/* 令牌：颜色取自 sagenic-tech.com，说明见 DESIGN.md */
:root {
  --navy: #0A1628;
  --navy-2: #13233D;
  --orange: #F57C00;
  --orange-soft: #FFB74D;
  --page: #F5F7FA;
  --paper: #FFFFFF;
  --ink: #1F2937;
  --ink-2: #4B5563;
  --muted: #6B7280;
  --rule: #E5E7EB;
  --rule-strong: #1F2937;
  --field: #FBFCFD;
  --field-line: #D1D5DB;
  --on-navy: #FFFFFF;
  --on-navy-2: #9AA8BD;
  --ok: #15803D;
  --warn: #B45309;
  --danger: #B91C1C;
  --notice-bg: #FFF4E5;
  --danger-bg: #FDECEC;
  --visited: #4B3F8F;

  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", sans-serif;
  --mono: "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --radius: 4px;
  --bar-h: 56px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--page); color: var(--ink);
  font: 16px/1.8 var(--sans); caret-color: var(--navy);
}
::selection { background: rgba(10, 22, 40, 0.15); }
a { color: var(--navy); text-underline-offset: 3px; }
a:visited { color: var(--visited); }
:focus-visible { outline: 2px solid var(--navy); outline-offset: 2px; }
h1 { font-size: 26px; line-height: 1.4; font-weight: 700; margin: 0 0 8px; }
h2 { font-size: 19px; line-height: 1.5; font-weight: 700; margin: 40px 0 12px; }
h3 { font-size: 17px; line-height: 1.6; font-weight: 700; margin: 32px 0 8px; }
code, pre, .mono { font-family: var(--mono); }
.num, .timer, .qnav a, .count { font-variant-numeric: tabular-nums; }

/* ---- 按钮与表单 ---- */
button, a.button {
  display: inline-block; text-decoration: none; font: inherit; font-size: 15px; line-height: 1.5;
  padding: 7px 16px; border: 1px solid var(--field-line); border-radius: var(--radius);
  background: var(--paper); color: var(--ink); cursor: pointer;
}
button:hover, a.button:hover { border-color: var(--ink-2); }
button.primary, a.button.primary { background: var(--orange); border-color: var(--orange); color: var(--navy); font-weight: 700; }
button.primary:hover, a.button.primary:hover { background: #E67300; border-color: #E67300; }
a.button.primary:visited { color: var(--navy); }
button.danger { color: var(--danger); border-color: var(--danger); }
button.link { border: 0; background: none; color: var(--navy); padding: 0; text-decoration: underline; text-underline-offset: 3px; }
button:disabled { opacity: 0.5; cursor: not-allowed; }
details > summary { cursor: pointer; color: var(--muted); margin: 12px 0; }
code.copyable { user-select: all; word-break: break-all; }
input, select, textarea {
  font: inherit; font-size: 16px; padding: 7px 10px; border: 1px solid var(--field-line); border-radius: var(--radius);
  background: var(--field); color: var(--ink); max-width: 100%;
}
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--navy); box-shadow: 0 0 0 1px var(--navy); }
label { display: block; margin: 12px 0; font-size: 15px; }
label > input:not([type=checkbox]), label > select, label > textarea { display: block; width: 100%; margin-top: 4px; }
label.check { display: flex; gap: 8px; align-items: flex-start; }
label.check input { margin-top: 7px; accent-color: var(--navy); }
.muted { color: var(--muted); }
.small { font-size: 14px; }
.error { color: var(--danger); }
.warn-text { color: var(--warn); font-weight: 700; }
.notice { background: var(--notice-bg); border-top: 1px solid var(--orange); border-bottom: 1px solid var(--orange); padding: 8px 12px; }
details.more { margin: 16px 0; }
.ledger-row { display: flex; align-items: center; gap: 12px; margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--rule); }
select.verdict { width: auto; min-width: 6em; }
details.more > summary { font-weight: 700; }
details.help { background: var(--notice-bg); border-top: 1px solid var(--orange); border-bottom: 1px solid var(--orange); padding: 0 12px; margin: 0 0 16px; }
details.help > summary { color: var(--ink); font-weight: 700; margin: 8px 0; }
details.help ol, details.help p { margin: 6px 0 10px; }
details.help li { margin: 2px 0; }
.flash { background: var(--paper); border-left: 0; border-top: 2px solid var(--navy); border-bottom: 1px solid var(--rule); padding: 8px 12px; }
.card { background: var(--paper); border: 1px solid var(--rule); padding: 16px 24px; margin: 16px 0; }
.inline { display: inline; }

/* ---- 品牌细条（欢迎页、交卷页） ---- */
.brandbar { background: var(--navy); color: var(--on-navy); padding: 0 24px; height: 44px; display: flex; align-items: center; gap: 12px; font-size: 15px; }
.brandbar .mark { font-weight: 700; letter-spacing: 0.04em; }
.brandbar .sub { color: var(--on-navy-2); }

/* ---- 纸张 ---- */
.sheet, .paper {
  background: var(--paper); border: 1px solid var(--rule); margin: 32px auto; padding: 48px;
}
.sheet { max-width: 720px; }
.sheet.small-sheet { max-width: 560px; }
.paper { max-width: 820px; }
.sheet .facts { color: var(--ink-2); margin: 0 0 24px; }
.sheet .facts strong { color: var(--ink); }
.sheet .divider, .md hr { border: 0; border-top: 1px solid var(--rule); margin: 32px 0; }
.rules ol { padding-left: 1.4em; margin: 8px 0 0; }
.rules li { margin: 6px 0; }
.privacy { color: var(--ink-2); font-size: 15px; }
.start-form button.primary { margin-top: 12px; padding: 10px 28px; font-size: 16px; }
.done-time { font-family: var(--mono); font-variant-numeric: tabular-nums; }

/* ---- 试卷正文 ---- */
.md > :first-child { margin-top: 0; }
.md h1 + p { color: var(--ink-2); }
.md h2 { position: relative; padding-bottom: 10px; }
.md h2::after { content: ""; position: absolute; left: 0; bottom: 0; width: 48px; height: 3px; background: var(--orange); }
.md p, .md li { margin: 8px 0; }
.md ol, .md ul { padding-left: 1.4em; }
/* 三线表。table 设成 block 才能在纸内横向滚动，所以粗线画在表头和末行的单元格上，跟着表格实际宽度走 */
.md table { border-collapse: collapse; margin: 16px 0; display: block; overflow-x: auto; max-width: 100%; font-size: 15px; }
.md thead th { border-top: 2px solid var(--rule-strong); border-bottom: 1px solid var(--rule-strong); }
.md tbody tr:last-child td { border-bottom: 2px solid var(--rule-strong); }
.md th, .md td { padding: 8px 12px; vertical-align: top; text-align: left; border: 0; }
.md th { font-weight: 700; white-space: nowrap; background: none; }
.md tbody tr + tr td { border-top: 1px solid var(--rule); }
.md td code { white-space: pre-wrap; word-break: break-word; }
.md pre { background: var(--page); border: 1px solid var(--rule); border-radius: var(--radius); padding: 12px 16px; overflow-x: auto; font-size: 14px; line-height: 1.6; }
.md pre code { white-space: pre-wrap; word-break: break-word; } /* 长行折行，免得考生漏看横向滚出去的内容 */
.md :not(pre) > code { background: var(--page); border: 1px solid var(--rule); padding: 0 4px; border-radius: 3px; font-size: 0.9em; }
.md blockquote { margin: 16px 0; padding: 4px 16px; border-left: 2px solid var(--rule-strong); color: var(--ink-2); }
.question { border-top: 1px solid var(--rule); margin: 32px 0 0; padding-top: 4px; scroll-margin-top: calc(var(--bar-h) + 24px); }
.question .md h3 { margin-top: 24px; }
.answer-label { font-weight: 700; font-size: 15px; margin: 16px 0 4px; }
textarea.answer { width: 100%; min-height: 240px; line-height: 1.8; resize: vertical; display: block; }
textarea.answer[hidden] { display: none; }
/* 选择题 */
.md ol.choices { list-style: none; padding-left: 0; }
.choice-key { font-weight: 700; margin-right: 4px; }
fieldset.choices-input { border: 0; padding: 0; margin: 16px 0 4px; }
fieldset.choices-input legend { font-weight: 700; font-size: 15px; padding: 0; margin-bottom: 8px; }
label.choice { display: flex; align-items: baseline; gap: 6px; padding: 10px 12px; margin: 6px 0; border: 1px solid var(--field-line);
  border-radius: var(--radius); background: var(--paper); cursor: pointer; }
label.choice:hover { border-color: var(--rule-strong); }
label.choice:has(input:checked) { border-color: var(--orange); background: var(--notice-bg); }
label.choice > input { display: inline-block; width: auto; flex: none; margin: 0 6px 0 0; padding: 0; accent-color: var(--orange); }
.choice-text { flex: 1; }
fieldset.choices-input:disabled label.choice { cursor: default; opacity: .7; }
/* 公式 */
/* 根号、大括号要靠带 MATH 表的数学字体才画得出来：macOS 自带 STIX Two Math，Windows 自带 Cambria Math */
math { font-family: "STIX Two Math", "Cambria Math", "Latin Modern Math", math; font-size: 1.05em; }
.math-block { overflow-x: auto; margin: 12px 0; }
math[display="block"] { margin: 0 auto; }
/* Chrome 不认 columnalign 属性；align/aligned 的「左边 = 右边」两列要贴在一起 */
mtd[columnalign="right"] { text-align: right; padding-right: 0; }
mtd[columnalign="left"] { text-align: left; padding-left: 0; }
code.math-error { color: var(--danger, #B91C1C); white-space: pre-wrap; }
textarea.answer[readonly] { background: #F3F4F6; border-style: dashed; color: var(--ink); }
.answer-meta { display: flex; flex-direction: row-reverse; justify-content: space-between; color: var(--muted); font-size: 14px; margin-top: 4px; }
.answer-placeholder { border: 1px dashed var(--field-line); border-radius: var(--radius); background: var(--field); padding: 32px; text-align: center; color: var(--muted); font-size: 14px; }

/* ---- 答题页顶栏 ---- */
body.exam { padding-top: var(--bar-h); }
.exambar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 10; display: flex; align-items: center; gap: 16px;
  padding: 0 20px; background: var(--navy); color: var(--on-navy); height: var(--bar-h);
}
.exambar :focus-visible { outline-color: var(--on-navy); }
.bar-title { display: flex; align-items: baseline; gap: 12px; min-width: 0; max-width: 34%; white-space: nowrap; }
.bar-title .mark { font-weight: 700; letter-spacing: 0.04em; }
.bar-title .paper-name { color: var(--on-navy-2); font-size: 14px; overflow: hidden; text-overflow: ellipsis; }
/* 题多时（如 38 题）横向滚动，不盖住左边的卷名 */
.qnav { display: flex; gap: 4px; flex-wrap: nowrap; flex: 1; min-width: 0; justify-content: safe center; overflow-x: auto; scrollbar-width: thin; }
.qnav a { flex: none; }
.qnav a {
  display: inline-block; min-width: 32px; height: 28px; line-height: 26px; text-align: center; padding: 0 4px;
  border: 1px solid var(--on-navy-2); border-radius: 2px; text-decoration: none; color: var(--on-navy-2);
  font-family: var(--mono); font-size: 14px;
}
.qnav a:hover { color: var(--on-navy); border-color: var(--on-navy); }
.qnav a.answered { background: var(--on-navy); border-color: var(--on-navy); color: var(--navy); font-weight: 700; }
.bar-right { display: flex; align-items: center; gap: 16px; }
.timer { font: 700 22px/1 var(--mono); min-width: 5.5ch; text-align: right; padding: 4px 6px; border-radius: 2px; color: var(--on-navy); }
.timer.low { background: var(--orange); color: var(--navy); }
.save-status { font-size: 14px; color: var(--on-navy-2); white-space: nowrap; }
.save-status.ok { color: var(--on-navy-2); }
.save-status.warn { color: var(--orange-soft); font-weight: 700; }
.banner {
  position: sticky; top: var(--bar-h); z-index: 9; margin: 0; padding: 10px 20px; text-align: center; font-weight: 700; font-size: 15px;
  background: var(--notice-bg); color: var(--ink); border-bottom: 1px solid var(--orange);
}
.banner.danger { background: var(--danger-bg); color: var(--danger); border-bottom-color: var(--danger); }
.exam-main { padding: 0 16px 80px; }
.end { text-align: center; margin: 48px 0 0; }
.end button.primary { padding: 10px 40px; font-size: 16px; }
dialog { border: 1px solid var(--rule); border-radius: 0; max-width: 480px; padding: 24px 28px; color: var(--ink); }
dialog::backdrop { background: rgba(10, 22, 40, 0.5); }
dialog h2 { margin-top: 0; }
.dialog-actions { display: flex; gap: 12px; justify-content: flex-end; margin-top: 16px; }

@media (max-width: 1023px) {
  .sheet, .paper { margin: 16px auto; padding: 32px; }
}
@media (max-width: 767px) {
  :root { --bar-h: 92px; }
  .exambar { flex-wrap: wrap; height: auto; min-height: var(--bar-h); padding: 6px 12px; gap: 6px 12px; align-content: center; }
  .bar-title { max-width: none; flex: 1 1 auto; }
  .bar-title .paper-name { display: none; }
  .bar-right { gap: 10px; }
  .save-status { display: none; }
  .qnav { order: 3; flex: 1 1 100%; justify-content: flex-start; }
  .qnav a { min-width: 0; flex: 1 1 0; max-width: 40px; height: 32px; line-height: 30px; }
  .timer { font-size: 20px; }
  .sheet, .paper { margin: 0; border-left: 0; border-right: 0; padding: 24px 20px; }
  .exam-main { padding: 0 0 64px; }
  .brandbar { padding: 0 20px; }
}

/* ---- 后台 ---- */
.adminbar { display: flex; gap: 20px; align-items: center; padding: 0 20px; height: 48px; background: var(--navy); color: var(--on-navy); font-size: 15px; }
.adminbar a, .adminbar a:visited { color: var(--on-navy-2); text-decoration: none; }
.adminbar a:hover { color: var(--on-navy); }
.adminbar .brand, .adminbar .brand:visited { font-weight: 700; color: var(--on-navy); letter-spacing: 0.04em; }
.adminbar .spacer { flex: 1; }
.adminbar .muted { color: var(--on-navy-2); }
.adminbar button.link { color: var(--on-navy-2); }
.adminbar :focus-visible { outline-color: var(--on-navy); }
.admin-main { padding: 8px 20px 64px; max-width: 1400px; margin: 0 auto; }
.admin-main h1 { margin-top: 24px; }
.toolbar { display: flex; flex-direction: column; gap: 6px; margin: 16px 0; font-size: 15px; }
.counts a { margin-right: 10px; text-decoration: none; padding: 2px 8px; border-radius: 2px; color: var(--ink-2); }
.counts a.on { background: var(--navy); color: var(--on-navy); }
table.list { width: 100%; border-collapse: collapse; background: var(--paper); border-top: 2px solid var(--rule-strong); border-bottom: 2px solid var(--rule-strong); font-size: 15px; }
table.list th, table.list td { border-bottom: 1px solid var(--rule); padding: 8px 10px; text-align: left; vertical-align: top; }
table.list th { font-size: 14px; white-space: nowrap; border-bottom: 1px solid var(--rule-strong); }
.pill { display: inline-block; padding: 0 8px; border-radius: 2px; font-size: 13px; background: var(--page); border: 1px solid var(--rule); white-space: nowrap; line-height: 1.7; }
.pill.in_progress { background: #EAF0F8; border-color: #C9D6E8; color: var(--navy); }
.pill.submitted { background: #EAF5EE; border-color: #BFE1CB; color: var(--ok); }
.pill.voided { color: var(--muted); text-decoration: line-through; }
.pill.warn { background: var(--notice-bg); border-color: #F5C58A; color: var(--warn); }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 900px) { .grid2 { grid-template-columns: 1fr; } }
table.kv th { text-align: left; padding-right: 16px; white-space: nowrap; color: var(--muted); font-weight: 400; vertical-align: top; }
form.row { display: flex; gap: 8px; align-items: center; margin: 6px 0; }
form.row input[type=number] { width: 80px; }
table.events td { padding: 2px 8px 2px 0; }
.sticky-grade { position: sticky; top: 0; z-index: 5; display: flex; gap: 12px; align-items: flex-end; flex-wrap: wrap; }
.sticky-grade label { margin: 0; }
.sticky-grade .grow { flex: 1; min-width: 200px; }
.review-answer { margin-top: 16px; border-top: 1px dashed var(--field-line); padding-top: 8px; }
.review-head { color: var(--muted); font-size: 14px; }
pre.answer-text { white-space: pre-wrap; word-break: break-word; background: var(--field); border: 1px solid var(--field-line); border-radius: var(--radius); padding: 10px 12px; font-family: var(--sans); font-size: 16px; }
.late { color: var(--warn); font-size: 15px; }
label.score > input { width: 90px; display: inline-block; margin: 0 4px; }
.exam-preview { background: var(--page); }
.narrow { max-width: 720px; margin: 0 auto; padding: 24px 16px 64px; }

/* ---- 打印 ---- */
@media print {
  body, body.exam { background: #fff; padding-top: 0; }
  .exambar, .banner, .brandbar, .adminbar, .end, dialog, button, .answer-meta, .start-form, .card:not(.paper) { display: none !important; }
  .sheet, .paper { border: 0; margin: 0; padding: 0; max-width: none; }
  .md table, .md pre, .question { break-inside: avoid; }
  textarea.answer { border: 1px solid #999; background: #fff; }
}

/* ---- 角色与阅卷（2026-11）---- */
.adminnav { display: flex; flex-wrap: wrap; gap: 0 20px; }
.tag { display: inline-block; padding: 0 8px; border-radius: 2px; font-size: 13px; line-height: 1.7; white-space: nowrap;
  background: var(--page); border: 1px solid var(--rule); color: var(--ink-2); text-decoration: none; }
.tag.ok { background: #EAF5EE; border-color: #BFE1CB; color: var(--ok); }
.tag.warn { background: var(--notice-bg); border-color: #F5C58A; color: var(--warn); }
.tag.danger { background: var(--danger-bg); border-color: #F2B8B8; color: var(--danger); }
a.tag:hover { border-color: currentColor; }
code.anon { font-family: var(--mono); font-size: 13px; letter-spacing: 0.06em; color: var(--ink-2); }
.table-scroll { overflow-x: auto; max-width: 100%; }
.crumbs { margin: 0 0 4px; color: var(--muted); }
.qlist { padding-left: 1.2em; }
.qlist li { margin: 2px 0; }
.grade-q { border-top: 1px solid var(--rule); padding-top: 16px; margin-top: 16px; }
.grade-q.locked { background: var(--page); padding: 12px; }
.grade-fields { display: grid; grid-template-columns: minmax(160px, 220px) 1fr; gap: 8px 16px; align-items: start; margin-top: 8px; }
.grade-fields .error { grid-column: 1 / -1; margin: 0; }
.grade-fields.has-error input, .grade-fields.has-error textarea { border-color: var(--danger); }
.grade-fields label.comment textarea { width: 100%; min-height: 3.6em; resize: vertical; }
.grade-fields input[type=number] { width: 6em; }
.readonly-score { color: var(--ink-2); }
.savebar { position: sticky; bottom: 0; display: flex; gap: 12px; padding: 12px 0; margin-top: 16px;
  background: var(--page); border-top: 1px solid var(--rule); z-index: 2; }
.stem summary { cursor: pointer; font-weight: 600; }
pre.answer-text.collapsed { max-height: 18em; overflow: hidden; }
details.history { margin: 6px 0; }
details.history ul { margin: 4px 0; padding-left: 1.2em; }
.dismissible { display: flex; gap: 12px; align-items: flex-start; justify-content: space-between; }
.dismissible p { margin: 0; }
fieldset.choice { border: 0; padding: 0; margin: 8px 0; }
fieldset.choice legend { padding: 0; font-size: 14px; color: var(--ink-2); }
.recuse { margin-top: 24px; }
.pager { margin-top: 16px; }
@media (max-width: 767px) {
  .adminbar { height: auto; flex-wrap: wrap; gap: 4px 16px; padding: 8px 16px; }
  .adminbar .brand { flex-basis: 100%; }
  .adminbar .spacer { display: none; }
  .adminnav a { display: inline-flex; align-items: center; }
  .grade-fields { grid-template-columns: 1fr; }
  .savebar button, .grade-fields input, .grade-fields textarea, .adminnav a { min-height: 44px; }
  .savebar { flex-wrap: wrap; }
}
.filters { display: flex; flex-wrap: wrap; gap: 8px 16px; align-items: flex-end; margin-bottom: 8px; }
.filters label { display: flex; flex-direction: column; font-size: 14px; color: var(--ink-2); }
.filters select { max-width: 280px; }