:root {
  --bg: #ffffff;
  --bg-soft: #f0f7ff;
  --bg-card: #ffffff;
  --surface: #f1f5f9;
  --text: #0f172a;
  --muted: #64748b;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.1);
  --accent-ring: rgba(37, 99, 235, 0.25);
  --border: #e2e8f0;
  --radius: 14px;
  --shadow: 0 4px 24px rgba(15, 23, 42, 0.06);
  --shadow-hover: 0 12px 40px rgba(37, 99, 235, 0.12);
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
  color: var(--accent-hover);
}

.container {
  width: min(1120px, 92vw);
  margin: 0 auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.8);
}

.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
  color: var(--accent);
}

.logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: linear-gradient(145deg, #3b82f6, #2563eb);
  display: grid;
  place-items: center;
  font-size: 0.85rem;
  font-weight: 800;
  color: #fff;
  box-shadow: 0 4px 14px var(--accent-ring);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
}

.nav a {
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 500;
  text-decoration: none;
}

.nav a:hover {
  color: var(--accent);
  text-decoration: none;
}

/* Hero */
.hero {
  padding: 4rem 0 3.25rem;
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 55%);
}

.hero::before {
  content: "";
  position: absolute;
  inset: -30% -15% auto;
  height: 85%;
  background: radial-gradient(ellipse 70% 50% at 50% 0%, rgba(37, 99, 235, 0.14), transparent 65%);
  pointer-events: none;
}

.hero .container {
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  border: 1px solid rgba(37, 99, 235, 0.15);
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin: 0 0 1rem;
  color: var(--text);
}

.hero-lead {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 38rem;
  margin: 0 0 1.75rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.hero-platform-link {
  margin: 1rem 0 0;
  font-size: 0.88rem;
  color: var(--muted);
}

.hero-platform-link a {
  word-break: break-all;
  font-weight: 500;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.4rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 14px var(--accent-ring);
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  box-shadow: 0 6px 20px var(--accent-ring);
}

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

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--bg-soft);
}

.btn-outline {
  background: var(--bg);
  border: 2px solid var(--accent);
  color: var(--accent);
}

.btn-outline:hover {
  background: var(--accent-soft);
  color: var(--accent-hover);
  border-color: var(--accent-hover);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 2rem;
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.hero-meta dt {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin: 0 0 0.25rem;
}

.hero-meta dd {
  margin: 0;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
}

/* Sections */
section {
  padding: 3.5rem 0;
}

.section-alt {
  background: var(--bg-soft);
}

.section-title {
  font-size: 1.65rem;
  font-weight: 800;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
  color: var(--text);
}

.section-desc {
  color: var(--muted);
  margin: 0 0 2rem;
  max-width: 42rem;
}

/* Feature grid */
.grid {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 900px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.35rem 1.5rem;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  box-shadow: var(--shadow);
}

.card:hover {
  border-color: rgba(37, 99, 235, 0.35);
  box-shadow: var(--shadow-hover);
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

.card p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--muted);
}

.card-icon {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  background: var(--accent-soft);
  color: var(--accent);
  display: grid;
  place-items: center;
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.85rem;
  border: 1px solid rgba(37, 99, 235, 0.12);
}

/* Contact */
.contact-wrap {
  display: grid;
  gap: 2rem;
  align-items: start;
}

@media (min-width: 768px) {
  .contact-wrap {
    grid-template-columns: 1fr 280px;
  }
}

.qr-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
  box-shadow: var(--shadow);
}

.qr-box img {
  width: 200px;
  height: 200px;
  object-fit: contain;
  border-radius: 8px;
  background: #fff;
  display: block;
  margin: 0 auto 1rem;
  border: 1px solid var(--border);
}

.qr-placeholder {
  width: 200px;
  height: 200px;
  margin: 0 auto 1rem;
  border-radius: 8px;
  border: 2px dashed var(--border);
  background: var(--surface);
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  color: var(--muted);
  font-size: 0.85rem;
  line-height: 1.4;
}

.qr-placeholder.visible {
  display: flex;
}

.qr-caption {
  font-size: 0.9rem;
  color: var(--muted);
  margin: 0;
  font-weight: 500;
}

/* Footer */
.site-footer {
  padding: 2rem 0 2.5rem;
  border-top: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.88rem;
  text-align: center;
}

.site-footer a {
  font-weight: 500;
}