:root {
  --bg: #f6f7f9;
  --border: #d8dee6;
  --text: #172033;
  --muted: #6c757d;
  --primary: #0d6efd;
  --secondary: #6c757d;
  --danger: #dc3545;
  --success: #198754;
  --info: #0dcaf0;
  --light: #f8f9fa;
  --white: #fff;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif; color: var(--text); background: var(--bg); line-height: 1.5; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: 100%; max-width: 1140px; margin: 0 auto; padding-left: 16px; padding-right: 16px; }
.page { max-width: 1120px; margin: 0 auto; }
.pb-5 { padding-bottom: 3rem; }
.mt-1 { margin-top: .25rem; } .mt-2 { margin-top: .5rem; } .mt-3 { margin-top: 1rem; } .mt-4 { margin-top: 1.5rem; }
.mb-0 { margin-bottom: 0; } .mb-2 { margin-bottom: .5rem; } .mb-3 { margin-bottom: 1rem; }
.ms-1 { margin-left: .25rem; } .ms-2 { margin-left: .5rem; } .me-auto { margin-right: auto; } .ms-auto { margin-left: auto; }
.p-3 { padding: 1rem; }
.d-flex { display: flex; } .d-grid { display: grid; }
.flex-wrap { flex-wrap: wrap; }
.justify-content-between { justify-content: space-between; } .justify-content-center { justify-content: center; }
.align-items-center { align-items: center; }
.gap-2 { gap: .5rem; }
.row { display: flex; flex-wrap: wrap; margin-left: -.5rem; margin-right: -.5rem; }
.row > * { padding-left: .5rem; padding-right: .5rem; width: 100%; }
.g-2 { row-gap: .5rem; } .g-3 { row-gap: 1rem; }
.col-6 { flex: 0 0 auto; width: 50%; }
.col-12 { flex: 0 0 auto; width: 100%; }
@media (min-width: 768px) {
  .col-md-2 { flex: 0 0 auto; width: 16.666667%; }
  .col-md-3 { flex: 0 0 auto; width: 25%; }
  .col-md-4 { flex: 0 0 auto; width: 33.333333%; }
  .col-md-5 { flex: 0 0 auto; width: 41.666667%; }
  .col-md-6 { flex: 0 0 auto; width: 50%; }
  .col-md-8 { flex: 0 0 auto; width: 66.666667%; }
}
.h4 { font-size: 1.5rem; } .h5 { font-size: 1.25rem; } .h6 { font-size: 1rem; }
.fs-4 { font-size: 1.5rem; } .fs-5 { font-size: 1.25rem; }
.fw-semibold { font-weight: 600; }
.small { font-size: .875rem; }
.text-muted { color: var(--muted); } .text-danger { color: var(--danger); } .text-success { color: var(--success); } .text-info { color: #087990; }
.bg-light { background: var(--light); }
.border { border: 1px solid var(--border); } .border-bottom { border-bottom: 1px solid var(--border); }
.rounded { border-radius: .375rem; }
.prewrap, .question-stem { white-space: pre-wrap; }
.question-stem { font-size: 1.08rem; }
.navbar { padding: .5rem 0; }
.navbar-brand { font-weight: 600; font-size: 1.25rem; color: var(--text); }
.navbar-nav { display: flex; flex-direction: row; gap: .25rem; padding-left: 0; margin: 0; list-style: none; }
.nav-link { display: block; padding: .5rem .65rem; color: #344054; border-radius: .35rem; }
.nav-link:hover { background: #eef2f7; text-decoration: none; }
.navbar-collapse { display: flex; align-items: center; width: 100%; }
.navbar-toggler { display: none; border: 1px solid var(--border); background: var(--white); border-radius: .375rem; padding: .35rem .55rem; }
.navbar-toggler-icon::before { content: "☰"; font-size: 1.2rem; }
.card { background: var(--white); border: 1px solid var(--border); border-radius: .5rem; }
.card-body { padding: 1rem; }
.h-100 { height: 100%; }
.list-group { display: flex; flex-direction: column; }
.list-group-item { display: block; padding: .85rem 1rem; background: var(--white); border: 1px solid var(--border); margin-bottom: -1px; }
.list-group-item:first-child { border-top-left-radius: .5rem; border-top-right-radius: .5rem; }
.list-group-item:last-child { border-bottom-left-radius: .5rem; border-bottom-right-radius: .5rem; margin-bottom: 0; }
.list-group-item-action:hover { background: #f8fafc; text-decoration: none; }
.definition-box { padding: .85rem 1rem; background: #f8fafc; border: 1px solid var(--border); border-radius: .5rem; color: #344054; font-size: .95rem; }
.definition-box > div + div { margin-top: .35rem; }
.wrong-core-stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.stat-box { height: 100%; padding: .85rem 1rem; background: var(--white); border: 1px solid var(--border); border-radius: .5rem; }
.stat-box-primary { border-color: #b6d4fe; background: #f8fbff; }
.overview-box { padding: .85rem 1rem; background: var(--white); border: 1px solid var(--border); border-radius: .5rem; }
.overview-grid { display: grid; grid-template-columns: minmax(260px, 1.3fr) minmax(180px, .8fr) minmax(180px, .8fr); gap: 1.25rem; }
.wrong-filter-form { align-items: flex-start; }
.wrong-filter-form .btn { min-width: 96px; }
.wrong-dist-row { display: grid; grid-template-columns: 72px 1fr 36px; align-items: center; gap: .5rem; margin-top: .45rem; }
.wrong-dist-bar { height: 8px; background: #eef2f7; border-radius: 999px; overflow: hidden; }
.wrong-dist-bar > div { height: 100%; background: #dc3545; border-radius: 999px; }
.btn { display: inline-block; border: 1px solid transparent; border-radius: .375rem; padding: .45rem .75rem; font-size: 1rem; line-height: 1.5; cursor: pointer; text-align: center; background: var(--white); color: var(--text); }
.btn:hover { text-decoration: none; filter: brightness(.97); }
.btn:disabled, .btn.disabled { opacity: .6; cursor: not-allowed; }
.btn-sm { padding: .25rem .5rem; font-size: .875rem; }
.btn-primary { background: var(--primary); color: var(--white); border-color: var(--primary); }
.btn-outline-primary { color: var(--primary); border-color: var(--primary); }
.btn-outline-secondary { color: var(--secondary); border-color: var(--secondary); }
.btn-outline-danger { color: var(--danger); border-color: var(--danger); }
.btn-outline-info { color: #087990; border-color: var(--info); }
.btn-outline-secondary:disabled { background: #f1f3f5; color: #6c757d; }
.w-100 { width: 100%; }
.form-control, .form-select { display: block; width: 100%; padding: .45rem .65rem; font-size: 1rem; line-height: 1.5; border: 1px solid #ced4da; border-radius: .375rem; background: var(--white); }
.form-label { display: inline-block; margin-bottom: .35rem; }
.form-text { color: var(--muted); font-size: .875rem; }
.form-check { display: block; }
.form-check-input { margin-right: .35rem; }
.option-label { display: block; padding: .75rem .9rem; border: 1px solid var(--border); border-radius: .5rem; background: var(--white); margin-bottom: .6rem; overflow-wrap: anywhere; word-break: break-word; }
.option-label input { margin-right: .5rem; }
.option-label.option-correct { border-color: #20c997; background: #d1e7dd; color: #0f5132; font-weight: 600; }
.option-label.option-wrong { border-color: #dc3545; background: #f8d7da; color: #842029; font-weight: 600; }
.option-label.option-after-submit { background: #f8fafc; color: #667085; }
.option-label.option-correct::after { content: "正确答案"; display: block; margin-top: .35rem; font-size: .875rem; font-weight: 600; text-align: right; }
.option-label.option-selected-correct::after { content: "已选正确"; }
.option-label.option-missed::after { content: "漏选答案"; }
.option-label.option-wrong::after { content: "你的选择"; display: block; margin-top: .35rem; font-size: .875rem; font-weight: 600; text-align: right; }
.alert { padding: .75rem 1rem; margin-bottom: 1rem; border: 1px solid transparent; border-radius: .375rem; }
.alert-success { color: #0f5132; background: #d1e7dd; border-color: #badbcc; }
.alert-danger, .alert-error { color: #842029; background: #f8d7da; border-color: #f5c2c7; }
.alert-warning { color: #664d03; background: #fff3cd; border-color: #ffecb5; }
.alert-info { color: #055160; background: #cff4fc; border-color: #b6effb; }
.badge { display: inline-block; padding: .35em .65em; font-size: .75em; font-weight: 700; border-radius: .375rem; }
.text-bg-info { color: #000; background: var(--info); }
.text-bg-secondary { color: #fff; background: var(--secondary); }
.text-bg-success { color: #fff; background: var(--success); }
.text-bg-warning { color: #664d03; background: #ffc107; }
.text-bg-danger { color: #fff; background: var(--danger); }
.practice-question-head { min-height: 34px; }
.practice-question-head form { margin: 0; }
.answer-feedback { display: inline-flex; align-items: center; flex-wrap: wrap; gap: .35rem .65rem; max-width: 100%; padding: .6rem .85rem; border: 1px solid transparent; border-radius: .5rem; font-weight: 600; }
.answer-feedback-title { white-space: nowrap; }
.answer-feedback-detail { font-weight: 500; overflow-wrap: anywhere; word-break: break-word; }
.answer-feedback-success { color: #0f5132; background: #d1e7dd; border-color: #20c997; }
.answer-feedback-danger { color: #842029; background: #f8d7da; border-color: #dc3545; }
.answer-feedback-info { color: #055160; background: #cff4fc; border-color: #0dcaf0; }
.practice-status-row { display: flex; align-items: center; flex-wrap: wrap; gap: .5rem; min-height: 28px; }
.status-dot { display: inline-block; width: 42px; height: 12px; border-radius: 999px; border: 1px solid transparent; }
.status-correct, .status-mastered { background: #d1e7dd; border-color: #20c997; }
.status-wrong { background: #f8d7da; border-color: #dc3545; }
.status-info { background: #cff4fc; border-color: #0dcaf0; }
.status-unmastered { background: #fff3cd; border-color: #ffc107; }
.wrong-stat-text { white-space: nowrap; }
.progress { height: 1rem; background: #e9ecef; border-radius: .375rem; overflow: hidden; }
.progress-bar { height: 100%; background: var(--primary); }
.collapse { display: none; }
.collapse.show { display: block; }
.navbar-collapse.collapse { display: flex; }
@media (max-width: 767px) {
  .container { padding-left: 14px; padding-right: 14px; }
  .btn { min-height: 42px; }
  .wrong-page-head { align-items: flex-start; flex-direction: column; }
  .wrong-actions { width: 100%; }
  .wrong-actions .btn { flex: 1 1 160px; }
  .wrong-core-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .75rem; }
  .overview-grid { grid-template-columns: 1fr; gap: .9rem; }
  .wrong-filter-form .btn { flex: 1 1 140px; }
  .wrong-dist-row { grid-template-columns: 64px 1fr 32px; }
  .navbar-toggler { display: inline-block; margin-left: auto; }
  .navbar-collapse { display: none; flex-direction: column; align-items: stretch; gap: .75rem; padding-top: .75rem; }
  .navbar-collapse.collapse { display: none; }
  .navbar-collapse.show { display: flex; }
  .navbar-nav { flex-direction: column; }
  .d-flex.navbar-mobile-row { display: flex; }
  .practice-question-head { align-items: flex-start; }
  .answer-feedback { display: flex; width: 100%; }
  .wrong-stat-text { flex-basis: 100%; margin-left: 0; white-space: normal; }
}
@media (max-width: 420px) {
  .wrong-core-stats { grid-template-columns: 1fr; }
}