columns:1fr 1fr}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px 20px}
.card h3{font-size:15px;margin-bottom:12px;display:flex;align-items:center;gap:8px}
.card h3 .dot{width:8px;height:8px;border-radius:50%;background:var(--primary)}
.view{animation:fade .25s ease}
@keyframes fade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;background:var(--primary);color:#fff;font-size:15px;font-weight:600;padding:11px 26px;border-radius:12px;transition:.2s}
.btn:hover{background:var(--primary-d);transform:translateY(-1px)}
.btn.big{padding:14px 40px;font-size:16px;border-radius:14px}
.btn.green{background:var(--green)} .btn.green:hover{background:var(--green-d)}
.btn.red{background:var(--red)} .btn.red:hover{background:#dc2626}
.btn.ghost{background:var(--primary-l);color:var(--primary-d)} .btn.ghost:hover{background:#dbeafe}
.btn.gray{background:#eef2f7;color:var(--ink2)} .btn.gray:hover{background:#e2e8f0}
.btn.sm{padding:7px 16px;font-size:13px;border-radius:9px}
.btn.wide{width:100%}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
.chip{display:inline-flex;align-items:center;padding:2px 10px;border-radius:999px;font-size:12px;font-weight:600;color:#fff}
.chip.line{background:#fff;border:1px solid var(--line);color:var(--ink2)}
.diff-sel{font-size:12.5px;padding:4px 6px;border:2px solid #cbd5e1;border-radius:8px;background:#fff;color:var(--ink);cursor:pointer;outline:none;transition:border-color .15s}
.stat-num{font-size:26px;font-weight:800;line-height:1.2}
.stat-lbl{font-size:12px;color:var(--ink3);margin-top:2px}
.stat-card{text-align:center;padding:16px 10px}
.link{color:var(--primary-d);font-size:13px;cursor:pointer}
.link:hover{text-decoration:underline}
.muted{color:var(--ink3);font-size:13px}
.hint{font-size:12.5px;color:var(--ink3);margin-top:8px}

/* 登录/注册界面 —— 改为纵向布局，版本信息规整地显示在卡片下方 */
.auth-wrap{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;background:linear-gradient(135deg,#2563eb,#60a5fa);padding:20px;gap:14px}
.auth-card{background:#fff;border-radius:20px;box-shadow:0 20px 60px rgba(0,0,0,.25);padding:34px 32px;width:100%;max-width:400px}
.auth-card .brand{justify-content:center;color:var(--primary-d);font-size:22px;margin-bottom:6px}
.auth-tabs{display:flex;background:#f1f5f9;border-radius:10px;padding:4px;margin:18px 0 6px}
.auth-tabs button{flex:1;padding:8px 0;border-radius:8px;font-size:14px;font-weight:600;color:var(--ink2)}
.auth-tabs button.on{background:#fff;color:var(--primary-d);box-shadow:var(--shadow)}
/* 登录屏版本徽标 */
.auth-ver{text-align:center;font-size:12px;font-weight:600;color:rgba(255,255,255,.92);background:rgba(255,255,255,.16);padding:4px 14px;border-radius:999px;white-space:nowrap;backdrop-filter:blur(4px)}

.hero{background:linear-gradient(135deg,#eff6ff,#e0f2fe);border:1px solid #dbeafe;border-radius:var(--radius);padding:20px 22px;margin-bottom:14px}
.hero .hi{font-size:19px;font-weight:800}
.hero .quote{margin-top:8px;font-size:14.5px;color:var(--ink2);background:rgba(255,255,255,.7);border-left:4px solid var(--primary);padding:10px 14px;border-radius:0 10px 10px 0}
.status-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:14px}
.status-pill{background:#fff;border-radius:12px;padding:12px 16px;flex:1;min-width:150px;box-shadow:var(--shadow);display:flex;align-items:center;gap:12px}
.status-pill .ic{width:42px;height:42px;border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:19px;font-weight:800}
.q-opt{display:flex;align-items:flex-start;gap:10px;padding:11px 14px;border:1.5px solid var(--line);border-radius:11px;margin-top:9px;cursor:pointer;transition:.15s;background:#fff}
.q-opt:hover{border-color:#bfdbfe;background:var(--primary-l)}
.q-opt.sel{border-color:var(--primary);background:var(--primary-l);font-weight:600}
.q-opt .key{width:22px;height:22px;border-radius:50%;border:1.5px solid var(--line);display:inline-flex;align-items:center;justify-content:center;font-size:12px;flex-shrink:0;margin-top:2px;background:#fff}
.q-opt.sel .key{background:var(--primary);border-color:var(--primary);color:#fff}
/* 即时反馈：答后标注对错（颜色 + 边框双重编码，兼顾色觉障碍） */
.q-opt.ok{border-color:var(--green);background:var(--green-l)}
.q-opt.ok .key{background:var(--green);border-color:var(--green);color:#fff}
.q-opt.bad{border-color:var(--red);background:#fef2f2}
.q-opt.bad .key{background:var(--red);border-color:var(--red);color:#fff}
.qwrap{scroll-margin-top:12px}
/* 移动端适配：放大点选区域、固定进度，降低误触（手机多为学生主要入口） */
@media (max-width:600px){
  .q-opt{padding:14px 16px;font-size:15px}
  .task-card{padding:12px}
  .hero{padding:14px 16px}
  .hero .hi{font-size:17px}
  .hero .quote{font-size:13.5px}
  .fill-in,.q-textarea{font-size:16px}
  .practice-top{position:sticky;top:0;background:#fff;z-index:5;padding:8px 0;box-shadow:0 2px 8px rgba(15,23,42,.05)}
  .side-foot .fs-ctl{margin-top:6px}
}
.q-opt.ok{border-color:var(--green);background:var(--green-l)} .q-opt.ok .key{background:var(--green);border-color:var(--green);color:#fff}
.q-opt.bad{border-color:var(--red);background:var(--red-l)} .q-opt.bad .key{background:var(--red);border-color:var(--red);color:#fff}

.qcard{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px;margin-top:12px}
.qmeta{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:9px}
.qtag{font-size:11.5px;color:var(--ink3);background:#f1f5f9;padding:2px 9px;border-radius:999px}
.qtext{font-size:15px;font-weight:600;margin-bottom:4px}
.subhead{display:flex;align-items:center;gap:10px;margin:22px 0 4px;font-size:16px;font-weight:800}
.subhead .bar{width:5px;height:18px;border-radius:3px}
.subhead .cnt{font-size:12px;font-weight:500;color:var(--ink3)}
.progress-bar{height:9px;background:#e2e8f0;border-radius:999px;overflow:hidden;margin-top:8px}
.progress-bar i{display:block;height:100%;background:linear-gradient(90deg,#60a5fa,#2563eb);border-radius:999px;transition:width .3s}
/* 每日刷题：左题右栏两栏布局 + 右侧悬浮进度面板 */
.practice-grid{display:flex;align-items:flex-start;gap:20px}
.practice-main{flex:1;min-width:0}
.practice-aside{width:280px;flex-shrink:0;position:sticky;top:16px;align-self:flex-start}
.pf-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px 16px 14px}
.pf-title{font-size:16px;font-weight:800;color:var(--ink);line-height:1.35;padding-bottom:12px;border-bottom:1px solid var(--line)}
.pf-progress{display:flex;align-items:baseline;gap:7px;margin-top:13px}
.pf-label{font-size:13px;color:var(--ink2)}
.pf-count{font-size:24px;font-weight:800;color:var(--primary-d);line-height:1}
.pf-count b{font-size:24px;font-weight:800;color:var(--primary-d)}
.pf-unit{font-size:13px;color:var(--ink2)}
.pf-meta{font-size:12.5px;color:var(--ink3);margin-top:10px}
.pa-submit{text-align:center;margin:26px 0 6px}
.pa-submit .btn{margin:5px}
/* 每日刷题：当前难度档说明横幅 */
.diff-banner{margin-bottom:14px}

.cal{display:grid;grid-template-columns:repeat(7,1fr);gap:7px}
.cal .wd{text-align:center;font-size:12px;color:var(--ink3);padding:4px 0}
.cal .day{aspect-ratio:1;border-radius:10px;display:flex;flex-direction:column;align-items:center;justify-content:center;font-size:14px;font-weight:600;background:#f8fafc;color:var(--ink3);position:relative}
.cal .day.done{background:var(--green-l);color:var(--green-d)}
.cal .day.done::after{content:"✓";font-size:10px;margin-top:-2px}
.cal .day.makeup{background:var(--amber-l);color:#b45309}
.cal .day.makeup::after{content:"补";font-size:10px;margin-top:-2px}
.cal .day.missed{background:#f1f5f9;color:#cbd5e1;text-decoration:line-through}
.cal .day.future{background:transparent;color:#cbd5e1}
.cal .day.pending{background:var(--primary-l);color:var(--primary-d)}
.cal .day.today{outline:2px solid var(--primary);outline-offset:1px}
.legend{display:flex;gap:14px;flex-wrap:wrap;font-size:12px;color:var(--ink2);margin-top:12px}
.legend i{display:inline-block;width:11px;height:11px;border-radius:3px;margin-right:5px;vertical-align:-1px}
.badge{display:flex;flex-direction:column;align-items:center;gap:6px;text-align:center}
.badge .medal{width:64px;height:64px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:14px;background:#e2e8f0;color:#94a3b8;border:3px solid #cbd5e1}
.badge.got .medal{background:linear-gradient(135deg,#fbbf24,#f59e0b);color:#fff;border-color:#fcd34d;box-shadow:0 4px 12px rgba(245,158,11,.35)}
.badge .bn{font-size:12.5px;font-weight:600}
.badge .bs{font-size:11px;color:var(--ink3)}

.ring-wrap{display:flex;align-items:center;gap:24px;flex-wrap:wrap}
.ring{position:relative;width:132px;height:132px;flex-shrink:0}
.ring svg{transform:rotate(-90deg)}
.ring .rv{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.ring .rv b{font-size:28px}
.ring .rv span{font-size:11px;color:var(--ink3)}
.report-line{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:9px 0;border-bottom:1px dashed var(--line);font-size:14px}
.report-line:last-child{border-bottom:none}
.ans-box{background:#f8fafc;border-radius:10px;padding:12px 14px;font-size:13.5px;margin-top:10px;border:1px solid var(--line)}
.ans-box .lbl{font-weight:700;color:var(--ink2);margin-right:6px}
.wrong-card{border:1px solid var(--line);border-radius:var(--radius);padding:15px 17px;background:#fff;margin-top:12px}

.bar-row{display:flex;align-items:center;gap:10px;margin-top:10px;font-size:13px}
.bar-row .bn{width:40px;flex-shrink:0;text-align:right;color:var(--ink2)}
.bar-row .bt{flex:1;height:14px;background:#eef2f7;border-radius:999px;overflow:hidden}
.bar-row .bt i{display:block;height:100%;border-radius:999px}
.bar-row .bv{width:52px;flex-shrink:0;font-weight:700;font-size:12.5px}
.trend-svg{width:100%;height:auto}
.rank-row{display:flex;align-items:center;gap:12px;padding:9px 10px;border-radius:10px;font-size:14px}
.rank-row.me{background:var(--primary-l);border:1px solid #bfdbfe}
.rank-row .no{width:24px;height:24px;border-radius:50%;background:#eef2f7;display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:700;color:var(--ink2);flex-shrink:0}
.rank-row .no.top{background:linear-gradient(135deg,#fbbf24,#f59e0b);color:#fff}
.rank-row .nm{flex:1;font-weight:600;min-width:0;overflow-wrap:anywhere}
.rank-row .muted{flex-shrink:0}
.rank-row b{margin-left:auto;flex-shrink:0;text-align:right;font-variant-numeric:tabular-nums}
.switch{position:relative;width:42px;height:23px;background:#cbd5e1;border-radius:999px;transition:.2s;flex-shrink:0;cursor:pointer}
.switch.on{background:var(--green)}
.switch::after{content:"";position:absolute;top:2.5px;left:3px;width:18px;height:18px;border-radius:50%;background:#fff;transition:.2s;box-shadow:0 1px 3px rgba(0,0,0,.2)}
.switch.on::after{left:21px}
.set-row{display:flex;align-items:center;justify-content:space-between;padding:12px 0;border-bottom:1px solid var(--line);font-size:14px}
.set-row:last-child{border-bottom:none}

.tbl{width:100%;border-collapse:collapse;font-size:13.5px}
.tbl th{background:#f8fafc;text-align:left;padding:9px 12px;color:var(--ink2);font-size:12.5px;white-space:nowrap}
.tbl td{padding:9px 12px;border-top:1px solid var(--line);vertical-align:middle}
.tbl tr:hover td{background:#fafbfc}

.mask{position:fixed;inset:0;background:rgba(15,23,42,.5);z-index:100;display:flex;align-items:center;justify-content:center;padding:18px;animation:fade .2s}
.modal{background:#fff;border-radius:18px;max-width:560px;width:100%;max-height:86vh;overflow-y:auto;padding:24px;box-shadow:0 20px 60px rgba(0,0,0,.25)}
.modal h3{font-size:17px;margin-bottom:14px}
.modal-x{float:right;font-size:20px;color:var(--ink3);cursor:pointer;line-height:1}
.modal-x:hover{color:var(--ink)}
#toast{position:fixed;left:50%;bottom:86px;transform:translateX(-50%) translateY(20px);background:rgba(15,23,42,.92);color:#fff;padding:11px 22px;border-radius:999px;font-size:14px;z-index:200;opacity:0;pointer-events:none;transition:.3s;max-width:86vw;text-align:center}
#toast.show{opacity:1;transform:translateX(-50%) translateY(0)}

nav.bottomnav{position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid var(--line);display:none;z-index:60;padding:5px 4px calc(5px + env(safe-area-inset-bottom))}
nav.bottomnav button{flex:1;display:flex;flex-direction:column;align-items:center;gap:2px;font-size:10.5px;color:var(--ink3);padding:4px 0}
nav.bottomnav button .icn{font-size:17px;font-weight:800;width:26px;height:26px;display:flex;align-items:center;justify-content:center;border-radius:8px}
nav.bottomnav button.on{color:var(--primary-d);font-weight:700}
nav.bottomnav button.on .icn{background:var(--primary-l)}
/* 底部导航「添加到主屏幕」行动按钮：用主色胶囊强调，区别于普通页面导航项（不进入 .on 选中态） */
nav.bottomnav button.addhome-tab{color:#fff;font-weight:700;background:var(--primary);border-radius:10px;margin:0 3px;padding:4px 0}
nav.bottomnav button.addhome-tab .icn{background:rgba(255,255,255,.22);color:#fff}
/* 已安装：变灰、禁用点击观感，提示「已添加」 */
nav.bottomnav button.addhome-tab[data-state="installed"]{background:var(--ink-l);color:var(--ink3)}
nav.bottomnav button.addhome-tab[data-state="installed"] .icn{background:rgba(100,116,139,.18);color:var(--ink3)}

/* 平板 / 手机：≤1024 隐藏左侧栏，改用顶栏 + 底部导航；练习区堆叠（保障登录/打卡/刷题体验） */
@media (max-width:1024px){
  .sidebar{display:none}
  .topbar{display:block}
  .layout{display:block}
  body{padding-bottom:72px}
  nav.bottomnav{display:flex;overflow-x:auto;-webkit-overflow-scrolling:touch;scrollbar-width:none}
  nav.bottomnav::-webkit-scrollbar{display:none}
  nav.bottomnav button{flex:0 0 auto;min-width:62px}
  .hd-in{gap:10px;padding:10px 12px}
  .brand{font-size:17px}
  .logo{width:32px;height:32px;font-size:15px}
  .hd-date{margin-left:auto;font-size:12px;padding:4px 10px}
  .hd-out{font-size:12px;padding:4px 10px}
  main{padding:14px 12px 26px}
  .grid.g2,.grid.g3{grid-template-columns:1fr 1fr}
  .stat-num{font-size:21px}
  .card{padding:14px 14px}
  .card h3{font-size:14px}
  .practice-grid{display:flex;flex-direction:column}
  .practice-aside{width:auto;order:-1;position:sticky;top:56px;z-index:40;margin-bottom:14px}
  .pf-card{padding:12px 14px}
  .pf-title{font-size:15px;padding-bottom:10px}
  .pf-count,.pf-count b{font-size:21px}
  .auth-card{padding:26px 20px;border-radius:16px}
  .btn{padding:11px 18px;font-size:14px}
  .btn.big{padding:13px 30px;font-size:15px}
  .modal{padding:18px;border-radius:14px}
  .report-line{font-size:13px;padding:8px 0}
  .tbl{font-size:12px}.tbl th,.tbl td{padding:7px 8px}
  /* 平板/移动端：进度面板贴合顶栏、卡片间距与环形图适配 */
  .practice-aside{top:var(--topbar-h)}
  .ring-wrap{gap:16px}
  .status-row{gap:10px}
  .grid.g4{grid-template-columns:repeat(2,1fr)}
}

/* ================= 手机端细化 ================= */
@media (max-width:760px){
  .g4{grid-template-columns:1fr 1fr}                 /* 勋章/排行两列，避免过小 */
  .fld,.fill-in,textarea,input,select{font-size:16px} /* iOS 聚焦防自动放大 */
  .card{padding:13px 12px}
  .card h3{font-size:13.5px}
  .modal{padding:16px}
  .bottomnav button .icn{font-size:18px}
  .btn{padding:12px 16px}
  /* 刷题类型选择：中屏两列，避免三列过于拥挤 */
  .practice-choose{grid-template-columns:1fr 1fr}
  /* 状态胶囊可收缩，防止横向溢出 */
  .status-row .status-pill{min-width:0;flex:1 1 46%}
  /* 日历格子间距收敛、字号减小，保持整齐 */
  .cal{gap:5px}
  .cal .day{font-size:12px}
  /* 即时反馈勾选项换行占满，避免挤压模式标签 */
  .mode-tabs label{margin-left:0;flex-basis:100%;margin-top:8px}
  /* 知识点热力块占满宽度，避免文字截断 */
  .hm-cell{max-width:none}
  /* 副标题与题目字号微调，层级更清晰 */
  .subhead{font-size:15px;margin:18px 0 4px}
  .qtext{font-size:14.5px}
  /* 作答提交按钮竖排且占满，便于单手点击 */
  .pa-submit{display:flex;flex-direction:column;gap:8px}
  .pa-submit .btn{width:100%;margin:0}
  /* 首页外层：今日任务 + 快捷入口 → 中屏（手机比例）改为上下单列堆叠，避免两卡并排挤压 */
  .home-cols{grid-template-columns:1fr}
  /* 首页快捷入口按钮占满宽度，文字不再折行错乱 */
  .home-cols .card .btn.wide{width:100%}
}
@media (max-width:420px){
  .g2,.g3,.g4{grid-template-columns:1fr}  /* 超窄屏统计卡单列，避免挤压 */
  .status-row{flex-direction:column;gap:8px}
  .status-row .status-pill{width:100%;flex:1 1 auto}
  .report-line{font-size:12.5px}
  .pf-card{padding:11px 12px}
  .mode-tabs{margin-bottom:10px}
}

/* ===== 练习模式切换（每日综合 / 单元测试） ===== */
.mode-tabs{display:flex;gap:8px;margin-bottom:14px;flex-wrap:wrap}
.mtab{padding:8px 18px;border:1.5px solid var(--line);background:#fff;border-radius:10px;font-size:14px;color:var(--ink2);cursor:pointer;transition:.18s}
.mtab:hover{border-color:var(--primary)}
.mtab.on{background:var(--primary);color:#fff;border-color:var(--primary);font-weight:700}
.mtab.ghost-tab{margin-left:auto;color:var(--ink2);background:#fff}
.mtab.ghost-tab:hover{border-color:var(--primary);color:var(--primary)}
/* 刷题类型「三选一」选择器（主科 / 副科 / 单元测试 平行卡片） */
.practice-choose{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:8px}
.pcard{display:flex;flex-direction:column;align-items:flex-start;text-align:left;padding:18px 16px;border:1.5px solid var(--line);border-radius:14px;background:#fff;cursor:pointer;transition:.18s}
.pcard:hover{border-color:var(--primary);box-shadow:0 6px 18px rgba(59,130,246,.12);transform:translateY(-2px)}
.pcard-ic{font-size:30px;line-height:1;margin-bottom:10px}
.pcard-t{font-size:16px;font-weight:800;color:var(--ink)}
.pcard-d{font-size:13px;color:var(--ink2);margin-top:6px;line-height:1.6}
.pcard-go{margin-top:12px;font-size:13px;font-weight:700;color:var(--primary)}
@media(max-width:560px){.practice-choose{grid-template-columns:1fr}}
/* ================= 无障碍增强 ================= */
/* 尊重「减少动态效果」系统偏好，关闭非必要动画（眩晕/注意力障碍友好） */
@media (prefers-reduced-motion: reduce){
  *{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
}
/* 提升次要文字对比度，满足 WCAG AA（正文 ≥4.5:1） */
.muted{color:#64748b}
/* 字号调节控件（侧栏 / 顶栏通用） */
.fs-ctl{display:inline-flex;align-items:center;gap:2px;background:rgba(255,255,255,.14);border-radius:999px;padding:3px 4px}
.fs-ctl button{width:26px;height:22px;border-radius:999px;color:#fff;font-size:12px;font-weight:700;line-height:1}
.fs-ctl button:hover{background:rgba(255,255,255,.28)}
.fs-ctl button.on{background:#fff;color:var(--primary-d)}
/* 键盘焦点可见性（仅键盘操作时显示轮廓） */
.q-opt:focus-visible{outline:3px solid var(--primary);outline-offset:2px}
.sidenav button:focus-visible,.bottomnav button:focus-visible,.btn:focus-visible,.pcard:focus-visible{outline:3px solid #fff;outline-offset:-3px}
/* 知识点可点击成卡片 */
.kp-link{color:var(--primary-d);cursor:pointer;border-bottom:1px dashed var(--primary)}
/* 分步讲解列表 */
.steps{margin:6px 0 0;padding-left:20px}
.steps li{margin:4px 0;font-size:13.5px;line-height:1.65}
/* 首页今日任务卡 */
.task-card{border:1.5px solid var(--line);border-radius:14px;padding:14px 15px;background:#fff;transition:.18s;display:flex;flex-direction:column;text-align:left}
.task-card:hover{box-shadow:0 6px 18px rgba(59,130,246,.1)}
.task-card.done{border-color:var(--green);background:var(--green-l)}
.task-card .tc-ic{font-size:24px;line-height:1}
.task-card .tc-t{font-weight:800;font-size:15px;margin-top:8px;min-width:0;overflow-wrap:anywhere}
.task-card .tc-d{font-size:12.5px;color:var(--ink2);margin-top:4px;flex:1;min-width:0;overflow-wrap:anywhere}
.task-card .tc-go{margin-top:10px;font-size:13px;font-weight:700}
.task-card.done .tc-go{color:var(--green-d)}
/* 即时反馈标记 */
.q-fb{font-size:12px;font-weight:700;margin-left:8px}
.q-fb.ok{color:var(--green-d)} .q-fb.bad{color:var(--red)}
/* 通用弹窗（知识卡片 / 纠错等） */
.modal-mask{position:fixed;inset:0;background:rgba(15,23,42,.45);display:none;align-items:center;justify-content:center;z-index:60;padding:16px}
.modal-box{background:#fff;border-radius:16px;max-width:560px;width:100%;max-height:84vh;overflow:auto;box-shadow:0 20px 60px rgba(15,23,42,.3)}
.modal-head{display:flex;align-items:center;justify-content:space-between;padding:14px 18px;border-bottom:1px solid var(--line);position:sticky;top:0;background:#fff;z-index:1}
.modal-x{border:none;background:#f1f5f9;width:30px;height:30px;border-radius:8px;font-size:18px;cursor:pointer;color:var(--ink2)}
.modal-x:hover{background:#e2e8f0}
.modal-body{padding:16px 18px}
/* 单元测试：解答题自评 */
.sa-self{display:flex;align-items:center;gap:8px;margin-top:8px}
.sa-self .muted{font-size:13px}
.sa-self .btn.sm{padding:5px 16px;font-size:13px}
.sa-self .btn.sm.green{background:var(--green);color:#fff}
.sa-self .btn.sm.red{background:var(--red);color:#fff}
/* 家长端「学生信息」卡片 */
.stu-card{border:1px solid var(--border)}
.stu-card .stu-head{display:flex;align-items:center;gap:12px}
.stu-card .stu-av{width:42px;height:42px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--purple));color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:18px;flex:0 0 auto}
.stu-card .stu-name{font-size:15.5px;font-weight:700;display:flex;align-items:center;gap:8px}
.stu-card .stu-id{margin-left:2px}
.stu-card .stu-sub{font-size:12.5px;margin-top:3px}
/* 难度面板：独立浅色区块，信息更聚焦 */
.stu-card .stu-diff{margin-top:14px;padding:14px;background:#f8fafc;border:1px solid var(--line);border-radius:12px}
.stu-card .stu-diff-top{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.stu-card .stu-diff-src{font-size:12px}
.stu-card .stu-diff-ctl{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:10px}
/* 操作行：虚线分隔，与难度面板层级清晰 */
.stu-card .stu-actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px;padding-top:12px;border-top:1px dashed var(--line)}
/* 学习路径 · 知识点掌握度热力图 */
.hm-sub{margin-top:12px}
.hm-sub:first-of-type{margin-top:4px}
.hm-sub-name{font-size:13.5px;font-weight:700;color:var(--text);margin-bottom:6px}
.hm-grid{display:flex;flex-wrap:wrap;gap:6px}
.hm-cell{position:relative;padding:7px 9px 8px;border-radius:9px;font-size:12.5px;font-weight:600;line-height:1.25;cursor:pointer;min-width:54px;max-width:140px;box-shadow:0 1px 2px rgba(0,0,0,.08);transition:transform .12s ease,box-shadow .12s ease}
.hm-cell:hover{transform:translateY(-2px);box-shadow:0 4px 10px rgba(0,0,0,.16)}
.hm-rate{display:block;font-size:11px;font-weight:700;opacity:.9;margin-top:2px}
.hm-weak{margin-top:14px;padding:11px 12px;background:var(--red-l);border:1px solid var(--red);border-radius:12px;font-size:13px;line-height:1.9}
.hm-weak .kp-link{display:inline-block;margin:0 2px;padding:1px 7px;border-radius:999px;background:#fff;border:1px solid var(--red);color:var(--red-d);font-weight:600;cursor:pointer}
.hm-weak .kp-link:hover{background:var(--red);color:#fff}

/* 公告栏（首页 / 家长首页） */
.ann-bar{display:flex;align-items:flex-start;gap:10px;margin-top:14px;padding:11px 13px;background:linear-gradient(135deg,#eff6ff,#f5f3ff);border:1px solid #c7d7ff;border-radius:12px;cursor:pointer;transition:transform .12s ease,box-shadow .12s ease}
.ann-bar:hover{transform:translateY(-1px);box-shadow:0 4px 12px rgba(59,130,246,.18)}
.ann-ic{font-size:18px;line-height:1.4}
.ann-body{flex:1;min-width:0}
.ann-title{font-size:14px;font-weight:700;color:var(--text);display:flex;align-items:center;gap:6px}
.ann-text{font-size:12.5px;color:var(--muted);margin-top:2px;line-height:1.5;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ann-pin{display:inline-block;font-size:11px;font-weight:700;color:#fff;background:var(--red);border-radius:6px;padding:1px 6px;line-height:1.5}
.ann-more{font-size:12px;color:var(--primary-d);font-weight:700;white-space:nowrap}
/* 「添加到主屏幕」入口卡片（公告栏下方） */
.addhome-card{padding:0;overflow:hidden}
.addhome-entry{display:flex;align-items:center;gap:12px;padding:14px 16px;cursor:pointer}
.addhome-entry .ah-icon{width:38px;height:38px;border-radius:10px;background:#e8f0ff;color:#2b6cff;display:flex;align-items:center;justify-content:center;font-size:20px;font-weight:700;flex:none}
.addhome-entry .ah-text{flex:1;min-width:0;display:flex;flex-direction:column;line-height:1.35}
.addhome-entry .ah-text b{font-size:15px;color:var(--text)}
.addhome-entry .ah-text .muted{font-size:12px;color:var(--muted)}
.addhome-entry .ah-arrow{color:#bbb;font-size:22px;flex:none}
.addhome-entry.ready:active{background:#f5f8ff}
.addhome-entry.installed .ah-icon{background:#e6f7ec;color:#1a9c4b}
/* 桌面端隐藏该入口（桌面不需要添加到主屏） */
@media (min-width:1025px){ .addhome-card{display:none} }
/* 管理端公告列表 */
.ann-row{display:flex;align-items:flex-start;gap:12px;padding:12px 0;border-bottom:1px solid var(--line)}
.ann-row:last-child{border-bottom:none}
.ann-row-main{flex:1;min-width:0}
.ann-row-title{font-size:14px;font-weight:700;color:var(--text);display:flex;align-items:center;gap:6px}
.ann-row-sub{font-size:12px;color:var(--muted);margin:3px 0}
.ann-row-content{font-size:13px;color:var(--text);line-height:1.5}
.ann-row-ops{display:flex;flex-direction:column;gap:6px;flex-shrink:0}