:root {
  color-scheme: light;
  --ink: #202321;
  --muted: #68716c;
  --line: #d9ddda;
  --surface: #ffffff;
  --page: #f4f5f3;
  --teal: #277565;
  --teal-dark: #205f53;
  --coral: #c86d4c;
  --radius: 6px;
  font-family: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  background: var(--page);
  color: var(--ink);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body { min-width: 320px; margin: 0; background: var(--page); color: var(--ink); letter-spacing: 0; }
button,
input { font: inherit; letter-spacing: 0; }
button,
a { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }

.app-bar {
  position: sticky;
  z-index: 20;
  top: 0;
  display: flex;
  min-height: 68px;
  padding: 0 max(20px, calc((100vw - 1160px) / 2));
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
}

.brand-symbol {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border-radius: 5px;
  background: var(--ink);
  color: #ffffff;
  font-size: 11px;
  font-weight: 800;
}

.brand-link strong,
.brand-link small { display: block; }
.brand-link strong { font-size: 14px; }
.brand-link small { margin-top: 2px; color: var(--muted); font-size: 10px; }

.page-nav { display: flex; gap: 22px; }
.page-nav a { color: #4f5852; font-size: 12px; font-weight: 700; text-decoration: none; }
.page-nav a:hover { color: var(--teal); }

main,
.site-footer {
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto;
}

.source-notice {
  display: grid;
  min-height: 72px;
  padding: 14px 0;
  align-items: center;
  border-bottom: 1px solid var(--line);
  grid-template-columns: 38px minmax(0, 1fr) auto;
  gap: 12px;
}

.source-notice > svg { width: 20px; height: 20px; color: var(--teal); }
.source-notice div { min-width: 0; }
.source-notice strong,
.source-notice span { display: block; }
.source-notice strong { font-size: 13px; }
.source-notice span { margin-top: 3px; color: var(--muted); font-size: 11px; line-height: 17px; }
.source-notice a { color: var(--teal); font-size: 12px; font-weight: 700; text-decoration: none; }

.help-intro {
  display: grid;
  min-height: 230px;
  padding: 44px 0;
  align-items: center;
  border-bottom: 1px solid var(--line);
  grid-template-columns: minmax(0, 1fr) minmax(330px, 0.7fr);
  gap: 56px;
}

.section-label { margin: 0 0 6px; color: var(--teal); font-size: 12px; font-weight: 700; }
.intro-copy h1 { margin: 0; font-size: 34px; line-height: 44px; }
.intro-copy > p:last-child {
  max-width: 580px;
  margin: 10px 0 0;
  color: #505853;
  font-size: 15px;
  line-height: 25px;
}

.search-box { position: relative; display: block; }
.search-box > svg {
  position: absolute;
  top: 15px;
  left: 15px;
  width: 20px;
  height: 20px;
  color: #747d77;
}
.search-box input {
  width: 100%;
  height: 50px;
  padding: 0 48px 0 45px;
  border: 1px solid #cbd1cd;
  border-radius: var(--radius);
  background: #ffffff;
  box-shadow: 0 8px 24px rgba(32, 35, 33, 0.06);
}
.search-box input:focus { border-color: var(--teal); box-shadow: 0 0 0 3px rgba(39, 117, 101, 0.12); outline: 0; }
.search-box button {
  position: absolute;
  top: 7px;
  right: 7px;
  display: grid;
  width: 36px;
  height: 36px;
  padding: 0;
  place-items: center;
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: #68716c;
}
.search-box button:hover { background: #f0f2ef; }
.search-box button svg { width: 17px; height: 17px; }

.guide-section,
.check-section,
.faq-section { padding: 42px 0 58px; }
.check-section,
.faq-section { border-top: 1px solid var(--line); }

.section-heading { display: flex; min-height: 52px; align-items: flex-end; justify-content: space-between; gap: 20px; }
.section-heading h2 { margin: 0; font-size: 24px; line-height: 32px; }
.section-heading > span { padding-bottom: 4px; color: var(--muted); font-size: 12px; }

.category-tabs {
  display: flex;
  margin-top: 20px;
  padding-bottom: 2px;
  overflow-x: auto;
  gap: 7px;
  scrollbar-width: thin;
}
.category-tabs button {
  display: inline-flex;
  min-height: 40px;
  padding: 0 13px;
  align-items: center;
  flex: 0 0 auto;
  gap: 7px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #ffffff;
  color: #505853;
  font-size: 12px;
}
.category-tabs button:hover { border-color: #aeb6b1; }
.category-tabs button.is-active { border-color: var(--ink); background: var(--ink); color: #ffffff; }
.category-tabs svg { width: 16px; height: 16px; }

.guide-grid {
  display: grid;
  margin-top: 22px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.guide-card {
  display: grid;
  min-width: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  grid-template-columns: 168px minmax(0, 1fr);
}
.guide-card.is-selected { border-color: var(--teal); box-shadow: 0 0 0 2px rgba(39, 117, 101, 0.1); }
.guide-card > img {
  display: block;
  width: 168px;
  height: 100%;
  min-height: 292px;
  object-fit: cover;
  border-right: 1px solid var(--line);
  background: #ecefeb;
}
.guide-copy { min-width: 0; padding: 18px; }
.guide-category { color: var(--teal); font-size: 11px; font-weight: 700; }
.guide-copy h3 { margin: 6px 0 0; font-size: 18px; line-height: 25px; }
.guide-summary { margin: 8px 0 0; color: var(--muted); font-size: 12px; line-height: 19px; }
.guide-copy dl { margin: 17px 0 0; padding-top: 15px; border-top: 1px solid #e3e6e3; }
.guide-copy dt { color: #78807b; font-size: 10px; font-weight: 700; }
.guide-copy dd { margin: 4px 0 13px; color: #3e4541; font-size: 11px; line-height: 18px; }
.guide-copy dd:last-child { margin-bottom: 0; }

.guide-empty {
  display: flex;
  min-height: 240px;
  padding: 26px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  color: #89908c;
  text-align: center;
}
.guide-empty svg { width: 32px; height: 32px; }
.guide-empty p { margin: 12px 0 0; color: #69716c; font-size: 13px; }
.secondary-button {
  min-height: 38px;
  margin-top: 16px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #ffffff;
  color: var(--ink);
  font-size: 12px;
  font-weight: 700;
}

.check-grid {
  display: grid;
  margin-top: 22px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}
.check-grid article { padding: 2px 0 0; }
.check-grid svg { width: 23px; height: 23px; color: var(--coral); }
.check-grid h3 { margin: 12px 0 0; font-size: 15px; line-height: 22px; }
.check-grid p { margin: 7px 0 0; color: var(--muted); font-size: 12px; line-height: 20px; }

.faq-list { margin-top: 22px; border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); background: transparent; }
.faq-list summary {
  min-height: 58px;
  padding: 18px 34px 16px 0;
  color: #303532;
  font-size: 13px;
  font-weight: 700;
  line-height: 22px;
  cursor: pointer;
}
.faq-list p { max-width: 760px; margin: -4px 0 18px; color: var(--muted); font-size: 12px; line-height: 21px; }

.site-footer {
  display: flex;
  min-height: 90px;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 11px;
}
.site-footer strong { color: var(--ink); font-size: 13px; }

@media (max-width: 920px) {
  .guide-card { grid-template-columns: 128px minmax(0, 1fr); }
  .guide-card > img { width: 128px; }
}

@media (max-width: 720px) {
  .app-bar { min-height: 58px; padding: 0 14px; }
  .brand-link small { display: none; }
  .page-nav { gap: 14px; }
  .page-nav a:first-child { display: none; }
  main,
  .site-footer { width: calc(100% - 28px); }
  .source-notice { min-height: 78px; grid-template-columns: 30px minmax(0, 1fr) auto; gap: 8px; }
  .help-intro { min-height: 0; padding: 28px 0 30px; grid-template-columns: 1fr; gap: 22px; }
  .intro-copy h1 { font-size: 28px; line-height: 38px; }
  .intro-copy > p:last-child { font-size: 14px; line-height: 23px; }
  .guide-section,
  .check-section,
  .faq-section { padding: 30px 0 40px; }
  .section-heading h2 { font-size: 21px; line-height: 29px; }
  .guide-grid { grid-template-columns: 1fr; }
  .guide-card { grid-template-columns: 116px minmax(0, 1fr); }
  .guide-card > img { width: 116px; min-height: 296px; }
  .guide-copy { padding: 14px; }
  .check-grid { grid-template-columns: 1fr; gap: 24px; }
  .site-footer { min-height: 86px; padding: 17px 0; align-items: flex-start; justify-content: center; flex-direction: column; gap: 5px; }
}

@media (max-width: 390px) {
  .guide-card { grid-template-columns: 98px minmax(0, 1fr); }
  .guide-card > img { width: 98px; min-height: 318px; }
  .section-heading > span { display: none; }
  .source-notice a { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}