* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 20px; }
body { min-width: 320px; margin: 0; background: var(--guide-color-canvas); color: var(--guide-color-ink); font-family: "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif; line-height: 1.7; }
a { color: var(--guide-color-ink); }
img, video { display: block; max-width: 100%; }
button, input { font: inherit; }
:focus-visible { outline: 3px solid var(--guide-color-primary); outline-offset: 3px; }
.skip-link { position: fixed; z-index: 20; top: 10px; left: 10px; padding: 8px 14px; border-radius: 999px; background: var(--guide-color-primary); color: var(--guide-color-on-primary); transform: translateY(-150%); }
.skip-link:focus { transform: none; }

.guide-shell {
  width: min(1180px, calc(100% - 40px));
  margin-inline: auto;
  background: var(--guide-color-surface);
  min-width: 0;
  margin-block: 20px;
  overflow: clip;
  border: 1px solid var(--guide-color-line);
  border-radius: 20px;
  box-shadow: var(--guide-shadow);
}

.brand-row { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 18px 32px; border-bottom: 1px solid var(--guide-color-line); color: var(--guide-color-muted); font-size: .9rem; font-weight: 900; }
.brand-row img { width: 170px; height: 60px; object-fit: contain; }
.article-list-link { color: var(--guide-color-primary); font-size: .84rem; text-decoration: none; }
.article-list-link:hover { text-decoration: underline; text-underline-offset: 3px; }

.guide-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(280px, .72fr);
  gap: 44px;
  align-items: center;
  min-width: 0;
  padding: clamp(30px, 5vw, 64px) 32px;
  border-bottom: 1px solid var(--guide-color-line);
}
.guide-hero-copy { min-width: 0; }
.author-hero-program { margin: 0 0 20px; }
.author-hero-program .eyebrow { margin-bottom: 4px; }
.author-hero-program p:last-child { margin: 0; color: var(--guide-color-muted); font-size: .94rem; font-weight: 750; }
.guide-hero h1 { max-width: 760px; margin: 0; color: var(--guide-color-primary); font-size: clamp(2.2rem, 5vw, 4.5rem); letter-spacing: -.05em; line-height: 1.08; }
.guide-hero-summary { max-width: 720px; margin: 20px 0 0; color: var(--guide-color-muted); font-size: 1.05rem; }
.profile-byline { margin: 20px 0 0; color: var(--guide-color-ink); font-size: .95rem; font-weight: 900; }
.eyebrow, .source-label { margin: 0 0 8px; color: var(--guide-color-primary); font-size: .78rem; font-weight: 900; letter-spacing: .08em; }
.guide-hero-media {
  aspect-ratio: 4 / 5;
  overflow: hidden;
  width: 100%;
  margin: 0;
  border: 1px solid var(--guide-color-line);
  border-radius: 20px;
  background: var(--guide-color-neutral-wash);
}
.guide-hero-media--profile-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.guide-hero-media--topic-visual img,
.guide-hero-media--default img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.guide-tools { display: grid; grid-template-columns: auto minmax(240px, 420px) 1fr; gap: 14px; align-items: center; padding: 16px 32px; border-bottom: 1px solid var(--guide-color-line); background: var(--guide-color-neutral-wash); }
.guide-tools label { font-weight: 900; }
.guide-tools input { width: 100%; padding: 10px 14px; border: 1px solid var(--guide-color-line); border-radius: 12px; background: var(--guide-color-surface); color: var(--guide-color-ink); }
.guide-tools p { justify-self: end; margin: 0; color: var(--guide-color-muted); font-size: .85rem; }

.guide-layout { display: grid; grid-template-columns: minmax(0, 1fr); gap: 24px; align-items: start; min-width: 0; padding: 24px 32px 32px; background: var(--guide-color-canvas); }
.guide-layout:has(.guide-toc) { grid-template-columns: 240px minmax(0, 1fr); }
.guide-toc { position: sticky; top: 20px; max-height: calc(100vh - 40px); overflow: auto; padding: 20px; border: 1px solid var(--guide-color-line); border-radius: 16px; background: var(--guide-color-surface); }
.aside-title { margin: 0 0 12px; color: var(--guide-color-primary); font-weight: 900; }
.guide-toc ol { display: grid; gap: 5px; margin: 0; padding: 0; list-style: none; }
.guide-toc a { display: grid; grid-template-columns: 34px 1fr; gap: 8px; padding: 8px; border-radius: 10px; color: var(--guide-color-muted); font-size: .85rem; font-weight: 750; text-decoration: none; }
.guide-toc a:hover { background: var(--guide-color-neutral-wash); color: var(--guide-color-primary); }
.guide-toc a span { color: var(--guide-color-primary); font-variant-numeric: tabular-nums; }

main { display: grid; gap: 24px; min-width: 0; }
.topic-panel, .guide-resource { min-width: 0; padding: clamp(22px, 4vw, 40px); border: 1px solid var(--guide-color-line); border-radius: 20px; background: var(--guide-color-surface); box-shadow: var(--guide-shadow); }
.topic-header { margin-bottom: 26px; }
.topic-header h2, .guide-resource h2, .footer-campaign-copy h2 { margin: 0; color: var(--guide-color-primary); font-size: clamp(1.55rem, 3vw, 2.45rem); line-height: 1.2; }
.issue-callout { margin: 12px 0 0; padding: 12px 16px; border-left: 4px solid var(--guide-color-primary); background: var(--guide-color-pale-indigo); color: var(--guide-color-muted); }
.learning-journey { display: grid; gap: 24px; min-width: 0; }
.learning-step { min-width: 0; }
.guide-resource > p:not(.eyebrow) { max-width: 780px; color: var(--guide-color-muted); }
.guide-resource a { display: block; overflow: hidden; margin-top: 24px; border: 1px solid var(--guide-color-line); border-radius: 16px; }
.guide-resource img, .guide-resource video { width: 100%; height: auto; background: var(--guide-color-primary); }
.guide-resource video { margin-top: 24px; border-radius: 16px; }

.teacher-source { min-width: 0; margin-top: 24px; }
.source-table-scroll { max-width: 100%; overflow-x: auto; border: 1px solid var(--guide-color-line); border-radius: 16px; }
.source-table { width: 100%; min-width: 620px; border-collapse: separate; border-spacing: 0; }
.source-table caption { padding: 12px 16px; background: var(--guide-color-primary); color: var(--guide-color-on-primary); font-weight: 900; text-align: left; }
.source-table th, .source-table td { padding: 14px 16px; border-right: 1px solid var(--guide-color-line); border-bottom: 1px solid var(--guide-color-line); vertical-align: middle; text-align: left; }
.source-table tr > :last-child { border-right: 0; }
.source-table tbody tr:last-child > * { border-bottom: 0; }
.source-table thead th { background: var(--guide-color-primary); color: var(--guide-color-on-primary); font-weight: 900; text-align: center; }
.source-table tbody th { background: var(--guide-color-pale-indigo); color: var(--guide-color-primary); font-weight: 900; }
.source-table tbody td { background: var(--guide-color-neutral-wash); color: var(--guide-color-ink); font-weight: 650; }
.source-table [data-needs-confirmation="true"] { outline: 3px solid var(--guide-color-ink); outline-offset: -3px; }
.source-sections { display: grid; gap: 12px; }
.argument-card { display: grid; grid-template-columns: minmax(140px, .32fr) minmax(0, 1fr); overflow: hidden; border: 1px solid var(--guide-color-line); border-radius: 14px; }
.argument-card h3 { margin: 0; padding: 16px; background: var(--guide-color-pale-indigo); color: var(--guide-color-primary); font-size: 1rem; }
.argument-card div { padding: 12px 16px; background: var(--guide-color-neutral-wash); color: var(--guide-color-ink); }
.argument-card p { margin: 0; }
.argument-card p + p { margin-top: 8px; padding-top: 8px; border-top: 1px solid var(--guide-color-line); }
.argument-card--parallel { display: block; }
.argument-card--parallel .parallel-paragraphs { padding: 16px; }

.practice-card { margin-top: 28px; padding: 24px; border-radius: 18px; background: var(--guide-color-primary); color: var(--guide-color-on-primary); }
.practice-card h3 { margin: 0 0 18px; font-size: 1.15rem; line-height: 1.7; }
.practice-card .eyebrow { color: var(--guide-color-on-primary); }
.question-source { margin: 0 0 10px; color: var(--guide-color-pale-indigo); font-size: .78rem; }
.practice-options { display: grid; gap: 10px; }
.practice-option { display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: center; width: 100%; padding: 12px 14px; border: 1px solid var(--guide-color-line-strong); border-radius: 14px; background: var(--guide-color-primary); color: var(--guide-color-on-primary); text-align: left; cursor: pointer; }
.practice-option:hover { border-color: var(--guide-color-on-primary); }
.practice-option.is-correct { border-color: var(--guide-color-on-primary); background: var(--guide-color-surface); color: var(--guide-color-primary); }
.practice-option.is-incorrect { border-color: var(--guide-color-line-strong); background: var(--guide-color-pale-indigo); color: var(--guide-color-ink); }
.option-key { display: grid; width: 32px; height: 32px; place-items: center; border: 1px solid var(--guide-color-on-primary); border-radius: 999px; font-weight: 900; }
.practice-option.is-correct .option-key { border-color: var(--guide-color-primary); }
.practice-option.is-incorrect .option-key { border-color: var(--guide-color-ink); }
.question-result { margin-top: 14px; font-weight: 900; }
.question-analysis { margin-top: 22px; padding-top: 18px; border-top: 1px solid var(--guide-color-line-strong); }
.analysis-item { padding: 14px 0; border-bottom: 1px solid var(--guide-color-line-strong); }
.analysis-item h4, .analysis-item p { margin: 0; }
.analysis-item p { margin-top: 4px; white-space: pre-line; }
.no-results { padding: 30px; border-radius: 16px; background: var(--guide-color-surface); color: var(--guide-color-ink); text-align: center; }

footer { padding: 0 32px 32px; background: var(--guide-color-canvas); color: var(--guide-color-ink); }
.footer-campaign { display: grid; gap: 20px; margin: 0; }
.footer-campaign-copy { padding: clamp(22px, 4vw, 40px); border: 1px solid var(--guide-color-line); border-radius: 20px; background: var(--guide-color-surface); box-shadow: var(--guide-shadow); }
.footer-campaign-copy > p:not(.eyebrow) { max-width: 880px; color: var(--guide-color-muted); }
.footer-campaign-cta { position: relative; display: block; aspect-ratio: 1462 / 444; overflow: hidden; border: 1px solid var(--guide-color-line); border-radius: 18px; background-color: var(--guide-color-surface); background-position: center; background-repeat: no-repeat; background-size: contain; box-shadow: var(--guide-shadow); }
.footer-campaign-discount { position: absolute; z-index: 1; top: 80.7%; left: 49%; margin: 0; padding: 5px 12px; border: 2px solid var(--guide-color-primary); border-radius: 999px; background: var(--guide-color-surface); color: var(--guide-color-primary); font-size: clamp(.74rem, 1.25vw, .95rem); font-weight: 900; line-height: 1.45; pointer-events: none; }
.footer-campaign-discount b, .discount-code--pending { color: var(--guide-color-primary); }

@media (max-width: 820px) {
  .guide-shell {
    width: min(100% - 24px, 1180px);
  }
  .brand-row { padding-inline: 20px; }
  .guide-hero { grid-template-columns: minmax(0, 1fr); gap: 24px; padding: 30px 20px; }
  .guide-hero-copy, .guide-hero-media, .guide-layout, main, .topic-panel, .learning-journey, .learning-step, .teacher-source, .source-table-scroll { min-width: 0; max-width: 100%; }
  .guide-hero-media { aspect-ratio: 4 / 5; }
  .guide-tools { grid-template-columns: minmax(0, 1fr); padding-inline: 20px; }
  .guide-tools p { justify-self: start; }
  .guide-layout, .guide-layout:has(.guide-toc) { grid-template-columns: minmax(0, 1fr); padding: 20px; }
  .guide-toc { position: static; max-height: none; }
  .source-table-scroll { width: 100%; }
  .source-table { max-width: 100%; }
  .argument-card { grid-template-columns: minmax(0, 1fr); }
  footer { padding: 0 20px 20px; }
}

@media (max-width: 520px) {
  .brand-row { flex-wrap: wrap; gap: 8px 14px; }
  .brand-row img { width: 136px; height: 48px; }
  .guide-hero h1 { font-size: clamp(2rem, 11vw, 3rem); }
  .topic-panel { padding: 22px 18px; }
  .footer-campaign-discount { top: 77%; left: 46%; padding: 3px 8px; font-size: clamp(.58rem, 2.5vw, .74rem); }
}

/* minimum-amount-and-partial-claim parallel argument cards */
.argument-card--parallel {
  display: block;
  padding: 24px;
  background: var(--guide-color-surface);
}
.argument-card--parallel .parallel-paragraphs { padding: 0; background: transparent; }
.argument-card--parallel .parallel-paragraphs > p:first-child {
  margin: 0 0 16px;
  color: var(--guide-color-primary);
  font-size: clamp(1.2rem, 2.5vw, 1.55rem);
  font-weight: 900;
}
.argument-card--parallel .parallel-paragraphs > p + p {
  margin: 0;
  padding: clamp(18px, 3vw, 28px);
  border: 1px solid var(--guide-color-line);
  border-left: 6px solid var(--guide-color-primary);
  border-radius: 16px;
  background: var(--guide-color-pale-indigo);
  white-space: pre-line;
}
@media (max-width: 520px) {
  .argument-card--parallel { padding: 18px; }
}

/* minimum-amount-and-partial-claim mobile reading refinement */
@media (max-width: 520px) {
  #topic-minimum-amount-judgment .argument-card > div {
    display: grid;
    gap: 12px;
    padding: 12px;
    background: transparent;
  }
  #topic-minimum-amount-judgment .argument-card > div > p { margin: 0; }
  #topic-minimum-amount-judgment .argument-card > div > p:first-child {
    padding: 0 4px 2px;
    color: var(--guide-color-primary);
    font-weight: 900;
  }
  #topic-minimum-amount-judgment .argument-card > div > p + p {
    margin: 0;
    padding: 16px;
    border: 1px solid var(--guide-color-line);
    border-left: 4px solid var(--guide-color-primary);
    border-radius: 12px;
    background: var(--guide-color-neutral-wash);
    line-height: 1.8;
  }
  #topic-minimum-vs-partial-table .source-table-scroll { overflow-x: hidden; }
  #topic-minimum-vs-partial-table .source-table {
    width: 100%;
    min-width: 0;
    table-layout: fixed;
  }
  #topic-minimum-vs-partial-table .source-table tr > :first-child { width: 23%; }
  #topic-minimum-vs-partial-table .source-table tr > :nth-child(2),
  #topic-minimum-vs-partial-table .source-table tr > :nth-child(3) { width: 38.5%; }
  #topic-minimum-vs-partial-table .source-table th,
  #topic-minimum-vs-partial-table .source-table td {
    padding: 8px 6px;
    font-size: clamp(0.69rem, 3vw, 0.75rem);
    line-height: 1.55;
    overflow-wrap: anywhere;
  }
  #topic-minimum-vs-partial-table .table-point { display: block; }
  #topic-minimum-vs-partial-table .table-point + .table-point {
    margin-top: 0.62em;
    padding-top: 0.62em;
    border-top: 1px dashed var(--guide-color-line);
  }
}


/* Formal Blog navigation */
.blog-index-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  margin: 16px max(20px, calc((100% - 1180px) / 2));
  padding: 0 16px;
  border: 1px solid rgba(49, 46, 129, 0.2);
  border-radius: 999px;
  background: #fff;
  color: #312e81;
  font-weight: 700;
  text-decoration: none;
}

.blog-index-link:hover,
.blog-index-link:focus-visible {
  background: #eef2ff;
  text-decoration: underline;
}

@media (max-width: 640px) {
  .blog-index-link {
    margin: 10px 12px;
    font-size: 0.95rem;
  }
}