:root{
  --bg: #0b1220;
  --fg: #e8eef9;
  --muted: #9fb0d0;
  --card: #121a2b;
  --accent: #4ea1ff;
  --border: #203056;
  --cyan: #00ffff;
}
*{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,Ubuntu,Cantarell,"Noto Sans",sans-serif}
.container{max-width:1100px;margin:0 auto;padding:16px}
.topbar{border-bottom:1px solid var(--border);background:rgba(0,0,0,.2);backdrop-filter: blur(6px);position:sticky;top:0;z-index:10}
.topbar h1{margin:0;font-weight:800;letter-spacing:.5px}
.topbar nav a{color:var(--muted);text-decoration:none;margin-left:16px}
.topbar nav a.active,.topbar nav a:hover{color:var(--fg)}
.footer{border-top:1px solid var(--border);color:var(--muted)}
.card{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:16px;box-shadow:0 6px 24px rgba(0,0,0,.25)}
.toolbar{display:flex;gap:12px;align-items:center}
.toolbar input, .toolbar select{background:#0f172a;border:1px solid var(--border);border-radius:10px;color:var(--fg);padding:10px 12px;outline:none}

.problems{width:100%;border-collapse:collapse}
.problems thead th{color:var(--muted);font-weight:600;text-align:left;padding:10px}
.problems tbody td{border-top:1px solid var(--border);padding:10px}
.problems .id{font-weight:700;color:var(--accent)}
.tag{display:inline-block;border:1px solid var(--border);border-radius:999px;padding:2px 10px;margin-right:8px;margin-bottom:6px;color:#cfe0ff;background:rgba(78,161,255,.06)}
.tags{margin:6px 0}
.empty{color:var(--muted);text-align:center;padding:16px}

.markdown-body pre code{display:block;overflow:auto;padding:12px;border-radius:10px;border:1px solid var(--border);background:#0a1323}
.markdown-body h1,.markdown-body h2,.markdown-body h3{border-bottom:1px dashed var(--border);padding-bottom:4px}
.markdown-body a{color:#00ffff}

section.card table.problems a:link,
        section.card table.problems a:visited {
            color: var(--cyan);
            text-decoration: none;
        }
        
        section.card table.problems a:hover,
        section.card table.problems a:active {
            color: #7fffd4;
            text-decoration: underline;
        }