:root {
  --bg: #dff8f7;
  --bg-alt: #eef9f8;
  --surface: #ffffff;
  --accent: #a2fff9;
  --accent-strong: #40a8f9;
  --text: #2a2d33;
  --text-muted: #565a61;
  --border: rgba(42, 45, 51, 0.08);
  --shadow: 0 18px 48px rgba(31, 42, 43, 0.08);
  --radius: 16px;
  --radius-lg: 24px;
  --header-h: 72px;
  --font: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.page-bg {
  position: fixed;
  inset: 0;
  background:
    linear-gradient(165deg, rgba(223, 248, 247, 0.92) 0%, rgba(238, 249, 248, 0.88) 45%, #f4f8f7 100%),
    url("assets/bg-texture.png") center / cover no-repeat;
  z-index: -1;
  pointer-events: none;
}

img {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 24px;
  height: var(--header-h);
  padding: 0 clamp(20px, 4vw, 48px);
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.125rem;
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-left: auto;
  font-size: 0.9375rem;
  font-weight: 500;
}

.nav-links a:hover {
  color: #1a6fa8;
}

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 40px;
  height: 40px;
  padding: 0;
  border: none;
  background: transparent;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 5px auto;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.2s, opacity 0.2s;
}

.header-cta {
  flex-shrink: 0;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
}

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

.btn--primary {
  background: var(--accent);
  color: #1f2a2b;
  box-shadow: 0 8px 24px rgba(162, 255, 249, 0.45);
}

.btn--primary:hover {
  background: #8ef5ee;
}

.btn--ghost {
  background: var(--surface);
  border-color: #e5e7eb;
  color: var(--text);
}

.btn--sm {
  padding: 10px 18px;
  font-size: 0.875rem;
}

.btn--disabled {
  cursor: default;
  opacity: 0.95;
}

.btn--disabled:hover {
  transform: none;
}

/* Hero */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  max-width: 1180px;
  margin: 0 auto;
  padding: clamp(48px, 8vw, 96px) clamp(20px, 4vw, 48px) 64px;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 12px;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(162, 255, 249, 0.55);
  font-size: 0.875rem;
  font-weight: 600;
  color: #1a4a52;
}

.hero h1 {
  margin: 0 0 20px;
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.02em;
}

.hero-lead {
  margin: 0 0 28px;
  font-size: 1.0625rem;
  color: var(--text-muted);
  max-width: 34em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 36px;
}

.hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.hero-stats li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hero-stats strong {
  font-size: 1.5rem;
  color: #1a6fa8;
  line-height: 1;
}

.hero-stats span {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.hero-visual {
  position: relative;
  min-height: 360px;
}

.hero-robot {
  position: absolute;
  top: -8px;
  right: 0;
  width: min(200px, 38vw);
  z-index: 2;
  filter: drop-shadow(0 12px 24px rgba(0, 0, 0, 0.08));
}

.hero-phone {
  position: relative;
  margin-top: 48px;
  padding: 20px;
  background: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.hero-phone img {
  display: block;
  border-radius: 12px;
}

/* Sections */
.section {
  max-width: 1180px;
  margin: 0 auto;
  padding: 72px clamp(20px, 4vw, 48px);
}

.section--alt {
  background: rgba(255, 255, 255, 0.55);
  border-radius: var(--radius-lg);
  max-width: calc(1180px + 96px);
  margin-left: auto;
  margin-right: auto;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

.section-head {
  text-align: center;
  margin-bottom: 48px;
}

.section-head h2 {
  margin: 0 0 12px;
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
}

.section-head p {
  margin: 0;
  color: var(--text-muted);
  font-size: 1.0625rem;
}

/* Features */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-card {
  padding: 28px 22px;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
}

.feature-icon {
  font-size: 1.75rem;
  margin-bottom: 14px;
}

.feature-card h3 {
  margin: 0 0 10px;
  font-size: 1.0625rem;
}

.feature-card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.55;
}

/* Steps */
.steps-panel {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 40px;
  align-items: center;
}

.steps-image {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.steps-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.steps-list li {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.step-num {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--accent);
  font-weight: 700;
  font-size: 1.125rem;
  color: #1f2a2b;
}

.steps-list h3 {
  margin: 0 0 6px;
  font-size: 1.0625rem;
}

.steps-list p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-muted);
}

.kaka-banner {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-top: 40px;
  padding: 22px 26px;
  background: linear-gradient(135deg, rgba(64, 168, 249, 0.12), rgba(162, 255, 249, 0.35));
  border-radius: var(--radius);
  border: 1px solid rgba(64, 168, 249, 0.2);
}

.kaka-banner img {
  border-radius: 50%;
  flex-shrink: 0;
}

.kaka-banner strong {
  display: block;
  margin-bottom: 4px;
  font-size: 1.0625rem;
}

.kaka-banner p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-muted);
}

/* AI section */
.ai-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 48px;
  align-items: center;
}

.ai-layout h2 {
  margin: 0 0 16px;
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.ai-layout > .ai-copy > p {
  margin: 0 0 20px;
  color: var(--text-muted);
}

.ai-points {
  margin: 0;
  padding: 0;
  list-style: none;
}

.ai-points li {
  position: relative;
  padding-left: 22px;
  margin-bottom: 12px;
  font-size: 0.9375rem;
}

.ai-points li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: #4a7c6f;
  font-weight: 700;
}

.ai-visual {
  display: flex;
  justify-content: center;
  padding: 24px;
  background: var(--surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.ai-visual img {
  max-width: 200px;
}

/* Tiers */
.tier-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.tier-card {
  padding: 28px 24px;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.tier-badge {
  display: inline-block;
  margin-bottom: 12px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--accent);
  font-size: 0.8125rem;
  font-weight: 700;
  color: #1f2a2b;
}

.tier-card h3 {
  margin: 0 0 10px;
  font-size: 1.125rem;
}

.tier-card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.tier-card--wide {
  grid-column: 1 / -1;
}

/* Download */
.download-card {
  text-align: center;
  padding: 56px 32px;
  background: linear-gradient(160deg, #ffffff 0%, #eef9f8 100%);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.download-logo {
  margin: 0 auto 20px;
}

.download-card h2 {
  margin: 0 0 12px;
  font-size: 1.75rem;
}

.download-card > p {
  margin: 0 auto 28px;
  max-width: 32em;
  color: var(--text-muted);
}

.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
  margin-bottom: 16px;
}

.download-hint {
  font-size: 0.875rem !important;
  color: #8a8f98 !important;
}

/* Footer */
.site-footer {
  margin-top: 24px;
  padding: 48px 24px 56px;
  background: rgba(42, 45, 51, 0.92);
  color: rgba(255, 255, 255, 0.88);
}

.footer-inner {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.125rem;
  margin-bottom: 8px;
}

.footer-tagline {
  margin: 0 0 20px;
  font-weight: 600;
  color: var(--accent);
}

.footer-legal,
.footer-copy {
  margin: 0 0 10px;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.65);
}

.policy-info {
  margin: 0 0 16px;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.65);
  text-align: center;
}

.policy-beian-line,
.policy-icp-line {
  margin: 0 0 10px;
}

.policy-beian-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  text-decoration: none;
  height: 20px;
  line-height: 20px;
  color: rgba(162, 255, 249, 0.9);
}

.policy-gongan-icon {
  display: inline-block;
  width: 20px;
  height: 20px;
  max-width: none;
  flex-shrink: 0;
  margin: 0;
}

.policy-info a {
  color: rgba(162, 255, 249, 0.9);
  text-decoration: none;
}

.policy-info a:hover {
  text-decoration: underline;
}

/* Mobile nav */
@media (max-width: 900px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .hero-visual {
    order: -1;
    min-height: 280px;
  }

  .steps-panel,
  .ai-layout {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 720px) {
  .nav-links {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    padding: 12px 20px 20px;
    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid var(--border);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.25s, opacity 0.25s;
  }

  .nav-links.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-links a {
    display: block;
    padding: 14px 0;
    border-bottom: 1px solid var(--border);
  }

  .nav-toggle {
    display: block;
  }

  .header-cta {
    display: none;
  }

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

  .hero-stats {
    gap: 20px;
  }
}