:root {
  --red: #e51b23;
  --ink: #1c1c1c;
  --muted: #5c5c5c;
  --line: #e6e2de;
  --paper: #f7f5f3;
  --card: #fff;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font: 16px/1.5 "PingFang SC", "Noto Sans SC", "Segoe UI", sans-serif;
}
a { color: var(--red); }
.wrap { max-width: 880px; margin: 0 auto; padding: 32px 20px 80px; }
.mark {
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--red);
  display: inline-block; vertical-align: -6px; margin-right: 8px;
}
header.top { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 28px; }
header.top nav { display: flex; gap: 14px; font-size: 14px; }
header.top nav a { color: var(--muted); text-decoration: none; }
header.top nav a:hover { color: var(--ink); }
h1 { font-size: 28px; font-weight: 650; letter-spacing: -0.02em; margin: 0 0 8px; }
.lead { color: var(--muted); margin: 0 0 28px; }
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 680px) { .grid { grid-template-columns: 1fr; } }
.card {
  display: block; background: var(--card); border: 1px solid var(--line);
  border-radius: 14px; padding: 18px 18px 16px; text-decoration: none; color: inherit;
}
.card:hover { border-color: #c8c2bc; }
.card strong { display: block; margin-bottom: 4px; }
.card span { color: var(--muted); font-size: 14px; }
.note { margin-top: 22px; color: var(--muted); font-size: 14px; }
.panel {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  min-height: 280px; padding: 28px;
}
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
button, .btn {
  appearance: none; border: 0; cursor: pointer;
  background: var(--red); color: #fff; border-radius: 999px;
  padding: 12px 18px; font: inherit;
}
button.ghost, .btn.ghost { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.status { margin-top: 14px; color: var(--muted); font-size: 14px; }
.frame-shell {
  background: #fff; border: 1px solid var(--line); border-radius: 16px;
  overflow: hidden; height: 640px;
}
.frame-shell iframe { width: 100%; height: 100%; border: 0; }
body.dark { background: #161616; color: #f3f3f3; }
body.dark .lead, body.dark .note, body.dark .status, body.dark header.top nav a { color: #b5b5b5; }
body.dark .panel, body.dark .card, body.dark .frame-shell { background: #222; border-color: #333; color: #f3f3f3; }