:root{--bg:#f7f5f0;--paper:#fff;--ink:#1c2230;--muted:#5d6675;--line:#e3ded4;--navy:#14223b;--navy2:#1f3357;--gold:#c9a24a;--gold2:#e2c477;--ok:#2e7d4f;--ng:#b3423a;--soft:#eef2f8;--radius:14px}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font-family:"Noto Sans JP","Hiragino Sans","Yu Gothic",Inter,system-ui,sans-serif;background:var(--bg);color:var(--ink);line-height:1.75;font-size:16px}
a{color:var(--navy2);text-decoration:none}a:hover{text-decoration:underline}
img{max-width:100%}
.wrap{max-width:1100px;margin:0 auto;padding:0 20px}
header.top{background:var(--navy);color:#fff;position:sticky;top:0;z-index:50;box-shadow:0 2px 10px rgba(0,0,0,.15)}
header.top .wrap{display:flex;align-items:center;justify-content:space-between;height:62px;gap:12px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:700;letter-spacing:.02em;white-space:nowrap}
.brand .mark{width:30px;height:30px;border-radius:50%;background:linear-gradient(135deg,var(--gold),var(--gold2));display:grid;place-items:center;color:var(--navy);font-weight:900;font-size:15px}
.brand small{display:block;font-weight:400;font-size:11px;opacity:.75;letter-spacing:.12em}
nav.main{display:flex;gap:18px;align-items:center}
nav.main a{color:#e8ecf3;font-size:14px}
nav.main a:hover{color:var(--gold2);text-decoration:none}
.langsw{display:flex;border:1px solid rgba(255,255,255,.35);border-radius:999px;overflow:hidden;font-size:12px}
.langsw button{background:transparent;color:#fff;border:0;padding:5px 11px;cursor:pointer;font-family:inherit}
.langsw button.on{background:var(--gold);color:var(--navy);font-weight:700}
.menu-btn{display:none;background:none;border:1px solid rgba(255,255,255,.4);color:#fff;border-radius:8px;padding:4px 9px;font-size:18px;cursor:pointer}
@media(max-width:820px){nav.main{display:none;position:absolute;top:62px;left:0;right:0;background:var(--navy2);flex-direction:column;padding:14px 20px;gap:12px}nav.main.open{display:flex}.menu-btn{display:block}}
/* language */
html[data-lang="ja"] .en{display:none!important}
html[data-lang="en"] .ja{display:none!important}
html[data-lang="both"] .en{color:var(--muted);font-size:.95em}
html[data-lang="both"] .bi>.en{margin-top:.25em}
/* hero */
.hero{background:radial-gradient(1200px 500px at 20% -10%,#2a4576 0%,var(--navy) 55%);color:#fff;padding:70px 0 60px}
.hero h1{font-size:clamp(28px,4.5vw,46px);line-height:1.3;margin:0 0 14px;font-weight:800}
.hero h1 em{font-style:normal;color:var(--gold2)}
.hero p.lead{font-size:17px;max-width:720px;opacity:.92;margin:0 0 26px}
.hero .en{color:#dfe5f0}
.btn{display:inline-block;background:var(--gold);color:var(--navy);font-weight:700;padding:12px 22px;border-radius:999px;border:0;cursor:pointer;font-family:inherit;font-size:15px}
.btn:hover{background:var(--gold2);text-decoration:none}
.btn.ghost{background:transparent;color:#fff;border:1px solid rgba(255,255,255,.6)}
.btn.ghost:hover{border-color:var(--gold2);color:var(--gold2)}
.btn.sm{padding:7px 14px;font-size:13px}
.stats{display:flex;gap:28px;flex-wrap:wrap;margin-top:34px}
.stats div{border-left:3px solid var(--gold);padding-left:12px}
.stats b{display:block;font-size:26px;line-height:1.1}
.stats span{font-size:12px;opacity:.8}
/* sections */
section{padding:56px 0}
section h2{font-size:26px;margin:0 0 6px;font-weight:800}
.sub{color:var(--muted);margin:0 0 26px}
.grid{display:grid;gap:18px;grid-template-columns:repeat(auto-fill,minmax(250px,1fr))}
.card{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:22px;transition:transform .15s,box-shadow .15s;position:relative}
.card:hover{transform:translateY(-3px);box-shadow:0 10px 26px rgba(20,34,59,.10);text-decoration:none}
.card .icon{width:42px;height:42px;border-radius:10px;background:var(--soft);display:grid;place-items:center;font-size:20px;color:var(--navy2);margin-bottom:12px}
.card h3{margin:0 0 8px;font-size:17px;line-height:1.4;color:var(--ink)}
.card p{margin:0;color:var(--muted);font-size:14px}
.card .num{position:absolute;top:16px;right:18px;font-size:12px;color:var(--muted);background:var(--soft);padding:2px 9px;border-radius:999px}
.badge{display:inline-block;font-size:11px;padding:2px 9px;border-radius:999px;background:var(--soft);color:var(--navy2);margin-right:6px;vertical-align:middle}
.badge.mc{background:#e7f1ea;color:var(--ok)}.badge.essay{background:#f6ebd9;color:#8a5a12}
.badge.basic{background:#eef2f8}.badge.intermediate{background:#e9e4f5;color:#4b3a8a}.badge.advanced{background:#f7e3e1;color:var(--ng)}
.steps{display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.step{background:var(--paper);border-radius:var(--radius);padding:22px;border-top:4px solid var(--gold)}
.step b{display:block;font-size:13px;color:var(--gold);letter-spacing:.15em;margin-bottom:6px}
.step h3{margin:0 0 8px;font-size:17px}
.step p{margin:0;font-size:14px;color:var(--muted)}
/* page */
.page{padding:40px 0 70px}
.crumb{font-size:13px;color:var(--muted);margin-bottom:14px}
.crumb a{color:var(--muted)}
.page h1{font-size:clamp(24px,3.4vw,36px);margin:0 0 8px;line-height:1.35}
.intro{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:22px 26px;margin:22px 0}
.prose h2{font-size:22px;margin:38px 0 10px;padding-left:12px;border-left:5px solid var(--gold)}
.prose h3{font-size:17px;margin:24px 0 6px}
.prose p{margin:0 0 14px}
.prose ol,.prose ul{padding-left:1.4em}
.prose li{margin-bottom:6px}
.prose table{border-collapse:collapse;width:100%;font-size:14px;background:var(--paper)}
.prose th,.prose td{border:1px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}
.prose th{background:var(--soft)}
.tablewrap{overflow-x:auto}
/* filters & list */
.filters{display:flex;flex-wrap:wrap;gap:8px;margin:18px 0;align-items:center}
.filters button{border:1px solid var(--line);background:var(--paper);border-radius:999px;padding:5px 13px;cursor:pointer;font-size:13px;font-family:inherit;color:var(--ink)}
.filters button.on{background:var(--navy);color:#fff;border-color:var(--navy)}
.progress{height:8px;background:var(--line);border-radius:999px;overflow:hidden;margin:8px 0 4px}
.progress i{display:block;height:100%;background:linear-gradient(90deg,var(--gold),var(--gold2));width:0}
.qlist{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.qlist li a{display:grid;grid-template-columns:56px 1fr auto;gap:12px;align-items:center;background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:12px 16px;color:var(--ink)}
.qlist li a:hover{border-color:var(--gold);text-decoration:none;box-shadow:0 4px 14px rgba(20,34,59,.08)}
.qlist .no{font-weight:800;color:var(--navy2);font-size:15px}
.qlist .done{color:var(--ok);font-size:14px;width:18px}
.qlist .t{font-size:15px}
@media(max-width:620px){.qlist li a{grid-template-columns:44px 1fr}.qlist .done{display:none}}
/* question */
.qhead{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-bottom:10px}
.qbox{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);padding:26px 28px;margin:18px 0}
.qbox .qtext{font-size:18px;font-weight:600;line-height:1.7}
.choices{list-style:none;padding:0;margin:20px 0 0;display:grid;gap:10px}
.choices li{border:1.5px solid var(--line);border-radius:10px;padding:12px 14px 12px 46px;cursor:pointer;position:relative;background:#fff;transition:.15s}
.choices li:hover{border-color:var(--navy2)}
.choices li::before{content:attr(data-l);position:absolute;left:12px;top:11px;width:24px;height:24px;border-radius:50%;background:var(--soft);color:var(--navy2);font-weight:700;font-size:13px;display:grid;place-items:center}
.choices li.correct{border-color:var(--ok);background:#eef7f1}.choices li.correct::before{background:var(--ok);color:#fff;content:"✓"}
.choices li.wrong{border-color:var(--ng);background:#fbeeed}.choices li.wrong::before{background:var(--ng);color:#fff;content:"✕"}
.choices.locked li{cursor:default}
.verdict{margin-top:14px;font-weight:700;display:none}
.verdict.ok{color:var(--ok);display:block}.verdict.ng{color:var(--ng);display:block}
textarea.draft{width:100%;min-height:150px;border:1.5px solid var(--line);border-radius:10px;padding:12px;font-family:inherit;font-size:15px;margin-top:14px;resize:vertical}
.actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}
.reveal{display:none}.reveal.show{display:block}
.panel{background:var(--paper);border:1px solid var(--line);border-left:6px solid var(--navy2);border-radius:12px;padding:20px 24px;margin:14px 0}
.panel.answer{border-left-color:var(--ok)}.panel.issue{border-left-color:var(--ng)}.panel.improve{border-left-color:var(--gold)}
.panel h2{margin:0 0 8px;font-size:15px;letter-spacing:.08em;color:var(--muted);text-transform:uppercase}
.panel p{margin:0;white-space:pre-line}
.pager{display:flex;justify-content:space-between;gap:10px;margin-top:30px;flex-wrap:wrap}
.pager a{background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:10px 16px;font-size:14px}
.tags{margin-top:8px;font-size:12px;color:var(--muted)}
/* quiz */
.quizbar{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:14px 0}
select{font-family:inherit;padding:8px 10px;border-radius:8px;border:1px solid var(--line);background:#fff;font-size:14px}
.score{font-weight:800;font-size:20px}
/* footer */
footer{background:var(--navy);color:#c9d2e3;padding:40px 0 30px;font-size:13px;margin-top:40px}
footer .cols{display:grid;gap:24px;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));margin-bottom:26px}
footer h4{color:#fff;margin:0 0 10px;font-size:14px}
footer a{color:#c9d2e3;display:block;margin-bottom:6px}
footer .credit{border-top:1px solid rgba(255,255,255,.15);padding-top:16px;margin-bottom:8px;color:#fff;font-size:14px}
footer .copy{opacity:.7}
.note{font-size:12px;color:var(--muted)}