:root {
  --color-bg: #f6f3eb;
  --color-surface: #faf8f2;
  --color-ink: #1e3a3a;
  --color-ink-muted: #3d5555;
  --color-accent: #b5651d;
  --color-border: #d8d4cb;
  --color-line: #2a5a5a;
  --font-serif: "Songti SC", "Noto Serif SC", "STSong", "SimSun", serif;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --width-page: 92%;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.75rem;
  --space-lg: 3rem;
  --space-xl: 4.5rem;
  --text-sm: 0.9375rem;
  --text-base: 1.0625rem;
  --text-lg: 1.25rem;
  --text-xl: clamp(1.75rem, 4vw, 2.35rem);
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --reveal-duration: 0.55s;
  --header-scroll-offset: 5.25rem;
  --page-max: 72rem;
  --rail-space: 5.25rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.75;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--color-line);
}

a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

#shouping,
#guanyu,
#hexin-yewu,
#hexin-youshi {
  scroll-margin-top: var(--header-scroll-offset);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.75rem;
  width: var(--width-page);
  max-width: 72rem;
  margin: 0 auto;
  padding: 0.45rem 0;
  min-height: 0;
  background: color-mix(in srgb, var(--color-bg) 92%, transparent);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(6px);
}

.site-name {
  flex: 1 1 auto;
  min-width: 0;
  font-family: var(--font-serif);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1.35;
  text-decoration: none;
  color: var(--color-ink);
}

.dot-nav--header {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 0.25rem 0.65rem;
  flex: 1 1 100%;
  max-width: 100%;
}

.dot-nav--rail {
  display: none;
}

.dot-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.8125rem;
  text-decoration: none;
  color: var(--color-ink-muted);
  padding: 0.15rem 0;
}

.dot {
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  border: 1px solid var(--color-line);
  background: var(--color-surface);
  transition: background var(--reveal-duration) var(--ease-out),
    transform var(--reveal-duration) var(--ease-out);
}

.dot-link:hover .dot,
.dot-link:focus-visible .dot {
  background: var(--color-accent);
  transform: scale(1.15);
}

main {
  width: var(--width-page);
  max-width: 72rem;
  margin: 0 auto;
  padding-bottom: var(--space-xl);
}

.section-reveal {
  opacity: 0;
  transform: translateY(1.25rem);
  transition: opacity var(--reveal-duration) var(--ease-out),
    transform var(--reveal-duration) var(--ease-out),
    box-shadow var(--reveal-duration) var(--ease-out);
}

.section-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.section-reveal.is-visible.draw-border {
  box-shadow: inset 0 0 0 1px var(--color-border);
}

.hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  padding: var(--space-lg) 0 var(--space-md);
  align-items: center;
}

.hero-copy {
  order: 1;
}

.hero-title {
  margin: 0 0 var(--space-md);
  font-family: var(--font-serif);
  font-size: var(--text-xl);
  font-weight: 700;
  line-height: 1.35;
  color: var(--color-ink);
}

.hero-title .char {
  display: inline-block;
  opacity: 0;
  transform: translateY(0.4em);
}

.hero-title.is-ready .char {
  animation: char-in 0.45s var(--ease-out) forwards;
  animation-delay: calc(var(--char-i) * 0.06s);
}

@keyframes char-in {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-sub {
  margin: 0 0 var(--space-sm);
  color: var(--color-ink-muted);
  max-width: 36em;
}

.hero-hook {
  margin: 0;
  padding-left: 0.75rem;
  border-left: 3px solid var(--color-accent);
  font-family: var(--font-serif);
  font-size: var(--text-lg);
  color: var(--color-line);
}

.hero-visual {
  order: 2;
  margin: 0;
  justify-self: center;
}

.about {
  padding: var(--space-lg) 0;
}

.about-quote {
  margin: 0 0 var(--space-md);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-serif);
  font-size: var(--text-lg);
  text-align: center;
  color: var(--color-ink);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  align-items: start;
}

.about-text p {
  margin: 0;
  color: var(--color-ink-muted);
}

.about-visual {
  margin: 0;
  justify-self: center;
}

.section-label {
  margin: 0 0 var(--space-md);
  padding-bottom: var(--space-xs);
  font-family: var(--font-serif);
  font-size: var(--text-lg);
  font-weight: 700;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.services {
  padding: var(--space-lg) 0;
}

.service-row {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  padding: var(--space-md) 0 var(--space-lg) 1.25rem;
  border-bottom: 1px solid var(--color-border);
}

.service-row:last-child {
  border-bottom: none;
}

.service-index {
  position: absolute;
  top: var(--space-md);
  left: -0.25rem;
  writing-mode: vertical-rl;
  font-family: var(--font-serif);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--color-accent);
  opacity: 0.85;
}

.service-title {
  margin: 0 0 0.35rem;
  font-family: var(--font-serif);
  font-size: var(--text-lg);
  font-weight: 700;
}

.service-hook {
  margin: 0 0 var(--space-sm);
  font-size: var(--text-sm);
  color: var(--color-line);
}

.service-text {
  margin: 0;
  color: var(--color-ink-muted);
}

.service-fig {
  margin: 0;
}

.advantages {
  padding: var(--space-lg) 0 var(--space-md);
}

.advantage-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.advantage-item {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xs);
  padding: var(--space-md) 0 var(--space-md) var(--space-sm);
  border-left: 4px solid var(--color-accent);
}

.advantage-title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: var(--text-base);
  font-weight: 700;
}

.advantage-text {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}

.site-footer {
  width: var(--width-page);
  max-width: 72rem;
  margin: 0 auto;
  padding: var(--space-md) 0 var(--space-lg);
  text-align: center;
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
  border-top: 1px solid var(--color-border);
}

.site-footer p {
  margin: 0.35rem 0;
}

@media (min-width: 768px) {
  :root {
    --header-scroll-offset: 3.75rem;
    --site-margin: calc((100vw - min(92vw, var(--page-max))) / 2);
  }

  .site-header {
    flex-wrap: nowrap;
    padding: 0.5rem 0;
  }

  .site-name {
    flex: 1 1 auto;
  }

  .dot-nav--header {
    display: none;
  }

  .dot-nav--rail {
    display: flex;
    position: fixed;
    top: 3.75rem;
    bottom: 3.75rem;
    right: max(0.75rem, calc(var(--site-margin) - var(--rail-space)));
    left: auto;
    flex-direction: column;
    align-items: flex-end;
    justify-content: center;
    gap: 0.5rem;
    width: auto;
    max-width: var(--rail-space);
    z-index: 30;
    pointer-events: auto;
  }

  main {
    padding-right: max(0px, calc(var(--rail-space) + 0.75rem - var(--site-margin)));
  }

  .hero {
    grid-template-columns: 1.2fr 0.8fr;
  }

  .hero-copy {
    order: 0;
  }

  .hero-visual {
    order: 0;
    justify-self: end;
  }

  .about-grid {
    grid-template-columns: 1.15fr 0.85fr;
  }

  .about-visual {
    justify-self: end;
  }

  .service-row--a {
    grid-template-columns: auto 1fr 1.1fr;
    padding-left: 1.5rem;
  }

  .service-row--a .service-index {
    position: static;
    writing-mode: vertical-rl;
    justify-self: start;
    padding-top: var(--space-sm);
  }

  .service-row--a .service-fig {
    order: 0;
  }

  .service-row--a .service-body {
    order: 0;
  }

  .service-row--b {
    grid-template-columns: 1.1fr 1fr auto;
    padding-left: 1.5rem;
  }

  .service-row--b .service-index {
    position: static;
    writing-mode: vertical-rl;
    order: 3;
    justify-self: end;
    padding-top: var(--space-sm);
  }

  .service-row--b .service-body {
    order: 0;
  }

  .service-row--b .service-fig {
    order: 0;
  }
}

@media (min-width: 1100px) {
  .hero {
    padding-top: var(--space-xl);
    gap: var(--space-lg);
  }

  .service-index {
    left: -0.5rem;
    font-size: 0.8125rem;
  }

  .advantage-list {
    position: relative;
    padding-left: 1.75rem;
  }

  .advantage-list::before {
    content: "";
    position: absolute;
    left: 0.35rem;
    top: 0.5rem;
    bottom: 0.5rem;
    width: 2px;
    background: linear-gradient(
      to bottom,
      var(--color-line),
      var(--color-border) 50%,
      var(--color-accent)
    );
  }

  .advantage-item {
    grid-template-columns: minmax(7rem, 9rem) 1fr;
    gap: var(--space-md);
    border-left: none;
    padding-left: var(--space-md);
  }

  .advantage-item::before {
    content: "";
    position: absolute;
    left: -1.45rem;
    top: 1.35rem;
    width: 0.55rem;
    height: 0.55rem;
    border-radius: 50%;
    background: var(--color-surface);
    border: 2px solid var(--color-line);
  }
}