:root { --bg:#0b0f14; --fg:#e8eef5; --muted:#a9b4c3; --card:#121822; --acc:#3b82f6; --border:#243041; }
*{ box-sizing:border-box; }
html,body{ margin:0; padding:0; background:var(--bg); color:var(--fg); font:16px/1.6 system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial; }
a{ color:var(--acc); text-decoration:none; }
a:hover{ text-decoration:underline; }

.container{ max-width:880px; margin:0 auto; padding:24px; }
header h1{ margin:0 0 6px; }
.actions{ display:flex; gap:12px; margin-top:8px; flex-wrap:wrap; }

.card{ background:var(--card); border:1px solid var(--border); border-radius:16px; padding:24px; }
.center{ text-align:center; }
.footnote{ color:var(--muted); text-align:center; }

.btn{ display:inline-block; padding:10px 16px; background:var(--acc); color:#fff; border-radius:12px; font-weight:600; }
.btn:hover{ filter:brightness(1.05); }
.btn-secondary{ background:transparent; color:var(--fg); border:1px solid var(--border); }
.btn-secondary:hover{ background:#162032; }

.block{ margin:16px 0; background:var(--card); border:1px solid var(--border); border-radius:14px; overflow:hidden; }
.block > summary{
  cursor:pointer; padding:16px 18px; font-weight:700; position:relative; list-style:none;
}
.block > summary::-webkit-details-marker{ display:none; }
.block[open] > summary{ border-bottom:1px solid var(--border); }
.block .content{ padding:16px 18px; }
h4{ margin:10px 0 6px; }
ul{ margin:6px 0 10px 18px; }
