:root {
  color-scheme: light;
  --ink: #111414;
  --muted: #5a625f;
  --line: #d8ddd8;
  --paper: #f7f7f2;
  --surface: #ffffff;
  --accent: #8c1d18;
  --accent-2: #0d5c63;
  --gold: #b18a3d;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
  line-height: 1.55;
}

a {
  color: inherit;
  text-decoration: none;
}

.topbar {
  align-items: center;
  background: rgba(247, 247, 242, 0.92);
  border-bottom: 1px solid var(--line);
  display: flex;
  height: 72px;
  justify-content: space-between;
  left: 0;
  padding: 0 clamp(20px, 4vw, 56px);
  position: sticky;
  right: 0;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(16px);
}

.brand,
.nav,
.hero-actions,
.brief-meta,
.footer {
  align-items: center;
  display: flex;
}

.brand {
  font-weight: 800;
  gap: 12px;
  letter-spacing: 0.08em;
}

.mark {
  align-items: center;
  background: var(--ink);
  color: var(--paper);
  display: inline-flex;
  font-size: 13px;
  height: 34px;
  justify-content: center;
  width: 34px;
}

.nav {
  gap: clamp(12px, 2vw, 28px);
  font-size: 14px;
  font-weight: 700;
}

.lang-toggle {
  background: var(--surface);
  border: 1px solid var(--ink);
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  font-weight: 800;
  min-height: 36px;
  padding: 0 12px;
}

.hero {
  display: grid;
  gap: 40px;
  grid-template-columns: minmax(0, 1.2fr) minmax(280px, 0.6fr);
  min-height: calc(100vh - 72px);
  padding: clamp(64px, 9vw, 120px) clamp(20px, 6vw, 84px) 48px;
}

.hero-copy {
  align-self: center;
  max-width: 900px;
}

.eyebrow {
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.16em;
  margin: 0 0 18px;
  text-transform: uppercase;
}

h1,
h2,
h3,
h4 {
  line-height: 1.05;
  margin: 0;
}

h1 {
  font-size: clamp(52px, 10vw, 132px);
  font-weight: 900;
}

h2 {
  font-size: clamp(28px, 4.2vw, 56px);
  max-width: 880px;
}

h3 {
  font-family: "Songti SC", SimSun, Georgia, serif;
  font-size: clamp(28px, 4.2vw, 50px);
  margin-top: 20px;
}

h4 {
  font-size: 18px;
  margin-bottom: 12px;
}

.lead {
  color: var(--muted);
  font-family: "Songti SC", SimSun, Georgia, serif;
  font-size: clamp(19px, 2.4vw, 30px);
  font-weight: 700;
  max-width: 980px;
}

.hero-actions {
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

.button {
  border: 1px solid var(--ink);
  display: inline-flex;
  font-weight: 800;
  justify-content: center;
  min-height: 48px;
  min-width: 156px;
  padding: 12px 18px;
}

.button.primary {
  background: var(--ink);
  color: var(--paper);
}

.button.secondary {
  background: transparent;
}

.signal-panel {
  align-self: end;
  background: var(--surface);
  border: 1px solid var(--line);
  display: grid;
}

.signal-panel div {
  display: grid;
  gap: 8px;
  padding: 24px;
}

.signal-panel div + div {
  border-top: 1px solid var(--line);
}

.signal-panel span,
.brief-meta,
.archive-item span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
}

.signal-panel strong {
  font-size: 22px;
}

.section {
  border-top: 1px solid var(--line);
  padding: clamp(56px, 8vw, 96px) clamp(20px, 6vw, 84px);
}

.section-heading {
  margin-bottom: 28px;
}

.brief {
  background: var(--surface);
  border: 1px solid var(--line);
  padding: clamp(24px, 5vw, 56px);
}

.brief-meta {
  flex-wrap: wrap;
  gap: 12px;
  justify-content: space-between;
}

.brief-lead {
  border-left: 4px solid var(--accent-2);
  color: var(--ink);
  font-size: clamp(18px, 2vw, 24px);
  font-weight: 700;
  margin: 28px 0 0;
  max-width: 980px;
  padding-left: 20px;
}

.brief-grid {
  display: grid;
  gap: 1px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: 40px;
}

.brief-grid div {
  background: #f1f2ec;
  min-height: 220px;
  padding: 24px;
}

.brief-grid p,
.membership-copy p {
  color: var(--muted);
  margin: 0;
}

.article-link-row {
  margin-top: 28px;
}

.split {
  display: grid;
  gap: 36px;
  grid-template-columns: minmax(220px, 0.45fr) minmax(0, 1fr);
}

.archive-list {
  border-top: 1px solid var(--line);
}

.archive-item {
  align-items: center;
  border-bottom: 1px solid var(--line);
  display: grid;
  gap: 16px;
  grid-template-columns: 160px minmax(0, 1fr);
  padding: 22px 0;
}

.membership {
  align-items: start;
  background: #e9efe9;
  display: grid;
  gap: 32px;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 420px);
}

.membership-copy {
  display: grid;
  gap: 22px;
}

.footer {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  justify-content: space-between;
  padding: 28px clamp(20px, 6vw, 84px);
}

.article-shell {
  margin: 0 auto;
  max-width: 980px;
  padding: clamp(48px, 8vw, 96px) clamp(20px, 5vw, 56px);
}

.article-title {
  font-size: clamp(34px, 6vw, 68px);
  margin-top: 24px;
}

.article-deck {
  color: var(--muted);
  font-family: "Songti SC", SimSun, Georgia, serif;
  font-size: clamp(19px, 2.4vw, 26px);
  font-weight: 700;
  margin: 28px 0 0;
}

.article-section {
  border-top: 1px solid var(--line);
  margin-top: 44px;
  padding-top: 32px;
}

.article-section h2 {
  font-size: clamp(24px, 3.4vw, 36px);
  margin-bottom: 18px;
}

.article-section p {
  color: #303635;
  font-size: 17px;
  line-height: 1.82;
}

.article-table {
  border: 1px solid var(--line);
  display: grid;
}

.article-table div {
  display: grid;
  gap: 12px;
  grid-template-columns: 120px minmax(0, 1fr);
  padding: 18px;
}

.article-table div + div {
  border-top: 1px solid var(--line);
}

.podcast-box {
  background: #eef1ea;
  border: 1px solid var(--line);
  padding: clamp(24px, 4vw, 40px);
}

.key-box,
.scenario-box,
.test-box {
  border: 1px solid var(--line);
  padding: clamp(22px, 4vw, 36px);
}

.key-box {
  background: #fffdf5;
}

.scenario-box {
  background: #f0f4f4;
}

.test-box {
  background: #f5f1ee;
}

.script-list {
  display: grid;
  gap: 14px;
  margin: 24px 0 0;
  padding-left: 22px;
}

.script-list li {
  color: #303635;
  font-size: 17px;
}

@media (max-width: 860px) {
  .topbar {
    height: auto;
    min-height: 64px;
    padding: 14px 18px;
  }

  .nav {
    gap: 10px;
  }

  .hero,
  .split,
  .membership {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .brief-grid {
    grid-template-columns: 1fr;
  }

  .archive-item {
    grid-template-columns: 1fr;
  }

  .article-table div {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .brand span:last-child {
    display: none;
  }

  .nav a {
    font-size: 13px;
  }

  .button {
    width: 100%;
  }

  .footer {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }
}