:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --line: #e3e6ea;
  --text: #24292f;
  --muted: #6a737d;
  --primary: #1f6feb;
  --danger: #cf222e;
  --ok: #1a7f37;
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 15px/1.6 -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  background: var(--card); border-bottom: 1px solid var(--line);
  padding: 10px 24px;
}
.brand { font-weight: 700; }
.brand .sub { color: var(--muted); font-weight: 400; font-size: 13px; margin-left: 6px; }
.nav { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.nav a { color: var(--primary); text-decoration: none; }
.sep { width: 1px; height: 16px; background: var(--line); }
.muted { color: var(--muted); }
.dim { color: #9aa1a9; }
.who { font-weight: 600; }
.main { max-width: 1080px; margin: 24px auto; padding: 0 24px; }
.footer { max-width: 1080px; margin: 24px auto; padding: 0 24px 32px; font-size: 12px; }

.flashes { margin-bottom: 16px; }
.flash { padding: 10px 14px; border-radius: 6px; margin-bottom: 8px; font-size: 14px; }
.flash-error { background: #ffebe9; color: var(--danger); border: 1px solid #ffc1bd; }
.flash-ok { background: #e6ffec; color: var(--ok); border: 1px solid #abf2bc; }

.login-card {
  max-width: 460px; margin: 48px auto; background: var(--card);
  border: 1px solid var(--line); border-radius: 10px; padding: 28px 32px;
}
.login-card h2 { margin: 0 0 8px; }
.login-form label { display: block; margin-top: 14px; color: var(--muted); font-size: 13px; }
.login-form input[type=text], .login-form input[type=password] {
  display: block; width: 100%; margin-top: 4px; padding: 8px 10px;
  border: 1px solid var(--line); border-radius: 6px; font-size: 15px;
}
.login-form input:focus { outline: 2px solid #bfdbfe; border-color: var(--primary); }
.captcha-row { display: flex; align-items: center; gap: 10px; margin-top: 4px; }
.captcha-row input { display: inline-block; width: 150px; padding: 8px 10px; border: 1px solid var(--line); border-radius: 6px; }
.captcha-img { height: 40px; border: 1px solid var(--line); border-radius: 4px; cursor: pointer; background: #fff; }
.login-form button { margin-top: 20px; width: 100%; }

.btn {
  display: inline-block; padding: 7px 16px; border-radius: 6px; font-size: 14px;
  border: 1px solid transparent; cursor: pointer; text-decoration: none;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: #1a5fd0; }
.btn-ghost { background: transparent; color: var(--primary); border-color: var(--line); }
.btn-ghost:hover { background: #f0f4ff; }

h2 { margin-top: 8px; }
.filter-bar {
  display: flex; align-items: flex-end; gap: 14px; flex-wrap: wrap;
  background: var(--card); border: 1px solid var(--line); border-radius: 8px;
  padding: 12px 16px; margin: 12px 0 16px;
}
.filter-bar label { display: flex; flex-direction: column; gap: 4px; color: var(--muted); font-size: 13px; }
.filter-bar select, .filter-bar input {
  padding: 7px 10px; border: 1px solid var(--line); border-radius: 6px; font-size: 14px; min-width: 160px;
}
.filter-total { margin-left: auto; font-size: 13px; }
.title-cell { max-width: 360px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tag { display: inline-block; padding: 1px 10px; border-radius: 10px; font-size: 12px; }
.tag-future { background: #eaf1ff; color: #1f5cd0; }
.tag-live { background: #e6ffec; color: var(--ok); }
.tag-done { background: #f0f1f3; color: var(--muted); }
.tag-plain { background: #f0f1f3; color: var(--muted); }
.pager { display: flex; align-items: center; gap: 14px; justify-content: center; margin: 18px 0; }

.tbl { width: 100%; border-collapse: collapse; background: var(--card); border: 1px solid var(--line); border-radius: 8px; }
.tbl th, .tbl td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; font-size: 14px; }
.tbl thead th { background: #fafbfc; color: var(--muted); font-weight: 600; }
.rowlink { cursor: pointer; }
.rowlink:hover td { background: #f6f9ff; }
.empty { background: var(--card); border: 1px dashed var(--line); padding: 32px; text-align: center; color: var(--muted); border-radius: 8px; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: 8px; padding: 16px 20px; margin: 12px 0; }
.kv { display: flex; gap: 12px; padding: 4px 0; }
.kv .k { width: 90px; color: var(--muted); flex: none; }
.inline-form { margin: 16px 0; display: flex; gap: 10px; }

.raw { margin-top: 24px; }

/* 课程总结页 */
.summary-head h2 { margin-bottom: 4px; }
.summary-head .btn-sm { margin-left: 10px; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; align-items: start; }
@media (max-width: 1000px) { .two-col { grid-template-columns: 1fr; } }
.chat-panel, .doc-panel {
  background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 16px 18px;
}
.chat-list { max-height: 56vh; overflow-y: auto; margin: 12px 0; display: flex; flex-direction: column; gap: 12px; }
.msg { border-radius: 10px; padding: 10px 14px; font-size: 14px; }
.msg-user { background: #eef4ff; border: 1px solid #d5e2ff; align-self: flex-end; max-width: 85%; }
.msg-ai { background: #f7f8fa; border: 1px solid var(--line); }
.msg-ts { color: #9aa1a9; font-size: 11px; margin-top: 6px; display: inline-block; }
.msg-foot { display: flex; justify-content: space-between; align-items: center; }
.msg-md h1, .msg-md h2, .msg-md h3 { margin: 10px 0 6px; font-size: 1.05em; }
.msg-md table, .doc-preview table { border-collapse: collapse; margin: 8px 0; }
.msg-md th, .msg-md td, .doc-preview th, .doc-preview td { border: 1px solid var(--line); padding: 4px 10px; font-size: 13px; }
.msg-md code, .doc-preview code { background: #f0f1f3; padding: 1px 5px; border-radius: 4px; font-size: 12px; }
.chat-input textarea { width: 100%; padding: 8px 10px; border: 1px solid var(--line); border-radius: 6px; font-size: 14px; resize: vertical; }
.chat-actions { display: flex; gap: 10px; margin-top: 8px; }
.doc-actions { display: flex; gap: 10px; margin: 10px 0; }
.doc-editor {
  width: 100%; font: 13px/1.55 ui-monospace, Menlo, monospace;
  border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; resize: vertical;
}
.doc-preview { margin-top: 12px; border-top: 1px dashed var(--line); padding-top: 10px; }
.btn-sm { padding: 4px 10px; font-size: 13px; }
.small { font-size: 13px; }
.raw pre {
  background: #0f172a; color: #dbe4ff; padding: 14px; border-radius: 8px;
  overflow: auto; max-height: 420px; font-size: 12px;
}

/* 逐题分析 */
.an-panel { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 16px 18px; margin: 14px 0; }
.an-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.an-top h3 { margin: 0; }
.an-actions { display: flex; align-items: center; gap: 12px; }
.an-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 14px; margin-top: 14px; }
.an-card { border: 1px solid var(--line); border-radius: 8px; padding: 12px 14px; background: #fdfdfe; display: flex; flex-direction: column; gap: 8px; }
.an-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.an-body { font-size: 13.5px; line-height: 1.6; max-height: 300px; overflow-y: auto; }
.an-body h1, .an-body h2, .an-body h3, .an-body h4 { font-size: 1em; margin: 8px 0 4px; }
.an-body ul, .an-body ol { margin: 4px 0; padding-left: 20px; }
.an-foot { display: flex; align-items: flex-end; justify-content: space-between; gap: 8px; border-top: 1px dashed var(--line); padding-top: 8px; }
.an-note {
  flex: 1; min-width: 0; resize: vertical;
  font: 12px/1.5 -apple-system, "PingFang SC", sans-serif;
  border: 1px solid var(--line); border-radius: 6px; padding: 6px 8px;
}
.an-note:focus { outline: 2px solid #bfdbfe; border-color: var(--primary); }
.an-body h2 { font-size: 14px; margin: 14px 0 6px; padding-bottom: 3px; border-bottom: 1px solid var(--line); }
.an-body h3 { font-size: 13.5px; color: var(--primary); margin: 10px 0 4px; }
.an-body h4 { font-size: 13px; color: var(--muted); margin: 8px 0 4px; }
.an-body p { margin: 6px 0; }
.an-body strong { color: #111418; }
.an-body table { border-collapse: collapse; margin: 6px 0; }
.an-body th, .an-body td { border: 1px solid var(--line); padding: 3px 8px; font-size: 12.5px; }
.an-body li { margin: 2px 0; }
.an-body code { background: #f0f1f3; padding: 1px 5px; border-radius: 4px; font-size: 12px; }

/* 学习完成情况 */
.charts-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 12px 0; }
@media (max-width: 1000px) { .charts-grid { grid-template-columns: 1fr; } }
.chart-card { border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; background: #fdfdfe; }
.chart-card h4 { margin: 0 0 6px; font-size: 13px; color: var(--muted); font-weight: 600; }
.chart { width: 100%; height: auto; display: block; }
.chart text.ct { font: 12px -apple-system, "PingFang SC", sans-serif; fill: var(--text); }
.tbl-wrap { overflow-x: auto; }
.tbl-tight th, .tbl-tight td { padding: 6px 8px; font-size: 13px; white-space: nowrap; }

/* 逐学员分析 */
.stu-list { margin-top: 12px; display: flex; flex-direction: column; gap: 10px; }
.stu-item { border: 1px solid var(--line); border-radius: 10px; background: #fdfdfe; }
.stu-item > summary {
  display: flex; align-items: center; gap: 12px; padding: 10px 14px; cursor: pointer;
  list-style: none; user-select: none; flex-wrap: wrap;
}
.stu-item > summary::-webkit-details-marker { display: none; }
.stu-item[open] > summary { border-bottom: 1px dashed var(--line); }
.stu-name { font-size: 15px; }
.stu-body { padding: 12px 14px; display: flex; flex-direction: column; gap: 14px; }
.stu-part { border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; background: #fff; }
.stu-part-head { display: flex; align-items: baseline; gap: 10px; margin-bottom: 8px; }
.stu-part-head b { font-size: 14px; }
.stu-part-actions { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; flex-wrap: wrap; }
.stu-instr {
  flex: 1; min-width: 200px; padding: 6px 10px; border: 1px solid var(--line);
  border-radius: 6px; font-size: 13px;
}
.stu-instr:focus { outline: 2px solid #bfdbfe; border-color: var(--primary); }
.stu-preview { margin-top: 8px; }
.stu-done { margin-left: auto; }
.step2-head h3 { margin: 0; }

/* 思考链与流式输出 */
details.think { border: 1px solid var(--line); border-radius: 6px; background: #f7f8fa; }
details.think summary { cursor: pointer; padding: 5px 10px; font-size: 12px; color: var(--muted); user-select: none; }
details.think[open] summary { border-bottom: 1px dashed var(--line); }
.think-pre, .live-pre {
  margin: 0; padding: 8px 10px; font: 12px/1.55 ui-monospace, Menlo, monospace;
  white-space: pre-wrap; word-break: break-word; max-height: 220px; overflow-y: auto; color: #4a5563;
}
.live-pre { max-height: 260px; color: var(--text); }
.live-label { font-size: 13px; color: var(--primary); font-weight: 600; margin-bottom: 6px; }
.spinner {
  display: inline-block; width: 12px; height: 12px; vertical-align: -2px; margin-right: 4px;
  border: 2px solid #cfe0ff; border-top-color: var(--primary); border-radius: 50%;
  animation: spin 0.9s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.msg-live { width: 100%; }
.msg-md ul, .msg-md ol, .doc-preview ul, .doc-preview ol, .an-body ul, .an-body ol { margin: 6px 0; padding-left: 22px; }