:root{color-scheme:light;--ink:#183946;--muted:#526b75;--teal:#237a79;--pale:#eef7f7;--line:#d4e2e7;--paper:#fff;--bg:#f3f8fa}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:"Noto Sans JP","Hiragino Kaku Gothic ProN","Yu Gothic",Meiryo,sans-serif;font-size:16px;line-height:1.85}a{color:var(--teal)}button,select{font:inherit}button,select,.action-link{min-height:44px;border-radius:8px;border:1px solid var(--line);background:var(--paper);color:var(--ink);padding:8px 14px}button{cursor:pointer}button:disabled{opacity:.45;cursor:default}button:focus-visible,select:focus-visible,a:focus-visible{outline:3px solid #bd7800;outline-offset:3px}.shell{max-width:900px;margin:auto;padding:24px 24px 50px}header{border-top:6px solid var(--teal);padding:20px 0 10px}header p{margin:0}.brand{font-size:12px;letter-spacing:.16em;color:var(--teal);font-weight:700}h1{font-size:clamp(23px,4.8vw,32px);line-height:1.45;margin:10px 0}h2{font-size:clamp(24px,4.5vw,34px);line-height:1.5;margin:10px 0 15px}h3{font-size:17px;line-height:1.55;margin:0 0 5px}.intro,.scope,figcaption{color:var(--muted);font-size:13px}.toolbar{display:flex;flex-wrap:wrap;gap:10px;align-items:end;padding:18px 0 22px}.toolbar label{display:grid;gap:4px;flex:1 1 250px;font-size:13px}.toolbar select{width:100%;font-size:16px}.chapter{background:var(--paper);padding:30px;border:1px solid var(--line);border-radius:12px;margin-bottom:20px;scroll-margin-top:16px}.chapter[hidden]{display:none}.eyebrow{font-size:12px;letter-spacing:.1em;font-weight:700;color:var(--teal)}.lead{font-size:17px;color:var(--muted);margin:0 0 24px}figure{margin:24px 0}figcaption{margin-top:9px;line-height:1.65}.screen{position:relative;overflow:hidden;border:1px solid var(--line);background:#edf6f8}.screen img{position:absolute;max-width:none;height:auto}.mark{position:absolute;transform:translate(-125%,-130%);display:grid;place-items:center;width:25px;height:25px;border-radius:50%;background:var(--teal);color:#fff;font-weight:700;font-size:14px;border:2px solid #fff;box-shadow:0 0 0 1px var(--teal)}.steps{counter-reset:step;list-style:none;padding:0}.steps li{counter-increment:step;position:relative;padding-left:39px;margin:22px 0}.steps li:before{content:counter(step);position:absolute;left:0;top:0;background:var(--teal);color:#fff;width:27px;height:27px;border-radius:50%;text-align:center;line-height:27px;font-weight:700;font-size:14px}.steps p{margin:0}.note{background:var(--pale);padding:15px 18px;border-left:4px solid var(--teal);margin:22px 0}.note p{margin:0}.route{font-size:14px;background:var(--bg);padding:13px 18px}.route ol{margin:5px 0 0;padding-left:22px}table{border-collapse:collapse;width:100%;font-size:15px;margin:22px 0;table-layout:fixed}th,td{padding:12px 10px;border-bottom:1px solid var(--line);vertical-align:top;text-align:left;overflow-wrap:anywhere}th:first-child{width:30%}thead{background:#d9eaf0}tbody tr:nth-child(even){background:#f6fafb}tbody th{font-weight:600}.prompt{white-space:pre-wrap;overflow-wrap:anywhere;background:var(--pale);padding:18px;font-family:ui-monospace,monospace;font-size:14px;line-height:1.8}.mobile-diagram{background:#e7f2f5;padding:12px;border-radius:9px}.shelf-bar{display:grid;grid-template-columns:1fr 2fr 1fr 1fr;background:white;padding:10px;text-align:center;gap:4px;font-size:14px}.mobile-tabs{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:6px;margin-top:10px;font-size:14px}.mobile-tabs span{background:var(--ink);color:white;text-align:center;padding:9px 0;border-radius:6px}.mobile-tabs span:first-child{background:var(--teal)}.pager{display:flex;align-items:center;justify-content:space-between;gap:12px}.pager button:last-child,.action-link{background:var(--teal);color:white;border-color:var(--teal)}.action-link{display:inline-block;text-decoration:none}.progress{font-size:14px;color:var(--muted);text-align:center}.foot{font-size:12px;color:var(--muted);margin-top:30px}.all-mode .pager{display:none}@media(max-width:520px){.shell{padding:12px 12px 28px}.chapter{padding:21px 16px;border-radius:8px}.toolbar{gap:8px}.toolbar label{flex-basis:100%}table{font-size:14px}th,td{padding:10px 7px}.mobile-tabs{font-size:12px;gap:4px}.shelf-bar{font-size:12px;padding:8px 4px}.lead{font-size:16px}}@media print{body{background:white}.shell{max-width:none;padding:0}.toolbar,.pager,header .intro{display:none}.chapter,.chapter[hidden]{display:block!important;border:0;break-before:page;padding:0}.screen{break-inside:avoid}header{border:0}a{color:inherit}.foot{display:none}}

.help-intro { margin: 14px 0 0; max-width: 44em; font-size: 14px; color: var(--muted); }
.site-links { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0 4px; }
.site-links a { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 8px 14px; border: 1px solid var(--line); border-radius: 8px; background: var(--paper); font-size: 14px; text-decoration: none; }
.site-links a:hover { background: var(--pale); border-color: var(--teal); }
@media (max-width: 520px) { .site-links a { flex: 1 1 auto; } }
@media print { .site-links, .help-intro { display: none; } }