:root {
  --bg: #0f172a;
  --card: #1e293b;
  --accent: #38bdf8;
  --ok: #4ade80;
  --text: #e2e8f0;
  --muted: #94a3b8;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #0f172a, #1e1b4b);
  color: var(--text);
  min-height: 100vh;
  padding: 40px 20px;
}
.container { max-width: 900px; margin: 0 auto; }
h1 { text-align: center; font-size: 2rem; margin-bottom: 8px; }
.subtitle { text-align: center; color: var(--muted); margin-bottom: 32px; font-size: .95rem; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; margin-bottom: 32px; }
.card {
  background: var(--card);
  border: 1px solid #334155;
  border-radius: 14px;
  padding: 24px;
  transition: transform .15s ease, border-color .15s ease;
}
.card:hover { transform: translateY(-4px); border-color: var(--accent); }
.card h2 { font-size: 1.2rem; margin-bottom: 12px; }
.card p { color: var(--muted); font-size: .9rem; margin-bottom: 16px; line-height: 1.5; }
.btn {
  display: inline-block;
  background: var(--accent);
  color: #0f172a;
  font-weight: 600;
  border: none;
  padding: 10px 18px;
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  font-size: .9rem;
}
.btn:hover { filter: brightness(1.1); }
.btn.block { width: 100%; text-align: center; }
.btn.outline { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.result {
  margin-top: 16px;
  padding: 12px;
  background: #0f172a;
  border-radius: 8px;
  font-family: ui-monospace, Menlo, Consolas, monospace;
  font-size: .85rem;
  min-height: 40px;
  color: var(--ok);
}
.speed-big { font-size: 1.6rem; font-weight: 700; color: var(--ok); }
.meta { color: var(--muted); font-size: .78rem; margin-top: 4px; }
video { width: 100%; border-radius: 10px; background: #000; }
.file-list { background: var(--card); border: 1px solid #334155; border-radius: 14px; padding: 24px; }
.file-item { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; border-bottom: 1px solid #334155; }
.file-item:last-child { border-bottom: none; }
.file-name { font-weight: 600; }
.file-size { color: var(--muted); font-size: .85rem; }
footer { text-align: center; color: var(--muted); font-size: .8rem; margin-top: 24px; }