:root {
  --red-900: #6b0f1a;
  --red-800: #8f1524;
  --red-700: #b01c2e;
  --red-600: #c92236;
  --red-500: #e03548;
  --red-200: #f5c4ca;
  --ink: #111111;
  --ink-soft: #3a3a3a;
  --ink-muted: #6e6e6e;
  --surface: #f7f5f4;
  --surface-2: #efecea;
  --white: #ffffff;
  --line: rgba(17, 17, 17, 0.1);
  --rail-w: 88px;
  --transition: 0.4s cubic-bezier(0.22, 1, 0.36, 1);
  --font-display: 'Noto Serif SC', 'Songti SC', serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', sans-serif;
}

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--surface);
  color: var(--ink);
  line-height: 1.7;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

/* —— 左侧轨道导航 —— */
.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--rail-w);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 28px 0;
  background: var(--ink);
  color: var(--white);
}

.rail-logo {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 1.1rem;
  letter-spacing: 0.12em;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  margin-bottom: 40px;
  color: var(--white);
}

.rail-nav {
  display: flex;
  flex-direction: column;
  gap: 22px;
  flex: 1;
  align-items: center;
}

.rail-nav a {
  writing-mode: vertical-rl;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  color: rgba(255, 255, 255, 0.4);
  transition: color var(--transition);
}

.rail-nav a:hover,
.rail-nav a.active {
  color: var(--red-500);
}

.rail-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--red-600);
  transition: transform var(--transition), box-shadow var(--transition);
}

.rail-dot:hover {
  transform: scale(1.25);
  box-shadow: 0 0 0 6px rgba(201, 34, 54, 0.2);
}

.menu-toggle {
  display: none;
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 1100;
  flex-direction: column;
  gap: 5px;
  background: var(--ink);
  border: none;
  border-radius: 2px;
  padding: 10px;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--white);
  transition: var(--transition);
}

.page {
  margin-left: var(--rail-w);
}

/* —— 首屏：全幅红黑视觉 —— */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  background: var(--ink);
  color: var(--white);
}

.hero-visual {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-wash {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, #0a0a0a 0%, #1a0a0c 42%, var(--red-800) 100%);
}

.hero-slash {
  position: absolute;
  width: 55%;
  height: 140%;
  right: -8%;
  top: -20%;
  background: linear-gradient(160deg, transparent 20%, rgba(201, 34, 54, 0.55) 50%, transparent 80%);
  transform: skewX(-18deg);
  animation: slash 14s ease-in-out infinite;
}

.hero-grain {
  position: absolute;
  inset: 0;
  opacity: 0.18;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(255, 255, 255, 0.12) 0 1px, transparent 1.5px),
    radial-gradient(circle at 80% 70%, rgba(255, 255, 255, 0.08) 0 1px, transparent 1.5px);
  background-size: 48px 48px, 72px 72px;
  animation: grain 20s linear infinite;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 640px;
  padding: 100px 56px 96px;
}

.hero-brand {
  font-family: var(--font-display);
  font-size: clamp(3rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: 0.1em;
  margin-bottom: 28px;
  animation: rise 0.9s var(--transition) both;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 2.4vw, 1.7rem);
  font-weight: 700;
  line-height: 1.5;
  margin-bottom: 16px;
  animation: rise 0.9s 0.1s var(--transition) both;
}

.hero-desc {
  color: rgba(255, 255, 255, 0.72);
  margin-bottom: 36px;
  max-width: 420px;
  animation: rise 0.9s 0.2s var(--transition) both;
}

.hero-content .btn {
  animation: rise 0.9s 0.3s var(--transition) both;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  font-family: inherit;
  font-size: 0.92rem;
  font-weight: 600;
  border: none;
  border-radius: 2px;
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary {
  background: var(--red-600);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--red-700);
  transform: translateY(-2px);
}

/* —— 关于 —— */
.about {
  background: var(--white);
  border-top: 1px solid var(--line);
}

.about-marquee {
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: var(--surface-2);
  padding: 14px 0;
}

.about-marquee p {
  white-space: nowrap;
  font-size: 0.8rem;
  letter-spacing: 0.4em;
  color: var(--red-700);
  font-weight: 600;
  animation: marquee 22s linear infinite;
  width: max-content;
}

.about-body {
  max-width: 900px;
  padding: 100px 48px 110px;
  margin: 0 auto;
}

.about-heading {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.5vw, 2.6rem);
  font-weight: 700;
  line-height: 1.45;
  color: var(--ink);
  margin-bottom: 40px;
}

.about-cols {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  margin-bottom: 40px;
}

.about-cols p {
  color: var(--ink-soft);
  font-size: 1.02rem;
}

.about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.about-tags li {
  padding: 8px 16px;
  border: 1px solid var(--line);
  color: var(--red-800);
  font-size: 0.88rem;
  font-weight: 500;
}

/* —— 业务：横向滑动 —— */
.services {
  padding: 72px 0 80px;
  background: var(--ink);
  color: var(--white);
}

.services-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 48px 28px;
}

.services-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
}

.services-controls {
  display: flex;
  gap: 8px;
}

.services-btn {
  width: 42px;
  height: 42px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  background: transparent;
  color: var(--white);
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
}

.services-btn:hover {
  background: var(--red-600);
  border-color: var(--red-600);
}

.services-track {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  padding: 8px 48px 16px;
  scrollbar-width: none;
}

.services-track::-webkit-scrollbar {
  display: none;
}

.services-panel {
  flex: 0 0 min(72vw, 340px);
  scroll-snap-align: start;
  min-height: 280px;
  padding: 36px 32px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  flex-direction: column;
  transition: background var(--transition), transform var(--transition), border-color var(--transition);
}

.services-panel:hover {
  background: rgba(201, 34, 54, 0.12);
  border-color: rgba(201, 34, 54, 0.35);
  transform: translateY(-4px);
}

.services-index {
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--red-500);
  margin-bottom: auto;
}

.services-panel h3 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  margin: 24px 0 12px;
}

.services-panel p {
  color: rgba(255, 255, 255, 0.68);
  font-size: 0.95rem;
}

/* —— 企业信息 —— */
.company {
  padding: 90px 48px 100px;
  background: var(--surface);
}

.company-head {
  max-width: 480px;
  margin-bottom: 48px;
}

.company-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  color: var(--ink);
  margin-bottom: 10px;
}

.company-head p {
  color: var(--ink-soft);
}

.company-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border-top: 1px solid var(--line);
}

.company-item {
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
  padding-right: 32px;
}

.company-item:nth-child(odd) {
  border-right: 1px solid var(--line);
  padding-right: 40px;
  padding-left: 0;
}

.company-item:nth-child(even) {
  padding-left: 40px;
}

.company-item-wide {
  grid-column: 1 / -1;
  border-right: none !important;
  padding-left: 0 !important;
  padding-right: 0 !important;
}

.company-item dt {
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  color: var(--ink-muted);
  margin-bottom: 10px;
}

.company-item dd {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink);
  line-height: 1.55;
}

/* —— 联络 —— */
.connect {
  background: var(--white);
  border-top: 1px solid var(--line);
  padding: 100px 24px 90px;
}

.connect-inner {
  max-width: 560px;
  margin: 0 auto;
  text-align: center;
}

.connect-label {
  font-size: 0.8rem;
  letter-spacing: 0.3em;
  color: var(--red-600);
  font-weight: 600;
  margin-bottom: 16px;
}

.connect-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  color: var(--ink);
  margin-bottom: 24px;
}

.connect-email {
  display: inline-block;
  font-size: clamp(1.15rem, 2.5vw, 1.5rem);
  font-weight: 600;
  color: var(--red-700);
  margin-bottom: 20px;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition);
}

.connect-email:hover {
  border-bottom-color: var(--red-500);
}

.connect-address {
  color: var(--ink-soft);
  font-size: 0.98rem;
  line-height: 1.8;
  margin-bottom: 12px;
}

.connect-company {
  color: var(--ink-muted);
  font-size: 0.92rem;
  margin-bottom: 40px;
}

.connect-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  text-align: left;
}

.connect-fields {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.connect-form input,
.connect-form textarea {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  font-family: inherit;
  font-size: 0.95rem;
  border-radius: 2px;
  transition: var(--transition);
}

.connect-form input:focus,
.connect-form textarea:focus {
  outline: none;
  border-color: var(--red-600);
  box-shadow: 0 0 0 3px rgba(201, 34, 54, 0.12);
}

.connect-form textarea {
  resize: vertical;
  min-height: 96px;
}

.connect-form .btn {
  align-self: stretch;
}

/* —— 页脚 —— */
.footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  padding: 22px 48px;
  background: var(--ink);
  color: rgba(255, 255, 255, 0.45);
  font-size: 0.85rem;
}

.footer a:hover {
  color: var(--red-500);
}

/* Reveal */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--transition), transform 0.7s var(--transition);
  transition-delay: calc(var(--delay, 0) * 0.08s);
}

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

@keyframes rise {
  from { opacity: 0; transform: translateY(22px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slash {
  0%, 100% { transform: skewX(-18deg) translateX(0); opacity: 0.9; }
  50% { transform: skewX(-18deg) translateX(-28px); opacity: 1; }
}

@keyframes grain {
  from { background-position: 0 0, 0 0; }
  to { background-position: 48px 48px, -72px 72px; }
}

@keyframes marquee {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* —— 响应式 —— */
@media (max-width: 900px) {
  .hero-content {
    padding: 80px 28px 72px;
  }

  .about-cols {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .about-body,
  .services-head,
  .services-track,
  .company,
  .footer {
    padding-left: 28px;
    padding-right: 28px;
  }

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

  .company-item:nth-child(odd),
  .company-item:nth-child(even) {
    border-right: none;
    padding-left: 0;
    padding-right: 0;
  }
}

@media (max-width: 768px) {
  :root {
    --rail-w: 0px;
  }

  .rail {
    width: min(220px, 78vw);
    transform: translateX(-105%);
    transition: transform var(--transition);
    box-shadow: 8px 0 30px rgba(0, 0, 0, 0.25);
  }

  .rail.open {
    transform: translateX(0);
  }

  .rail-nav {
    align-items: flex-start;
    padding-left: 28px;
    width: 100%;
  }

  .rail-nav a {
    writing-mode: horizontal-tb;
    letter-spacing: 0.08em;
    font-size: 1rem;
  }

  .rail-logo {
    writing-mode: horizontal-tb;
    margin: 8px 0 36px;
  }

  .menu-toggle {
    display: flex;
  }

  .menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

  .menu-toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .connect-fields {
    grid-template-columns: 1fr;
  }
}