:root {
  --bg-0: #0B0F14;
  --bg-1: #141A22;
  --text: #E8EEF5;
  --muted: #9AA8B8;
  --accent: #2EE6A6;
  --accent-hover: #5FF0BC;
  --line: rgba(232, 238, 245, 0.08);
  --max: 1120px;
  --header-h: 64px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  font-weight: 400;
  color: var(--text);
  background: linear-gradient(180deg, var(--bg-0) 0%, var(--bg-1) 40%, var(--bg-0) 100%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  line-height: 1.6;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.25s ease;
}

a:hover,
a:focus {
  color: var(--accent-hover);
}

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background 0.25s ease, border-color 0.25s ease, backdrop-filter 0.25s ease;
}

.site-header.is-scrolled {
  background: rgba(11, 15, 20, 0.82);
  border-bottom-color: var(--line);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.logo {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text);
}

.logo:hover {
  color: var(--text);
}

.nav {
  display: flex;
  align-items: center;
  gap: 8px 20px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav a {
  color: var(--muted);
  font-size: 0.9375rem;
}

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

.nav-cta {
  margin-left: 8px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  font-size: 0.9375rem;
  border-radius: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.25s ease, color 0.25s ease, border-color 0.25s ease;
  font-family: inherit;
}

.btn-primary {
  background: var(--accent);
  color: #0B0F14;
  font-weight: 600;
}

.btn-primary:hover,
.btn-primary:focus {
  background: var(--accent-hover);
  color: #0B0F14;
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line);
}

.btn-ghost:hover,
.btn-ghost:focus {
  border-color: var(--accent);
  color: var(--accent);
}

/* Hero */
.hero {
  min-height: calc(100vh - var(--header-h));
  display: flex;
  align-items: center;
  padding: 72px 0 96px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 70% 20%, rgba(46, 230, 166, 0.12), transparent 55%),
    radial-gradient(ellipse 60% 40% at 10% 80%, rgba(46, 230, 166, 0.06), transparent 50%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: 720px;
  animation: hero-in 0.8s ease-out both;
}

@keyframes hero-in {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-brand {
  margin: 0 0 16px;
  font-size: clamp(2.5rem, 6vw, 3.75rem);
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.15;
}

.hero-lead {
  margin: 0 0 32px;
  font-size: 1.125rem;
  color: var(--muted);
  max-width: 36em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* Sections */
.section {
  padding: 88px 0;
  border-top: 1px solid var(--line);
}

.section-title {
  margin: 0 0 12px;
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.section-desc {
  margin: 0 0 40px;
  color: var(--muted);
  max-width: 36em;
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px 32px;
}

.service-item h3 {
  margin: 0 0 8px;
  font-size: 1.25rem;
  font-weight: 600;
}

.service-item p {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.975rem;
}

.service-item .tags {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  color: var(--accent);
  font-size: 0.8125rem;
}

.service-item .tags li {
  border: 1px solid var(--line);
  padding: 4px 10px;
  border-radius: 4px;
  color: var(--muted);
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  counter-reset: step;
}

.process-step {
  counter-increment: step;
}

.process-step::before {
  content: counter(step, decimal-leading-zero);
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 12px;
  letter-spacing: 0.08em;
}

.process-step h3 {
  margin: 0 0 8px;
  font-size: 1.0625rem;
}

.process-step p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.case-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.case-item {
  padding: 24px 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 24px;
  align-items: baseline;
}

.case-item:last-child {
  border-bottom: 1px solid var(--line);
}

.case-industry {
  margin: 0;
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.case-item h3 {
  margin: 0 0 6px;
  font-size: 1.125rem;
}

.case-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.contact-wechat {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-top: 8px;
}

.contact-wechat .wx-id {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
}

.copy-feedback {
  min-height: 1.25em;
  margin: 12px 0 0;
  font-size: 0.875rem;
  color: var(--accent);
  opacity: 0;
  transition: opacity 0.2s ease;
}

.copy-feedback.is-visible {
  opacity: 1;
}

.footer {
  border-top: 1px solid var(--line);
  padding: 28px 0;
  text-align: center;
  color: var(--muted);
  font-size: 0.8125rem;
}

.footer p {
  margin: 0;
}

.footer a {
  color: var(--muted);
}

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

@media (max-width: 900px) {
  .service-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .process-steps {
    grid-template-columns: 1fr 1fr;
  }

  .case-item {
    grid-template-columns: 1fr;
    gap: 8px;
  }
}

@media (max-width: 640px) {
  .nav a:not(.btn) {
    display: none;
  }

  .process-steps {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 48px 0 72px;
    min-height: auto;
  }

  .section {
    padding: 64px 0;
  }
}