/* Use-case pages (/use, /zh/use). Same palette as the app (style.css), standalone so these pages stay light. */
:root {
  --bg: #FFF4E3; --panel: #FFFFFF; --panel-2: #F5F1E8; --ink: #16171C; --muted: #5B5D66;
  --pink: #FF5C8A; --yellow: #FFD23F; --radius: 16px; --bw: 3px;
  --font-display: "Space Grotesk", -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font-family: var(--font-body); line-height: 1.6; }
a { color: var(--ink); }
.u-nav { max-width: 920px; margin: 0 auto; padding: 18px 16px; display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; }
.u-logo { font-family: var(--font-display); font-weight: 800; font-size: 20px; text-decoration: none; }
.u-nav nav { font-weight: 700; font-size: 14px; }
.u-main { max-width: 920px; margin: 0 auto; padding: 8px 16px 48px; }
h1 { font-family: var(--font-display); font-size: clamp(28px, 6vw, 44px); line-height: 1.15; margin: 16px 0 12px; }
h2 { font-family: var(--font-display); font-size: 22px; margin: 36px 0 10px; }
.u-sub { font-size: 18px; color: var(--muted); max-width: 720px; margin: 0 0 20px; }
.u-ctas { display: flex; gap: 12px; flex-wrap: wrap; margin: 20px 0; }
.u-btn { display: inline-block; background: var(--pink); color: #fff; text-decoration: none; font-weight: 800; padding: 12px 20px;
  border: var(--bw) solid var(--ink); border-radius: 12px; box-shadow: 4px 4px 0 var(--ink); }
.u-btn2 { background: var(--panel); color: var(--ink); }
.u-shot { margin: 24px 0; }
.u-shot img { display: block; width: 100%; height: auto; border: var(--bw) solid var(--ink); border-radius: var(--radius); box-shadow: 6px 6px 0 var(--ink); background: var(--panel); }
.u-shot-phone img { max-width: 360px; }
.u-shot figcaption { font-size: 14px; color: var(--muted); margin-top: 10px; }
.u-steps, .u-get, .u-isnt, .u-limits ul, .u-more ul { padding-left: 1.3em; }
.u-steps li, .u-get li, .u-isnt li, .u-limits li { margin: 6px 0; }
.u-limits { background: var(--panel); border: var(--bw) solid var(--ink); border-radius: var(--radius); padding: 4px 20px 12px; margin-top: 32px; }
.u-faq details { background: var(--panel); border: 2px solid var(--ink); border-radius: 12px; padding: 12px 16px; margin: 10px 0; }
.u-faq summary { font-weight: 800; cursor: pointer; }
.u-faq p { margin: 8px 0 0; }
.u-bottom { text-align: center; margin-top: 48px; }
.u-bottom .u-ctas { justify-content: center; }
.u-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; margin: 28px 0; }
.u-card { display: block; text-decoration: none; background: var(--panel); border: var(--bw) solid var(--ink); border-radius: var(--radius); box-shadow: 4px 4px 0 var(--ink); padding: 16px 18px; }
.u-card h2 { font-size: 18px; margin: 0 0 8px; }
.u-card p { margin: 0; color: var(--muted); font-size: 15px; }
.u-embed { background: var(--yellow); border: var(--bw) solid var(--ink); border-radius: var(--radius); padding: 8px 20px 20px; margin-top: 40px; }
.u-more { margin-top: 40px; }
.u-foot { margin-top: 40px; font-size: 14px; color: var(--muted); text-align: center; }