/*
 * 家庭助理简洁下载页样式：参考用户提供的单卡片布局，以浅灰蓝背景和蓝色下载按钮为主。
 * PC 限制卡片宽度并居中，手机缩小边距；不依赖外部字体、JavaScript 或组件库。
 */
:root {
  color-scheme: light;
  --ink: #172033;
  --muted: #667085;
  --line: #e8ecf2;
  --blue: #2563eb;
  --page: #f5f7fb;
}

/* min-height 而非固定高度，使短屏和横屏也能自然滚动到安装说明。 */
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 32px 20px;
  background:
    radial-gradient(ellipse at 12% 8%, rgba(59, 130, 246, .08), transparent 38%),
    radial-gradient(ellipse at 90% 92%, rgba(99, 102, 241, .05), transparent 36%),
    var(--page);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; -webkit-tap-highlight-color: transparent; }
img, svg { display: block; }
::selection { background: #dbeafe; }
.page { width: 100%; max-width: 500px; }

/* 键盘用户可直接跳至主内容；焦点不会因为卡片圆角被裁切。 */
.skip-link {
  position: absolute;
  top: -70px;
  left: 16px;
  z-index: 1;
  padding: 11px 15px;
  border-radius: 8px;
  background: var(--blue);
  color: white;
}
.skip-link:focus { top: 12px; }
.brandline {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  margin-bottom: 19px;
  color: #667085;
  font-size: 13px;
  font-weight: 550;
  letter-spacing: .7px;
}
.brandmark {
  display: grid;
  place-items: center;
  width: 27px;
  height: 27px;
  border-radius: 8px;
  background: var(--blue);
  color: white;
}
.download-card {
  border: 1px solid #e4e9f1;
  border-radius: 22px;
  background: white;
  box-shadow: 0 16px 50px rgba(16, 24, 40, .065);
}

/* 所有应用信息为真实文本，复制或关闭样式后仍按正常阅读顺序呈现。 */
.app-intro { padding: 33px 30px 25px; text-align: center; }
.app-icon {
  display: grid;
  place-items: center;
  width: 78px;
  height: 78px;
  margin: 0 auto 20px;
  border: 1px solid #dceaff;
  border-radius: 22px;
  background: #eff6ff;
}
h1 { margin: 0; font-size: 28px; line-height: 1.4; font-weight: 650; letter-spacing: -.8px; }
h1 span { display: inline-block; margin-left: 5px; color: #8a94a5; font-size: 19px; font-weight: 450; letter-spacing: -.5px; }
.app-description { margin: 11px 0 0; color: var(--muted); font-size: 13px; line-height: 1.8; }
.app-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}
.app-meta li {
  padding: 6px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fbfcfe;
  color: #667085;
  font-size: 11px;
  line-height: 1.5;
}

/* 下载使用原生链接，即使没有脚本也能请求同一份已存在的安装包。 */
.download-area { padding: 0 30px 27px; }
.download-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 53px;
  padding: 13px 15px;
  border-radius: 12px;
  background: var(--blue);
  box-shadow: 0 6px 15px rgba(37, 99, 235, .17);
  color: white;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.6;
  text-decoration: none;
  touch-action: manipulation;
  transition: background .15s ease, transform .15s ease;
}
.download-button:hover { transform: translateY(-1px); background: #1d4ed8; }
.download-button:focus-visible { outline: 3px solid #93c5fd; outline-offset: 4px; }
.download-button svg { flex-shrink: 0; }
.download-note { margin: 12px 0 0; color: #929bab; text-align: center; font-size: 11px; line-height: 1.7; }
.download-note span { padding: 0 5px; color: #c0c7d2; }

/* 安装说明控制为三步；编号不重复进入读屏文本，由有序列表提供步骤语义。 */
.installation { border-top: 1px solid var(--line); padding: 23px 30px 26px; }
.installation h2 { margin: 0 0 16px; color: #344054; font-size: 14px; font-weight: 600; }
.install-steps { display: grid; gap: 13px; margin: 0; padding: 0; list-style: none; }
.install-steps li { display: flex; align-items: flex-start; gap: 11px; color: #667085; font-size: 12px; line-height: 1.85; }
.step-number { flex: 0 0 22px; display: grid; place-items: center; height: 22px; border-radius: 50%; background: #eff6ff; color: var(--blue); font-size: 11px; font-weight: 600; }
.desktop-note { margin: 19px 0 0; padding: 11px 12px; border-radius: 9px; background: #f8fafc; color: #8b95a5; font-size: 11px; line-height: 1.8; }
footer { padding-top: 19px; color: #98a2b3; text-align: center; font-size: 11px; line-height: 1.7; }

/* 小屏只缩小留白，保持按钮和正文尺寸；元信息可自行换行。 */
@media (max-width: 420px) {
  body { padding: 23px 13px; }
  .brandline { margin-bottom: 17px; font-size: 12px; }
  .download-card { border-radius: 19px; }
  .app-intro { padding: 28px 21px 23px; }
  .app-icon { width: 72px; height: 72px; margin-bottom: 18px; border-radius: 20px; }
  h1 { font-size: 26px; }
  h1 span { font-size: 18px; }
  .app-description { font-size: 12px; }
  .app-meta { gap: 7px; margin-top: 19px; }
  .app-meta li { padding: 6px 9px; }
  .download-area { padding: 0 21px 24px; }
  .download-button { font-size: 14px; }
  .download-note { font-size: 10px; }
  .installation { padding: 21px 21px 24px; }
}

/* 遵循减少动态效果的系统设置，不通过按钮移动反馈悬停。 */
@media (prefers-reduced-motion: reduce) {
  .download-button { transition: none; }
  .download-button:hover { transform: none; }
}