/* ==================== 基础设置：颜色、字体、页面宽度 ==================== */
@font-face { font-family: Outfit; src: url('fonts/outfit/Outfit-Regular.ttf') format('truetype'); font-display: swap; }
:root {
  --blue: #007aff;
  --text: #333;
  --muted: #8b9096;
  --page-width: 1168px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--text); font: 16px/1.6 Outfit, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif; background: #fff; }
a { color: inherit; text-decoration: none; }
a:hover { color: var(--blue); }
button, summary, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
img { max-width: 100%; vertical-align: middle; }
p, h1, h2 { margin: 0; }
button, summary { cursor: pointer; }
summary { list-style: none; }
summary::-webkit-details-marker { display: none; }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 2px solid var(--blue); outline-offset: 5px; }
.page-width { max-width: var(--page-width); margin: 0 auto; padding: 0 24px; }

/* ==================== 顶部导航 ==================== */
.site-header { height: 100px; background: #fff; }
.navbar { display: flex; align-items: center; height: 100%; gap: 60px; }
.brand { width: 130px; }
.site-nav { display: flex; align-items: center; justify-content: space-between; flex: 1; }
.nav-group { display: flex; align-items: center; gap: 32px; }
.primary-button { display: inline-block; padding: 9px 24px; border-radius: 8px; color: #fff; background: var(--blue); }
.primary-button:hover { color: #fff; background: #0066dc; }
.nav-dropdown { position: relative; }
.nav-dropdown summary::after { content: ''; display: inline-block; width: 6px; height: 6px; margin: 0 0 3px 8px; border: solid currentColor; border-width: 0 1px 1px 0; transform: rotate(45deg); }
.dropdown-panel { position: absolute; left: -20px; top: 35px; z-index: 5; min-width: 180px; padding: 12px 20px; background: #fff; border-radius: 10px; box-shadow: 0 4px 24px #0002; }
.dropdown-panel a { display: block; padding: 8px 0; white-space: nowrap; }
.menu-toggle { display: none; border: 0; padding: 6px; background: none; }
.menu-toggle img { width: 24px; height: 24px; }

/* ==================== 下载区域：改间距、尺寸可从这里开始 ==================== */
.download-section { text-align: center; padding: 70px 24px 80px; }
.app-logo { width: 90px; height: 90px; }
h1 { font-size: 28px; line-height: 1.4; font-weight: 400; margin-top: 14px; }
.tagline { color: var(--muted); margin: 14px auto 26px; }
.download-buttons { display: flex; gap: 6px; align-items: center; justify-content: center; }
.download-button img { display: block; height: 42px; width: auto; }
.qr-download { position: relative; }
.qr-download summary img { width: 42px; height: 42px; }
.qr-panel { position: absolute; top: 50px; left: 50%; transform: translateX(-50%); z-index: 4; width: 210px; background: #fff; border: 1px solid #eee; padding: 14px; border-radius: 8px; box-shadow: 0 4px 20px #0002; }
.qr-panel span { display: block; color: var(--muted); font-size: 14px; }
.security-card { text-align: left; width: 452px; max-width: 100%; margin: 38px auto 0; font-size: 12px; }
.security-notice { position: relative; background: #fffaee; border: 1px solid #f4e7c7; padding: 20px 16px; border-radius: 16px; }
.guard { position: absolute; width: 76px; right: -6px; top: -26px; }
.bullet { position: relative; padding-left: 8px; margin: 3px 0; }
.bullet::before { content: '•'; position: absolute; left: 0; }
.official-domain { display: block; height: 34px; margin: 8px 0 10px 20px; }
.security-notice hr { border: 0; height: 1px; background: #eee3c7; margin: 12px 0; }
.scam-link { color: #d28d28; }
.scam-link img, .learn-more img { width: 12px; }
.checksum { background: #f8f8f8; border-radius: 0 0 16px 16px; }
.checksum summary { padding: 14px 16px; }
.checksum summary img { width: 12px; margin-left: 6px; transition: transform .2s; }
.checksum[open] summary img { transform: rotate(180deg); }
.checksum-content { padding: 0 16px 20px; color: #737880; }
.checksum-content h2 { font-size: 12px; font-weight: 500; margin-top: 14px; color: var(--text); }
.checksum-hash { overflow-wrap: anywhere; }
.learn-more { display: inline-block; margin-top: 14px; color: var(--blue); }

/* ==================== 功能介绍 ==================== */
.features { background: #f3f7fa; padding: 60px 0; }
.feature-grid { display: grid; grid-template-columns: 1fr 1fr; max-width: 900px; gap: 80px; }
.feature { text-align: center; }
.feature > img { width: 52px; height: 52px; margin-bottom: 20px; }
.feature h2 { font-size: 24px; font-weight: 400; margin-bottom: 8px; }
.feature p { color: var(--muted); font-size: 16px; }

/* ==================== 页脚 ==================== */
.site-footer { padding-top: 60px; padding-bottom: 30px; }
.footer-links { display: grid; grid-template-columns: repeat(5, 1fr); gap: 32px; }
.footer-links h2 { font-size: 16px; margin-bottom: 16px; font-weight: 500; }
.footer-links a { display: block; margin: 10px 0; color: #777a80; font-size: 14px; }
.footer-links a:hover { color: var(--blue); }
.footer-bottom { display: flex; justify-content: space-between; align-items: flex-end; gap: 30px; margin-top: 45px; }
.social-links { display: flex; gap: 22px; margin-bottom: 22px; }
.social-links img { width: 24px; height: 24px; }
.legal { display: flex; gap: 18px; align-items: center; color: var(--muted); font-size: 12px; flex-wrap: wrap; }
.language img { width: 16px; margin-right: 6px; }
.newsletter { min-width: 220px; font-size: 14px; }
.newsletter > a { display: block; padding: 12px 14px; border: 1px solid #e5e5e5; border-radius: 6px; }
.newsletter span { float: right; color: var(--blue); }
.newsletter p { font-size: 12px; margin-top: 8px; color: var(--muted); }
.disclaimer { margin-top: 28px; font-size: 12px; color: #aaa; line-height: 1.7; }
.back-to-top { display: none; }

/* ==================== 移动端适配 ==================== */
@media (max-width: 768px) {
  .page-width { padding-left: 16px; padding-right: 16px; }
  .site-header { height: 80px; }
  .navbar { justify-content: space-between; gap: 0; }
  .brand { width: 108px; }
  .menu-toggle { display: block; }
  .site-nav { display: none; position: absolute; inset: 80px 0 auto; z-index: 10; padding: 22px; background: #fff; border-top: 1px solid #eee; box-shadow: 0 14px 20px #0001; max-height: calc(100dvh - 80px); overflow: auto; }
  .site-nav.is-open { display: block; }
  .nav-group { align-items: stretch; flex-direction: column; gap: 0; }
  .nav-group > a, .nav-dropdown summary { display: block; padding: 12px 0; }
  .nav-group .primary-button { margin-top: 14px; text-align: center; padding: 10px; }
  .dropdown-panel { position: static; padding: 0 16px 10px; box-shadow: none; background: #f8f9fb; }
  .download-section { padding: 64px 16px 58px; }
  .app-logo { width: 70px; height: 70px; }
  h1 { font-size: 22px; margin-top: 10px; }
  .tagline { max-width: 430px; font-size: 16px; line-height: 1.7; margin: 12px auto 14px; }
  .download-buttons { flex-direction: column; gap: 12px; }
  .download-button img { height: 44px; }
  .qr-download { display: none; }
  /* 真机按系统显示对应按钮；桌面窄窗口保留所有下载方式，方便预览。 */
  html[data-device="ios"] .android-download { display: none; }
  html[data-device="android"] .ios-download { display: none; }
  .security-card { margin-top: 34px; width: 452px; }
  .security-notice { padding: 16px 12px; }
  .guard { display: none; }
  .official-domain { max-width: calc(100% - 20px); height: auto; max-height: 34px; }
  .security-notice hr { display: none; }
  .security-notice .bullet:first-of-type { margin-bottom: 7px; }
  .security-notice .official-domain { margin-bottom: 18px; }
  .checksum summary { padding: 14px 12px; }
  .features { padding: 0; }
  .feature-grid { display: block; padding: 0 16px; }
  .feature { display: flex; gap: 16px; align-items: flex-start; text-align: left; padding: 26px 0; }
  .feature > img { width: 36px; height: 36px; flex-shrink: 0; margin: 0; }
  .feature h2 { font-size: 18px; margin-bottom: 6px; }
  .feature p { font-size: 14px; line-height: 1.7; }
  .feature + .feature { border-top: 1px solid #e8edf0; }
  .site-footer { text-align: center; padding-top: 30px; }
  .footer-links, .social-links, .newsletter, .language { display: none; }
  .footer-bottom { display: block; margin: 0; }
  .legal { display: flex; align-items: center; flex-direction: column; gap: 8px; font-size: 12px; }
  .disclaimer { text-align: left; font-size: 11px; margin-top: 22px; }
  .back-to-top { display: inline-block; margin-top: 18px; }
  .back-to-top img { width: 28px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }