:root {
  color-scheme: light dark;
  --paper: #f5f6f8;
  --surface: #ffffff;
  --ink: #17223a;
  --muted: #5d687d;
  --line: #d6dce6;
  --navy: #12275a;
  --blue: #365a9e;
  --blue-soft: #edf2fc;
  --gold: #c99220;
  --gold-soft: #fff4d8;
  --good: #176b49;
  --bad: #a43a45;
  --content: 780px;
  --radius: 14px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body { margin: 0; min-width: 320px; background: var(--paper); color: var(--ink); font-family: "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif; font-size: 16px; line-height: 1.75; }
a { color: inherit; }
img { display: block; max-width: 100%; }
button { font: inherit; }
:focus-visible { outline: 3px solid var(--gold); outline-offset: 3px; }
.skip-link { position: fixed; top: 10px; left: 10px; z-index: 3; transform: translateY(-160%); padding: 7px 12px; background: var(--navy); color: #fff; border-radius: 6px; }
.skip-link:focus { transform: translateY(0); }
.content-shell { width: min(calc(100% - 32px), var(--content)); margin-inline: auto; }
.site-header { border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--surface) 92%, transparent); }
.nav-line { min-height: 66px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand img { width: 112px; height: 38px; object-fit: contain; }
.back-link { color: var(--blue); font-weight: 800; font-size: .92rem; text-decoration: none; }
.back-link:hover { text-decoration: underline; text-underline-offset: 4px; }
.intro { padding-block: clamp(46px, 10vw, 86px) 36px; }
.article-kicker, .topic-heading > p, .question-header p { margin: 0 0 10px; color: var(--blue); font-size: .82rem; font-weight: 900; letter-spacing: .06em; }
h1, h2, h3, h4, p { overflow-wrap: anywhere; }
h1 { margin: 0; max-width: 11ch; color: var(--navy); font-size: clamp(2.4rem, 8vw, 4.8rem); line-height: 1.12; letter-spacing: -.055em; }
.lead { max-width: 39rem; margin: 18px 0 30px; color: var(--muted); font-size: clamp(1.03rem, 2.7vw, 1.2rem); }
.author-byline { display: flex; align-items: center; gap: 18px; padding: 18px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.author-byline img { width: 88px; height: 88px; flex: 0 0 auto; padding: 4px; border: 0; border-radius: 50%; background: var(--blue); object-fit: cover; box-shadow: 0 0 0 3px color-mix(in srgb, var(--blue) 24%, transparent); }
.author-byline a { display: inline-block; margin-top: 5px; color: var(--blue); font-size: .9rem; font-weight: 900; text-decoration-thickness: 1px; text-underline-offset: 3px; }
.author-byline p { margin: 0; color: var(--muted); font-size: .78rem; font-weight: 800; }
.author-byline h2 { margin: 0; color: var(--navy); font-size: 1.14rem; line-height: 1.4; }
.author-byline span { color: var(--muted); font-size: .9rem; }
.study-list { display: grid; gap: 52px; padding-block: 8px 64px; }
.study-topic { scroll-margin-top: 22px; }
.study-topic .question-card { margin-top: 24px; }
.topic-heading { margin-bottom: 18px; }
.topic-heading h2 { margin: 0; color: var(--navy); font-size: clamp(1.55rem, 5vw, 2.2rem); line-height: 1.3; letter-spacing: -.025em; }
.topic-heading span { display: block; margin-top: 7px; color: var(--muted); }
.source-table-wrap { width: 100%; overflow-x: clip; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.source-table { width: 100%; table-layout: fixed; border-collapse: collapse; }
.source-table caption { padding: 10px 13px; border-bottom: 1px solid var(--line); background: var(--blue-soft); color: var(--navy); font-weight: 900; text-align: left; }
.source-table th, .source-table td { min-width: 0; padding: clamp(5px, 1.8vw, 13px); border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); overflow-wrap: anywhere; word-break: break-word; font-size: clamp(.69rem, 2.8vw, .98rem); line-height: 1.55; vertical-align: middle; white-space: pre-line; }
.source-table tr > :last-child { border-right: 0; }
.source-table tbody tr:last-child > * { border-bottom: 0; }
.source-table thead th { background: var(--navy); color: #fff; text-align: center; }
.source-table tbody th { background: color-mix(in srgb, var(--blue-soft) 72%, var(--surface)); color: var(--navy); font-weight: 900; }
.source-table strong { color: inherit; font-weight: 950; }
.source-table u { text-decoration-thickness: 2px; text-underline-offset: 3px; }
.source-sections { display: grid; gap: 14px; }
.source-section { display: grid; grid-template-columns: minmax(120px, .28fr) minmax(0, 1fr); border-top: 1px solid var(--line); }
.source-section h3 { margin: 0; padding: 14px 14px 14px 0; color: var(--navy); font-size: 1rem; line-height: 1.5; }
.source-section div { padding: 14px 0 14px 16px; border-left: 3px solid var(--blue); }
.source-section p { margin: 0; }
.source-section p + p { margin-top: 11px; }
.source-section strong { color: var(--navy); }
.question-card { padding: clamp(20px, 4vw, 30px); border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); box-shadow: 0 12px 32px rgb(18 39 90 / .06); }
.question-card + .question-card { margin-top: 20px; }
.question-header { display: flex; align-items: baseline; justify-content: space-between; gap: 14px; margin-bottom: 12px; }
.question-header p { margin: 0; }
.question-header span { color: var(--muted); font-size: .85rem; font-weight: 800; }
.question-card h3 { margin: 0; color: var(--ink); font-size: 1.1rem; line-height: 1.75; }
.answer-options { display: grid; gap: 9px; margin-top: 20px; }
.answer-option { display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 10px; width: 100%; padding: 12px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); color: var(--ink); cursor: pointer; text-align: left; transition: border-color .18s ease, background .18s ease, transform .18s ease; }
.answer-option:hover { border-color: var(--blue); background: var(--blue-soft); }
.answer-option:active { transform: translateY(1px); }
.answer-option b { display: grid; width: 29px; height: 29px; place-items: center; border: 1px solid currentColor; border-radius: 50%; color: var(--navy); line-height: 1; }
.answer-option.is-selected { border-width: 2px; }
.answer-option.is-correct { border-color: var(--good); background: #edf8f2; color: #104c35; }
.answer-option.is-incorrect { border-color: var(--bad); background: #fff1f2; color: #7f1f2c; }
.answer-status { min-height: 1.8em; margin: 13px 0 0; color: var(--navy); font-weight: 900; }
.full-analysis { margin-top: 16px; padding: 16px; border: 1px solid #ebd69c; border-radius: 12px; background: var(--gold-soft); }
.full-analysis > h3 { margin: 0 0 12px; color: var(--navy); font-size: 1.08rem; }
.option-analysis { padding: 12px 0; border-top: 1px solid color-mix(in srgb, var(--gold) 45%, var(--line)); }
.option-analysis:first-of-type { border-top: 0; }
.option-analysis h4 { margin: 0; color: var(--navy); font-size: 1rem; }
.option-analysis p { margin: 6px 0 0; white-space: pre-line; }
.footer { padding-bottom: 26px; }
.footer > p { margin: 16px 0 0; color: var(--muted); font-size: .82rem; text-align: center; }

.review-overview { padding-block: 18px 50px; }
.review-overview header > h2 { margin: 0; color: var(--navy); font-size: clamp(1.9rem, 6vw, 3rem); line-height: 1.2; }
.review-overview header > p { margin: 10px 0 0; color: var(--muted); }
.method-note { padding: 10px 12px; border-left: 4px solid var(--gold); background: var(--gold-soft); color: var(--ink) !important; font-size: .9rem; }
.review-summary { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin: 24px 0; }
.review-summary div { min-width: 0; padding: 13px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); }
.review-summary dt { color: var(--muted); font-size: .8rem; font-weight: 800; }
.review-summary dd { margin: 3px 0 0; color: var(--navy); font-size: 1.05rem; font-weight: 950; overflow-wrap: anywhere; }
.overview-group + .overview-group { margin-top: 26px; }
.overview-group h3 { margin: 0 0 10px; color: var(--navy); font-size: 1.15rem; }
.overview-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.overview-card { display: grid; min-width: 0; gap: 5px; padding: 14px; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); color: inherit; text-decoration: none; }
.overview-card:hover { border-color: var(--blue); background: var(--blue-soft); }
.overview-card > span { color: var(--blue); font-size: .78rem; font-weight: 950; }
.overview-card strong { color: var(--navy); line-height: 1.35; overflow-wrap: anywhere; }
.overview-card p { margin: 0; color: var(--muted); font-size: .84rem; line-height: 1.5; }
.overview-card em, .topic-stat { width: fit-content; max-width: 100%; padding: 3px 8px; border-radius: 999px; background: var(--blue-soft); color: var(--blue); font-size: .78rem; font-style: normal; font-weight: 900; overflow-wrap: anywhere; }
.topic-stat { display: block; margin-top: 10px; }
.free-question-cta { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-bottom: 50px; padding: clamp(16px, 3vw, 22px); border: 1px solid color-mix(in srgb, var(--blue) 35%, var(--line)); border-radius: var(--radius); background: linear-gradient(135deg, var(--navy), var(--blue)); color: #fff; }
.free-question-cta p { margin: 0 0 2px; color: color-mix(in srgb, #fff 74%, transparent); font-size: .78rem; font-weight: 900; letter-spacing: .06em; }
.free-question-cta strong { display: block; font-size: clamp(1.08rem, 3vw, 1.35rem); line-height: 1.35; }
.free-question-cta span { display: block; margin-top: 3px; color: color-mix(in srgb, #fff 82%, transparent); font-size: .9rem; }
.free-question-cta a { flex: 0 0 auto; padding: 10px 14px; border: 2px solid var(--gold); border-radius: 999px; background: #fff; color: var(--navy); font-size: .9rem; font-weight: 950; text-decoration: none; white-space: nowrap; }
.free-question-cta a:hover { background: var(--gold-soft); }

@media (max-width: 560px) {
  .content-shell { width: min(calc(100% - 24px), var(--content)); }
  .nav-line { min-height: 58px; }
  .brand img { width: 96px; }
  .back-link { font-size: .84rem; }
  .intro { padding-top: 42px; }
  h1 { max-width: 100%; }
  .author-byline { align-items: flex-start; gap: 13px; padding: 14px; }
  .author-byline img { width: 76px; height: 76px; }
  .review-summary, .overview-grid { grid-template-columns: 1fr; }
  .overview-card { padding: 13px; }
  .topic-stat { width: 100%; }
  .free-question-cta { align-items: stretch; flex-direction: column; gap: 13px; margin-bottom: 40px; }
  .free-question-cta a { width: 100%; text-align: center; }
  .study-list { gap: 42px; padding-block: 48px 60px; }
  .source-section { grid-template-columns: 1fr; }
  .source-section h3 { padding: 12px 0 0; }
  .source-section div { margin-top: 8px; padding: 0 0 0 12px; }
  .source-table th, .source-table td { padding: 5px; line-height: 1.42; }
  .question-card { padding: 19px; }
  .question-card h3 { font-size: 1rem; }
}

@media (prefers-color-scheme: dark) {
  :root { --paper: #101827; --surface: #182236; --ink: #edf3ff; --muted: #b8c5da; --line: #34445f; --navy: #dce7ff; --blue: #9fbcff; --blue-soft: #213659; --gold: #f1c454; --gold-soft: #3f3213; --good: #7ad8a8; --bad: #ffabb4; }
  .site-header { background: color-mix(in srgb, var(--surface) 94%, transparent); }
  .source-table thead th { background: #223b70; color: #f5f8ff; }
  .source-table tbody th { background: #213659; color: #edf3ff; }
  .answer-option { background: var(--surface); }
  .answer-option.is-correct { background: #173b2c; color: #e5fff1; }
  .answer-option.is-incorrect { background: #48232b; color: #ffeef0; }
  .full-analysis { background: #453715; color: #fff8df; }
}

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } .answer-option { transition: none; } }