:root {
  --ink: #12343a;
  --ink-strong: #082f34;
  --muted: #5f6f72;
  --line: #d8e3e4;
  --surface: #f5f8f8;
  --white: #ffffff;
  --accent: #17b8ad;
  --accent-dark: #087d78;
  --warm: #b58435;
  --max: 1160px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--white);
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0;
}

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  height: 72px;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid rgba(18, 52, 58, 0.12);
  backdrop-filter: blur(12px);
}

.header-inner {
  width: min(calc(100% - 40px), var(--max));
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  min-width: 250px;
}

.brand img {
  width: 42px;
  height: 42px;
  object-fit: contain;
}

.brand strong,
.brand span {
  display: block;
  line-height: 1.25;
  letter-spacing: 0;
}

.brand strong {
  color: var(--ink-strong);
  font-size: 16px;
}

.brand span {
  margin-top: 2px;
  color: var(--muted);
  font-size: 10px;
}

.main-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 18px;
}

.main-nav a {
  color: var(--ink);
  text-decoration: none;
  font-size: 14px;
  font-weight: 700;
  white-space: nowrap;
}

.main-nav a:hover,
.main-nav a:focus-visible {
  color: var(--accent-dark);
}

.header-cta,
.hero-cta,
.final-cta a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: 5px;
  padding: 0 20px;
  background: var(--accent);
  color: #062f32;
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
}

.header-cta:hover,
.hero-cta:hover,
.final-cta a:hover {
  background: #2cd0c4;
}

.hero {
  position: relative;
  min-height: 570px;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background-color: var(--ink-strong);
  background-position: center;
  background-size: cover;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(5, 43, 48, 0.97) 0%, rgba(5, 43, 48, 0.86) 44%, rgba(5, 43, 48, 0.22) 78%, rgba(5, 43, 48, 0.08) 100%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
  padding: 106px 0 78px;
}

.hero-copy {
  max-width: 760px;
}

.hero h1 {
  max-width: 720px;
  margin: 0;
  color: var(--white);
  font-size: 56px;
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: 0;
}

.hero p {
  max-width: 690px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.84);
  font-size: 18px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px;
  margin-top: 32px;
}

.hero-phone {
  color: var(--white);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
}

.hero-phone:hover,
.hero-phone:focus-visible {
  color: #7ce1da;
}

.content-shell {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
  padding: 86px 0 96px;
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 72px;
  align-items: start;
}

.toc {
  position: sticky;
  top: 104px;
  padding-left: 18px;
  border-left: 3px solid var(--accent);
}

.toc strong {
  display: block;
  margin-bottom: 12px;
  color: var(--ink-strong);
  font-size: 14px;
}

.toc a {
  display: block;
  padding: 6px 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.45;
  text-decoration: none;
}

.toc a:hover,
.toc a:focus-visible {
  color: var(--accent-dark);
}

.article {
  min-width: 0;
}

.article > h2 {
  margin: 76px 0 20px;
  padding-top: 4px;
  color: var(--ink-strong);
  font-size: 32px;
  line-height: 1.28;
  font-weight: 800;
  letter-spacing: 0;
}

.article > h2:first-child {
  margin-top: 0;
}

.article h3 {
  margin: 36px 0 10px;
  color: var(--ink);
  font-size: 21px;
  line-height: 1.4;
  font-weight: 800;
  letter-spacing: 0;
}

.article p,
.article li {
  color: #304c51;
  font-size: 16px;
}

.article p {
  margin: 0 0 18px;
}

.article ul,
.article ol {
  margin: 16px 0 28px;
  padding-left: 24px;
}

.article li {
  margin: 8px 0;
  padding-left: 4px;
}

.article strong {
  color: var(--ink-strong);
}

.article blockquote {
  margin: 32px 0;
  padding: 24px 28px;
  background: var(--surface);
  border-left: 4px solid var(--warm);
}

.article blockquote p {
  margin: 0;
  font-weight: 700;
}

.article hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 44px 0;
}

.article a {
  color: var(--accent-dark);
}

.final-cta {
  padding: 74px 20px;
  background: var(--ink-strong);
  color: var(--white);
  text-align: center;
}

.final-cta h2 {
  max-width: 760px;
  margin: 0 auto;
  font-size: 34px;
  line-height: 1.35;
  letter-spacing: 0;
}

.final-cta p {
  max-width: 720px;
  margin: 16px auto 28px;
  color: rgba(255, 255, 255, 0.76);
}

.site-footer {
  padding: 34px 20px;
  background: #061f23;
  color: rgba(255, 255, 255, 0.62);
  text-align: center;
  font-size: 13px;
}

.site-footer a {
  color: rgba(255, 255, 255, 0.78);
}

@media (max-width: 980px) {
  .main-nav {
    display: none;
  }

  .brand {
    min-width: 0;
  }

  .hero {
    min-height: 520px;
    background-position: 62% center;
  }

  .hero::before {
    background: linear-gradient(90deg, rgba(5, 43, 48, 0.96) 0%, rgba(5, 43, 48, 0.78) 68%, rgba(5, 43, 48, 0.35) 100%);
  }

  .hero h1 {
    font-size: 46px;
  }

  .content-shell {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .toc {
    position: static;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 24px;
    padding: 16px 20px;
    border: 0;
    background: var(--surface);
  }

  .toc strong {
    grid-column: 1 / -1;
  }
}

@media (max-width: 640px) {
  .site-header {
    height: 64px;
  }

  .header-inner {
    width: min(calc(100% - 28px), var(--max));
    gap: 12px;
  }

  .brand img {
    width: 36px;
    height: 36px;
  }

  .brand strong {
    max-width: 210px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 12px;
  }

  .brand > span > span {
    display: none;
  }

  .header-cta {
    min-height: 38px;
    padding: 0 13px;
    font-size: 13px;
  }

  .hero {
    min-height: 560px;
    background-position: 67% center;
  }

  .hero::before {
    background: linear-gradient(180deg, rgba(5, 43, 48, 0.72) 0%, rgba(5, 43, 48, 0.94) 72%, rgba(5, 43, 48, 0.98) 100%);
  }

  .hero-inner {
    width: min(calc(100% - 28px), var(--max));
    padding: 120px 0 54px;
  }

  .hero h1 {
    font-size: 38px;
    line-height: 1.18;
  }

  .hero p {
    margin-top: 18px;
    font-size: 16px;
    line-height: 1.7;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
    gap: 14px;
    margin-top: 26px;
  }

  .hero-cta {
    width: 100%;
  }

  .hero-phone {
    text-align: center;
  }

  .content-shell {
    width: min(calc(100% - 28px), var(--max));
    padding: 56px 0 70px;
  }

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

  .article > h2 {
    margin-top: 56px;
    font-size: 27px;
  }

  .article h3 {
    margin-top: 30px;
    font-size: 20px;
  }

  .article p,
  .article li {
    font-size: 15px;
  }

  .final-cta {
    padding: 58px 20px;
  }

  .final-cta h2 {
    font-size: 27px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}