/* ============================================================
   WhatsApp 中文导航站 — 公共样式
   主色: #00A884 (WhatsApp 2024 绿) / 强调: #0F7B5D
   ============================================================ */

:root {
  --green: #00A884;
  --green-dark: #0F7B5D;
  --green-light: #E7F8F3;
  --green-mid: #25D366;
  --text-primary: #1A1A2E;
  --text-secondary: #4A5568;
  --text-muted: #718096;
  --bg-page: #F7FAFA;
  --bg-white: #FFFFFF;
  --border: #E2EBE9;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 4px rgba(0,0,0,.06);
  --shadow: 0 4px 16px rgba(0,168,132,.1);
  --shadow-lg: 0 12px 40px rgba(0,168,132,.14);
  --font: 'PingFang SC','Microsoft YaHei','Helvetica Neue',Arial,sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text-primary);
  background: var(--bg-page);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--green); text-decoration: none; }
a:hover { color: var(--green-dark); }
img { max-width: 100%; display: block; }

/* ── Container ── */
.container { max-width: 1140px; margin: 0 auto; padding: 0 20px; }

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: var(--radius);
  font-size: .95rem; font-weight: 600; cursor: pointer;
  border: 2px solid transparent; transition: all .22s ease;
  text-decoration: none; white-space: nowrap;
  font-family: var(--font);
}
.btn-primary { background: var(--green); color: #fff; border-color: var(--green); }
.btn-primary:hover { background: var(--green-dark); border-color: var(--green-dark); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow); }
.btn-white { background: #fff; color: var(--green-dark); border-color: #fff; }
.btn-white:hover { background: var(--green-light); color: var(--green-dark); }
.btn-outline { background: transparent; color: #fff; border-color: rgba(255,255,255,.6); }
.btn-outline:hover { background: rgba(255,255,255,.15); border-color: #fff; color: #fff; }
.btn-outline-green { background: transparent; color: var(--green); border-color: var(--green); }
.btn-outline-green:hover { background: var(--green-light); }
.btn-lg { padding: 15px 32px; font-size: 1.05rem; border-radius: 14px; }
.btn-sm { padding: 8px 18px; font-size: .85rem; border-radius: 8px; }
.btn:disabled { opacity: .65; cursor: not-allowed; }

/* ── Header / Nav ── */
header {
  position: sticky; top: 0; z-index: 999;
  background: rgba(255,255,255,.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 8px rgba(0,0,0,.05);
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; height: 66px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.1rem; color: var(--text-primary); }
.logo span { letter-spacing: -.3px; }
.logo:hover { color: var(--green); }
.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a {
  color: var(--text-secondary); font-weight: 500; padding: 7px 14px;
  border-radius: 8px; transition: all .18s;
}
.nav-links a:hover, .nav-links a.active { color: var(--green); background: var(--green-light); }
.nav-cta { margin-left: 8px; }

/* Hamburger */
.hamburger { display: none; background: none; border: none; cursor: pointer; padding: 6px; border-radius: 8px; }
.hamburger:hover { background: var(--green-light); }
.mobile-menu {
  display: none; flex-direction: column;
  background: #fff; border-top: 1px solid var(--border);
  padding: 12px 20px 16px;
}
.mobile-menu a, .mobile-menu button {
  display: block; padding: 12px 0; border-bottom: 1px solid #f0f0f0;
  color: var(--text-secondary); font-weight: 500; font-size: 1rem;
  background: none; border-left: none; border-right: none; border-top: none;
  text-align: left; width: 100%; cursor: pointer; font-family: var(--font);
}
.mobile-menu a:last-child, .mobile-menu button:last-child { border-bottom: none; }
.mobile-menu a.active, .mobile-menu a:hover { color: var(--green); }
.mobile-menu.open { display: flex; }

/* ── Hero — Index ── */
.hero-index {
  background: linear-gradient(135deg, #0F7B5D 0%, #00A884 45%, #25D366 100%);
  padding: 90px 0 80px;
  position: relative; overflow: hidden;
}
.hero-index::before {
  content: ''; position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-grid { display: grid; grid-template-columns: 1fr 420px; gap: 60px; align-items: center; position: relative; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: rgba(255,255,255,.18); color: #fff;
  padding: 6px 14px; border-radius: 20px;
  font-size: .82rem; font-weight: 600; margin-bottom: 20px;
  border: 1px solid rgba(255,255,255,.25);
}
.hero-index h1 {
  font-size: clamp(2rem, 4vw, 3rem); font-weight: 800;
  color: #fff; line-height: 1.2; margin-bottom: 20px; letter-spacing: -.5px;
}
.hero-index p { color: rgba(255,255,255,.88); font-size: 1.1rem; margin-bottom: 32px; max-width: 520px; }
.hero-btns { display: flex; flex-wrap: wrap; gap: 12px; }

.hero-card {
  background: rgba(255,255,255,.12);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,.2);
  border-radius: var(--radius-lg);
  padding: 32px;
}
.hero-stat-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.hero-stat {
  background: rgba(255,255,255,.15); border-radius: var(--radius);
  padding: 18px 14px; text-align: center;
}
.hero-stat-num { font-size: 1.8rem; font-weight: 800; color: #fff; }
.hero-stat-label { font-size: .78rem; color: rgba(255,255,255,.8); margin-top: 2px; }
.hero-card-title { font-weight: 700; color: #fff; font-size: 1rem; margin-bottom: 16px; display: flex; align-items: center; gap: 8px; }

/* ── Section shared ── */
.section { padding: 72px 0; }
.section-alt { background: #fff; }
.section-title { font-size: clamp(1.5rem, 2.5vw, 2.1rem); font-weight: 800; color: var(--text-primary); margin-bottom: 12px; }
.section-sub { color: var(--text-secondary); font-size: 1.05rem; max-width: 600px; }
.section-head { text-align: center; margin-bottom: 52px; }
.tag-pill {
  display: inline-block; background: var(--green-light);
  color: var(--green-dark); font-size: .78rem; font-weight: 700;
  padding: 4px 12px; border-radius: 20px; margin-bottom: 10px; letter-spacing: .4px;
}

/* ── Features grid ── */
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px,1fr)); gap: 24px; }
.feature-card {
  background: #fff; border-radius: var(--radius-lg); padding: 32px 28px;
  border: 1px solid var(--border); transition: all .22s;
}
.feature-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); border-color: var(--green); }
.feature-icon {
  width: 52px; height: 52px; border-radius: 14px;
  background: var(--green-light); display: flex; align-items: center; justify-content: center;
  margin-bottom: 18px;
}
.feature-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.feature-card p { color: var(--text-secondary); font-size: .92rem; line-height: 1.65; }

/* ── Platform cards ── */
.platform-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px,1fr)); gap: 20px; }
.platform-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 28px 22px; text-align: center; transition: all .22s; cursor: pointer;
}
.platform-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); border-color: var(--green); }
.platform-card.featured { border-color: var(--green); background: var(--green-light); position: relative; }
.platform-card.featured::before {
  content: '推荐'; position: absolute; top: -1px; right: 20px;
  background: var(--green); color: #fff; font-size: .72rem; font-weight: 700;
  padding: 3px 10px; border-radius: 0 0 8px 8px; letter-spacing: .3px;
}
.platform-icon { width: 56px; height: 56px; margin: 0 auto 14px; }
.platform-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 4px; }
.platform-card p { font-size: .82rem; color: var(--text-secondary); margin-bottom: 16px; }

/* ── Steps ── */
.steps-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px,1fr)); gap: 24px; counter-reset: step; }
.step-card {
  background: #fff; border-radius: var(--radius-lg); padding: 32px 24px;
  border: 1px solid var(--border); position: relative; text-align: center;
  counter-increment: step;
}
.step-card::before {
  content: counter(step); position: absolute; top: -16px; left: 50%; transform: translateX(-50%);
  width: 32px; height: 32px; background: var(--green); color: #fff;
  border-radius: 50%; font-weight: 800; font-size: .9rem;
  display: flex; align-items: center; justify-content: center;
  line-height: 32px; text-align: center;
}
.step-icon { margin: 0 auto 14px; color: var(--green); }
.step-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; }
.step-card p { font-size: .88rem; color: var(--text-secondary); }

/* ── FAQ ── */
.faq-list { max-width: 820px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; transition: border-color .18s;
}
.faq-item.open { border-color: var(--green); }
.faq-q {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 22px; cursor: pointer; gap: 12px;
  font-weight: 600; font-size: .97rem; color: var(--text-primary);
  user-select: none;
}
.faq-q:hover { color: var(--green); }
.faq-icon { flex-shrink: 0; transition: transform .2s; color: var(--green); }
.faq-item.open .faq-icon { transform: rotate(45deg); }
.faq-a {
  max-height: 0; overflow: hidden;
  transition: max-height .3s ease, padding .3s ease;
}
.faq-a-inner { padding: 0 22px 18px; color: var(--text-secondary); font-size: .93rem; line-height: 1.75; }
.faq-item.open .faq-a { max-height: 400px; }

/* ── Breadcrumb ── */
.breadcrumb { display: flex; align-items: center; gap: 8px; font-size: .85rem; color: rgba(255,255,255,.75); margin-bottom: 20px; }
.breadcrumb a { color: rgba(255,255,255,.85); }
.breadcrumb a:hover { color: #fff; }
.breadcrumb span { color: rgba(255,255,255,.5); }

/* ── Hero — Download ── */
.hero-dl {
  background: linear-gradient(135deg, #0A5C44 0%, #00A884 60%, #34D399 100%);
  padding: 72px 0 64px; position: relative; overflow: hidden;
}
.hero-dl::after {
  content: ''; position: absolute; right: -80px; top: -80px;
  width: 400px; height: 400px; border-radius: 50%;
  background: rgba(255,255,255,.05);
}
.hero-dl h1 { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: #fff; margin-bottom: 14px; }
.hero-dl p { color: rgba(255,255,255,.85); font-size: 1.05rem; max-width: 580px; margin-bottom: 24px; }
.dl-meta-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.dl-tag {
  display: inline-flex; align-items: center; gap: 6px;
  background: rgba(255,255,255,.15); color: rgba(255,255,255,.9);
  padding: 5px 13px; border-radius: 20px; font-size: .82rem; font-weight: 500;
  border: 1px solid rgba(255,255,255,.2);
}

/* ── Windows Featured Card ── */
.win-featured {
  background: linear-gradient(135deg, #0F7B5D 0%, #00A884 100%);
  border-radius: var(--radius-lg); padding: 40px; margin-bottom: 40px;
  position: relative; overflow: hidden; color: #fff;
}
.win-featured::before {
  content: ''; position: absolute; right: -60px; bottom: -60px;
  width: 260px; height: 260px; border-radius: 50%;
  background: rgba(255,255,255,.07);
}
.win-featured-badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: rgba(255,255,255,.2); color: #fff;
  padding: 5px 14px; border-radius: 20px; font-size: .8rem; font-weight: 700;
  margin-bottom: 18px; border: 1px solid rgba(255,255,255,.3);
}
.win-featured-inner { display: grid; grid-template-columns: 1fr auto; gap: 32px; align-items: center; }
.win-featured h2 { font-size: 1.8rem; font-weight: 800; margin-bottom: 12px; }
.win-featured p { color: rgba(255,255,255,.88); font-size: 1rem; margin-bottom: 24px; max-width: 480px; }
.win-feature-list { display: flex; flex-direction: column; gap: 8px; margin-bottom: 28px; }
.win-feature-item { display: flex; align-items: center; gap: 8px; font-size: .9rem; color: rgba(255,255,255,.9); }
.win-dl-btn {
  background: #fff; color: var(--green-dark); border: none;
  padding: 15px 32px; border-radius: 12px; font-size: 1.05rem;
  font-weight: 700; cursor: pointer; display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font); transition: all .2s; white-space: nowrap;
}
.win-dl-btn:hover { background: var(--green-light); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.15); }
.win-dl-btn:disabled { opacity: .7; cursor: not-allowed; }

.win-sys-reqs {
  background: rgba(255,255,255,.12); border-radius: var(--radius); padding: 18px 22px;
  margin-top: 20px;
}
.win-sys-reqs h4 { font-size: .9rem; font-weight: 700; color: #fff; margin-bottom: 10px; display: flex; align-items: center; gap: 6px; }
.req-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.req-item { font-size: .82rem; color: rgba(255,255,255,.8); display: flex; align-items: flex-start; gap: 6px; }

/* ── Other platforms ── */
.other-platforms { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px,1fr)); gap: 20px; margin-bottom: 48px; }
.other-plat-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 28px; display: flex; flex-direction: column; align-items: flex-start; gap: 12px;
  transition: all .22s;
}
.other-plat-card:hover { box-shadow: var(--shadow); border-color: var(--green); }
.other-plat-header { display: flex; align-items: center; gap: 12px; }
.other-plat-header h3 { font-size: 1.05rem; font-weight: 700; }
.other-plat-card p { font-size: .88rem; color: var(--text-secondary); line-height: 1.6; }

/* ── Install steps ── */
.install-section { background: #fff; }
.install-steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px,1fr)); gap: 0; position: relative; }
.install-steps::before {
  content: ''; position: absolute; top: 36px; left: 10%; right: 10%;
  height: 2px; background: linear-gradient(90deg, var(--green-light), var(--green), var(--green-light));
  z-index: 0;
}
.install-step { text-align: center; padding: 24px 16px; position: relative; z-index: 1; }
.install-step-num {
  width: 48px; height: 48px; border-radius: 50%;
  background: var(--green); color: #fff; font-weight: 800; font-size: 1.1rem;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 14px; box-shadow: 0 0 0 6px var(--green-light);
}
.install-step h4 { font-size: .97rem; font-weight: 700; margin-bottom: 6px; }
.install-step p { font-size: .85rem; color: var(--text-secondary); }

/* ── Hero — Web ── */
.hero-web {
  background: linear-gradient(135deg, #064E3B 0%, #00A884 55%, #6EE7B7 100%);
  padding: 80px 0 70px; position: relative; overflow: hidden;
}
.hero-web h1 { font-size: clamp(1.8rem, 3.5vw, 2.6rem); font-weight: 800; color: #fff; margin-bottom: 14px; }
.hero-web p { color: rgba(255,255,255,.88); font-size: 1.05rem; max-width: 580px; margin-bottom: 28px; }

/* ── QR zone ── */
.qr-section { background: var(--bg-page); }
.qr-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
.qr-box {
  background: #fff; border-radius: var(--radius-lg); padding: 40px;
  border: 1px solid var(--border); text-align: center;
}
.qr-placeholder {
  width: 200px; height: 200px; margin: 0 auto 20px;
  border: 3px solid var(--green); border-radius: 16px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 10px; background: var(--green-light);
}
.qr-placeholder p { font-size: .78rem; color: var(--green-dark); font-weight: 600; }
.qr-steps { display: flex; flex-direction: column; gap: 20px; }
.qr-step { display: flex; align-items: flex-start; gap: 16px; }
.qr-step-num {
  flex-shrink: 0; width: 36px; height: 36px; border-radius: 50%;
  background: var(--green); color: #fff; font-weight: 800; font-size: .9rem;
  display: flex; align-items: center; justify-content: center;
}
.qr-step-text h4 { font-size: .95rem; font-weight: 700; margin-bottom: 4px; }
.qr-step-text p { font-size: .87rem; color: var(--text-secondary); }

/* ── Browser compat ── */
.browser-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px,1fr)); gap: 16px; }
.browser-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 16px; text-align: center; transition: all .2s;
}
.browser-card:hover { border-color: var(--green); box-shadow: var(--shadow); }
.browser-card svg { margin: 0 auto 10px; }
.browser-card h4 { font-size: .92rem; font-weight: 700; }
.browser-card p { font-size: .78rem; color: var(--text-muted); }

/* ── Comparison table ── */
.compare-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-sm); }
.compare-table th, .compare-table td { padding: 14px 18px; text-align: left; border-bottom: 1px solid var(--border); font-size: .92rem; }
.compare-table th { background: var(--green); color: #fff; font-weight: 700; }
.compare-table tr:last-child td { border-bottom: none; }
.compare-table tr:nth-child(even) { background: #fafffe; }
.check { color: var(--green); }
.cross { color: #E53E3E; }
.partial { color: #D69E2E; }

/* ── Trust bar ── */
.trust-bar {
  background: var(--green-light); border-top: 1px solid #c6ede1; border-bottom: 1px solid #c6ede1;
  padding: 14px 0;
}
.trust-inner { display: flex; align-items: center; justify-content: center; gap: 32px; flex-wrap: wrap; }
.trust-item { display: flex; align-items: center; gap: 8px; font-size: .85rem; font-weight: 600; color: var(--green-dark); }

/* ── Footer ── */
footer {
  background: var(--text-primary); color: rgba(255,255,255,.75);
  padding: 56px 0 24px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 48px; margin-bottom: 40px; }
.footer-brand { display: flex; align-items: center; gap: 10px; color: #fff; font-weight: 700; font-size: 1.05rem; margin-bottom: 14px; }
.footer-desc { font-size: .88rem; color: rgba(255,255,255,.6); line-height: 1.7; max-width: 280px; }
.footer-col h4 { color: #fff; font-size: .9rem; font-weight: 700; margin-bottom: 14px; letter-spacing: .3px; }
.footer-col a { display: block; font-size: .87rem; color: rgba(255,255,255,.6); margin-bottom: 9px; }
.footer-col a:hover { color: var(--green-mid); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1); padding-top: 22px;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 10px; font-size: .82rem; color: rgba(255,255,255,.45);
}
.footer-safety {
  background: rgba(37,211,102,.1); border: 1px solid rgba(37,211,102,.25);
  border-radius: 8px; padding: 10px 16px;
  font-size: .84rem; color: rgba(255,255,255,.75);
  margin-bottom: 20px; display: flex; align-items: flex-start; gap: 8px;
}

/* ── Notice / Alert ── */
.notice {
  background: #FFF7ED; border: 1px solid #FED7AA; border-radius: 10px;
  padding: 14px 18px; display: flex; align-items: flex-start; gap: 10px;
  font-size: .88rem; color: #9C4221; margin-bottom: 24px;
}
.notice svg { flex-shrink: 0; margin-top: 1px; }

/* ── Testimonials / Stats ── */
.stats-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px,1fr)); gap: 24px; }
.stat-box {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 28px; text-align: center;
}
.stat-box-num { font-size: 2.2rem; font-weight: 800; color: var(--green); line-height: 1; margin-bottom: 6px; }
.stat-box-label { font-size: .88rem; color: var(--text-secondary); }

/* ── Tips / Use cases ── */
.tips-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px,1fr)); gap: 24px; }
.tip-card {
  background: #fff; border-radius: var(--radius-lg); border: 1px solid var(--border); padding: 28px;
  display: flex; flex-direction: column; gap: 10px; transition: all .2s;
}
.tip-card:hover { box-shadow: var(--shadow); border-color: var(--green); }
.tip-tag {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--green-light); color: var(--green-dark);
  font-size: .75rem; font-weight: 700; padding: 3px 10px; border-radius: 20px; align-self: flex-start;
}
.tip-card h3 { font-size: 1rem; font-weight: 700; }
.tip-card p { font-size: .88rem; color: var(--text-secondary); line-height: 1.65; }

/* ── Spinner ── */
@keyframes spin { to { transform: rotate(360deg); } }
.spin { animation: spin .8s linear infinite; display: inline-block; }

/* ── Responsive ── */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-card { display: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .win-featured-inner { grid-template-columns: 1fr; }
  .qr-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav-links { display: none; }
  .hamburger { display: flex; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .section { padding: 52px 0; }
  .install-steps::before { display: none; }
  .hero-index, .hero-dl, .hero-web { padding: 60px 0 50px; }
}