:root{
  --cpp-ink:#0f1b2d;--cpp-ink-2:#334155;--cpp-muted:#64748b;
  --cpp-line:#dfe7ef;--cpp-bg:#f7fafd;--cpp-bg-2:#eef4fa;
  --cpp-card:#ffffff;--cpp-accent:#0369a1;--cpp-accent-2:#0ea5e9;
}
body{font-family:"Hiragino Sans","Noto Sans JP","Yu Gothic",system-ui,-apple-system,sans-serif !important;background:#f7fafd !important;color:var(--cpp-ink) !important;line-height:1.72 !important}
.top-nav{position:sticky;top:0;z-index:50;background:rgba(247,250,253,.92);backdrop-filter:saturate(150%) blur(8px);border-bottom:1px solid var(--cpp-line)}
.top-nav-inner{max-width:1120px;margin:0 auto;padding:12px 20px;display:flex;gap:20px;align-items:center;flex-wrap:wrap;font-size:14px}
.top-nav .brand{font-weight:800;color:var(--cpp-ink);text-decoration:none;letter-spacing:.02em;font-size:15px}
.top-nav .brand em{font-style:normal;color:var(--cpp-accent)}
.top-nav-links{display:flex;gap:16px;margin-left:auto;flex-wrap:wrap;align-items:center}
.top-nav-links a{color:var(--cpp-ink-2);text-decoration:none;font-weight:600}
.top-nav-links a:hover{color:var(--cpp-accent)}
.top-nav-links .div{color:#cbd5e1}
.page-wrap{max-width:920px;margin:0 auto;padding:0 20px}
.crumb{padding:16px 0 8px;font-size:13px;color:var(--cpp-muted)}
.crumb a{color:var(--cpp-accent);text-decoration:none}
.crumb a:hover{text-decoration:underline}
.page-head{padding:24px 0 12px}
.page-head h1{font-size:clamp(26px,3.5vw,34px);font-weight:800;color:var(--cpp-ink);line-height:1.4;letter-spacing:.01em}
.page-head .lead{color:var(--cpp-ink-2);font-size:15.5px;margin-top:10px;line-height:1.8}

/* Intro box */
.intro-box{background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:10px;padding:18px 22px;margin:20px 0}
.intro-box h3{font-size:14px;font-weight:700;color:var(--cpp-ink);margin-bottom:10px;letter-spacing:.02em}
.intro-box ul{font-size:14px;color:var(--cpp-ink-2);line-height:1.9;margin:0;padding-left:22px}
.intro-box code{background:var(--cpp-bg-2);border:1px solid var(--cpp-line);padding:1px 5px;border-radius:4px;font-size:12.5px;color:var(--cpp-ink);font-family:"Consolas","Monaco",monospace}

/* Sticky score bar */
.score-bar{position:sticky;top:53px;z-index:40;background:#fff;border:1px solid var(--cpp-line);border-radius:10px;padding:14px 18px;margin:16px 0;box-shadow:0 2px 10px rgba(15,27,45,.04)}
.score-row{display:flex;align-items:center;gap:14px;font-size:14px;color:var(--cpp-ink-2);flex-wrap:wrap}
.score-row b{color:var(--cpp-ink);font-size:18px}
.score-row .cat-chip{padding:3px 10px;border-radius:999px;background:var(--cpp-bg-2);color:var(--cpp-ink-2);font-size:12px;font-weight:700;border:1px solid var(--cpp-line);cursor:pointer;text-decoration:none}
.score-row .cat-chip:hover{border-color:var(--cpp-accent)}
.score-row .cat-chip.done{background:#ecfdf5;color:#047857;border-color:#bbf7d0}
.score-row .cat-chip.partial{background:#fef3c7;color:#92400e;border-color:#fde68a}
.score-progress{margin-top:10px;height:6px;background:var(--cpp-bg-2);border-radius:3px;overflow:hidden}
.score-fill{height:100%;width:0%;background:linear-gradient(90deg,var(--cpp-accent-2),var(--cpp-accent));transition:width .3s}

/* Category sections */
.cat{background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:12px;padding:22px 26px;margin:18px 0;scroll-margin-top:150px}
.cat-head{display:flex;align-items:center;gap:10px;margin-bottom:16px;border-bottom:1px solid var(--cpp-line);padding-bottom:10px}
.cat-badge{padding:4px 11px;border-radius:4px;font-size:11.5px;font-weight:700;color:#fff;letter-spacing:.04em}
.cat-title{font-size:17px;font-weight:700;color:var(--cpp-ink)}
.cat-counter{margin-left:auto;font-size:12px;color:var(--cpp-muted);font-family:monospace}

/* Question cards */
.q{border:1px solid var(--cpp-line);border-radius:8px;padding:18px 20px;margin:14px 0;background:var(--cpp-bg)}
.q h3{font-size:15.5px;font-weight:700;color:var(--cpp-ink);margin-bottom:12px;line-height:1.6}
.q h3 .num{display:inline-block;margin-right:6px;padding:2px 8px;background:var(--cpp-accent);color:#fff;border-radius:4px;font-size:12px;font-weight:800}
.q .code-snippet{background:#0f172a;color:#cbd5e1;padding:12px 14px;border-radius:6px;font-family:"Consolas","Monaco",monospace;font-size:13px;margin:8px 0;white-space:pre;overflow-x:auto;line-height:1.6}
.q .code-snippet .k{color:#c084fc}
.q .code-snippet .f{color:#60a5fa}
.q .code-snippet .s{color:#86efac}
.q .code-snippet .c{color:#64748b;font-style:italic}
.q .code-snippet .n{color:#fbbf24}
.q .code-snippet .t{color:#22d3ee}
.q .code-snippet .p{color:#f472b6}
.q-opt{display:block;padding:10px 14px;margin:6px 0;border:1px solid var(--cpp-line);border-radius:6px;background:#fff;cursor:pointer;font-size:14.5px;color:var(--cpp-ink-2);transition:.15s;font-family:"Consolas","Monaco",monospace}
.q-opt:hover{border-color:var(--cpp-accent-2);background:#eaf4fb}
.q-opt.ok{border-color:#22a56a;background:#e9f7ef;color:#185a38;font-weight:700}
.q-opt.ng{border-color:#dc2626;background:#fbeaea;color:#8a1a1a}
.q-opt.disabled{pointer-events:none}
.q-ex{display:none;margin-top:10px;padding:12px 14px;background:#fff;border:1px solid var(--cpp-line);border-left:3px solid var(--cpp-accent-2);border-radius:6px;font-size:13.5px;color:var(--cpp-ink-2);line-height:1.8}
.q-ex.show{display:block}

/* Fill-in question */
.q-fill{display:flex;gap:8px;align-items:center;flex-wrap:wrap;font-family:"Consolas","Monaco",monospace;font-size:14px;margin:8px 0;padding:12px 14px;background:#fff;border:1px solid var(--cpp-line);border-radius:6px}
.q-fill input{padding:6px 10px;border:1px solid var(--cpp-line);border-radius:4px;font-family:inherit;font-size:14px;background:#fff;min-width:160px}
.q-fill input:focus{outline:none;border-color:var(--cpp-accent)}
.q-fill input.ok{border-color:#22a56a;background:#e9f7ef}
.q-fill input.ng{border-color:#dc2626;background:#fbeaea}
.q-fill button{padding:7px 14px;border:none;border-radius:6px;background:var(--cpp-accent);color:#fff;font-family:inherit;font-size:13px;font-weight:700;cursor:pointer}
.q-fill button:hover{background:#075985}

/* Trace/output question */
.q-trace{background:#fff;border:1px solid var(--cpp-line);border-radius:6px;padding:10px 14px;margin:8px 0;font-family:monospace;font-size:13.5px}
.q-trace input{padding:6px 10px;border:1px solid var(--cpp-line);border-radius:4px;font-family:inherit;font-size:14px;background:#fff;width:200px}

/* Result screen */
.result{display:none;margin:32px 0;padding:32px;text-align:center;background:var(--cpp-card);border:2px solid var(--cpp-accent);border-radius:12px}
.result.show{display:block}
.result h2{font-size:22px;font-weight:800;color:var(--cpp-ink);margin-bottom:14px}
.result-score{font-size:54px;font-weight:800;color:var(--cpp-accent);font-family:"Consolas","Monaco",monospace;margin:12px 0}
.result-comment{font-size:15px;color:var(--cpp-ink-2);margin-bottom:16px;line-height:1.8}
.result-breakdown{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:10px;margin:20px 0;max-width:680px;margin-left:auto;margin-right:auto}
.result-cat{background:var(--cpp-bg);border:1px solid var(--cpp-line);border-radius:8px;padding:12px}
.result-cat .n{font-size:12px;color:var(--cpp-muted);font-weight:700;letter-spacing:.04em;text-transform:uppercase}
.result-cat .v{font-size:20px;font-weight:800;color:var(--cpp-ink);margin-top:4px;font-family:monospace}
.result-retry{display:inline-block;margin-top:10px;padding:10px 22px;background:var(--cpp-accent);color:#fff;border-radius:6px;text-decoration:none;font-weight:700;border:none;cursor:pointer;font-size:14px}
.result-retry:hover{background:#075985}

.related{margin:32px 0 10px}
.related h2{font-size:18px;font-weight:700;color:var(--cpp-ink);margin-bottom:12px;border-left:3px solid var(--cpp-accent);padding-left:12px}
.rel-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:10px}
.rel-card{display:block;background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:8px;padding:14px 16px;text-decoration:none;color:inherit;transition:.15s}
.rel-card:hover{border-color:var(--cpp-accent);background:var(--cpp-bg-2)}
.rel-card .k{font-size:11px;color:var(--cpp-muted);font-weight:700;letter-spacing:.06em}
.rel-card .t{font-size:14.5px;font-weight:700;color:var(--cpp-ink);margin-top:3px}
.rel-card .d{font-size:13px;color:var(--cpp-ink-2);margin-top:4px;line-height:1.6}
.pager{margin:20px 0;display:flex;gap:12px;flex-wrap:wrap}
.pager a{flex:1;min-width:220px;display:block;background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:8px;padding:16px 18px;text-decoration:none;color:inherit;transition:.15s}
.pager a:hover{border-color:var(--cpp-accent);background:var(--cpp-bg-2)}
.pager a.next{text-align:right;background:var(--cpp-bg-2)}
.pager a .k{font-size:11px;color:var(--cpp-muted)}
.pager a .t{font-size:14.5px;font-weight:700;color:var(--cpp-ink);margin-top:4px}
.page-footer{max-width:1120px;margin:30px auto 0;padding:20px;color:var(--cpp-muted);font-size:13px;border-top:1px solid var(--cpp-line);display:flex;gap:16px;justify-content:space-between;align-items:center;flex-wrap:wrap}
.page-footer nav{display:flex;gap:16px;flex-wrap:wrap}
.page-footer a{color:var(--cpp-ink-2);text-decoration:none}
.page-footer a:hover{color:var(--cpp-accent)}