:root {
  --color-primary: #298fdb;
  --color-secondary: #9463c9;
  --color-warning: #ff942e;
  --color-danger: #e83b45;
  --color-text-primary: #000000;
  --color-text-secondary: #8e8e93;
  --color-background-default: #ffffff;
  --space-xs: 4px;
  --space-s: 8px;
  --space-m: 16px;
  --space-l: 24px;
  --space-xl: 32px;
  --radius-small: 4px;
  --radius-medium: 8px;
  --radius-large: 12px;
  --font-title-size: 28px;
  --font-headline-size: 17px;
  --font-subheadline-size: 15px;
  --font-caption-size: 12px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Manrope", "Noto Sans SC", "Segoe UI", sans-serif;
  color: var(--color-text-primary);
  background: radial-gradient(circle at 15% 10%, rgba(41, 143, 219, 0.2), transparent 35%),
    radial-gradient(circle at 80% 15%, rgba(255, 148, 46, 0.24), transparent 30%),
    linear-gradient(160deg, #eef7ff, #fef8ee 55%, #ffffff);
  min-height: 100vh;
  line-height: 1.55;
}

.ambient {
  position: fixed;
  z-index: -1;
  width: 40vmax;
  height: 40vmax;
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.35;
  pointer-events: none;
}

.ambient-top {
  top: -18vmax;
  left: -10vmax;
  background: rgba(41, 143, 219, 0.55);
  animation: drift 12s ease-in-out infinite alternate;
}

.ambient-bottom {
  right: -15vmax;
  bottom: -15vmax;
  background: rgba(255, 148, 46, 0.45);
  animation: drift 14s ease-in-out infinite alternate-reverse;
}

.site-header {
  max-width: 1160px;
  margin: 0 auto;
  padding: calc(var(--space-l) + var(--space-s)) var(--space-l);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-s);
}

.brand-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: linear-gradient(120deg, var(--color-primary), var(--color-warning));
  box-shadow: 0 0 0 6px rgba(41, 143, 219, 0.15);
}

.brand-text {
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.brand-name-group {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
}

.brand-text-en {
  font-weight: 700;
  font-size: 0.85em;
  color: var(--color-text-secondary);
  letter-spacing: 0.04em;
}

.brand-text-zh {
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.brand-name-sep {
  margin: 0 2px;
  color: var(--color-text-secondary);
  opacity: 0.4;
  font-size: 0.75em;
}

.site-nav {
  display: inline-flex;
  gap: var(--space-m);
}

.site-nav a {
  text-decoration: none;
  color: var(--color-text-secondary);
  font-weight: 600;
  transition: color 0.2s ease;
}

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

main,
.site-footer {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 var(--space-l);
}

.hero {
  padding: var(--space-xl) 0 calc(var(--space-xl) + var(--space-l));
}

.eyebrow {
  margin: 0;
  font-size: var(--font-caption-size);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 700;
}

.hero h1 {
  margin: var(--space-s) 0 var(--space-m);
  font-size: clamp(2rem, 4vw, 3.8rem);
  line-height: 1.1;
  max-width: 15ch;
  text-wrap: balance;
}

.hero-copy {
  margin: 0;
  max-width: 62ch;
  color: var(--color-text-secondary);
}

.hero-actions {
  margin-top: var(--space-l);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-s);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  min-height: 44px;
  padding: 0 var(--space-m);
  border-radius: 999px;
  font-weight: 700;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

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

.btn-primary {
  background: linear-gradient(120deg, var(--color-primary), #1571b2);
  color: #ffffff;
  box-shadow: 0 10px 20px rgba(16, 91, 146, 0.25);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.9);
  color: var(--color-text-primary);
  border: 1px solid rgba(0, 0, 0, 0.08);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-m);
}

.metric-card,
.feature-card,
.platform-panel,
.story-card,
.faq-item {
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(4px);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: calc(var(--radius-large) + 2px);
  box-shadow: 0 8px 22px rgba(20, 54, 77, 0.06);
}

.metric-card {
  padding: var(--space-l);
}

.metric-value {
  margin: 0;
  font-size: clamp(2rem, 3vw, 2.5rem);
  line-height: 1;
  font-weight: 800;
  color: var(--color-primary);
}

.metric-label {
  margin: var(--space-s) 0 0;
  font-weight: 700;
}

.metric-desc {
  margin: var(--space-xs) 0 0;
  color: var(--color-text-secondary);
}

.section {
  padding: calc(var(--space-xl) + var(--space-l)) 0 0;
}

.section-heading h2 {
  margin: var(--space-s) 0 0;
  font-size: clamp(1.8rem, 2.2vw, 2.4rem);
}

.feature-grid {
  margin-top: var(--space-l);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-m);
}

.feature-card {
  padding: var(--space-l);
}

.feature-card h3 {
  margin: 0;
  font-size: 1.1rem;
}

.feature-card p {
  margin: var(--space-s) 0 0;
  color: var(--color-text-secondary);
}

.platform-panel {
  margin-top: var(--space-l);
  padding: var(--space-l);
}

.platform-panel p {
  margin: 0;
  color: var(--color-text-secondary);
}

.platform-panel ul {
  margin: var(--space-m) 0 0;
  padding-left: 1.1rem;
}

.platform-panel li + li {
  margin-top: var(--space-s);
}

.story-grid {
  margin-top: var(--space-l);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-m);
}

.story-card {
  padding: var(--space-l);
}

.story-tag {
  margin: 0;
  color: var(--color-primary);
  font-size: var(--font-caption-size);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 700;
}

.story-card h3 {
  margin: var(--space-s) 0;
  font-size: 1.1rem;
}

.story-card p {
  margin: 0;
  color: var(--color-text-secondary);
}

.story-author {
  margin-top: var(--space-m) !important;
  color: var(--color-text-primary) !important;
  font-weight: 600;
}

.faq-list {
  margin-top: var(--space-l);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-m);
}

.faq-item {
  padding: var(--space-m) var(--space-l);
}

.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  list-style: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  float: right;
  color: var(--color-primary);
}

.faq-item[open] summary::after {
  content: "-";
}

.faq-item p {
  margin: var(--space-s) 0 0;
  color: var(--color-text-secondary);
}

.site-footer {
  padding: calc(var(--space-xl) + var(--space-l)) var(--space-l) var(--space-xl);
  color: var(--color-text-secondary);
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

@keyframes drift {
  from {
    transform: translate3d(0, 0, 0) scale(1);
  }
  to {
    transform: translate3d(3%, -3%, 0) scale(1.06);
  }
}

@media (max-width: 980px) {
  .metrics,
  .feature-grid,
  .story-grid,
  .faq-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .site-nav {
    display: none;
  }
}

@media (max-width: 700px) {
  .site-header,
  main,
  .site-footer {
    padding-left: var(--space-m);
    padding-right: var(--space-m);
  }

  .metrics,
  .feature-grid,
  .story-grid,
  .faq-list {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: var(--space-l);
  }
}