:root {
  --bg: #8ccff5;
  --card-bg: #ffffff;
  --muted: #5f6a74;
  --link: #2c92c3;
  --mobile-width: 420px;
  --feed-left-gap: 10px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", "Helvetica Neue", sans-serif;
  background: #fff;
  color: #111;
}
.app-shell {
  width: 100%;
  max-width: var(--mobile-width);
  margin: 0 auto;
  min-height: 100vh;
  padding-bottom: calc(84px + env(safe-area-inset-bottom));
  background: radial-gradient(circle at 10% 15%, #bde4fb 0, #bde4fb 20%, transparent 20%) 0 0/36px 36px,
              radial-gradient(circle at 80% 70%, #bde4fb 0, #bde4fb 18%, transparent 18%) 0 0/48px 48px,
              var(--bg);
}
.topbar { background: #f8f8f8; border-bottom: 1px solid #ddd; position: sticky; top: 0; z-index: 4; }
.topbar-row { display: flex; align-items: center; justify-content: space-between; padding: 10px 12px; }
.icon-btn { border: 0; background: transparent; font-size: 26px; cursor: default; }
.channel { display: flex; align-items: center; gap: 10px; flex: 1; margin: 0 10px; }
.avatar { width: 42px; height: 42px; border-radius: 50%; background: #d6d6d6; display: grid; place-items: center; font-weight: 600; }
.channel-title { font-size: 18px; font-weight: 600; }
.channel-sub { color: #777; font-size: 13px; }
.pinned { background: #fff; padding: 8px 14px 10px; }
.pinned-label { color: #2f8ebb; font-size: 16px; margin-bottom: 2px; }
.pinned-text { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 18px; }
.feed { padding: 10px 0 0 var(--feed-left-gap); }
.post-card {
  background: var(--card-bg);
  border-radius: 20px;
  padding: 8px 12px 10px;
  margin-bottom: 12px;
  margin-right: calc(25% + var(--feed-left-gap));
  box-shadow: 0 1px 0 rgba(0,0,0,.1);
}
.post-card-zero { margin-top: 2px; }
.post-chip { width: max-content; margin: 0 auto 8px; background: #8fcbe9; color: #fff; border-radius: 16px; padding: 2px 14px; font-size: 20px; }
.post-images { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2px; margin: 0 -12px 8px; }
.post-image { width: 100%; aspect-ratio: 1 / 1; object-fit: cover; background: #e3e3e3; }
.post-title { margin: 4px 0 10px; font-size: 24px; font-weight: 500; }
.post-line { margin: 0 0 10px; font-size: 21px; line-height: 1.22; }
.post-link { display: inline-block; color: var(--link); text-decoration: underline; font-size: 20px; margin: 2px 0 10px; }
.post-body { font-size: 21px; line-height: 1.22; }
.post-body a { color: var(--link); text-decoration: underline; }
.post-muted { color: var(--muted); font-size: 16px; margin: 0 0 8px; }
.post-zero { margin: 0 0 10px; font-size: 22px; line-height: 1.3; }
.post-meta { color: #778; font-size: 18px; display: flex; justify-content: flex-end; gap: 6px; }
.cta-wrap {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 8px 12px calc(8px + env(safe-area-inset-bottom));
  background: #f8f8f8;
  border-top: 1px solid #d9d9d9;
  z-index: 5;
}
.cta-btn {
  width: min(var(--mobile-width), 100%);
  display: block;
  margin: 0 auto;
  border: 0;
  background: #f8f8f8;
  color: #2f8ebb;
  text-decoration: underline;
  font-size: 40px;
  line-height: 1;
  padding: 10px 0;
}
@media (max-width: 420px) {
  .app-shell { max-width: 100%; }
  .post-card { margin-right: calc(25% + var(--feed-left-gap)); }
  .post-title { font-size: 20px; }
  .post-line, .post-link, .post-zero { font-size: 17px; }
  .post-meta { font-size: 15px; }
  .cta-btn { font-size: 34px; }
}