:root {
  color-scheme: light;
  --ink: #223c39;
  --muted: #76847e;
  --green: #216955;
  --green-light: #eaf3ec;
  --border: #e4e7df;
  --red: #b14c47;
  font-family: "Segoe UI", "Microsoft YaHei", system-ui, sans-serif;
  color: var(--ink);
  background: #f6f7f1;
  font-synthesis: none;
}
* { box-sizing: border-box; scrollbar-width: thin; scrollbar-color: #bccbbd transparent; }
*::-webkit-scrollbar { width: 6px; height: 6px; }
*::-webkit-scrollbar-track { background: transparent; }
*::-webkit-scrollbar-thumb { border-radius: 10px; background: #bccbbd; }
*::-webkit-scrollbar-thumb:hover { background: #8fa992; }
body { margin: 0; }
button, input { font: inherit; }
button, a, input, label { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
button:disabled { cursor: default; opacity: .45; }
button:focus-visible, a:focus-visible, input:focus-visible, label:has(input:focus-visible) { outline: 3px solid #dbb66b; outline-offset: 4px; }
[hidden] { display: none !important; }
.site-header { height: 98px; max-width: 1344px; margin: auto; padding: 0 40px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--border); }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--ink); font-weight: 700; font-size: 18px; letter-spacing: 1px; }
.brand-icon { display: grid; place-items: center; width: 44px; height: 44px; background: var(--green); color: #fff; border-radius: 14px; }
.brand-icon svg { width: 29px; height: 29px; }
.brand small { display: block; font-size: 9px; font-weight: 500; letter-spacing: 2.1px; margin-top: 4px; color: var(--muted); }
.edition { display: flex; align-items: center; gap: 8px; font-size: 12px; color: #526b5f; padding: 9px 13px; background: #eaf0e5; border-radius: 30px; }
.edition > span { width: 6px; height: 6px; border-radius: 50%; background: #74955e; }
.workspace { max-width: 1344px; margin: 0 auto; padding: 42px 40px 30px; display: grid; grid-template-columns: 278px minmax(0, 1fr); gap: 38px; align-items: start; }
.workspace > main { min-width: 0; }
.sidebar { display: grid; gap: 20px; }
.progress-card { border-radius: 18px; background: #eaf0e4; padding: 25px 22px; }
.eyebrow { color: var(--muted); font-size: 10px; font-weight: 650; letter-spacing: 1.8px; margin: 0 0 12px; }
.progress-card .eyebrow { color: #7e9273; font-size: 9px; }
.progress-card h2 { margin: 0 0 27px; font-size: 19px; font-weight: 650; }
.progress-caption { display: flex; justify-content: space-between; gap: 10px; font-size: 11px; color: #6f806b; }
.progress-caption strong { font-weight: 650; color: var(--green); }
progress { display: block; appearance: none; border: 0; width: 100%; height: 5px; background: #d6dfd1; border-radius: 5px; margin: 12px 0 24px; overflow: hidden; }
progress::-webkit-progress-bar { background: #d6dfd1; }
progress::-webkit-progress-value { background: var(--green); border-radius: 5px; }
progress::-moz-progress-bar { background: var(--green); }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); }
.stats > div { display: flex; flex-direction: column; gap: 8px; }
.stats > div + div { padding-left: 17px; border-left: 1px solid #d5dfcf; }
.stats strong { font-size: 25px; font-weight: 600; line-height: 1; font-variant-numeric: tabular-nums; }
.stats span, .legend > span { display: flex; align-items: center; gap: 5px; color: #7a8576; font-size: 10px; }
.dot { display: inline-block; flex-shrink: 0; width: 6px; height: 6px; border-radius: 50%; }
.dot.correct { background: #62967c; }
.dot.incorrect { background: #ca8174; }
.dot.pending { background: #b4beb0; }
.dot.current { background: var(--green); }
.navigation-card { padding: 23px 19px 20px; background: #fdfefb; border: 1px solid var(--border); border-radius: 18px; }
.section-heading { display: flex; align-items: center; justify-content: space-between; }
.section-heading h2 { font-size: 14px; margin: 0; font-weight: 650; }
.section-heading > span { font-size: 10px; color: var(--muted); }
.jump-form { display: flex; gap: 6px; margin: 18px 0; }
.jump-form input { width: 0; min-width: 0; flex: 1; border: 1px solid var(--border); border-radius: 7px; padding: 9px 10px; font-size: 11px; color: var(--ink); background: #fafbf7; }
.jump-form input::placeholder { color: #98a096; }
.jump-form button { font-size: 11px; border: 1px solid var(--border); color: var(--green); background: #f0f4eb; padding: 0 10px; border-radius: 7px; }
.question-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); align-content: start; gap: 7px; max-height: 309px; overflow-y: auto; scrollbar-width: thin; scrollbar-color: #d5ddd1 transparent; padding: 4px; margin: -4px; }
.question-grid button { min-height: 33px; border: 1px solid #e6e9df; border-radius: 6px; color: #7e887c; background: #fafbf6; font-size: 11px; font-variant-numeric: tabular-nums; }
.question-grid button:hover { border-color: #a5bca9; }
.question-grid button.answered-correct { color: #3d785c; background: #e7f1e8; border-color: #c9dfcd; }
.question-grid button.answered-incorrect { color: #ad5e50; background: #fbede7; border-color: #edcfc5; }
.question-grid button[aria-current="true"] { background: var(--green); color: white; border-color: var(--green); box-shadow: 0 2px 5px #21695522; }
.legend { display: flex; justify-content: center; gap: 17px; margin-top: 20px; padding-top: 15px; border-top: 1px solid var(--border); }
.sidebar-note { margin: 0; padding-left: 4px; font-size: 11px; line-height: 1.9; color: #929b8d; }
.page-heading { min-height: 84px; display: flex; align-items: start; justify-content: space-between; gap: 15px; padding-top: 5px; margin-bottom: 21px; }
.page-heading h1 { font-size: 29px; font-weight: 650; letter-spacing: -.5px; margin: 0; }
.page-heading h1 span { font-size: 14px; color: #84907e; font-weight: 400; letter-spacing: 1px; margin-left: 17px; border-left: 1px solid #d7ded0; padding-left: 17px; vertical-align: middle; }
.total-label { color: #8e9888; font-size: 11px; padding-top: 36px; white-space: nowrap; }
.practice-settings { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px 16px; margin-bottom: 16px; font-size: 12px; color: #718268; }
.practice-settings label { display: flex; align-items: center; gap: 8px; min-height: 44px; cursor: pointer; }
.practice-settings input { width: 18px; height: 18px; margin: 0; accent-color: var(--green); }
.keyboard-hint { font-size: 11px; color: var(--muted); }
.mobile-practice-link { display: none; }
.question-card { padding: 31px 36px 0; border: 1px solid var(--border); border-radius: 20px; background: #fffefa; box-shadow: 0 6px 25px #334b3210; }
.question-topline, .question-label { display: flex; align-items: center; gap: 12px; }
.question-topline { justify-content: space-between; }
#question-number { color: var(--green); font-size: 13px; font-weight: 650; letter-spacing: .5px; }
.type-badge { padding: 5px 9px; background: #f1f1e6; color: #8a835c; font-size: 10px; border-radius: 5px; }
.chapter-label { color: #919b8c; font-size: 11px; }
#question-title { font-size: 21px; font-weight: 600; line-height: 1.85; margin: 25px 0 9px; overflow-wrap: anywhere; }
#question-title:focus { outline: none; }
.selection-hint { color: #8a9485; font-size: 12px; line-height: 1.7; margin: 0 0 23px; }
.image-notice { padding: 12px; border-radius: 8px; background: #fff4da; color: #8a6927; font-size: 12px; line-height: 1.7; overflow-wrap: anywhere; }
.options { border: 0; padding: 0; margin: 0; display: grid; gap: 12px; min-width: 0; }
.option { display: flex; position: relative; align-items: center; gap: 15px; min-height: 68px; border: 1px solid #e4e8de; padding: 15px 18px; border-radius: 10px; cursor: pointer; background: #fffefa; transition: background .15s, border-color .15s; }
.option:hover { background: #f6f8f1; border-color: #b9cbb5; }
.option:has(input:checked) { background: #edf4eb; border-color: #619071; }
.option-letter { display: grid; place-items: center; flex-shrink: 0; height: 31px; width: 31px; color: #7d8976; background: #f3f5ee; border: 1px solid #e5e8df; border-radius: 7px; font-size: 12px; font-weight: 600; }
.option:has(input:checked) .option-letter { color: white; background: var(--green); border-color: var(--green); }
.option-text { flex: 1; font-size: 14px; line-height: 1.85; overflow-wrap: anywhere; min-width: 0; }
.option input { appearance: none; margin: 0; flex-shrink: 0; width: 17px; height: 17px; border: 1px solid #cfd7c9; border-radius: 4px; background: #fff; }
.option input[type="radio"] { border-radius: 50%; }
.option input:checked { background: var(--green); border-color: var(--green); box-shadow: inset 0 0 0 3px #fff; }
.option:has(input:disabled) { cursor: default; }
.option.is-correct { border-color: #76a185; background: #eef6ee; }
.option.is-wrong { border-color: #cd8a80; background: #fcf0eb; }
.option.is-wrong .option-letter { background: var(--red); border-color: var(--red); color: #fff; }
.option-mark { font-size: 10px; font-weight: 600; white-space: nowrap; color: #4e805d; }
.is-wrong .option-mark { color: var(--red); }
.feedback { padding: 15px 17px; border-radius: 9px; margin-top: 22px; background: #edf5eb; color: #326746; font-size: 13px; line-height: 1.8; }
.feedback.incorrect { background: #fcf0e9; color: #9f5140; }
.feedback strong { display: block; font-size: 14px; margin-bottom: 3px; }
.answer-actions { min-height: 108px; display: flex; align-items: center; gap: 17px; flex-wrap: wrap; padding: 24px 0; }
.primary-button { display: flex; align-items: center; gap: 23px; background: var(--green); color: white; border: 1px solid var(--green); border-radius: 8px; padding: 13px 19px; font-size: 13px; font-weight: 600; }
.primary-button:not(:disabled):hover { background: #18523f; }
.primary-button:disabled { opacity: .55; }
.answer-actions > span { color: #96a08e; font-size: 11px; }
.text-button { background: transparent; border: 0; color: var(--green); font-size: 12px; padding: 10px 0; }
.text-button:hover { text-decoration: underline; }
.source-line { display: flex; gap: 15px; flex-wrap: wrap; justify-content: space-between; border-top: 1px solid #eef0e7; margin: 0 -36px; padding: 16px 36px; color: #97a08f; font-size: 10px; line-height: 1.7; }
.page-navigation { display: flex; align-items: center; justify-content: space-between; margin-top: 22px; }
.secondary-button { display: flex; align-items: center; gap: 17px; background: #fbfcf7; border: 1px solid #dce3d5; border-radius: 8px; padding: 12px 18px; font-size: 12px; color: #5b7057; }
.secondary-button:not(:disabled):hover { border-color: #96ae8c; background: #eef3e8; }
#page-position { color: #929c88; font-size: 12px; font-variant-numeric: tabular-nums; }
.practice-note { margin-top: 26px; text-align: center; color: #96a08d; font-size: 11px; line-height: 1.9; }
.site-footer { max-width: 1264px; margin: 0 auto; padding: 23px 20px; border-top: 1px solid var(--border); color: #99a08f; text-align: center; font-size: 10px; line-height: 1.8; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.noscript-message { position: fixed; bottom: 0; left: 0; right: 0; margin: 0; background: #fff0cf; padding: 20px; text-align: center; }
@media (min-width: 1500px) { .workspace { padding-top: 56px; } }
@media (max-width: 1050px) {
  .workspace { padding: 30px 24px; gap: 24px; grid-template-columns: 240px minmax(0, 1fr); }
  .site-header { padding: 0 24px; }
  .total-label { display: none; }
  .question-card { padding: 25px 24px 0; }
  .source-line { margin: 0 -24px; padding: 15px 24px; }
  #question-title { font-size: 19px; }
  .option { padding: 14px; gap: 11px; }
}
@media (max-width: 760px) {
  .site-header { height: 82px; padding: 0 18px; }
  .brand { font-size: 15px; gap: 9px; }
  .brand-icon { width: 37px; height: 37px; border-radius: 11px; }
  .brand small { font-size: 8px; letter-spacing: 1.4px; }
  .edition { font-size: 10px; padding: 8px 10px; }
  .workspace { display: flex; flex-direction: column; padding: 24px 16px; gap: 28px; }
  main { width: 100%; order: -1; }
  .page-heading { min-height: auto; margin-bottom: 23px; padding: 0 4px; }
  .page-heading h1 { font-size: 26px; }
  .page-heading h1 span { font-size: 13px; }
  .practice-settings { gap: 6px 12px; margin-bottom: 12px; }
  .keyboard-hint { display: none; }
  .mobile-practice-link { display: inline-flex; align-items: center; min-height: 44px; color: var(--green); font-size: 12px; text-underline-offset: 4px; }
  .question-card { padding: 23px 20px 0; border-radius: 16px; scroll-margin-top: 16px; }
  #practice-sidebar { scroll-margin-top: 16px; }
  .question-topline { gap: 8px; flex-wrap: wrap; }
  .chapter-label { font-size: 10px; }
  #question-title { font-size: 18px; margin-top: 23px; line-height: 1.9; }
  .selection-hint { font-size: 11px; }
  .option-text { font-size: 15px; }
  .option { padding: 13px 11px; gap: 10px; }
  .option-letter { width: 27px; height: 29px; }
  .option-mark { display: none; }
  .source-line { margin: 0 -20px; padding: 14px 20px; font-size: 9px; }
  .answer-actions { gap: 10px 14px; padding: 20px 0; }
  .answer-actions > span { flex-basis: 100%; line-height: 1.7; }
  .primary-button { padding: 12px 16px; min-height: 46px; }
  .text-button { min-height: 44px; padding: 10px; }
  .page-navigation { position: sticky; bottom: 0; z-index: 2; gap: 8px; margin: 16px -16px 0; padding: 12px 16px calc(12px + env(safe-area-inset-bottom)); border-top: 1px solid var(--border); background: #f6f7f1f5; box-shadow: 0 -4px 16px #334b3208; }
  .page-navigation .secondary-button { justify-content: center; min-height: 46px; padding: 12px; gap: 8px; flex: 1; }
  #page-position { min-width: 64px; text-align: center; }
  .practice-note { font-size: 10px; margin: 20px 10px 0; }
  .sidebar { width: 100%; grid-template-columns: 1fr; }
  .progress-card { padding: 22px; }
  .progress-card h2 { font-size: 18px; margin-bottom: 20px; }
  .stats > div { align-items: center; }
  .stats > div + div { padding-left: 0; }
  .jump-form input { font-size: 16px; min-height: 44px; }
  .jump-form button { min-width: 64px; }
  .question-grid { grid-template-columns: repeat(auto-fit, minmax(44px, 1fr)); max-height: 248px; overscroll-behavior-y: contain; }
  .question-grid button { min-height: 44px; font-size: 12px; }
  .sidebar-note { display: none; }
}
@media (max-width: 380px) {
  .edition { display: none; }
  .question-card { padding-left: 16px; padding-right: 16px; }
  .source-line { margin-left: -16px; margin-right: -16px; padding-left: 16px; padding-right: 16px; overflow-wrap: anywhere; }
  .page-heading h1 span { margin-left: 10px; padding-left: 10px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }