:root {
  --blue: #2563eb;
  --orange: #f59e0b;
  --green: #16a34a;
  --text: #1f2937;
  --muted: #6b7280;
  --line: #e5e7eb;
  --soft: #f6f8fb;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--soft);
  color: var(--text);
  font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
}
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 32px;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}
.site-brand {
  color: var(--text);
  text-decoration: none;
  font-weight: 900;
}
.site-nav { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.site-nav a {
  color: #374151;
  text-decoration: none;
  font-weight: 700;
  padding: 8px 10px;
  border-radius: 8px;
}
.site-nav a:hover, .site-nav a[aria-current="page"] {
  color: var(--blue);
  background: #eef4ff;
}
.page { max-width: 1160px; margin: 0 auto; padding: 40px 24px; }
.hero {
  min-height: 560px;
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: 32px;
  align-items: center;
}
.eyebrow { color: var(--blue); font-weight: 800; margin-bottom: 14px; }
h1 { font-size: 56px; line-height: 1.08; margin: 0 0 18px; letter-spacing: 0; }
h2 { margin: 0 0 12px; font-size: 22px; letter-spacing: 0; }
p { color: var(--muted); font-size: 17px; line-height: 1.75; margin: 0; }
.actions { display: flex; gap: 12px; margin-top: 28px; flex-wrap: wrap; }
.button, .download {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 700;
}
.button.primary { background: var(--blue); color: #fff; }
.button.secondary { border: 1px solid var(--line); color: var(--text); background: #fff; }
.contract-wall, .section article, .downloads {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 18px 38px rgba(15, 23, 42, 0.06);
}
.contract-wall { padding: 28px; }
.wall-title { font-size: 24px; font-weight: 900; margin-bottom: 18px; }
.nodes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
.nodes span {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: #f3f4f6;
  color: var(--muted);
  font-weight: 900;
  border: 1px solid var(--line);
}
.nodes span.done { background: #dcfce7; color: var(--green); border-color: #bbf7d0; }
.nodes span.final { background: #fff7ed; color: #9a3412; border-color: #fed7aa; }
.section { margin-top: 24px; }
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.section article, .downloads { padding: 24px; }
.feature-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.feature-links a {
  min-height: 142px;
  padding: 22px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  text-decoration: none;
  color: var(--text);
  box-shadow: 0 18px 38px rgba(15, 23, 42, 0.06);
}
.feature-links span { color: var(--blue); font-weight: 800; }
.feature-links strong { font-size: 20px; line-height: 1.4; letter-spacing: 0; }
.download-row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 18px; }
.download { background: #f3f4f6; color: var(--muted); border: 1px solid var(--line); }
.download.disabled { cursor: not-allowed; }
.site-footer {
  max-width: 1160px;
  margin: 20px auto 0;
  padding: 26px 24px 34px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  border-top: 1px solid var(--line);
}
.site-footer p {
  margin-top: 6px;
  font-size: 14px;
}
.footer-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.footer-links a {
  color: var(--blue);
  font-weight: 800;
  text-decoration: none;
}
.detail-page { padding-top: 32px; }
.detail-hero {
  min-height: 480px;
  display: grid;
  grid-template-columns: 1fr 0.92fr;
  gap: 32px;
  align-items: center;
}
.detail-hero h1 { font-size: 48px; }
.tool-preview, .sentence-board, .audio-panel, .grade-map {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 18px 38px rgba(15, 23, 42, 0.06);
  padding: 28px;
}
.preview-top { color: var(--muted); font-weight: 700; }
.preview-word { margin-top: 24px; font-size: 56px; font-weight: 900; color: var(--blue); letter-spacing: 0; }
.preview-cn { font-size: 24px; font-weight: 800; margin-top: 4px; }
.preview-example { color: var(--muted); font-size: 18px; margin-top: 14px; }
.preview-actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 24px; }
.preview-actions span {
  padding: 8px 12px;
  border-radius: 8px;
  background: #f3f4f6;
  font-weight: 700;
}
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}
.workflow {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
  box-shadow: 0 18px 38px rgba(15, 23, 42, 0.06);
}
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 18px;
}
.steps div {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  background: #fbfcfe;
}
.steps span { color: var(--orange); font-weight: 900; }
.steps strong { display: block; margin: 10px 0 8px; font-size: 18px; }
.steps p { font-size: 15px; line-height: 1.6; }
.sentence-line {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  margin-top: 12px;
  font-size: 19px;
  font-weight: 800;
  background: #fbfcfe;
}
.sentence-line.active { border-color: #bfdbfe; background: #eef4ff; color: var(--blue); }
.sentence-note {
  margin-top: 10px;
  padding: 12px 14px;
  border-radius: 8px;
  background: #fff7ed;
  color: #9a3412;
  font-weight: 700;
}
.audio-panel { text-align: center; }
.audio-bars { height: 150px; display: flex; justify-content: center; align-items: end; gap: 10px; }
.audio-bars span {
  width: 24px;
  border-radius: 8px 8px 0 0;
  background: var(--blue);
}
.audio-bars span:nth-child(1) { height: 58px; }
.audio-bars span:nth-child(2) { height: 106px; background: var(--orange); }
.audio-bars span:nth-child(3) { height: 138px; }
.audio-bars span:nth-child(4) { height: 86px; background: var(--green); }
.audio-bars span:nth-child(5) { height: 116px; }
.audio-title { margin: 20px 0 14px; font-size: 24px; font-weight: 900; }
.audio-options { display: flex; justify-content: center; gap: 10px; flex-wrap: wrap; }
.audio-options button {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  min-height: 40px;
  padding: 0 14px;
  font-weight: 800;
}
.grade-map {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.grade-map span {
  min-height: 74px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #fbfcfe;
  font-weight: 900;
}
.grade-table {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
  box-shadow: 0 18px 38px rgba(15, 23, 42, 0.06);
}
.table-like {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 18px;
}
.table-like div {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  background: #fbfcfe;
}
.table-like strong { display: block; margin-bottom: 8px; }
.table-like p { font-size: 15px; line-height: 1.6; }

@media (max-width: 860px) {
  .site-header { align-items: flex-start; flex-direction: column; padding: 14px 20px; }
  .site-footer { align-items: flex-start; flex-direction: column; }
  .hero, .grid, .feature-links, .detail-hero, .split, .steps, .table-like { grid-template-columns: 1fr; }
  h1 { font-size: 40px; }
  .detail-hero h1 { font-size: 36px; }
}