:root {
  --ink: #0c1a24;
  --ink-soft: #243644;
  --muted: #5c7383;
  --paper: #eef4f7;
  --accent: #1a8f8a;
  --accent-deep: #126e6a;
  --glow: rgba(26, 143, 138, 0.35);
  --line: rgba(12, 26, 36, 0.08);
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.7;
  background:
    radial-gradient(1200px 700px at 12% -10%, #d7ebef 0%, transparent 55%),
    radial-gradient(900px 600px at 95% 8%, #cfe6e2 0%, transparent 50%),
    linear-gradient(180deg, #f4f8fa 0%, var(--paper) 45%, #e8f0f3 100%);
  overflow-x: hidden;
}

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

.atmosphere {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 0;
}

.mist {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.55;
  animation: drift 18s ease-in-out infinite alternate;
}

.mist-a {
  width: 42vw;
  height: 42vw;
  min-width: 280px;
  min-height: 280px;
  top: -8%;
  left: -6%;
  background: rgba(120, 190, 200, 0.45);
}

.mist-b {
  width: 36vw;
  height: 36vw;
  min-width: 240px;
  min-height: 240px;
  top: 18%;
  right: -8%;
  background: rgba(90, 170, 160, 0.35);
  animation-duration: 22s;
  animation-delay: -4s;
}

.grain {
  position: absolute;
  inset: 0;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.site-header,
main,
.site-footer {
  position: relative;
  z-index: 1;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1120px;
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
}

.brand-mark {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.nav {
  display: flex;
  gap: 1.5rem;
}

.nav a {
  color: var(--muted);
  font-size: 0.9375rem;
  font-weight: 500;
  transition: color 0.25s ease;
}

.nav a:hover {
  color: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 2rem;
  max-width: 1120px;
  margin: 0 auto;
  min-height: calc(100vh - 5rem);
  padding: 2rem 1.5rem 4rem;
}

.brand-name {
  margin: 0 0 1.25rem;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 4.8vw, 3.6rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.04em;
  color: var(--ink);
}

.hero-lead {
  margin: 0 0 2rem;
  max-width: 28rem;
  color: var(--ink-soft);
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.875rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: 0 1.35rem;
  border-radius: 0.5rem;
  font-size: 0.9375rem;
  font-weight: 500;
  transition:
    background 0.25s ease,
    color 0.25s ease,
    border-color 0.25s ease,
    transform 0.25s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

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

.btn-ghost {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.45);
  color: var(--ink-soft);
  backdrop-filter: blur(8px);
}

.btn-ghost:hover {
  border-color: rgba(12, 26, 36, 0.18);
  color: var(--ink);
}

.hero-visual {
  display: grid;
  place-items: center;
  min-height: 280px;
}

.orbit {
  position: relative;
  width: min(360px, 72vw);
  aspect-ratio: 1;
}

.orbit-ring {
  position: absolute;
  inset: 12%;
  border: 1px solid rgba(26, 143, 138, 0.35);
  border-radius: 50%;
  animation: spin 28s linear infinite;
}

.orbit-ring-2 {
  inset: 24%;
  border-color: rgba(12, 26, 36, 0.12);
  animation-direction: reverse;
  animation-duration: 36s;
}

.orbit-core {
  position: absolute;
  inset: 38%;
  border-radius: 50%;
  background:
    radial-gradient(circle at 35% 30%, #ffffff 0%, transparent 45%),
    radial-gradient(circle at 50% 55%, #2aabb0 0%, #126e6a 70%);
  box-shadow: 0 0 60px var(--glow);
  animation: pulse 5s ease-in-out infinite;
}

.orbit-dot {
  position: absolute;
  top: 12%;
  left: 50%;
  width: 10px;
  height: 10px;
  margin-left: -5px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 16px var(--glow);
  animation: spin 28s linear infinite;
  transform-origin: 5px 140px;
}

.section {
  max-width: 720px;
  margin: 0 auto;
  padding: 4.5rem 1.5rem;
}

.section + .section {
  border-top: 1px solid var(--line);
}

.section-title {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.section-text {
  margin: 0;
  color: var(--ink-soft);
  font-size: 1.0625rem;
}

.contact-email {
  display: inline-block;
  margin-top: 1.5rem;
  color: var(--accent-deep);
  font-size: 1.25rem;
  font-weight: 500;
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease;
}

.contact-email:hover {
  border-bottom-color: var(--accent);
}

.site-footer {
  max-width: 1120px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 3rem;
  border-top: 1px solid var(--line);
  text-align: center;
  color: var(--muted);
  font-size: 0.875rem;
}

.footer-name {
  margin: 0 0 0.5rem;
  color: var(--ink-soft);
}

.beian {
  color: var(--muted);
  transition: color 0.25s ease;
}

.beian:hover {
  color: var(--ink);
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  animation: rise 0.9s ease forwards;
}

.reveal-delay-1 {
  animation-delay: 0.15s;
}

.reveal-delay-2 {
  animation-delay: 0.3s;
}

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

@keyframes drift {
  from {
    transform: translate3d(0, 0, 0) scale(1);
  }
  to {
    transform: translate3d(4%, 6%, 0) scale(1.08);
  }
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
    box-shadow: 0 0 50px var(--glow);
  }
  50% {
    transform: scale(1.04);
    box-shadow: 0 0 72px rgba(26, 143, 138, 0.5);
  }
}

@media (max-width: 820px) {
  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding-top: 3rem;
    padding-bottom: 3rem;
  }

  .hero-visual {
    order: -1;
    min-height: 220px;
  }

  .orbit {
    width: min(260px, 70vw);
  }

  .orbit-dot {
    transform-origin: 5px 100px;
  }

  .section {
    padding: 3.25rem 1.5rem;
  }
}

.reduce-motion .mist,
.reduce-motion .orbit-ring,
.reduce-motion .orbit-ring-2,
.reduce-motion .orbit-core,
.reduce-motion .orbit-dot,
.reduce-motion .reveal {
  animation: none !important;
}

.reduce-motion .reveal {
  opacity: 1;
  transform: none;
}