* { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #f4f6fb;
  --card: #ffffff;
  --primary: #4a6cf7;
  --primary-2: #6a8bff;
  --text: #1e2433;
  --muted: #7c869b;
  --line: #e8ecf5;
  --ok: #22c55e;
  --warn: #f59e0b;
  --danger: #ef4444;
}
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  padding-bottom: 40px;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 16px; }
header.top {
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color: #fff; padding: 18px 16px; border-radius: 0 0 18px 18px;
  box-shadow: 0 4px 18px rgba(74,108,247,.25);
}
header.top .row { max-width: 760px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 10px; }
header.top h1 { font-size: 18px; font-weight: 600; }
header.top .sub { font-size: 12px; opacity: .85; margin-top: 2px; }
.linkbtn { background: rgba(255,255,255,.18); border: 0; color: #fff; padding: 6px 12px; border-radius: 8px; font-size: 13px; cursor: pointer; }
.linkbtn:hover { background: rgba(255,255,255,.3); }

.card { background: var(--card); border-radius: 14px; padding: 16px; margin-top: 14px; box-shadow: 0 2px 12px rgba(30,36,51,.06); }
.card h2 { font-size: 15px; margin-bottom: 12px; display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.card h2 .tag { font-size: 12px; color: var(--muted); font-weight: 400; }

label { display: block; font-size: 13px; color: var(--muted); margin: 10px 0 6px; }
input[type=text], input[type=password], textarea, select {
  width: 100%; padding: 11px 12px; border: 1px solid var(--line); border-radius: 10px;
  font-size: 15px; background: #fbfcfe; color: var(--text); outline: none; font-family: inherit;
}
input:focus, textarea:focus, select:focus { border-color: var(--primary); background: #fff; }
textarea { resize: vertical; min-height: 76px; }

button.primary, .btn {
  width: 100%; padding: 12px; border: 0; border-radius: 10px; font-size: 15px; font-weight: 600;
  background: linear-gradient(135deg, var(--primary), var(--primary-2)); color: #fff; cursor: pointer; margin-top: 14px;
}
button.primary:active, .btn:active { transform: scale(.99); }
.btn.ghost { background: #fff; color: var(--primary); border: 1px solid var(--primary); font-weight: 500; }
.btn.small { width: auto; padding: 7px 14px; font-size: 13px; margin-top: 0; }
.btn.gray { background: #f0f2f7; color: var(--muted); }
.btn.danger { background: #fff; color: var(--danger); border: 1px solid #fecaca; }
.btnrow { display: flex; gap: 8px; flex-wrap: wrap; }

.msg { margin-top: 12px; font-size: 13px; padding: 9px 12px; border-radius: 8px; display: none; }
.msg.err { display: block; background: #fef2f2; color: #b91c1c; }
.msg.ok { display: block; background: #f0fdf4; color: #15803d; }

/* 进度条 */
.big-progress { text-align: center; padding: 8px 0 4px; }
.big-progress .num { font-size: 42px; font-weight: 700; color: var(--primary); line-height: 1.1; }
.big-progress .num small { font-size: 18px; font-weight: 500; }
.big-progress .label { font-size: 13px; color: var(--muted); }
.bar { height: 14px; background: #eef1f8; border-radius: 99px; overflow: hidden; margin-top: 10px; }
.bar > i { display: block; height: 100%; border-radius: 99px; background: linear-gradient(90deg, var(--primary), #57d9a3); transition: width .5s ease; }
.bar.sm { height: 8px; margin-top: 6px; }

.chapters { display: grid; gap: 8px; margin-top: 6px; }
.chapter {
  display: flex; align-items: center; gap: 10px; padding: 10px 12px; border: 1px solid var(--line);
  border-radius: 10px; cursor: pointer; background: #fbfcfe; font-size: 14px;
}
.chapter.active { border-color: var(--primary); background: #eef2ff; }
.chapter .dot { width: 18px; height: 18px; border-radius: 50%; border: 2px solid #cbd5e1; flex: none; }
.chapter.active .dot { border-color: var(--primary); background: var(--primary); box-shadow: inset 0 0 0 3px #fff; }
.chapter.done .dot { border-color: var(--ok); background: var(--ok); box-shadow: inset 0 0 0 3px #fff; }
.chapter .idx { color: var(--muted); font-size: 12px; }

input[type=range] { width: 100%; margin: 8px 0; accent-color: var(--primary); }

/* 单元 → 课 两级列表 */
.unit-list { display: flex; flex-direction: column; gap: 8px; margin-top: 6px; }
.unit { border: 1px solid var(--line); border-radius: 10px; background: #fbfcfe; overflow: hidden; }
.unit.open { background: #fff; }
.unit-head { display: flex; align-items: center; gap: 10px; padding: 11px 12px; cursor: pointer; user-select: none; }
.unit-head .utag {
  width: 22px; height: 22px; border-radius: 50%; background: var(--primary); color: #fff;
  font-size: 12px; display: inline-flex; align-items: center; justify-content: center; flex: none;
}
.unit.open .unit-head { background: #eef2ff; }
.unit-head .uname { flex: 1; font-weight: 600; font-size: 14px; }
.unit-head .uinfo { color: var(--muted); font-size: 12px; }
.unit-head .uarrow { color: var(--muted); font-size: 14px; }
.unit-body { padding: 4px 8px 10px; display: flex; flex-direction: column; gap: 6px; }
.lesson {
  display: flex; align-items: center; gap: 10px; padding: 9px 12px;
  border: 1px solid var(--line); border-radius: 8px; cursor: pointer; background: #fff; font-size: 14px;
}
.lesson.active { border-color: var(--primary); background: #eef2ff; font-weight: 500; }
.lesson.done .dot { border-color: var(--ok); background: var(--ok); box-shadow: inset 0 0 0 3px #fff; }
.lesson .dot { width: 16px; height: 16px; border-radius: 50%; border: 2px solid #cbd5e1; flex: none; }
.lesson.active .dot { border-color: var(--primary); background: var(--primary); box-shadow: inset 0 0 0 3px #fff; }

.subj-card .pos { font-size: 12px; color: var(--muted); margin: 6px 0 8px; min-height: 16px; }

/* 题目上传 */
.qform { display: flex; flex-direction: column; gap: 10px; }
.qfile { display: block; cursor: pointer; }
.qfile input { display: none; }
.qfile-pick { border: 2px dashed #cbd5e1; border-radius: 10px; padding: 22px; text-align: center; color: var(--muted); background: #fbfcfe; }
.qfile-pick .ic { font-size: 32px; margin-bottom: 4px; }
.qfile img { max-width: 100%; max-height: 280px; border-radius: 10px; display: none; margin-top: 8px; }

.qlist { display: flex; flex-direction: column; gap: 10px; margin-top: 14px; }
.qitem { display: flex; gap: 10px; padding: 10px; background: #fbfcfe; border: 1px solid var(--line); border-radius: 10px; }
.qitem img { width: 80px; height: 80px; object-fit: cover; border-radius: 8px; flex: none; cursor: zoom-in; background: #eef1f8; }
.qitem .qmeta { flex: 1; min-width: 0; }
.qitem .qtxt { font-size: 14px; word-break: break-all; margin-bottom: 4px; }
.qitem .qfoot { font-size: 12px; color: var(--muted); display: flex; gap: 8px; align-items: center; }
.qitem .qans { margin-top: 6px; padding: 8px 10px; background: #f0fdf4; border-radius: 6px; font-size: 13px; color: #166534; }
.pill { display: inline-block; padding: 2px 8px; border-radius: 99px; font-size: 11px; }
.pill.ok { background: #dcfce7; color: #15803d; }
.pill.warn { background: #fef3c7; color: #b45309; }

/* 题目标签徽章 */
.tab .badge { display: inline-block; background: #ef4444; color: #fff; font-size: 11px; padding: 0 6px; border-radius: 99px; margin-left: 4px; vertical-align: 1px; font-weight: 600; }

/* 答疑列表 */
.qa-filters { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 8px 0 14px; }
.qa-filters .btn { width: auto; margin: 0; padding: 7px 14px; font-size: 13px; }
.qa-filters .btn.on { background: linear-gradient(135deg, #ef4444, #f87171); }
.qa-filters .sel { padding: 7px 10px; border-radius: 8px; border: 1px solid var(--line); font-size: 13px; background: #fbfcfe; }
.qa-list { display: flex; flex-direction: column; gap: 12px; }
.qcard { display: flex; gap: 12px; padding: 12px; background: #fbfcfe; border: 1px solid var(--line); border-radius: 12px; }
.qcard .qimg img { width: 110px; height: 110px; object-fit: cover; border-radius: 8px; background: #eef1f8; cursor: zoom-in; flex: none; }
.qcard .qbody { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 6px; }
.qcard .qhead { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; font-size: 13px; }
.qcard .qname { font-weight: 600; }
.qcard .qacc, .qcard .qtime { color: var(--muted); font-size: 12px; }
.qcard .qsub { background: #eef2ff; color: var(--primary); padding: 2px 8px; border-radius: 99px; font-size: 11px; }
.qcard .qtxt { font-size: 14px; word-break: break-all; }
.qcard .qans { padding: 8px 10px; background: #f0fdf4; border-radius: 6px; font-size: 13px; color: #166534; }
.qcard .qacts { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-top: 6px; }
.qcard .qacts .btn { width: auto; margin: 0; padding: 6px 12px; font-size: 12px; }
.qcard .qans-input { flex: 1; min-width: 140px; padding: 6px 10px; border: 1px solid var(--line); border-radius: 6px; font-size: 13px; background: #fff; }

@media (max-width: 600px) {
  .qcard { flex-direction: column; }
  .qcard .qimg img { width: 100%; height: 160px; }
}

table { width: 100%; border-collapse: collapse; font-size: 13px; }
th, td { padding: 9px 6px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: middle; }
th { color: var(--muted); font-weight: 500; font-size: 12px; }
td .nm { font-weight: 600; }
td .acc { color: var(--muted); font-size: 12px; }
.tbl-wrap { overflow-x: auto; }

.hist { list-style: none; font-size: 13px; }
.hist li { padding: 8px 0; border-bottom: 1px dashed var(--line); display: flex; justify-content: space-between; gap: 10px; }
.hist li:last-child { border: 0; }
.hist .t { color: var(--muted); font-size: 12px; flex: none; }

.qr-box { text-align: center; }
.qr-box img, .qr-box svg { width: 220px; height: 220px; background: #fff; padding: 8px; border-radius: 12px; border: 1px solid var(--line); }
.url-list { margin-top: 12px; font-size: 13px; word-break: break-all; }
.url-list div { padding: 7px 10px; background: #f7f9ff; border-radius: 8px; margin-top: 6px; display: flex; justify-content: space-between; gap: 8px; align-items: center; }
.copy { color: var(--primary); cursor: pointer; font-size: 12px; flex: none; border: 0; background: none; }

.tabs { display: flex; gap: 8px; margin-top: 14px; }
.tab { flex: 1; text-align: center; padding: 9px; border-radius: 10px; background: #fff; font-size: 14px; cursor: pointer; border: 1px solid var(--line); color: var(--muted); }
.tab.on { background: var(--primary); color: #fff; border-color: var(--primary); }
.hidden { display: none; }
.tip { font-size: 12px; color: var(--muted); margin-top: 8px; }
.footer { text-align: center; font-size: 12px; color: var(--muted); margin-top: 24px; }
.stat { display: flex; gap: 10px; }
.stat div { flex: 1; background: #f7f9ff; border-radius: 10px; padding: 10px; text-align: center; }
.stat b { display: block; font-size: 20px; color: var(--primary); }
.stat span { font-size: 12px; color: var(--muted); }
.login-logo { text-align: center; padding: 30px 0 10px; }
.login-logo .ic { font-size: 40px; }

/* 多科目 */
.subj-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 10px; }
.subj-card {
  background: #fbfcfe; border: 1px solid var(--line); border-radius: 12px; padding: 12px;
  cursor: pointer; transition: .15s;
}
.subj-card:hover { border-color: var(--primary); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(74,108,247,.12); }
.subj-card .head { display: flex; align-items: baseline; justify-content: space-between; gap: 6px; margin-bottom: 6px; }
.subj-card .name { font-weight: 600; font-size: 15px; }
.subj-card .grade { font-size: 11px; color: var(--muted); }
.subj-card .meter { height: 6px; background: #eef1f8; border-radius: 99px; overflow: hidden; margin-top: 6px; }
.subj-card .meter > i { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), #57d9a3); }
.subj-card .foot { display: flex; justify-content: space-between; align-items: center; margin-top: 6px; font-size: 12px; color: var(--muted); }
.subj-card .pct { color: var(--primary); font-weight: 600; font-size: 14px; }
.empty { text-align: center; padding: 30px 12px; color: var(--muted); font-size: 13px; }
.pill { display: inline-block; font-size: 11px; padding: 2px 8px; border-radius: 99px; background: #eef2ff; color: var(--primary); }
.pill.warn { background: #fff7ed; color: #c2410c; }
.pill.ok { background: #f0fdf4; color: #15803d; }
.pill.gray { background: #f1f5f9; color: var(--muted); }

.template-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 8px; }
.template-grid .tg { background: #fbfcfe; border: 1px solid var(--line); border-radius: 10px; padding: 10px; font-size: 13px; }
.template-grid .tg b { display: block; font-size: 14px; margin-bottom: 4px; }
.template-grid .tg .ver { font-size: 11px; color: var(--muted); margin-bottom: 6px; }
.template-grid .tg button { width: 100%; margin-top: 4px; padding: 6px; font-size: 12px; }

.subject-row { display: flex; align-items: center; gap: 10px; padding: 10px; background: #fbfcfe; border: 1px solid var(--line); border-radius: 10px; margin-top: 8px; }
.subject-row .info { flex: 1; min-width: 0; }
.subject-row .info .nm { font-weight: 600; font-size: 14px; }
.subject-row .info .ver { font-size: 11px; color: var(--muted); }
.subject-row .meter { width: 80px; height: 6px; background: #eef1f8; border-radius: 99px; overflow: hidden; }
.subject-row .meter > i { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), #57d9a3); }
.subject-row .pct { font-size: 13px; color: var(--primary); font-weight: 600; width: 44px; text-align: right; }
.subject-row .act { display: flex; gap: 4px; }

.grade-tabs { display: flex; gap: 6px; margin: 10px 0 12px; }
.grade-tabs .gt { padding: 6px 14px; border-radius: 99px; background: #fff; border: 1px solid var(--line); font-size: 13px; cursor: pointer; color: var(--muted); }
.grade-tabs .gt.on { background: var(--primary); color: #fff; border-color: var(--primary); }

/* Modal */
.modal-mask { position: fixed; inset: 0; background: rgba(15,23,42,.45); z-index: 100; display: flex; align-items: center; justify-content: center; padding: 16px; }
.modal { background: #fff; border-radius: 14px; width: 100%; max-width: 520px; max-height: 90vh; overflow-y: auto; padding: 18px; box-shadow: 0 10px 40px rgba(0,0,0,.18); }
.modal h3 { font-size: 16px; margin-bottom: 6px; }
.modal .meta { font-size: 12px; color: var(--muted); margin-bottom: 12px; }
.modal .btnrow { display: flex; gap: 8px; margin-top: 14px; }
.modal .btnrow button { flex: 1; margin: 0; }
.modal textarea { resize: vertical; min-height: 260px; font-family: ui-monospace, "Cascadia Code", Menlo, Consolas, monospace; font-size: 13px; line-height: 1.7; }