:root {
  --color-ink: #1c2f3a;
  --color-gold: #b8922a;
  --color-paper: #f3ece0;
  --color-water: #3a7d7c;
  --color-paper-deep: #e8dfd0;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Songti SC", "Noto Serif SC", "STSong", "SimSun", serif;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1.25rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4.5rem;
  --sidebar-w: 5.5rem;
  --header-h: 3.25rem;
  --content-max: 45rem;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --shadow-soft: 0 12px 32px rgba(28, 47, 58, 0.12);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--color-ink);
  background: var(--color-paper);
}

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-ink);
  color: var(--color-paper);
  z-index: 100;
}

.skip-link:focus {
  left: var(--space-sm);
}

/* 顶栏 / 侧栏导航 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--color-paper);
  border-bottom: 1px solid rgba(28, 47, 58, 0.12);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-xs) var(--space-md);
  min-height: var(--header-h);
}

.brand-mark {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  text-decoration: none;
  color: var(--color-ink);
  font-weight: 600;
  letter-spacing: 0.08em;
}

.brand-text {
  font-size: 0.95rem;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  padding: 0.35rem 0.5rem;
  border: 1px solid var(--color-ink);
  background: transparent;
  color: var(--color-ink);
  cursor: pointer;
  font-family: inherit;
  font-size: 0.75rem;
}

.nav-toggle-bar {
  display: block;
  width: 1.25rem;
  height: 2px;
  background: var(--color-ink);
  box-shadow: 0 5px 0 var(--color-ink), 0 10px 0 var(--color-ink);
}

.site-nav {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  background: var(--color-paper);
  border-bottom: 1px solid rgba(28, 47, 58, 0.15);
  padding: var(--space-sm) var(--space-md) var(--space-md);
}

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

.site-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.site-nav a {
  display: block;
  padding: var(--space-xs) 0;
  color: var(--color-ink);
  text-decoration: none;
  border-left: 3px solid transparent;
  padding-left: var(--space-sm);
  transition: border-color 0.2s var(--ease-out), color 0.2s;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--color-water);
}

.site-nav a.is-active {
  border-left-color: var(--color-gold);
  color: var(--color-ink);
  font-weight: 600;
}

.nav-rail {
  display: none;
}

/* 布局 */
.layout {
  display: block;
}

.sidebar {
  display: none;
}

.main {
  padding: var(--space-md);
  max-width: calc(var(--content-max) + var(--space-xl));
}

/* 首屏斜切 */
.hero {
  position: relative;
  min-height: 28rem;
  padding-bottom: var(--space-xl);
  margin-bottom: var(--space-2xl);
}

.hero-scroll-wrap {
  position: absolute;
  right: 0;
  top: 0;
  opacity: 0.35;
  pointer-events: none;
  transform-origin: top center;
  animation: scroll-unroll 0.6s var(--ease-out) forwards;
}

@keyframes scroll-unroll {
  from {
    transform: scaleY(0.15);
    opacity: 0;
  }
  to {
    transform: scaleY(1);
    opacity: 0.35;
  }
}

.hero-brand-block {
  position: relative;
  z-index: 2;
  margin-bottom: var(--space-lg);
}

.hero-vertical-brand {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-serif);
  font-size: 1.75rem;
  letter-spacing: 0.35em;
  margin: 0;
  color: var(--color-ink);
}

.hero-gold-line {
  display: inline-block;
  width: 2px;
  height: 4rem;
  background: var(--color-gold);
  margin-top: var(--space-sm);
  margin-left: 0.5rem;
}

.hero-panel {
  position: relative;
  z-index: 1;
  margin-top: var(--space-lg);
  margin-left: 0;
  padding: var(--space-lg) var(--space-md);
  max-width: 36rem;
  background: var(--color-ink);
  color: var(--color-paper);
  clip-path: polygon(8% 0, 100% 0, 100% 100%, 0 100%);
  box-shadow: var(--shadow-soft);
}

.hero-claim {
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 4vw, 1.75rem);
  font-weight: 600;
  line-height: 1.45;
  margin: 0 0 var(--space-md);
  text-wrap: pretty;
}

@media (max-width: 480px) {
  .hero-claim {
    font-size: clamp(1.05rem, 4.2vw, 1.28rem);
    line-height: 1.55;
    letter-spacing: 0.01em;
  }
}

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

.hero-sub {
  margin: 0 0 var(--space-lg);
  opacity: 0.92;
  font-size: 0.98rem;
}

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

.btn {
  display: inline-block;
  padding: 0.55rem 1.1rem;
  font-size: 0.9rem;
  text-decoration: none;
  border-radius: 2px;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.btn-primary {
  background: var(--color-gold);
  color: var(--color-ink);
  border: 1px solid var(--color-gold);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: #a07f22;
  border-color: #a07f22;
  color: var(--color-paper);
}

.btn-outline {
  border: 1px solid var(--color-paper);
  color: var(--color-paper);
  background: transparent;
}

.btn-outline:hover,
.btn-outline:focus-visible {
  background: rgba(243, 236, 224, 0.12);
}

.section-title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  margin: 0 0 var(--space-lg);
  padding-bottom: var(--space-xs);
  border-bottom: 2px solid var(--color-gold);
  display: inline-block;
}

/* 关于 */
.about {
  margin-bottom: var(--space-2xl);
}

.about-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.about-quote {
  margin: 0;
  padding: 0;
  border: none;
}

.about-quote p {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  line-height: 1.85;
  margin: 0;
  text-align: left;
}

.channel-strips {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.channel-strip {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: var(--space-sm) var(--space-md);
  border-left: 3px solid var(--color-gold);
  background: rgba(28, 47, 58, 0.04);
}

.strip-title {
  font-weight: 600;
  font-size: 0.95rem;
}

.strip-spot {
  font-size: 0.88rem;
  color: var(--color-water);
}

/* 业务错落卡片 */
.services {
  margin-bottom: var(--space-2xl);
}

.service-cards {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.service-card {
  position: relative;
  padding: var(--space-md) var(--space-md) var(--space-md) calc(var(--space-md) + 6px);
  background: var(--color-paper-deep);
  border: 1px solid rgba(28, 47, 58, 0.14);
  border-radius: 2px;
  max-width: 100%;
  transition: box-shadow 0.25s var(--ease-out), border-color 0.25s;
}

.service-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--color-gold);
  transition: box-shadow 0.25s, width 0.25s;
}

.service-card:hover::before,
.service-card:focus-within::before {
  width: 5px;
  box-shadow: 0 0 0 1px var(--color-gold), 0 0 12px rgba(184, 146, 42, 0.45);
}

.card-1::before { background: var(--color-gold); }
.card-2::before { background: var(--color-water); }
.card-3::before { background: #2a5c5b; }
.card-4::before { background: var(--color-ink); }

.service-name {
  font-size: 1.1rem;
  margin: 0 0 var(--space-xs);
}

.service-spot {
  margin: 0 0 var(--space-sm);
  color: var(--color-water);
  font-size: 0.92rem;
}

.service-body {
  margin: 0;
  font-size: 0.95rem;
}

/* 核心优势 */
.advantages {
  margin-bottom: var(--space-2xl);
}

.advantage-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.advantage-item {
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: var(--space-md);
  align-items: start;
}

.advantage-num {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  color: var(--color-gold);
  line-height: 1;
}

.advantage-content {
  border-left: 2px solid var(--color-gold);
  padding-left: var(--space-md);
}

.advantage-name {
  margin: 0 0 var(--space-xs);
  font-size: 1.05rem;
}

.advantage-desc {
  margin: 0;
  font-size: 0.95rem;
}

/* 页脚 */
.site-footer {
  text-align: center;
  padding: var(--space-lg) var(--space-md) var(--space-xl);
  border-top: 1px solid rgba(28, 47, 58, 0.15);
  font-size: 0.88rem;
  background: var(--color-paper-deep);
}

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

.footer-beian a {
  color: var(--color-water);
  text-decoration: none;
}

.footer-beian a:hover,
.footer-beian a:focus-visible {
  text-decoration: underline;
}

/* 区块进入动效 */
.reveal-section,
.reveal-card,
.reveal-item {
  opacity: 0;
  transform: translateY(1.25rem);
  transition: opacity 0.55s var(--ease-out), transform 0.55s var(--ease-out);
}

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

@media (prefers-reduced-motion: reduce) {
  .hero-scroll-wrap {
    animation: none;
    opacity: 0.35;
    transform: none;
  }

  .reveal-section,
  .reveal-card,
  .reveal-item {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

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

  .site-nav {
    display: block;
    position: static;
    border: none;
    padding: 0;
  }

  .site-nav ul {
    flex-direction: row;
    gap: var(--space-md);
  }

  .site-nav a {
    border-left: none;
    border-bottom: 2px solid transparent;
    padding-left: 0;
    padding-bottom: 0.2rem;
  }

  .site-nav a.is-active {
    border-left: none;
    border-bottom-color: var(--color-gold);
  }

  .header-inner {
    max-width: calc(var(--sidebar-w) + var(--content-max) + var(--space-2xl));
    margin: 0 auto;
    padding-left: var(--space-lg);
    padding-right: var(--space-lg);
  }

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

  .hero-panel {
    margin-left: 12%;
    padding: var(--space-xl) var(--space-lg);
  }

  .about-grid {
    flex-direction: row;
    align-items: flex-start;
    gap: var(--space-xl);
  }

  .about-quote {
    flex: 1 1 55%;
  }

  .channel-strips {
    flex: 0 0 38%;
  }

  .service-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl) var(--space-lg);
    align-items: start;
  }

  .service-card.card-2,
  .service-card.card-4 {
    margin-top: 1.75rem;
  }
}

/* 桌面侧栏 */
@media (min-width: 1100px) {
  :root {
    --sidebar-w: 11rem;
    --content-max: 58rem;
  }

  .site-header {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-w);
    border-bottom: none;
    border-right: 1px solid rgba(28, 47, 58, 0.12);
    display: flex;
    flex-direction: column;
    padding-top: var(--space-lg);
    overflow: hidden;
  }

  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-lg);
    padding: var(--space-md);
    max-width: none;
  }

  .brand-mark {
    flex-direction: column;
    align-items: flex-start;
  }

  .brand-text {
    writing-mode: vertical-rl;
    letter-spacing: 0.2em;
    font-size: 0.85rem;
  }

  .site-nav ul {
    flex-direction: column;
    gap: var(--space-md);
    align-items: flex-start;
    width: 100%;
  }

  .site-nav a {
    writing-mode: horizontal-tb;
    text-orientation: mixed;
    white-space: nowrap;
    font-size: 0.95rem;
    letter-spacing: 0.04em;
    line-height: 1.4;
    border-bottom: none;
    border-right: none;
    border-left: 3px solid transparent;
    padding: 0.2rem 0 0.2rem 0.65rem;
    width: auto;
    max-width: none;
  }

  .site-nav a.is-active {
    border-bottom-color: transparent;
    border-right-color: transparent;
    border-left-color: var(--color-gold);
  }

  .nav-rail {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex: 1;
    margin-top: var(--space-md);
    position: relative;
    padding-bottom: var(--space-lg);
  }

  .rail-line {
    width: 2px;
    flex: 1;
    background: linear-gradient(to bottom, var(--color-gold), var(--color-water));
    opacity: 0.5;
  }

  .rail-tick {
    position: absolute;
    left: 50%;
    width: 10px;
    height: 10px;
    margin-left: -5px;
    border-radius: 50%;
    border: 2px solid var(--color-paper-deep);
    background: var(--color-paper);
    transition: background 0.2s, transform 0.2s;
  }

  .rail-tick[data-tick="home"] { top: 8%; }
  .rail-tick[data-tick="about"] { top: 32%; }
  .rail-tick[data-tick="services"] { top: 56%; }
  .rail-tick[data-tick="advantages"] { top: 80%; }

  .rail-tick.is-active {
    background: var(--color-gold);
    transform: scale(1.15);
  }

  .layout {
    display: flex;
    justify-content: center;
    margin-left: var(--sidebar-w);
  }

  .sidebar {
    display: none;
  }

  .sidebar-vertical {
    writing-mode: vertical-rl;
    font-family: var(--font-serif);
    font-size: 1.1rem;
    letter-spacing: 0.4em;
    margin: 0;
    color: rgba(28, 47, 58, 0.35);
  }

  .sidebar-gold-line {
    display: block;
    width: 1px;
    height: 6rem;
    background: var(--color-gold);
    margin: var(--space-md) auto 0;
    opacity: 0.6;
  }

  .main {
    margin-left: 0;
    padding: var(--space-xl) var(--space-lg) var(--space-2xl);
    width: min(var(--content-max), calc(100% - 4rem));
    max-width: var(--content-max);
  }

  .hero {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) 7.5rem;
    column-gap: var(--space-lg);
    align-items: start;
  }

  .hero-brand-block {
    grid-column: 1;
    grid-row: 1;
    margin-bottom: 0;
  }

  .hero-panel {
    grid-column: 2;
    grid-row: 1;
    margin-left: 0;
    margin-top: 3.5rem;
    max-width: none;
    padding-left: 4.75rem;
  }

  .hero-scroll-wrap {
    position: relative;
    grid-column: 3;
    grid-row: 1;
    right: auto;
    top: auto;
    justify-self: end;
    opacity: 0.4;
  }

  .site-footer {
    margin-left: var(--sidebar-w);
  }

  body {
    background: var(--color-paper);
  }
}