:root{--deep:#173a48;--teal:#1a8794;--mint:#e6f3f3;--line:#dbe7e8;--muted:#5d7178;--accent:#f2c94c;--bg:#f4f8f8;--ng:#d38b7c;--ngbg:#fdf1ee}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--deep);font-family:"Noto Sans JP",system-ui,sans-serif;line-height:1.7;-webkit-text-size-adjust:100%}
button{font:inherit;cursor:pointer;color:inherit}
.top{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
.top-in{max-width:880px;margin:auto;padding:10px 16px;display:flex;align-items:center;justify-content:space-between;gap:12px}
.brand{display:flex;align-items:center;gap:10px;border:0;background:none;padding:0;text-align:left}
.logo{width:30px;height:30px;border-radius:9px;background:linear-gradient(135deg,var(--teal),var(--deep));display:grid;place-items:center;color:#fff;font:700 13px Inter,sans-serif}
.brand b{font-size:15px;display:block;line-height:1.3}.brand small{display:block;font:500 9px Inter,sans-serif;letter-spacing:.18em;color:var(--muted)}
.nav{display:flex;gap:4px}
.nav button{border:0;background:none;border-radius:10px;padding:8px 12px;color:var(--muted);font-size:14px}
.nav button i{font-style:normal;margin-right:4px}
.nav button.on{background:var(--mint);color:var(--teal);font-weight:700}
main{max-width:880px;margin:auto;padding:16px 16px 24px}
.foot{text-align:center;color:var(--muted);font-size:11px;padding:10px 16px 100px;line-height:1.8}
@media(max-width:640px){
  .nav{position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid var(--line);justify-content:space-around;padding:6px 0 calc(8px + env(safe-area-inset-bottom));z-index:20}
  .nav button{display:flex;flex-direction:column;align-items:center;font-size:10.5px;padding:4px 10px;background:none!important}
  .nav button i{font-size:18px;margin:0;line-height:1.3}
}
/* hero */
.hero{border-radius:20px;padding:24px 22px;color:#fff;background:linear-gradient(120deg,var(--teal),var(--deep));position:relative;overflow:hidden}
.hero:before{content:"";position:absolute;right:-50px;top:-50px;width:200px;height:200px;border-radius:50%;border:1px solid #ffffff33}
.hero:after{content:"";position:absolute;right:10px;top:30px;width:100px;height:100px;border-radius:50%;border:1px solid #ffffff22}
.hero small{font:500 10px Inter,sans-serif;letter-spacing:.18em;opacity:.75}
.hero h1{font-weight:300;font-size:clamp(22px,5vw,32px);line-height:1.45;margin:8px 0 6px;position:relative;z-index:1}
.hero h1 u{text-decoration:none;background:linear-gradient(transparent 68%,#f2c94c99 68%)}
.hero p{font-size:13px;opacity:.88;margin:0;position:relative;z-index:1}
.btn{display:inline-block;border:0;border-radius:99px;padding:11px 20px;font-weight:700;font-size:14px;background:var(--deep);color:#fff}
.btn.white{background:#fff;color:var(--deep);margin-top:16px;position:relative;z-index:1}
.btn.sub{background:var(--mint);color:var(--teal)}
.btn.line{background:#fff;border:1px solid var(--line);color:var(--deep)}
.btn:disabled{opacity:.4;cursor:default}
.row{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin:12px 0}
.st{background:#fff;border:1px solid var(--line);border-radius:12px;padding:10px 12px;font-size:11px;color:var(--muted)}
.st b{display:block;font:500 22px Inter,sans-serif;color:var(--teal)}
.sec{display:flex;justify-content:space-between;align-items:end;margin:22px 0 6px;gap:10px}
.sec h2{font-size:17px;margin:0}.sec span{font-size:12px;color:var(--muted)}
.card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:14px;margin:8px 0;display:flex;gap:12px;align-items:center;width:100%;text-align:left}
button.card:hover{border-color:#9cc9cd}
.ic{width:42px;height:42px;border-radius:12px;background:var(--mint);display:grid;place-items:center;font-size:20px;flex-shrink:0}
.card b{font-size:15px;font-weight:500;display:block}.card .s{font-size:12px;color:var(--muted)}
.card .go{margin-left:auto;color:var(--teal);font-weight:700}
.bar{height:5px;background:#e3eced;border-radius:9px;margin-top:7px;overflow:hidden}.bar i{display:block;height:100%;background:linear-gradient(90deg,var(--teal),var(--deep));border-radius:9px}
.box{background:#fff;border:1px solid var(--line);border-radius:16px;padding:18px}
.muted{color:var(--muted);font-size:13px}
.chip{display:inline-block;font-size:11px;background:var(--mint);color:var(--teal);border-radius:99px;padding:3px 10px;font-weight:700;margin-right:4px}
.chip.lv{background:#fff6dc;color:#9a7412}
/* quiz */
.qhead{display:flex;justify-content:space-between;font-size:13px;color:var(--muted)}
.qbar{height:5px;background:#e3eced;border-radius:9px;margin:8px 0 14px;overflow:hidden}.qbar i{display:block;height:100%;background:var(--teal);transition:width .3s}
.q{font-size:17px;line-height:1.7;margin:10px 0 16px;font-weight:500}
.ans{display:flex;gap:10px;width:100%;text-align:left;background:#fff;border:1px solid var(--line);border-radius:12px;padding:12px 14px;margin-bottom:9px;font-size:14.5px}
.ans span{font:700 13px Inter,sans-serif;color:var(--muted);flex-shrink:0}
.ans:not(:disabled):hover{border-color:var(--teal)}
.ans.ok{border-color:var(--teal);background:#e8f6f5}.ans.ok span{color:var(--teal)}
.ans.ng{border-color:var(--ng);background:var(--ngbg)}
.ans .why{display:block;font-size:12px;color:#7a5a52;margin-top:3px}
.ans:disabled{cursor:default;color:inherit}
.exp{background:var(--mint);border-left:3px solid var(--teal);border-radius:8px;padding:12px 14px;font-size:13.5px;margin-top:6px}
.exp b{color:var(--teal)}
.result{text-align:center;padding:10px 0}
.result .big{font:300 48px Inter,sans-serif;color:var(--teal)}
.modes{display:grid;gap:8px}
/* practice */
h3.lb{font-size:13px;color:var(--teal);margin:18px 0 6px}
pre{white-space:pre-wrap;font-family:inherit;font-size:13.5px;border-radius:10px;padding:12px;margin:0;line-height:1.75}
pre.data{background:#f6f6f2}pre.bad{background:var(--ngbg)}pre.good{background:var(--mint)}
textarea,input[type=text]{width:100%;font:inherit;font-size:15px;padding:11px 12px;border:1px solid var(--line);border-radius:10px;background:#fff;color:var(--deep)}
textarea{min-height:110px;resize:vertical}
textarea:focus,input:focus{outline:2px solid #9cc9cd;border-color:transparent}
ul.pt{margin:0;padding-left:20px;font-size:14px}
label.ck{display:flex;gap:10px;align-items:flex-start;font-size:14px;padding:8px 0;border-bottom:1px solid var(--line)}
label.ck input{width:18px;height:18px;margin-top:3px;accent-color:var(--teal)}
.done{color:var(--teal);font-weight:700;font-size:13px}
.notice{font-size:12px;color:var(--muted);margin-top:14px}
.toast{position:fixed;left:50%;bottom:90px;transform:translateX(-50%);background:var(--deep);color:#fff;padding:10px 18px;border-radius:99px;font-size:13px;z-index:50;opacity:0;transition:opacity .25s;pointer-events:none}
.toast.show{opacity:1}
.field{margin-top:14px}.field b{font-size:14px;display:block}.field .h{font-size:12px;color:var(--muted);margin-bottom:4px}
.iv{background:linear-gradient(120deg,var(--teal),var(--deep));color:#fff;border-radius:14px;padding:16px;margin-top:18px}
.iv textarea{margin-top:8px;min-height:150px}
.back{border:0;background:none;color:var(--teal);font-weight:700;padding:4px 0;margin-bottom:8px}
.day{display:flex;align-items:center;gap:10px;width:100%;border:0;border-bottom:1px solid var(--line);background:none;padding:10px 0;text-align:left;font-size:14px}
.day:last-child{border-bottom:0}
.day .dn{font:700 12px Inter,"Noto Sans JP",sans-serif;color:var(--teal);width:44px;flex-shrink:0}
.day .dt{flex:1}.day .dk{color:var(--teal);font-weight:700;width:16px}
.day:hover .dt{color:var(--teal)}
.day .dr{font:500 13px Inter,sans-serif;color:var(--teal);width:40px;text-align:right}
.day .dt .bar{display:block;margin-top:4px}
.qhead b{font:700 14px Inter,sans-serif;color:var(--teal)}
.ans.sel{border-color:var(--teal);background:#e8f6f5}
.grid60{display:grid;grid-template-columns:repeat(10,1fr);gap:4px;margin-top:16px}
.grid60 button{border:1px solid var(--line);background:#fff;border-radius:6px;font:500 11px Inter,sans-serif;padding:5px 0;color:var(--muted)}
.grid60 button.a{background:var(--mint);color:var(--teal);border-color:#bfdfe1}
.grid60 button.c{outline:2px solid var(--teal)}
.mrow{display:flex;justify-content:space-between;padding:8px 0;border-bottom:1px solid var(--line);font-size:14px}
.ov{position:fixed;inset:0;background:#0f1d2499;z-index:60;display:flex;align-items:flex-end;justify-content:center;padding:16px}
@media(min-width:641px){.ov{align-items:center}}
.sheet{background:#fff;border-radius:20px;padding:22px 20px;width:100%;max-width:420px;max-height:90vh;overflow:auto;text-align:left}
.sheet h2{font-size:18px;text-align:center;margin:10px 0 2px}
.soon{font-size:11px;background:#fff6dc;color:#9a7412;border-radius:99px;padding:2px 9px;margin-left:6px;vertical-align:middle}
.price{text-align:center;font:300 34px Inter,sans-serif;color:var(--teal);margin:4px 0 10px}.price small{font-size:13px;color:var(--muted)}
.sheet ul.pt{margin:0 0 10px}
.foot .badge{margin-top:12px}.foot .badge img{width:150px;height:auto;opacity:.85;vertical-align:middle}.foot .badge a:hover img{opacity:1}