:root{
  --ink:#1a1a1a; --muted:#6b7280; --line:#e5e7eb; --accent:#1d4ed8;
  --ok-bg:#dcfce7; --ok-fg:#166534; --warn-bg:#fef9c3; --warn-fg:#854d0e;
  --pending-bg:#f3f4f6; --pending-fg:#6b7280; --paper:#fcfcfc;
}
*{box-sizing:border-box}
body{
  font-family:Georgia,"Latin Modern Roman","Times New Roman",serif;
  color:var(--ink); background:var(--paper); line-height:1.6;
  margin:0; padding:0;
}
main{max-width:820px; margin:0 auto; padding:2rem 1.25rem 4rem}
.topbar{
  display:flex; justify-content:space-between; align-items:center; gap:1rem;
  max-width:820px; margin:0 auto; padding:1rem 1.25rem; border-bottom:1px solid var(--line);
  font-family:-apple-system,system-ui,sans-serif; font-size:.9rem;
}
.topbar a{color:var(--accent); text-decoration:none}
.topbar a:hover{text-decoration:underline}
.topbar .pdf{font-weight:600}
h1.exam-title,h1{font-size:1.8rem; line-height:1.2; margin:.2rem 0 .4rem}
.meta,.lead,.progress{color:var(--muted); font-family:-apple-system,system-ui,sans-serif; font-size:.92rem}
.lead{font-size:1rem; max-width:60ch}
.progress{font-weight:600; color:var(--ink)}
h2{font-size:1.3rem; margin-top:2rem; border-bottom:2px solid var(--line); padding-bottom:.3rem}
h3{font-size:1.08rem; margin-top:1.6rem}
.solution p{margin:.7rem 0}
.badge{
  display:inline-block; font-family:-apple-system,system-ui,sans-serif;
  font-size:.78rem; font-weight:600; padding:.12rem .5rem; border-radius:999px;
}
.badge.ok{background:var(--ok-bg); color:var(--ok-fg)}
.badge.warn{background:var(--warn-bg); color:var(--warn-fg)}
.badge.pending{background:var(--pending-bg); color:var(--pending-fg)}
.muted{color:var(--muted)}
table{width:100%; border-collapse:collapse; margin:.6rem 0 1rem; font-family:-apple-system,system-ui,sans-serif; font-size:.95rem}
th,td{text-align:left; padding:.5rem .4rem; border-bottom:1px solid var(--line)}
th{font-size:.8rem; text-transform:uppercase; letter-spacing:.03em; color:var(--muted)}
td a{color:var(--accent); text-decoration:none}
td a:hover{text-decoration:underline}
pre{background:#f6f8fa; border:1px solid var(--line); border-radius:6px; padding:.8rem 1rem; overflow-x:auto; font-size:.88rem}
code{font-family:"SF Mono",Menlo,Consolas,monospace}
blockquote{border-left:3px solid var(--line); margin:1rem 0; padding:.3rem 1rem; color:var(--muted); background:#fafafa}
hr{border:none; border-top:1px solid var(--line); margin:2rem 0}
.pagefoot{font-family:-apple-system,system-ui,sans-serif; font-size:.85rem; color:var(--muted)}
.pagefoot a{color:var(--accent); text-decoration:none}
.katex-display{overflow-x:auto; overflow-y:hidden; padding:.2rem 0}