:root {
  --bg: #e8eef3;
  --paper: #ffffff;
  --ink: #102033;
  --muted: #3e4e5c;
  --line: #d5e0e8;
  --navy: #071826;
  --navy-2: #0d2a3f;
  --accent: #1ec9ad;
  --accent-2: #075c4c;
  --link: #075c4c;
  --sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.7 var(--sans);
}
a { color: inherit; text-decoration: none; }
a:hover { color: var(--link); }

.mast {
  background: linear-gradient(180deg, var(--navy) 0%, var(--navy-2) 100%);
  color: #e8f4f2;
  border-bottom: 3px solid var(--accent);
}
.mast-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 22px 22px 16px;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 16px;
}
.logo-en {
  margin: 0 0 4px;
  font-size: 14px;
  letter-spacing: 0.28em;
  color: var(--accent);
  font-weight: 700;
}
.logo-en a { color: inherit; }
.logo-en a:hover { color: #7ef0db; }
.site-title,
.mast h1.site-title {
  margin: 0;
  font-size: clamp(26px, 7vw, 40px);
  letter-spacing: 0.18em;
  font-weight: 700;
  color: #e8f4f2;
}
.mast h1 {
  margin: 0;
  font-size: clamp(26px, 7vw, 40px);
  letter-spacing: 0.18em;
  font-weight: 700;
}
.mast-meta {
  margin: 0;
  font-size: 12px;
  color: #9bb0c0;
  letter-spacing: 0.06em;
  text-align: right;
  line-height: 1.7;
}
.nav {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 10px 4px;
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
}
.nav a {
  color: #c5d8e4;
  text-align: center;
  white-space: nowrap;
  padding: 11px 4px 14px;
  font-size: 13px;
  letter-spacing: 0.04em;
  border-bottom: 2px solid transparent;
}
.nav a:hover,
.nav a.is-on {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 22px 22px 80px;
}

.lead {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 8px 28px;
  margin-bottom: 24px;
  min-width: 0;
}
.lead-main {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.15fr);
  align-items: stretch;
  min-width: 0;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  overflow: hidden;
}
.thumb {
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(30, 201, 173, 0.18), transparent 55%),
    linear-gradient(180deg, #d5e8e4, #d3e0ea);
}
.lead-main .thumb {
  min-width: 0;
  width: 100%;
  height: 100%;
}
.thumb img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 20%;
}
.lead-body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 16px 20px 18px;
  background: var(--paper);
  position: relative;
  z-index: 1;
}
.kicker {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--accent-2);
  font-weight: 700;
}
.kicker a { color: inherit; }
.lead-main h2 {
  margin: 0 0 10px;
  font-size: clamp(20px, 3vw, 28px);
  line-height: 1.35;
}
.lead-main .excerpt {
  margin: 0;
  color: #3d4b58;
  font-size: 15px;
}
.lead-time {
  margin-top: 12px;
  font-size: 12px;
  color: var(--muted);
}

.lead-side { min-width: 0; }
.side-item {
  display: grid;
  grid-template-columns: 76px 1fr;
  gap: 12px;
  align-items: start;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
}
.side-item:not(:has(.thumb)) { grid-template-columns: 1fr; }
.side-item:first-child { padding-top: 2px; }
.side-item .thumb {
  width: 72px;
  aspect-ratio: 4 / 3;
  height: auto;
  border: 1px solid var(--line);
}
.side-item h3 {
  margin: 0;
  font-size: 15px;
  line-height: 1.4;
  font-weight: 600;
}
.side-item .meta {
  margin-top: 5px;
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.side-item .meta b {
  color: var(--accent-2);
  font-weight: 700;
}

.wire {
  background: var(--navy);
  color: #d7e6ef;
  padding: 16px 18px 10px;
  margin: 0 0 8px;
}
.wire h2 {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--accent);
}
.wire ol {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 28px;
  counter-reset: wire;
}
.wire li {
  padding: 9px 0 9px 28px;
  border-bottom: 1px solid rgba(213, 224, 232, 0.12);
  position: relative;
  counter-increment: wire;
}
.wire li::before {
  content: counter(wire, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 10px;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--accent);
}
.wire a {
  display: block;
  font-size: 14px;
  line-height: 1.45;
  color: #eaf3f8;
}
.wire a:hover { color: var(--accent); }
.wire time {
  display: block;
  margin-top: 3px;
  font-size: 11px;
  color: #8aa0b0;
}

.section { margin: 28px 0 0; scroll-margin-top: 12px; }
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  border-bottom: 2px solid var(--navy);
  padding-bottom: 6px;
  margin-bottom: 14px;
}
.section-head h2 {
  margin: 0;
  font-size: 18px;
  letter-spacing: 0.1em;
}
.section-head span,
.section-head .more {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.08em;
}
.section-head .more:hover { color: var(--link); }
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
  margin: 0 0 18px;
  font-size: 13px;
  color: var(--muted);
}
.crumbs a { color: var(--accent-2); }
.crumbs .sep { color: #b7c4ce; }
.crumbs .now {
  color: var(--ink);
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: min(100%, 36em);
}
.article-wrap .crumbs { margin-bottom: 16px; }
.page-cat .section-head { margin-top: 4px; }
.cat-head {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 10px;
  padding-bottom: 12px;
}
.cat-head-top {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  width: 100%;
}
.cat-head h1 {
  margin: 0;
  font-size: 22px;
  letter-spacing: 0.08em;
}
.cat-intro {
  margin: 0;
  width: 100%;
  max-width: none;
  color: #3d4b58;
  font-size: 15px;
  line-height: 1.75;
}
.cat-cards {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px 16px;
}
.cat-card {
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--paper);
  border: 1px solid var(--line);
  overflow: hidden;
}
.cat-card .thumb {
  width: 100%;
  aspect-ratio: 4 / 3;
  height: auto;
  border: 0;
  border-bottom: 1px solid var(--line);
}
.cat-card .thumb.is-empty {
  background:
    linear-gradient(135deg, rgba(30, 201, 173, 0.16), transparent 55%),
    linear-gradient(180deg, #d5e8e4, #d3e0ea);
}
.cat-card-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: 12px 14px 14px;
  min-width: 0;
}
.cat-card h2,
.cat-card h3 {
  margin: 0 0 8px;
  font-size: 15px;
  line-height: 1.45;
  font-weight: 650;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.cat-card p {
  margin: 0;
  font-size: 13px;
  line-height: 1.55;
  color: #4a5966;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.cat-card time {
  display: block;
  margin-top: auto;
  padding-top: 10px;
  font-size: 12px;
  color: var(--muted);
}
.pager {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 28px 0 8px;
}
.pager a,
.pager span {
  min-width: 36px;
  padding: 6px 10px;
  text-align: center;
  border: 1px solid var(--line);
  background: var(--paper);
  font-size: 13px;
}
.pager a.is-on,
.pager a:hover {
  border-color: var(--accent);
  color: var(--accent-2);
}
.empty { margin: 48px 0 12px; }
@media (max-width: 1000px) {
  .cat-cards { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 860px) {
  .cat-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px 12px; }
}
@media (max-width: 520px) {
  .cat-cards { grid-template-columns: 1fr; }
}
.cat-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: 16px 28px;
  min-width: 0;
}
.section.is-flip .cat-grid {
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
}
.section.is-flip .cat-feats { order: 2; }
.section.is-flip .cat-list { order: 1; }
.cat-feats {
  display: grid;
  gap: 18px;
  min-width: 0;
}
.cat-feature {
  display: grid;
  grid-template-columns: 176px 1fr;
  gap: 16px;
  align-items: start;
  min-width: 0;
}
.cat-feature .thumb {
  width: 176px;
  aspect-ratio: 4 / 3;
  height: auto;
  border: 1px solid var(--line);
}
.cat-copy { min-width: 0; }
.cat-feature h3 {
  margin: 0 0 6px;
  font-size: 18px;
  line-height: 1.4;
}
.cat-feature p {
  margin: 0;
  font-size: 14px;
  color: #4a5966;
}
.cat-list { list-style: none; margin: 0; padding: 0; }
.cat-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
}
.cat-list li:first-child { padding-top: 0; }
.cat-list a { display: block; font-size: 15px; line-height: 1.45; }
.cat-list time {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  color: var(--muted);
}

.top-cat {
  color: #c5d8e4;
}
.top-cat:hover { color: var(--accent); }
.foot {
  background: var(--navy);
  color: #8ea3b3;
  padding: 28px 22px 32px;
  font-size: 13px;
}
.foot-inner {
  max-width: 1120px;
  margin: 0 auto;
}
.foot-line {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: flex-start;
  gap: 10px 14px;
  margin: 0 0 8px;
}
.foot-brand {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.12em;
  color: #e8f4f2;
  white-space: nowrap;
}
.foot-sep {
  color: #7f94a4;
}
.foot-contact {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0;
  color: #c5d8e4;
  white-space: nowrap;
}
.foot-desc {
  margin: 0 0 14px;
  max-width: 52em;
  line-height: 1.7;
  color: #9bb0c0;
}
.foot-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin-bottom: 14px;
}
.foot-nav a {
  color: #c5d8e4;
  font-size: 13px;
}
.foot-nav a:hover { color: var(--accent); }
.foot-contact a {
  color: #e8f4f2;
}
.foot-contact a:hover { color: var(--accent); }
.foot-copy {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: #7f94a4;
}

@media (max-width: 860px) {
  .mast-inner { flex-direction: column; align-items: flex-start; }
  .mast-meta { text-align: left; }
  .nav {
    display: grid;
    grid-template-columns: repeat(12, minmax(0, 1fr));
    padding: 0 6px 6px;
  }
  .nav a {
    font-size: 12px;
    letter-spacing: 0;
    padding: 10px 2px 12px;
    grid-column: span 3;
  }
  .nav a:nth-child(n + 5) { grid-column: span 3; }
  .lead,
  .lead-main,
  .cat-grid,
  .cat-feature,
  .section.is-flip .cat-grid,
  .wire ol { grid-template-columns: 1fr; }
  .section.is-flip .cat-feats,
  .section.is-flip .cat-list { order: 0; }
  .lead-main .thumb,
  .cat-feature .thumb {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
    grid-row: auto;
  }
}

.top {
  background: var(--navy);
  color: #d5e6ef;
  border-bottom: 2px solid var(--accent);
}
.top-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 14px 22px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  font-size: 13px;
  letter-spacing: 0.08em;
}
.brand {
  color: #fff;
  font-weight: 700;
  letter-spacing: 0.16em;
}
.article-wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 22px 80px;
}
.article-wrap .title {
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1.35;
  font-weight: 700;
  margin: 0 0 12px;
}
.article-wrap .meta {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 18px;
}
.article-hero {
  width: 100%;
  margin: 0 0 18px;
  background: transparent;
  border: 0;
}
.article-hero:empty { display: none; }
.article-hero .thumb {
  display: block;
  width: 100%;
  aspect-ratio: 5 / 2;
  height: auto;
  overflow: hidden;
  background: none;
}
.article-hero .thumb img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.toc-card {
  margin: 0 0 18px;
  background: var(--paper);
  border: 1px solid var(--line);
  overflow: hidden;
}
.toc-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 16px;
  background: linear-gradient(180deg, var(--navy) 0%, var(--navy-2) 100%);
  color: #e8f4f2;
  padding: 14px 20px 13px;
  border-bottom: 3px solid var(--accent);
}
.toc-kicker {
  margin: 0 0 3px;
  font-size: 10px;
  letter-spacing: 0.32em;
  color: var(--accent);
}
.toc-label {
  margin: 0;
  font-size: 16px;
  letter-spacing: 0.18em;
  font-weight: 700;
  color: #fff;
}
.toc-count {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: #9bb0c0;
  white-space: nowrap;
  padding-bottom: 2px;
}
.toc-card .toc {
  list-style: none;
  margin: 0;
  padding: 8px 10px 10px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px 8px;
}
.toc-card .toc a {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) 14px;
  align-items: center;
  gap: 4px;
  padding: 11px 10px;
  font-size: 14px;
  line-height: 1.45;
  border-radius: 2px;
}
.toc-card .toc a:hover {
  background: #eef7f5;
  color: var(--link);
}
.toc-num {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--accent-2);
  font-weight: 700;
}
.toc-text { min-width: 0; }
.toc-go {
  color: var(--accent);
  font-size: 18px;
  line-height: 1;
  opacity: 0.55;
}
.toc-card .toc a:hover .toc-go { opacity: 1; }
.prose {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 28px 30px 36px;
}
.prose > .toc {
  list-style: none;
  margin: 0 0 28px;
  padding: 8px 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px 12px;
  counter-reset: toc;
}
.prose > .toc li { counter-increment: toc; }
.prose > .toc a {
  display: block;
  padding: 8px 0 8px 36px;
  position: relative;
  font-size: 14px;
  line-height: 1.45;
  border-bottom: 1px solid var(--line);
}
.prose > .toc a::before {
  content: counter(toc, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 8px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--accent-2);
  font-weight: 700;
}
.prose > .toc p { margin: 0; }
.prose > p { margin: 0 0 1.1em; }
.prose h2 {
  font-size: 21px;
  line-height: 1.4;
  margin: 1.8em 0 0.7em;
  padding-top: 0.4em;
  border-top: 1px solid var(--line);
}
.prose h2:first-of-type { border-top: 0; }
.prose img {
  width: auto;
  max-width: 100%;
  height: auto;
  display: block;
  margin: 1.2em auto;
}
.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.4em 0 1.8em;
  font-size: 14px;
}
.prose th, .prose td {
  border: 1px solid var(--line);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}
.prose th { background: #eef4f7; }
.summary-title { margin-top: 2.2em !important; color: var(--accent-2); }
.faq-q { font-weight: 700; margin: 1.1em 0 0.25em !important; }
.faq-a { color: #3d4b58; padding-left: 1.5em; }
@media (max-width: 640px) {
  .prose { padding: 20px 16px 28px; }
  .toc-card .toc,
  .prose > .toc { grid-template-columns: 1fr; }
}