: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 (shared) */
.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}

.learn-box{background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:10px;padding:20px 22px;margin:20px 0}
.learn-box .ttl{font-size:14px;font-weight:700;color:var(--cpp-ink);margin-bottom:14px;letter-spacing:.02em}
.learn-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media(max-width:720px){.learn-grid{grid-template-columns:1fr}}
.learn-col{background:#fff;border:1px solid var(--cpp-line);border-radius:8px;padding:14px 16px}
.learn-col .hd{font-size:12.5px;font-weight:700;margin-bottom:8px;letter-spacing:.04em}
.learn-col.min{background:#ecfdf5;border-color:#bbf7d0}
.learn-col.min .hd{color:#047857}
.learn-col.opt{background:#fffbeb;border-color:#fde68a}
.learn-col.opt .hd{color:#b45309}
.learn-col ul{font-size:14px;color:var(--cpp-ink-2);line-height:1.85;margin:0;padding-left:20px}
.learn-col code{background:#fff;border:1px solid var(--cpp-line);padding:1px 6px;border-radius:4px;font-size:13px;color:var(--cpp-ink);font-family:"Consolas","Monaco","Courier New",monospace}

.toc{background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:10px;padding:16px 20px;margin:20px 0}
.toc .hd{font-size:12px;font-weight:700;color:var(--cpp-muted);margin-bottom:10px;letter-spacing:.08em;text-transform:uppercase}
.toc ol{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:4px}
.toc li a{display:flex;gap:12px;padding:8px 12px;border-radius:6px;text-decoration:none;color:var(--cpp-ink-2);font-size:14.5px;border:1px solid transparent;transition:.15s}
.toc li a:hover{background:var(--cpp-bg-2);border-color:var(--cpp-line);color:var(--cpp-ink)}
.toc li a .n{min-width:22px;color:var(--cpp-accent);font-weight:700}

section.block{background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:12px;padding:28px 30px;margin:20px 0;scroll-margin-top:80px}
section.block h2{font-size:22px;font-weight:700;color:var(--cpp-ink);margin-bottom:14px;letter-spacing:.01em;border-left:3px solid var(--cpp-accent);padding-left:12px}
section.block h3{font-size:16.5px;font-weight:700;color:var(--cpp-ink);margin:20px 0 10px}
section.block p{font-size:15px;color:var(--cpp-ink-2);line-height:1.9;margin:10px 0}
section.block b{color:var(--cpp-ink)}
section.block code{background:#eef4fa;border:1px solid var(--cpp-line);padding:1px 6px;border-radius:4px;font-size:13.5px;color:var(--cpp-ink);font-family:"Consolas","Monaco","Courier New",monospace}
section.block ul{font-size:15px;color:var(--cpp-ink-2);line-height:1.95;padding-left:22px;margin:10px 0}
section.block ul li{margin:4px 0}
.note{background:var(--cpp-bg-2);border-left:3px solid var(--cpp-accent-2);padding:12px 16px;border-radius:0 8px 8px 0;margin:14px 0;font-size:14px;color:var(--cpp-ink-2);line-height:1.8}
.note b{color:var(--cpp-ink)}
.warn{background:#fff7ed;border-left:3px solid #f97316;padding:12px 16px;border-radius:0 8px 8px 0;margin:14px 0;font-size:14px;color:#7c2d12;line-height:1.8}
.warn b{color:#7c2d12}

/* Before/After code compare */
.ba{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:16px 0}
@media(max-width:680px){.ba{grid-template-columns:1fr}}
.ba-card{background:#0f172a;border-radius:10px;border:1px solid #1e293b;overflow:hidden}
.ba-bar{background:#1e293b;padding:8px 14px;display:flex;justify-content:space-between;align-items:center;font-family:"Consolas","Monaco",monospace}
.ba-bar .fn{font-size:12px;color:#94a3b8}
.ba-bar .tag{font-size:10.5px;font-weight:700;padding:2px 10px;border-radius:4px;letter-spacing:.05em}
.ba-bar .tag.c{background:#475569;color:#e2e8f0}
.ba-bar .tag.cpp{background:var(--cpp-accent);color:#fff}
.ba-code{padding:14px 16px;font-family:"Consolas","Monaco",monospace;font-size:13px;line-height:1.75;color:#cbd5e1;white-space:pre;overflow-x:auto}
.ba-code .k{color:#c084fc}
.ba-code .f{color:#60a5fa}
.ba-code .s{color:#86efac}
.ba-code .c{color:#64748b;font-style:italic}
.ba-code .n{color:#fbbf24}
.ba-code .t{color:#22d3ee}
.ba-code .p{color:#f472b6}
.ba-foot{background:#020617;padding:8px 14px;border-top:1px solid #1e293b;font-size:12px;color:#94a3b8}
.ba-foot .hi{color:#fbbf24;font-weight:700}

/* Output box */
.term{background:#0b1220;color:#a6e3a1;padding:12px 16px;border-radius:8px;font-family:"Consolas","Monaco",monospace;font-size:13px;line-height:1.7;margin:10px 0;border:1px solid #1e293b;white-space:pre;overflow-x:auto}
.term .prompt{color:#6ee7b7}
.term .dim{color:#64748b}

/* Interactive demo boxes */
.demo{background:var(--cpp-bg-2);border:1px solid var(--cpp-line);border-radius:10px;padding:16px 18px;margin:14px 0}
.demo .hd{font-size:13px;font-weight:700;color:var(--cpp-accent);margin-bottom:8px;letter-spacing:.04em}
.demo .sub{font-size:13px;color:var(--cpp-muted);margin-bottom:10px;line-height:1.7}
.demo-row{display:flex;gap:10px;align-items:center;flex-wrap:wrap;font-family:"Consolas","Monaco",monospace;font-size:14px;color:var(--cpp-ink)}
.demo-row input{padding:7px 10px;border:1px solid var(--cpp-line);border-radius:6px;font-family:inherit;font-size:14px;background:#fff;min-width:180px}
.demo-row input:focus{outline:none;border-color:var(--cpp-accent)}
.demo-row select{padding:7px 10px;border:1px solid var(--cpp-line);border-radius:6px;font-family:inherit;font-size:14px;background:#fff}
.demo-row 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;transition:.15s}
.demo-row button:hover{background:#075985}
.demo-row button.sec{background:#64748b}
.demo-row button.sec:hover{background:#475569}
.demo-out{margin-top:10px;padding:10px 12px;background:#0b1220;color:#a6e3a1;border-radius:6px;font-family:"Consolas","Monaco",monospace;font-size:13.5px;min-height:30px;white-space:pre-wrap;line-height:1.7}

/* SSO visualization */
.sso-viz{background:#fff;border:1px solid var(--cpp-line);border-radius:10px;padding:16px;margin:12px 0}
.sso-stage{display:flex;gap:18px;flex-wrap:wrap;align-items:flex-start}
@media(max-width:720px){.sso-stage{flex-direction:column}}
.sso-col{flex:1;min-width:260px}
.sso-col-title{font-size:13px;font-weight:700;color:var(--cpp-ink);margin-bottom:8px;display:flex;gap:8px;align-items:center}
.sso-col-title .badge{padding:2px 8px;border-radius:4px;font-size:11px;letter-spacing:.04em}
.sso-col-title .badge.stk{background:#dbeafe;color:#1e40af}
.sso-col-title .badge.hp{background:#fce7f3;color:#9f1239}
.sso-block{background:#f8fafc;border:1px solid var(--cpp-line);border-radius:6px;padding:10px;font-family:"Consolas","Monaco",monospace;font-size:12px;color:var(--cpp-ink-2)}
.sso-row{display:flex;align-items:center;gap:6px;margin:3px 0}
.sso-label{width:78px;color:var(--cpp-muted);font-size:11px}
.sso-cells{display:flex;gap:2px;flex-wrap:wrap}
.sso-cell{width:22px;height:22px;display:flex;align-items:center;justify-content:center;background:#fff;border:1px solid #cbd5e1;border-radius:3px;font-size:11px;font-weight:700;color:var(--cpp-ink)}
.sso-cell.filled{background:#dbeafe;color:#1e40af;border-color:#93c5fd}
.sso-cell.filled.hp{background:#fce7f3;color:#9f1239;border-color:#f9a8d4}
.sso-cell.null{background:#f1f5f9;color:#94a3b8}
.sso-arrow{display:inline-block;padding:2px 8px;background:#e2e8f0;border-radius:4px;color:var(--cpp-ink-2);font-weight:700;font-size:11px}
.sso-status{margin-top:10px;padding:8px 12px;border-radius:6px;font-size:13px;font-weight:700}
.sso-status.stk{background:#dbeafe;color:#1e3a8a}
.sso-status.hp{background:#fce7f3;color:#831843}

/* Method playground */
.methods-pg{background:#fff;border:1px solid var(--cpp-line);border-radius:10px;padding:14px}
.methods-tbl{width:100%;border-collapse:collapse;font-size:13px}
.methods-tbl th,.methods-tbl td{border:1px solid var(--cpp-line);padding:8px 10px;text-align:left}
.methods-tbl th{background:var(--cpp-bg-2);color:var(--cpp-ink);font-weight:700}
.methods-tbl code{background:#f1f5f9;padding:1px 6px;border-radius:4px;font-size:12px}
.methods-tbl tr.hi{background:#fef3c7}

/* Opt divider */
.opt-divider{display:flex;align-items:center;gap:14px;margin:32px 0 18px;padding:16px 20px;background:linear-gradient(90deg,#fffbeb,#fef3c7);border:1px solid #fde68a;border-left:4px solid #f59e0b;border-radius:8px}
.opt-divider .icon{font-size:22px}
.opt-divider .txt{flex:1}
.opt-divider .ttl{font-size:15px;font-weight:700;color:#92400e;letter-spacing:.02em}
.opt-divider .sub{font-size:13px;color:#b45309;margin-top:3px;line-height:1.65}

/* Quiz */
.quiz-block{background:var(--cpp-card);border:1px solid var(--cpp-line);border-radius:12px;padding:24px 28px;margin:28px 0}
.quiz-block h2{font-size:20px;font-weight:700;color:var(--cpp-ink);margin-bottom:8px}
.quiz-block .sub{font-size:14px;color:var(--cpp-muted);margin-bottom:18px}
.q-card{border:1px solid var(--cpp-line);border-radius:8px;padding:18px 20px;margin:14px 0;background:var(--cpp-bg)}
.q-card h3{font-size:15.5px;font-weight:700;color:var(--cpp-ink);margin-bottom:12px}
.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}
.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:var(--cpp-bg-2);border:1px solid var(--cpp-line);border-radius:6px;font-size:14px;color:var(--cpp-ink-2);line-height:1.8}
.q-ex.show{display:block}

/* Related & nav */
.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}

.share{margin:20px 0;text-align:center}
.share .lbl{font-size:12px;font-weight:700;color:var(--cpp-muted);margin-bottom:8px}
.share-row{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.share-row a{display:inline-flex;align-items:center;gap:6px;padding:7px 14px;border-radius:6px;font-size:12.5px;font-weight:700;color:#fff;text-decoration:none}

.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)}