/* ============================================================
   设计 Token
   ============================================================ */
:root {
  /* 色彩 */
  --color-primary:       #1B6EF3;
  --color-primary-dark:  #1457C8;
  --color-primary-light: #EBF2FF;
  --color-accent:        #00C6FF;
  --color-bg:            #FFFFFF;
  --color-bg-light:      #F7F9FC;
  --color-text:          #1A202C;
  --color-text-muted:    #718096;
  --color-border:        #E2E8F0;
  --color-white:         #FFFFFF;

  /* 字体 */
  --font-sans: Inter, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;

  /* 间距 */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  40px;
  --space-2xl: 64px;
  --space-3xl: 96px;

  /* 圆角 */
  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,.10), 0 2px 4px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 30px rgba(0,0,0,.10), 0 4px 8px rgba(0,0,0,.06);

  /* 动画 */
  --ease: cubic-bezier(.4,0,.2,1);
  --duration: 250ms;
}

/* ============================================================
   Reset & Base
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

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

img { display: block; max-width: 100%; }
a  { text-decoration: none; color: inherit; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ============================================================
   Layout
   ============================================================ */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
}
.section--light {
  background: var(--color-bg-light);
}

.section__header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}
.section__title {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}
.section__sub {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 600;
  transition: transform var(--duration) var(--ease),
              box-shadow var(--duration) var(--ease),
              background var(--duration) var(--ease);
}
.btn--primary {
  background: var(--color-primary);
  color: var(--color-white);
  box-shadow: 0 4px 14px rgba(27,110,243,.35);
}
.btn--primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(27,110,243,.45);
}
.btn--outline {
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
}
.btn--outline:hover {
  background: var(--color-primary-light);
  transform: translateY(-2px);
}

/* ============================================================
   Navbar
   ============================================================ */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--duration) var(--ease),
              box-shadow var(--duration) var(--ease);
}
.navbar.scrolled {
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}
.navbar__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.navbar__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text);
}
.navbar__logo img {
  width: 32px; height: 32px;
}
.navbar__links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}
.navbar__links a {
  font-size: .95rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--duration) var(--ease);
  position: relative;
}
.navbar__links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0; right: 0;
  height: 2px;
  background: var(--color-primary);
  transform: scaleX(0);
  transition: transform var(--duration) var(--ease);
}
.navbar__links a:hover { color: var(--color-primary); }
.navbar__links a:hover::after { transform: scaleX(1); }

.navbar__actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

/* 语言切换 */
.lang-toggle {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: .85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--color-border);
  transition: all var(--duration) var(--ease);
}
.lang-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.lang-toggle__zh,
.lang-toggle__en {
  transition: color var(--duration) var(--ease), font-weight var(--duration);
}
.lang-en .lang-toggle__en,
.lang-zh .lang-toggle__zh {
  color: var(--color-primary);
  font-weight: 700;
}

/* 汉堡菜单 */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  width: 28px;
  padding: 4px;
}
.hamburger span {
  display: block;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--duration) var(--ease), opacity var(--duration);
}
.hamburger.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  padding-top: calc(64px + var(--space-3xl));
  padding-bottom: 0;
  background: linear-gradient(135deg, #EBF2FF 0%, #FFFFFF 60%, #F0FAFF 100%);
  overflow: hidden;
}
.hero__inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-2xl);
  align-items: center;
  padding-bottom: var(--space-3xl);
}
.hero__badge {
  display: inline-block;
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-size: .85rem;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-lg);
}
.hero__title {
  font-size: clamp(2rem, 4.5vw, 3.25rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-lg);
  background: linear-gradient(135deg, var(--color-text) 0%, var(--color-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero__sub {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  line-height: 1.8;
  margin-bottom: var(--space-xl);
}
.hero__cta {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}
.hero__qr {
  text-align: center;
}
.hero__qr-img {
  width: 180px; height: 180px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border: 4px solid white;
  object-fit: cover;
  background: var(--color-bg-light);
}
.hero__qr-tip {
  margin-top: var(--space-sm);
  font-size: .85rem;
  color: var(--color-text-muted);
}

/* 统计栏 */
.hero__stats {
  background: var(--color-primary);
}
.hero__stats-inner {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: var(--space-xl) 0;
}
.stat-item {
  text-align: center;
  color: white;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  border-right: 1px solid rgba(255,255,255,.2);
}
.stat-item:last-child { border-right: none; }
.stat-num {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  line-height: 1;
}
.stat-unit {
  font-size: 1.25rem;
  font-weight: 700;
}
.stat-label {
  font-size: .85rem;
  opacity: .85;
}

/* ============================================================
   Feature Grid
   ============================================================ */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}
.feature-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-lg);
  transition: transform var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-light);
}
.feature-card__icon {
  font-size: 2rem;
  margin-bottom: var(--space-md);
}
.feature-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}
.feature-card p {
  font-size: .92rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ============================================================
   Steps
   ============================================================ */
.steps {
  display: flex;
  align-items: flex-start;
  gap: var(--space-lg);
  justify-content: center;
  flex-wrap: wrap;
}
.step {
  flex: 1;
  min-width: 160px;
  max-width: 220px;
  text-align: center;
}
.step__num {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: white;
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-md);
  box-shadow: 0 4px 14px rgba(27,110,243,.35);
}
.step__body h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}
.step__body p {
  font-size: .88rem;
  color: var(--color-text-muted);
}
.step__arrow {
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-top: 14px;
  opacity: .5;
  flex-shrink: 0;
}

/* ============================================================
   Merchant
   ============================================================ */
.benefit-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}
.benefit-card {
  background: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-lg);
  text-align: center;
  border: 1px solid var(--color-border);
  transition: transform var(--duration) var(--ease), box-shadow var(--duration) var(--ease);
}
.benefit-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.benefit-card__icon {
  font-size: 2rem;
  margin-bottom: var(--space-md);
}
.benefit-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}
.benefit-card p {
  font-size: .88rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* 入驻流程 */
.process {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
}
.process__item {
  flex: 1;
  min-width: 140px;
  max-width: 200px;
  text-align: center;
}
.process__icon {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: var(--color-primary-light);
  font-size: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-md);
}
.process__item h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}
.process__item p {
  font-size: .88rem;
  color: var(--color-text-muted);
}
.process__arrow {
  font-size: 1.5rem;
  color: var(--color-primary);
  opacity: .4;
  margin-top: 14px;
  flex-shrink: 0;
}

.merchant__cta {
  text-align: center;
  margin-top: var(--space-2xl);
  padding: var(--space-xl);
  background: linear-gradient(135deg, var(--color-primary-light), #F0FAFF);
  border-radius: var(--radius-lg);
}
.merchant__cta p {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
}

/* ============================================================
   About
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: start;
}
.about__intro h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: var(--space-lg);
  color: var(--color-primary);
}
.about__intro p {
  color: var(--color-text-muted);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}
.about__intro strong {
  color: var(--color-primary);
}
.about__contact h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: var(--space-lg);
}
.contact-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}
.contact-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
}
.contact-icon {
  font-size: 1.25rem;
  flex-shrink: 0;
  margin-top: 2px;
}
.contact-label {
  display: block;
  font-size: .8rem;
  color: var(--color-text-muted);
  margin-bottom: 2px;
}
.contact-value {
  font-size: .95rem;
  font-weight: 500;
}

/* ============================================================
   Download
   ============================================================ */
.download {
  background: linear-gradient(135deg, var(--color-primary) 0%, #0099e6 100%);
  color: white;
}
.download .section__title { color: white; }
.download .section__sub { color: rgba(255,255,255,.8); }

.download__body {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2xl);
  flex-wrap: wrap;
}
.download__qr-wrap {
  text-align: center;
}
.download__qr {
  width: 200px; height: 200px;
  border-radius: var(--radius-lg);
  border: 6px solid rgba(255,255,255,.3);
  object-fit: cover;
  background: white;
}
.download__qr-label {
  margin-top: var(--space-sm);
  font-size: .9rem;
  opacity: .85;
}
.download__tips {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}
.tip-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  font-size: 1rem;
  opacity: .9;
}
.tip-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  background: var(--color-text);
  color: rgba(255,255,255,.6);
  padding: var(--space-xl) 0;
}
.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
}
.footer__brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: rgba(255,255,255,.8);
  font-weight: 600;
}
.footer__copy {
  font-size: .85rem;
}

/* ============================================================
   Reveal Animation
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
.reveal.visible {
  opacity: 1;
  transform: none;
}

/* ============================================================
   Responsive — Tablet (< 1024px)
   ============================================================ */
@media (max-width: 1023px) {
  .benefit-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ============================================================
   Responsive — Mobile (< 768px)
   ============================================================ */
@media (max-width: 767px) {
  /* Nav */
  .navbar__links {
    display: none;
    flex-direction: column;
    gap: var(--space-lg);
    position: absolute;
    top: 64px; left: 0; right: 0;
    background: white;
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-lg) var(--space-lg) var(--space-xl);
    box-shadow: var(--shadow-md);
  }
  .navbar__links.open { display: flex; }
  .hamburger { display: flex; }
  .navbar { position: fixed; }

  /* Hero */
  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero__cta { justify-content: center; }
  .hero__qr { display: none; } /* 移动端隐藏 hero 二维码，download 区有专属展示 */
  .hero__stats-inner {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-lg) 0;
  }
  .stat-item { border-right: none; border-bottom: 1px solid rgba(255,255,255,.2); }
  .stat-item:nth-child(3),
  .stat-item:nth-child(4) { border-bottom: none; }

  /* Sections */
  .feature-grid { grid-template-columns: 1fr; }
  .benefit-grid { grid-template-columns: 1fr; }
  .about-grid   { grid-template-columns: 1fr; }
  .steps { flex-direction: column; align-items: center; }
  .step__arrow { transform: rotate(90deg); margin: 0; }
  .process { flex-direction: column; align-items: center; }
  .process__arrow { transform: rotate(90deg); margin: 0; }

  /* Download */
  .download__body { flex-direction: column; }

  /* Footer */
  .footer__inner { flex-direction: column; text-align: center; }
}