/* =========================================================
   发票二维码识别下载工具 · 官网样式（浅色 / 精致 / 响应式）
   纯静态，无外部依赖，可直接部署到任意 Web 服务器。
   ========================================================= */
:root {
  --bg: #f4f7fc;
  --bg-soft: #eef3fb;
  --surface: #ffffff;
  --ink: #0f172a;
  --ink-2: #334155;
  --muted: #64748b;
  --border: #e4ebf3;
  --primary: #2563eb;
  --primary-600: #1d4ed8;
  --primary-50: #eff5ff;
  --accent: #06b6d4;
  --accent-50: #ecfeff;
  --ok: #10b981;
  --warn: #f59e0b;
  --grad: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
  --grad-soft: linear-gradient(135deg, #eef4ff 0%, #ecfeff 100%);
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06), 0 2px 8px rgba(15, 23, 42, .05);
  --shadow: 0 10px 30px rgba(15, 23, 42, .08);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, .14);
  --radius: 18px;
  --radius-sm: 12px;
  --maxw: 1140px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", "Noto Sans CJK SC", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

img { max-width: 100%; display: block; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 22px;
}

.section { padding: 84px 0; }
.section-tight { padding: 56px 0; }

/* ---------- 导航 ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 66px;
}
.brand { display: flex; align-items: center; gap: 11px; font-weight: 800; font-size: 17px; letter-spacing: .2px; }
.brand img { width: 34px; height: 34px; border-radius: 9px; box-shadow: var(--shadow-sm); }
.brand small { font-weight: 500; color: var(--muted); font-size: 12px; display: block; margin-top: -4px; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { color: var(--ink-2); font-weight: 600; font-size: 15px; transition: color .15s; }
.nav-links a:hover { color: var(--primary); }
.nav-cta {
  background: var(--grad);
  color: #fff !important;
  padding: 9px 18px;
  border-radius: 999px;
  font-weight: 700;
  box-shadow: 0 6px 18px rgba(37, 99, 235, .35);
  transition: transform .15s, box-shadow .15s;
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(37, 99, 235, .45); }
.nav-toggle { display: none; }

/* ---------- 英雄区 ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(1200px 600px at 85% -10%, rgba(6, 182, 212, .18), transparent 60%),
    radial-gradient(900px 500px at 0% 10%, rgba(37, 99, 235, .16), transparent 55%),
    var(--bg);
}
.hero .container {
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 48px;
  align-items: center;
  padding-top: 80px;
  padding-bottom: 88px;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  border: 1px solid var(--border);
  color: var(--primary-600);
  font-weight: 700;
  font-size: 13px;
  padding: 7px 14px;
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
}
.badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--ok); }
.hero h1 {
  font-size: 46px;
  line-height: 1.18;
  margin: 20px 0 16px;
  letter-spacing: -.5px;
  font-weight: 850;
}
.hero h1 .hl {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p.lead {
  font-size: 18px;
  color: var(--ink-2);
  max-width: 540px;
  margin: 0 0 28px;
}
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-weight: 700;
  font-size: 15px;
  padding: 13px 24px;
  border-radius: 12px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .15s, box-shadow .15s, background .15s;
}
.btn-primary { background: var(--grad); color: #fff; box-shadow: 0 10px 26px rgba(37, 99, 235, .38); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 32px rgba(37, 99, 235, .48); }
.btn-ghost { background: #fff; color: var(--ink); border-color: var(--border); box-shadow: var(--shadow-sm); }
.btn-ghost:hover { transform: translateY(-2px); border-color: #cdd9ea; }
.hero-meta { display: flex; gap: 26px; margin-top: 30px; color: var(--muted); font-size: 14px; flex-wrap: wrap; }
.hero-meta b { color: var(--ink); font-size: 20px; font-weight: 800; display: block; }

/* 英雄区右侧：模拟卡片 */
.hero-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: var(--shadow-lg);
  padding: 20px;
  transform: rotate(1.2deg);
}
.hero-card .hd {
  display: flex; align-items: center; gap: 10px;
  padding-bottom: 14px; border-bottom: 1px dashed var(--border); margin-bottom: 14px;
}
.hero-card .hd img { width: 30px; height: 30px; border-radius: 8px; }
.hero-card .hd .t { font-weight: 800; font-size: 14px; }
.hero-card .hd .v { margin-left: auto; font-size: 12px; color: var(--muted); }
.hero-card .row {
  display: grid; grid-template-columns: 1fr auto; gap: 8px;
  padding: 9px 10px; border-radius: 10px; font-size: 13.5px;
  background: var(--bg-soft); margin-bottom: 8px;
}
.hero-card .row .name { font-weight: 700; color: var(--ink-2); }
.hero-card .row .tag { font-size: 11.5px; font-weight: 700; padding: 2px 9px; border-radius: 999px; }
.tag-ok { background: #dcfce7; color: #15803d; }
.tag-warn { background: #fef3c7; color: #b45309; }
.hero-card .foot { margin-top: 6px; font-size: 12px; color: var(--muted); text-align: center; }

/* 信任条 */
.trust {
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: #fff;
}
.trust .container { display: flex; gap: 40px; justify-content: center; flex-wrap: wrap; padding: 26px 22px; }
.trust .item { display: flex; align-items: center; gap: 11px; color: var(--ink-2); font-weight: 600; font-size: 15px; }
.trust .item .ic { width: 34px; height: 34px; border-radius: 9px; background: var(--grad-soft); display: grid; place-items: center; font-size: 17px; }

/* ---------- 标题块 ---------- */
.head { text-align: center; max-width: 720px; margin: 0 auto 46px; }
.head .eyebrow { color: var(--primary); font-weight: 800; letter-spacing: 2px; font-size: 13px; text-transform: uppercase; }
.head h2 { font-size: 34px; margin: 12px 0 12px; letter-spacing: -.4px; font-weight: 850; }
.head p { color: var(--muted); font-size: 17px; margin: 0; }

/* ---------- 功能卡片 ---------- */
.grid { display: grid; gap: 22px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 24px;
  box-shadow: var(--shadow-sm);
  transition: transform .18s, box-shadow .18s, border-color .18s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #d4e0f1; }
.card .ic {
  width: 50px; height: 50px; border-radius: 14px;
  background: var(--grad-soft); display: grid; place-items: center;
  font-size: 24px; margin-bottom: 16px;
}
.card h3 { margin: 0 0 8px; font-size: 19px; font-weight: 800; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

/* ---------- 使用场景（交替卡片） ---------- */
.case {
  display: grid; grid-template-columns: 64px 1fr; gap: 18px; align-items: start;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow-sm); transition: transform .18s, box-shadow .18s;
}
.case:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.case .num {
  width: 52px; height: 52px; border-radius: 14px; background: var(--grad); color: #fff;
  display: grid; place-items: center; font-weight: 850; font-size: 20px; box-shadow: 0 8px 18px rgba(37,99,235,.35);
}
.case h3 { margin: 4px 0 6px; font-size: 18px; }
.case p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* ---------- 步骤 ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; counter-reset: s; }
.step { position: relative; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 30px 24px 26px; box-shadow: var(--shadow-sm); }
.step .n {
  position: absolute; top: -18px; left: 24px; width: 40px; height: 40px; border-radius: 12px;
  background: var(--grad); color: #fff; font-weight: 850; display: grid; place-items: center; box-shadow: var(--shadow);
}
.step h3 { margin: 14px 0 8px; font-size: 18px; }
.step p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* ---------- 下载页 ---------- */
.dl-hero { background: var(--grad); color: #fff; }
.dl-hero .container { padding: 70px 22px 64px; text-align: center; }
.dl-hero h1 { font-size: 40px; margin: 0 0 12px; font-weight: 850; letter-spacing: -.5px; }
.dl-hero p { font-size: 18px; opacity: .92; margin: 0 auto; max-width: 620px; }

.dl-card {
  background: #fff; border: 1px solid var(--border); border-radius: 22px; box-shadow: var(--shadow-lg);
  max-width: 760px; margin: -42px auto 0; padding: 34px; position: relative; z-index: 2;
}
.dl-top { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.dl-top img { width: 64px; height: 64px; border-radius: 16px; box-shadow: var(--shadow); }
.dl-top .meta h3 { margin: 0; font-size: 22px; font-weight: 850; }
.dl-top .meta .sub { color: var(--muted); font-size: 14px; margin-top: 3px; }
.dl-ver { margin-left: auto; display: flex; gap: 10px; flex-wrap: wrap; }
.chip { background: var(--primary-50); color: var(--primary-600); font-weight: 800; font-size: 13px; padding: 7px 13px; border-radius: 999px; border: 1px solid #dbeafe; }
.chip.gray { background: var(--bg-soft); color: var(--ink-2); border-color: var(--border); }
.dl-actions { margin-top: 26px; display: flex; gap: 14px; flex-wrap: wrap; }
.dl-actions .btn { flex: 1; min-width: 220px; justify-content: center; padding: 16px 22px; font-size: 16px; }
.btn-download { background: var(--grad); color: #fff; box-shadow: 0 12px 28px rgba(37,99,235,.4); }
.btn-download:hover { transform: translateY(-2px); box-shadow: 0 16px 34px rgba(37,99,235,.5); }
/* 安装版按钮：白底 + 主色描边，与渐变主按钮并列时主次分明 */
.btn-installer { background: #fff; color: var(--primary-600); border-color: #bcd2fb; box-shadow: var(--shadow-sm); }
.btn-installer:hover { transform: translateY(-2px); background: var(--primary-50); border-color: var(--primary); box-shadow: 0 14px 32px rgba(37,99,235,.18); }
.dl-hint { margin: 16px 0 0; font-size: 13.5px; color: var(--muted); text-align: center; line-height: 1.95; }
.dl-hint b { color: var(--ink-2); }
.dl-note { margin-top: 16px; font-size: 13.5px; color: var(--muted); text-align: center; }
.dl-note a { color: var(--primary); font-weight: 700; }

.dl-info { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 44px; }
.dl-info .box { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow-sm); }
.dl-info .box h4 { margin: 0 0 8px; font-size: 15px; color: var(--primary-600); }
.dl-info .box p { margin: 0; color: var(--muted); font-size: 14px; }
.dl-info .box ul { margin: 8px 0 0; padding-left: 18px; color: var(--ink-2); font-size: 14px; }
.dl-info .box li { margin: 3px 0; }

/* FAQ */
.faq { max-width: 820px; margin: 0 auto; }
.faq details { background: #fff; border: 1px solid var(--border); border-radius: 14px; padding: 4px 20px; margin-bottom: 14px; box-shadow: var(--shadow-sm); }
.faq summary { cursor: pointer; font-weight: 700; padding: 16px 0; list-style: none; display: flex; justify-content: space-between; align-items: center; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 22px; color: var(--primary); font-weight: 800; }
.faq details[open] summary::after { content: "−"; }
.faq .ans { padding: 0 0 16px; color: var(--muted); font-size: 15px; }

/* ---------- CTA 区 ---------- */
.cta-band { background: var(--grad); color: #fff; border-radius: 24px; padding: 52px 40px; text-align: center; box-shadow: var(--shadow-lg); }
.cta-band h2 { margin: 0 0 10px; font-size: 30px; font-weight: 850; }
.cta-band p { margin: 0 0 26px; font-size: 17px; opacity: .92; }
.cta-band .btn-white { background: #fff; color: var(--primary-600); font-weight: 800; padding: 14px 30px; border-radius: 12px; box-shadow: var(--shadow); }
.cta-band .btn-white:hover { transform: translateY(-2px); }

/* ---------- 页脚 ---------- */
.footer { background: #0f172a; color: #cbd5e1; }
.footer .container { padding: 54px 22px 30px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 30px; }
.footer .brand { color: #fff; }
.footer .brand small { color: #94a3b8; }
.footer p.desc { color: #94a3b8; font-size: 14px; margin: 14px 0 0; max-width: 320px; }
.footer h5 { color: #fff; font-size: 15px; margin: 0 0 14px; }
.footer ul { list-style: none; padding: 0; margin: 0; }
.footer ul li { margin: 9px 0; font-size: 14px; }
.footer ul li a:hover { color: #fff; }
.footer .bottom { border-top: 1px solid #1e293b; margin-top: 36px; padding-top: 22px; font-size: 13px; color: #64748b; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero .container { grid-template-columns: 1fr; gap: 36px; padding-top: 56px; }
  .hero h1 { font-size: 38px; }
  .hero-card { transform: none; max-width: 480px; }
  .grid-3, .steps { grid-template-columns: repeat(2, 1fr); }
  .dl-info { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .section { padding: 60px 0; }
  .nav-links { display: none; }
  .hero h1 { font-size: 31px; }
  .head h2 { font-size: 27px; }
  .grid-3, .grid-2, .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .dl-hero h1 { font-size: 30px; }
  .cta-band { padding: 38px 22px; }
}