:root {
  --color-deep: #0f2a2a;
  --color-page: #f4f7f6;
  --color-panel: #e8ecef;
  --color-surf: #e8ecef;
  --color-accent: #e86f4a;
  --color-tech: #3a8f8f;
  --color-header: #dfe4e8;
  --color-text: #1a2e2e;
  --color-card: #ffffff;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Songti SC", "Noto Serif SC", "STSong", "SimSun", serif;
  --max-content: 1200px;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1.25rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --header-h: 3.25rem;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --reveal-x: 1.25rem;
  --reveal-y: 0.75rem;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-h);
}

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

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-page);
  overflow-x: hidden;
}

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

a {
  color: inherit;
}

.page-frame {
  position: relative;
  width: 100%;
  max-width: 100%;
  margin: 0 auto;
  background: var(--color-page);
}

.tide-marker {
  position: fixed;
  top: var(--header-h);
  left: 0;
  width: 4px;
  height: 3rem;
  background: linear-gradient(180deg, var(--color-accent), var(--color-tech));
  transform: translateY(0);
  z-index: 40;
  pointer-events: none;
  opacity: 0.85;
  transition: transform 0.15s linear;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  background: var(--color-header);
  border-bottom: 1px solid rgba(15, 42, 42, 0.12);
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  max-width: var(--max-content);
  width: 100%;
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--space-md);
  box-sizing: border-box;
}

.brand {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.05rem;
  text-decoration: none;
  color: var(--color-deep);
  letter-spacing: 0.04em;
}

.nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 2.75rem;
  height: calc(var(--header-h) - 0.5rem);
  max-height: 100%;
  padding: 0 var(--space-sm);
  border: 1px solid rgba(15, 42, 42, 0.25);
  background: var(--color-surf);
  font: inherit;
  color: var(--color-deep);
  cursor: pointer;
}

.nav-toggle-label {
  font-size: 0.875rem;
}

.site-nav {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  flex-direction: column;
  background: var(--color-header);
  border-bottom: 1px solid rgba(15, 42, 42, 0.12);
  padding: var(--space-sm) var(--space-md) var(--space-md);
}

.site-nav.is-open {
  display: flex;
}

.nav-link {
  position: relative;
  display: block;
  padding: 0.85rem 0.25rem;
  text-decoration: none;
  color: var(--color-deep);
  font-size: 0.95rem;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0.5rem;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width 0.35s var(--ease-out);
}

.nav-link.is-active::after {
  width: 2.5rem;
  animation: nav-pulse 0.6s var(--ease-out);
}

@keyframes nav-pulse {
  0% { opacity: 0.4; width: 1rem; }
  50% { opacity: 1; width: 3rem; }
  100% { opacity: 1; width: 2.5rem; }
}

.hero {
  position: relative;
  background: var(--color-page);
  color: var(--color-text);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 2.5rem), 0 100%);
  padding-bottom: 2.5rem;
}

.hero-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  max-width: var(--max-content);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md) var(--space-xl);
}

.hero-title {
  margin: 0 0 var(--space-sm);
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 5vw, 1.85rem);
  font-weight: 600;
  line-height: 1.35;
  color: var(--color-deep);
}

.hero-hook {
  margin: 0 0 var(--space-sm);
  font-size: 1.05rem;
  color: var(--color-accent);
}

.hero-sub {
  margin: 0 0 var(--space-md);
  font-size: 0.95rem;
  max-width: 36em;
  opacity: 0.92;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: 0.5rem 1.1rem;
  text-decoration: none;
  font-size: 0.9rem;
  border-radius: 2px;
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-deep);
  border-color: var(--color-accent);
}

.btn-ghost {
  background: transparent;
  color: var(--color-deep);
  border-color: var(--color-tech);
}

.hero-visual {
  margin: 0;
  align-self: stretch;
}

.hero-visual img {
  width: 100%;
  max-height: 16rem;
  object-fit: contain;
  border: 1px solid rgba(58, 143, 143, 0.35);
}

.about {
  background: var(--color-panel);
  color: var(--color-text);
}

.about-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  max-width: var(--max-content);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-md);
}

.about-rail {
  display: flex;
  flex-direction: row;
  align-items: baseline;
  gap: var(--space-sm);
  writing-mode: horizontal-tb;
}

.about-index {
  font-family: var(--font-serif);
  font-size: 2rem;
  color: var(--color-tech);
  line-height: 1;
}

.about-rail-title {
  font-size: 0.85rem;
  letter-spacing: 0.2em;
  color: var(--color-deep);
}

.about-body {
  flex: 1;
}

.section-heading {
  margin: 0 0 var(--space-md);
  font-family: var(--font-serif);
  font-size: 1.35rem;
  color: var(--color-deep);
}

.about-prose {
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.75;
}

.about-prose p {
  margin: 0;
}

.business {
  background: var(--color-page);
  color: var(--color-text);
  padding: var(--space-xl) 0;
}

.business-inner {
  max-width: var(--max-content);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.business-head .section-heading {
  color: var(--color-deep);
}

.business-layout {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.business-tide {
  display: none;
}

.business-cards {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  width: 100%;
}

.biz-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: var(--color-card);
  border: 1px solid rgba(58, 143, 143, 0.4);
  border-radius: 2px;
  opacity: 0;
  transform: translate(var(--reveal-x), var(--reveal-y));
  transition: opacity 0.4s var(--ease-out), transform 0.4s var(--ease-out);
}

.biz-card.is-visible {
  opacity: 1;
  transform: translate(0, 0);
}

.biz-card--lead {
  width: 100%;
}

.biz-card--w2,
.biz-card--w3,
.biz-card--w4 {
  width: 100%;
  margin-left: 0;
}

.biz-card-head {
  border-left: 3px solid var(--color-accent);
  padding-left: var(--space-sm);
}

.biz-title {
  margin: 0 0 0.25rem;
  font-size: 1.1rem;
  color: var(--color-deep);
}

.biz-hook {
  margin: 0;
  font-size: 0.9rem;
  color: var(--color-tech);
}

.biz-text {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.7;
  opacity: 0.92;
}

.advantages {
  background: var(--color-panel);
  padding: var(--space-xl) 0;
}

.advantages-inner {
  max-width: var(--max-content);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.adv-list {
  list-style: none;
  margin: var(--space-lg) 0 0;
  padding: 0;
}

.adv-item {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-sm);
  padding: var(--space-md) 0;
  border-bottom: 1px solid rgba(15, 42, 42, 0.15);
}

.adv-item:first-child {
  border-top: 1px solid rgba(15, 42, 42, 0.15);
}

.adv-title {
  margin: 0;
  font-size: 1.05rem;
  color: var(--color-deep);
}

.adv-text {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.7;
}

.site-footer {
  background: var(--color-page);
  color: var(--color-text);
  text-align: center;
  padding: var(--space-lg) var(--space-md);
  font-size: 0.875rem;
  border-top: 1px solid rgba(15, 42, 42, 0.1);
}

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

.footer-beian a {
  color: var(--color-tech);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

@media (orientation: landscape) and (max-height: 500px) {
  :root {
    --header-h: 2.75rem;
  }

  .hero-inner {
    padding-top: var(--space-md);
    padding-bottom: var(--space-md);
  }

  .hero-visual img {
    max-height: 9rem;
  }

  .hero-title {
    font-size: 1.2rem;
  }

  .hero-sub {
    font-size: 0.85rem;
    margin-bottom: var(--space-sm);
  }

  .site-nav.is-open {
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }
}

@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }

  .site-nav {
    display: flex;
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-md);
    padding: 0;
    border: none;
    background: transparent;
  }

  .nav-link {
    padding: 0.5rem 0;
  }

  .hero-inner {
    flex-direction: row;
    align-items: center;
  }

  .hero-copy {
    flex: 5 1 0;
    min-width: 0;
  }

  .hero-visual {
    flex: 7 1 0;
    min-width: 0;
  }

  .about-inner {
    flex-direction: row;
    align-items: flex-start;
  }

  .about-rail {
    flex: 0 0 4rem;
    flex-direction: column;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    align-items: center;
    gap: var(--space-md);
  }

  .about-body {
    flex: 1;
    min-width: 0;
  }

  .business-layout {
    flex-direction: row;
    align-items: stretch;
  }

  .business-tide {
    display: block;
    flex: 0 0 3rem;
  }

  .business-tide img {
    width: 100%;
    height: 100%;
    min-height: 100%;
    object-fit: cover;
  }

  .business-cards {
    flex: 1;
    min-width: 0;
  }

  .biz-card--lead {
    flex-direction: row;
    align-items: flex-start;
    gap: var(--space-lg);
  }

  .biz-card--lead .biz-card-head {
    flex: 4 1 0;
    min-width: 0;
  }

  .biz-card--lead .biz-text {
    flex: 8 1 0;
    min-width: 0;
  }

  .biz-card--w2 {
    width: 66.666%;
    margin-left: auto;
  }

  .biz-card--w3,
  .biz-card--w4 {
    width: 50%;
    margin-left: auto;
  }

  .adv-item--odd {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }

  .adv-item--even {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }

  .adv-item--even .adv-title {
    order: 2;
  }

  .adv-item--even .adv-text {
    order: 1;
  }
}

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

  .about-inner,
  .business-inner,
  .advantages-inner {
    padding-left: var(--space-lg);
    padding-right: var(--space-lg);
  }

  .hero-copy {
    flex: 4 1 0;
  }

  .hero-visual {
    flex: 8 1 0;
  }

  .about-rail {
    flex: 0 0 5rem;
  }

  .about-body {
    flex: 8 1 0;
  }
}

@media (min-width: 1440px) {
  .page-frame {
    max-width: var(--max-content);
    margin-left: auto;
    margin-right: auto;
  }

  .header-inner,
  .hero-inner,
  .about-inner,
  .business-inner,
  .advantages-inner {
    padding-left: var(--space-xl);
    padding-right: var(--space-xl);
  }
}

@media (min-aspect-ratio: 2/1) {
  .hero-inner {
    max-width: min(var(--max-content), 90vw);
  }

  .hero-visual img {
    max-height: 14rem;
  }

  .about-prose {
    column-count: 1;
    max-width: 52rem;
  }

  .business-cards {
    gap: var(--space-lg);
  }
}

@media (max-aspect-ratio: 3/4) {
  .hero-title {
    font-size: clamp(1.25rem, 4.5vw, 1.65rem);
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }

  .biz-card {
    padding: var(--space-md) var(--space-sm);
  }
}

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

  .biz-card {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .nav-link::after,
  .tide-marker {
    transition: none;
    animation: none;
  }
}