:root{--bg:#f8f7f3;--surface:#fff;--ink:#213333;--muted:#697979;--line:#e0e8e3;--accent:#16685e;--accent-wash:#eaf5ef;--gold:#cfaa50;--shadow:0 10px 36px rgba(34,65,58,.045)}
*{box-sizing:border-box}html{font-family:-apple-system,BlinkMacSystemFont,"Hiragino Kaku Gothic ProN","Hiragino Sans","Yu Gothic",Meiryo,sans-serif;-webkit-text-size-adjust:100%}body{margin:0;background:var(--bg);color:var(--ink);min-height:100dvh}button,input{font:inherit}button{cursor:pointer}button:focus-visible,input:focus-visible{outline:3px solid #6bbba7;outline-offset:2px}.site{max-width:750px;margin:auto;padding:0 23px;min-height:100dvh;display:flex;flex-direction:column}.site-footer{display:block;font-size:11px;color:#8d9b94;margin-top:auto;padding:32px 0 21px;border-top:1px solid var(--line)}#app{padding-bottom:20px}.eyebrow{display:block;font-size:12px;font-weight:750;letter-spacing:.14em;color:var(--accent);margin:10px 0 12px}.hero{padding:33px 0 28px}.hero h1{font-size:clamp(28px,6vw,40px);font-weight:800;letter-spacing:-.07em;line-height:1.46;margin:0 0 12px}.hero p{margin:0;color:var(--muted);font-size:15px;line-height:1.9}.title{font-size:24px;line-height:1.55;letter-spacing:-.055em;margin:2px 0 9px}.sub{font-size:14px;color:var(--muted);line-height:1.75;margin:0 0 20px}.cards{display:grid;gap:12px}.profiles{grid-template-columns:repeat(3,minmax(0,1fr))}.card,.panel{background:var(--surface);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow)}.card{padding:24px 16px;min-height:137px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;color:var(--ink);text-align:center}.card:hover,.mapitem:hover{border-color:#9acbbe;background:#fafffc}.card-icon{font-size:26px;width:55px;height:55px;background:var(--accent-wash);border-radius:50%;display:flex;align-items:center;justify-content:center;color:var(--accent)}.card-name{font-weight:800;font-size:17px;overflow-wrap:anywhere}.card-desc{color:var(--muted);font-size:11px}.panel{padding:26px;margin:15px 0}.section-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px;margin:28px 0 12px}.section-head h2{margin:0;font-size:18px;letter-spacing:-.03em}.section-head .small{font-size:12px;color:var(--muted)}.actions{display:grid;gap:11px}.btn{border-radius:13px;min-height:54px;padding:13px 20px;font-weight:750;border:1px solid var(--line);background:#fff;color:var(--ink);text-align:center}.btn-primary{background:var(--accent);border-color:var(--accent);color:white}.btn-subtle{background:var(--accent-wash);color:var(--accent);border-color:transparent}.btn-outline{border-color:#b6cbc3}.btn:disabled{opacity:.45;cursor:not-allowed}.btn-small{min-height:39px;padding:9px 13px;font-size:12px;border-radius:10px}.btn-row{display:grid;grid-template-columns:1fr 1fr;gap:10px}.text-link{display:inline-block;border:0;background:transparent;padding:10px 4px;color:var(--accent);font-weight:700}.info-line{font-size:13px;color:var(--muted);line-height:1.8}.stack{display:flex;flex-direction:column;gap:10px}.label{font-weight:800;font-size:13px}.statline{display:flex;justify-content:space-between;gap:12px;align-items:center;padding:10px 0;font-size:14px;border-bottom:1px solid var(--line)}.statline:last-child{border-bottom:0}.status{color:var(--accent);font-size:12px;font-weight:800;white-space:nowrap}.quiet{color:var(--muted);font-size:13px;line-height:1.8}.capsule{display:inline-flex;align-items:center;justify-content:center;border-radius:99px;background:var(--accent-wash);color:var(--accent);font-size:12px;font-weight:750;padding:6px 10px}.map-tabs{display:flex;gap:8px;margin:18px 0 15px;flex-wrap:wrap}.tab{min-height:43px;padding:10px 16px;border:1px solid var(--line);border-radius:99px;color:var(--muted);background:white;font-weight:750}.tab[aria-pressed=true]{background:var(--accent);border-color:var(--accent);color:white}.map-list{display:grid;gap:8px}.mapitem{background:white;border:1px solid var(--line);border-radius:13px;padding:14px 15px;text-align:left;display:flex;align-items:center;gap:12px;width:100%;color:var(--ink)}.mapitem strong{display:block;font-size:14px;line-height:1.5}.mapitem small{display:block;font-size:11px;color:var(--muted);line-height:1.6;margin-top:2px}.stepno{min-width:42px;text-align:center;background:#f1f6f2;padding:8px 4px;border-radius:9px;font-size:11px;font-weight:800;color:var(--accent)}.mapitem .status{margin-left:auto;text-align:right}.quiz-top{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:16px 0 15px}.progress{background:#e1eae3;height:7px;border-radius:50px;overflow:hidden;margin:0 0 27px}.progress>div{background:var(--accent);height:100%;border-radius:50px;transition:width .2s ease}.problem{min-height:155px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:14px 12px 12px;margin:0 0 14px}.problem .problem-text{font-size:clamp(26px,6.4vw,42px);font-weight:800;letter-spacing:-.035em;line-height:1.45;overflow-wrap:anywhere;display:flex;align-items:center;justify-content:center;flex:1;min-height:70px;width:100%}.problem .problem-caption{font-size:14px;color:var(--muted);line-height:1.8}.dots{font-size:29px;letter-spacing:.13em;line-height:1.65;color:var(--accent);word-break:break-all}.answerbox{margin:0 auto 14px;max-width:330px}.answerbox input{width:100%;height:66px;border:2px solid #c9dad1;background:#fff;color:var(--ink);border-radius:14px;text-align:center;font-size:30px;font-weight:750;font-variant-numeric:tabular-nums}.keypad{max-width:330px;margin:auto;display:grid;grid-template-columns:repeat(3,1fr);gap:9px}.key{min-height:55px;border:1px solid var(--line);background:white;border-radius:12px;font-size:23px;font-weight:700;color:var(--ink)}.key.action-key{font-size:16px;background:#edf3ef}.choicegrid{display:grid;gap:10px;margin:4px 0 15px}.choice{background:white;border:1.5px solid var(--line);border-radius:13px;min-height:58px;font-size:21px;font-weight:750;color:var(--ink)}.choice.selected{border-color:var(--accent);background:var(--accent-wash)}.feedback{padding:15px 17px;border-radius:12px;background:#eef7f3;color:var(--ink);font-size:14px;line-height:1.8;margin:16px 0}.feedback.negative{background:#fbf6e9}.feedback strong{display:block;margin-bottom:4px}.result-num{font-size:58px;font-weight:800;color:var(--accent);letter-spacing:-.06em;line-height:1.1;margin:12px 0}.result-num small{font-size:19px;color:var(--muted)}.result{padding:35px 16px;text-align:center}.result h1{font-size:26px;line-height:1.5;letter-spacing:-.04em}.result p{line-height:1.9;color:var(--muted);font-size:15px}.setting-label{display:block;font-size:13px;font-weight:800;margin-bottom:8px}.setting-input{width:100%;border:1px solid #b7cfc3;border-radius:11px;background:#fff;color:var(--ink);min-height:48px;padding:11px 13px;font-size:17px}.minor-head{font-weight:800;font-size:15px;margin:26px 0 10px}.summary-list{padding-left:20px;color:var(--ink);font-size:14px;line-height:2}.note{font-size:12px;color:var(--muted);line-height:1.75}.hidden{display:none!important}.sep{height:1px;background:var(--line);margin:22px 0}.practice-now{background:linear-gradient(130deg,#edf6ef,#f7fbf7);border:1px solid #d8e8dc;border-radius:17px;padding:23px;margin-bottom:16px}.practice-now h2{margin:7px 0 9px;font-size:20px}.practice-now p{font-size:14px;color:var(--muted);line-height:1.75}.practice-now .btn{width:100%}@media(max-width:520px){.site{padding:0 15px}.hero{padding:21px 0 20px}.profiles{grid-template-columns:repeat(3,minmax(0,1fr));gap:8px}.card{min-height:122px;padding:14px 7px}.card-name{font-size:14px}.card-icon{width:45px;height:45px}.panel{padding:18px;margin:12px 0}.mapitem{padding:12px 10px;gap:8px}.mapitem strong{font-size:13px}.stepno{min-width:35px}.quiz-top{font-size:12px}.footer-copy{font-size:10px}.site-footer{font-size:10px}}
@media print{.site-header,.site-footer,.btn,.keypad,.answerbox,.progress,.quiz-top,.site{max-width:100%}}

/* v0.2: 学習画面は問題と入力を優先し、進捗は操作エリアの下へ。 */
.footer-nav,.footer-copy{display:flex;align-items:center;justify-content:space-between;gap:12px}
.footer-nav{justify-content:flex-end;margin-bottom:14px}
.footer-link{border:0;background:transparent;color:var(--muted);font-size:12px;padding:6px 2px;font-weight:650}
.footer-copy{font-size:11px}
.quiz-bottom{margin-top:25px}
.quiz-bottom .quiz-top{margin:0 0 12px;color:var(--muted);font-size:12px}
.quiz-bottom .quiz-top strong{font-weight:650}
.quiz-bottom .quiz-top .quiet{font-size:12px}
.quiz-bottom .progress{margin:0}

/* v0.3: one shared layout, with quiz controls in the two lower corners. */
.problem-controls{width:100%;display:flex;justify-content:flex-end;align-items:flex-end;gap:12px;margin-top:4px}
.problem-button{width:123px;min-width:123px;min-height:44px;padding:9px 10px;font-size:13px;border-radius:12px;white-space:nowrap}
.quiz-actions{margin-top:14px}

/* v0.4: 五問の進捗は問題枠内の縦丸で表示。CSSは全画面幅で共通。 */
.problem-body{display:grid;grid-template-columns:minmax(0,1fr);align-items:center;flex:1;width:100%;min-height:89px}
.problem-body.has-dots{grid-template-columns:23px minmax(0,1fr) 23px}
.problem-content{grid-column:1;grid-row:1;min-width:0;display:flex;flex-direction:column;align-items:center;justify-content:center}
.has-dots .problem-content{grid-column:2}
.problem-content .problem-text{min-height:58px}
.progress-dots{grid-column:1;grid-row:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:6px;align-self:stretch}
.progress-dot{display:block;width:14px;height:14px;border:2px solid #b6c4be;border-radius:50%;background:transparent;flex-shrink:0}
.progress-dot.first{background:#2877c7;border-color:#2877c7}
.progress-dot.retry{background:#e9b93e;border-color:#e9b93e}
.progress-dot.skipped{background:#d65b58;border-color:#d65b58}
.quiz-bottom .quiz-top{margin-bottom:0}
.quiz-bottom .progress{margin-top:12px}

/* v0.5: result page -- result, next action, today's history only. */
.result-simple{padding:16px 0 12px;text-align:center}
.result-simple .result-num{margin:4px 0 8px}
.result-actions{display:grid;gap:11px}
.result-nav{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:11px}
.result-nav .btn{min-width:0;padding-inline:8px}

.today-history{margin:26px 0 16px}
.today-history h2{font-size:16px;letter-spacing:-.025em;margin:0 0 12px}
.history-list{background:#fff;border:1px solid var(--line);border-radius:16px;overflow:hidden}
.history-item{padding:13px 15px;border-bottom:1px solid var(--line)}
.history-item:last-child{border-bottom:0}
.history-topic,.history-bottom{display:flex;align-items:baseline;justify-content:space-between;gap:12px}
.history-topic{justify-content:flex-start;align-items:flex-start;margin-bottom:9px}
.history-ordinal{flex:0 0 auto;white-space:nowrap;color:var(--muted);font-size:12px}
.history-title{font-size:13px;font-weight:700;line-height:1.5;overflow-wrap:anywhere}
.history-bottom{align-items:center}
.history-dots{display:flex;align-items:center;gap:8px}
.history-dot{width:13px;height:13px;border-radius:50%;display:inline-block;flex:none}
.history-dot.first{background:#2877c7}
.history-dot.retry{background:#e9b93e}
.history-dot.skipped{background:#d65b58}
.history-dot.pending{border:1px solid #bccbc6;background:white}
.history-score{white-space:nowrap;font-size:14px;font-variant-numeric:tabular-nums}
.history-unavailable{font-size:11px;color:var(--muted)}
.history-legend{display:flex;align-items:center;gap:10px 16px;flex-wrap:wrap;padding:11px 1px 0;color:var(--muted);font-size:11px}
.history-legend>span{display:inline-flex;align-items:center;gap:5px}
.history-legend .history-dot{height:9px;width:9px}
.history-toggle{width:100%;margin-top:10px}
.result-end{margin:12px 0 20px}
.result-end .btn{width:100%}

/* v0.6: 学習の地図は状態ラベルだけを色分け。全端末共通CSS。 */
.mapitem .status{border-radius:999px;padding:6px 9px;flex-shrink:0}
.mapitem .status-upcoming{color:#63736e;background:#edf1ef}
.mapitem .status-practicing{color:#256b9c;background:#e7f2fa}
.mapitem .status-checking{color:#88630f;background:#fbf2d7}
.mapitem .status-mastered{color:#176c4d;background:#e3f3e9}

/* v0.7: 学習画面には説明を増やさず、Welcome・地図の下に保護者向け情報を格納。 */
.parent-guide,.progress-guide{margin:24px 0 22px;border:1px solid var(--line);border-radius:15px;background:#fff;overflow:hidden}
.parent-guide>summary,.progress-guide>summary{cursor:pointer;list-style-position:inside;font-size:15px;font-weight:750;padding:17px 18px;color:var(--ink)}
.parent-guide>summary:focus-visible,.progress-guide>summary:focus-visible{outline:3px solid #6bbba7;outline-offset:-3px}
.parent-guide[open]>summary,.progress-guide[open]>summary{border-bottom:1px solid var(--line)}
.parent-guide-body,.progress-guide-body{padding:17px 19px 21px}
.parent-guide-body h3{margin:24px 0 9px;font-size:15px;line-height:1.55}
.parent-guide-body p{margin:8px 0 12px;font-size:13px;line-height:1.9;color:var(--ink)}
.parent-guide-body .parent-idea{text-align:center;font-weight:800;font-size:clamp(16px,4.1vw,22px);line-height:1.7;margin:7px 0 10px;letter-spacing:-.04em}
.parent-guide-body .parent-cycle{text-align:center;font-weight:700;color:var(--accent);font-size:13px;margin:10px 0 26px;line-height:1.7}
.parent-guide-body .parent-privacy{font-size:12px;color:var(--muted);border-top:1px solid var(--line);padding-top:16px;margin-top:22px}
.progress-guide-item{display:flex;align-items:flex-start;gap:10px;margin:0 0 16px}
.progress-guide-item .status{min-width:104px;text-align:center;border-radius:999px;padding:6px 9px}
.progress-guide-item p{margin:0;flex:1;font-size:13px;line-height:1.75}
.progress-guide-note{padding-top:12px;margin:0;border-top:1px solid var(--line);color:var(--muted);font-size:12px;line-height:1.85}

/* v0.8: 習得表示は短く、判定の条件を別段落で説明する。 */
.progress-guide-rules{border-top:1px solid var(--line);padding-top:13px;margin-top:3px;font-size:13px;line-height:1.75}
.progress-guide-rules strong{display:block;font-size:13px;margin-bottom:6px}
.progress-guide-rules p{margin:7px 0;color:var(--muted)}

/* v0.9: 筆算用のA4方眼を補助資料として開く。端末別CSSは増やさない。 */
.worksheet-utility{margin:16px 0 8px;text-align:center}
.worksheet-link{display:inline-block;padding:9px 7px;color:var(--accent);font-weight:700;font-size:13px;line-height:1.6;text-decoration:underline;text-underline-offset:3px}
.worksheet-link:focus-visible{outline:3px solid #6bbba7;outline-offset:3px;border-radius:5px}

/* v0.11: 横式・縦式は表示の切替のみ。共通CSSでスマホ・PCに対応。 */
.problem-controls{justify-content:space-between}
.hissan-toggle{padding:8px 4px;border:0;background:transparent;color:var(--accent);font-weight:700;font-size:13px;min-height:44px;white-space:nowrap;text-decoration:underline;text-underline-offset:3px}
.hissan-toggle:focus-visible{outline:3px solid #6bbba7;outline-offset:2px;border-radius:6px}
.hissan-view{display:inline-flex;flex-direction:column;align-items:stretch;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-variant-numeric:tabular-nums;margin:5px auto 0;color:var(--ink)}
.hissan-row{display:grid;grid-template-columns:28px repeat(var(--hissan-cols), 32px);align-items:center;line-height:1.25;text-align:center;min-height:37px}
.hissan-row .hissan-digit{font-size:29px;font-weight:750}
.hissan-sign{font-size:24px;font-weight:700;text-align:center}
.hissan-line{height:2px;background:currentColor;margin:2px 0}
.hissan-result{min-height:22px}
.hissan-result .hissan-digit{font-size:1px}
.hissan-worksheet-link{text-align:center;margin:8px 0 4px;font-size:12px}
.hissan-worksheet-link a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}
.worksheet-utility>span{font-size:12px;color:var(--muted);display:block;margin-bottom:5px}
.worksheet-sizes{display:flex;flex-wrap:wrap;gap:6px;justify-content:center}
.worksheet-sizes a{font-size:13px;display:inline-block;padding:7px 11px;border:1px solid var(--line);border-radius:9px;color:var(--accent);font-weight:700;background:#fff}
.worksheet-sizes a:focus-visible{outline:3px solid #6bbba7;outline-offset:2px}

/* v0.13: 筆算見本（2桁・3桁）を共通CSSで表示。 */
.worksheet-guide-link{display:block;margin:0 auto 12px;min-height:44px;padding:8px 14px;background:white;border:1px solid #b6cbc3;border-radius:11px;font-weight:750;color:var(--accent)}
.guide-tabs{display:flex;flex-wrap:wrap;gap:8px;margin:16px 0;justify-content:center}
.guide-panel{max-width:580px;margin:10px auto 20px;text-align:center}
.guide-panel h2{margin:5px 0 18px;font-size:20px}
.guide-progress{font-size:12px;color:var(--muted);margin:0}
.guide-columns{--col:clamp(52px,14vw,69px);max-width:max-content;margin:10px auto 24px;font-family:ui-monospace,SFMono-Regular,Consolas,monospace;font-variant-numeric:tabular-nums;color:var(--ink)}
.guide-head,.guide-numbers,.guide-carry-row,.guide-answer{display:grid;grid-template-columns:28px repeat(var(--guide-cols,2),var(--col));align-items:center;justify-content:center}
.guide-head{font-family:inherit;font-size:13px;color:var(--muted);line-height:1.4}
.guide-carry-row{height:26px;line-height:1}
.guide-carry{font-size:20px;color:var(--accent);font-weight:800}
.guide-numbers{min-height:56px}
.guide-numbers .guide-digit,.guide-answer .guide-digit{font-size:37px;font-weight:800;line-height:1.25}
.guide-sign{font-size:27px;font-weight:700}
.guide-answer{border-top:2px solid var(--ink);padding-top:9px;min-height:57px}
.guide-answer .guide-digit{color:var(--accent)}
.guide-overwrite{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:0;position:relative}
.guide-overwrite .guide-new{font-size:16px;color:var(--accent);font-weight:800;line-height:1}
.guide-overwrite .guide-old{font-size:30px;color:var(--ink);text-decoration:line-through;line-height:1.1}
.guide-explain{font-size:15px;line-height:1.8;min-height:3em;margin:8px auto 18px;max-width:26em}
.guide-next{width:100%;max-width:320px}
.guide-paper{text-align:center;font-size:13px;margin:8px 0 25px}
.guide-paper a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}

/* v0.14: かけ算の筆算は途中の積を位ごとに右揃えで示す。端末共通。 */
.guide-mul .guide-head,.guide-mul-row{display:grid;grid-template-columns:28px repeat(3,var(--col));align-items:center;justify-content:center}
.guide-mul-row{min-height:53px}
.guide-mul-row .guide-digit{font-size:35px;font-weight:800;line-height:1.3}
.guide-mul-line{border-top:2px solid var(--ink);margin:3px 0 5px}
.guide-mul-row.guide-partial .guide-digit{color:var(--ink)}
.guide-mul-row.guide-total .guide-digit{color:var(--accent)}
.hissan-subline{opacity:.3}

/* v0.15: 共通CSS。余りのある割り算は商と余りを別々に入力。 */
.answerbox-remainder{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:12px;max-width:400px;margin-inline:auto}
.answerbox-remainder label{font-size:13px;color:var(--muted);font-weight:700;display:grid;gap:6px;text-align:center}
.answerbox-remainder input{min-width:0;width:100%;border:1px solid #b6d4ca;border-radius:12px;text-align:center;font-size:30px;font-weight:750;color:var(--ink);background:#fff;min-height:65px}
.hissan-division{font-family:ui-monospace,SFMono-Regular,Consolas,monospace;display:flex;gap:4px;align-items:center;font-size:30px;font-weight:750}
.hissan-div-bracket{border-top:2px solid currentColor;border-left:2px solid currentColor;border-radius:8px 0 0 0;padding:7px 4px 1px 8px;letter-spacing:.04em}
.guide-mul .guide-head,.guide-mul-row{grid-template-columns:28px repeat(var(--guide-mul-cols,3),var(--col))}
/* v0.16: 商・わられる数・途中計算を共通の桁グリッドへ。 */
.guide-div{
  --div-cell:clamp(32px,10vw,44px);
  --div-side:48px;
  --div-bracket:11px;
  font-family:ui-monospace,SFMono-Regular,Consolas,monospace;
  font-variant-numeric:tabular-nums;
  width:max-content;
  max-width:100%;
  margin:12px auto 23px;
  font-size:30px;
  font-weight:750;
}
.guide-div-result,.guide-div-equation,.guide-div-workrow{
  display:grid;
  grid-template-columns:var(--div-side) var(--div-bracket) repeat(var(--div-len),var(--div-cell));
  align-items:end;
}
.guide-div-digits,.guide-div-workdigits{
  grid-column:3 / -1;
  display:grid;
  grid-template-columns:repeat(var(--div-len),var(--div-cell));
  text-align:center;
}
.guide-div-result{min-height:40px;color:var(--accent)}
.guide-div-equation{margin-top:1px}
.guide-div-divisor{font-size:30px;text-align:right;padding-right:4px}
.guide-div-bracket{border-top:2px solid var(--ink);border-left:2px solid var(--ink);border-radius:8px 0 0 0;min-height:45px}
.guide-div-number{border-top:2px solid var(--ink);min-height:45px}
.guide-div-workrow{min-height:39px;font-size:27px}
.guide-div-workdigits{position:relative;min-height:35px}
.guide-div-workrow.is-sub .guide-div-workdigits::after{
  content:"";position:absolute;
  left:calc(var(--div-cell) * var(--work-start));right:0;bottom:0;
  border-bottom:1px solid var(--muted);
}
.guide-div-work-sign{
  position:absolute;
  left:calc(var(--div-cell) * var(--work-start) - 24px);
  top:0;font-size:20px;line-height:1.4;
}

/* v0.17: 画面内テンキーだけを表示。ボタン型表示枠はソフトキーボードを起動しない。 */
.answerbox .answer-display{
  display:flex;align-items:center;justify-content:center;
  width:100%;min-height:66px;padding:8px 12px;
  border:2px solid #c9dad1;border-radius:14px;
  background:#fff;color:var(--ink);font-size:30px;font-weight:750;
  font-variant-numeric:tabular-nums;cursor:pointer;
}
.answerbox .answer-display .is-empty{color:var(--muted);font-size:17px;font-weight:650}
.answerbox-remainder .answer-part{display:flex;flex-direction:column;align-items:stretch;min-width:0;gap:6px}
.answerbox-remainder .answer-label{font-size:13px;color:var(--muted);font-weight:700;text-align:center}
.answerbox-remainder .answer-display{min-height:65px;border-width:1px;border-color:#b6d4ca;border-radius:12px}
.answerbox-remainder .answer-display.is-selected{border-width:2px;border-color:var(--accent);background:#f5faf7}
.answerbox .answer-display:focus-visible{outline:3px solid #6bbba7;outline-offset:2px}
.answerbox .answer-display:disabled{opacity:1;cursor:default}

/* v0.17: わる数・わられる数を同じ行高と中心位置に配置する。 */
.guide-div-equation{align-items:stretch}
.guide-div-equation .guide-div-divisor{
  display:flex;align-items:center;justify-content:flex-end;
  min-height:45px;padding-right:4px;line-height:1;border-top:2px solid transparent;
}
.guide-div-equation .guide-div-number{min-height:45px;align-items:center}
.guide-div-equation .guide-div-number>span{
  display:flex;align-items:center;justify-content:center;
  min-height:45px;line-height:1;
}

/* v0.18 小数点ボタンは答え枠に隣接。3列テンキーの大きさは変えない。 */
.decimal-answerbox{max-width:330px;display:grid;grid-template-columns:minmax(0,1fr) 54px;gap:9px;align-items:stretch}
.decimal-answerbox .decimal-insert{min-width:0;border:1px solid var(--line);background:#fff;border-radius:12px;color:var(--ink);font-size:27px;font-weight:800;min-height:66px}
.decimal-answerbox .decimal-insert:disabled{opacity:.45;cursor:not-allowed}

/* v0.19: 独立した端末別CSSは作らず、分数の表示と入力欄だけ追加。 */
.problem-button{margin-left:auto}
.math-fraction{display:inline-flex;vertical-align:middle;flex-direction:column;align-items:center;justify-content:center;font-variant-numeric:tabular-nums;font-size:.75em;line-height:1.05;margin:0 .12em;white-space:nowrap;min-width:1.15em}
.math-fraction>span{display:block;text-align:center;min-width:100%;padding:0 .09em}
.math-fraction>span:first-child{border-bottom:2px solid currentColor;padding-bottom:.07em}
.math-fraction>span:last-child{padding-top:.07em}
.problem-text.has-fractions{display:flex;justify-content:center;align-items:center;flex-wrap:wrap;white-space:pre-line;line-height:1.9;font-size:clamp(24px,5.5vw,38px)}
.fraction-figure{margin:14px auto 2px;max-width:270px;width:75%}
.fraction-bar{display:flex;min-height:40px;border:2px solid #437e72;border-radius:6px;overflow:hidden}
.fraction-segment{flex:1;min-width:0;background:#fff;border-right:1px solid #98b9ac}
.fraction-segment.is-filled{background:#80c8b2}
.fraction-segment:last-child{border-right:0}
.fraction-number-line{width:min(250px,80%);margin:24px auto 2px}
.fraction-number-track{position:relative;height:2px;background:#437e72;margin:22px 7px 14px}
.fraction-tick{position:absolute;top:-7px;width:2px;height:16px;background:#437e72;transform:translateX(-50%)}
.fraction-tick.is-current{height:20px;top:-9px;background:#13695b}
.fraction-tick.is-current::before{content:'';position:absolute;top:-16px;left:-6px;width:14px;height:14px;background:#13695b;border-radius:100%}
.fraction-endpoints{display:flex;justify-content:space-between;font-size:15px;color:var(--muted)}
.choice .math-fraction{font-size:1em}
.answerbox-fraction{display:flex;justify-content:center;margin:12px auto 16px}
.fraction-entry{display:flex;flex-direction:column;align-items:stretch;gap:6px;width:min(190px,55vw)}
.fraction-entry-line{height:3px;border-radius:2px;background:var(--ink)}
.answerbox-fraction .answer-display{height:62px;min-height:62px;padding:4px 10px;border:2px solid #c9dad1;border-radius:12px;background:#fff;color:var(--ink);font-size:28px;font-weight:750}
.answerbox-fraction .answer-display.is-selected{border-color:var(--accent);background:#f5faf7}
.answerbox-fraction .answer-display .is-empty{font-size:16px;font-weight:650;color:var(--muted)}
.answerbox-fraction .answer-display:disabled{opacity:1}

/* v0.21: selected short fraction questions remain one continuous line. */
.problem-text.has-fractions.fraction-compact {
  white-space:nowrap!important;flex-wrap:nowrap;overflow-wrap:normal;word-break:keep-all;
  font-size:clamp(14px,4.1vw,24px);line-height:1.4;letter-spacing:-.05em;
}
.problem-text.fraction-compact .math-fraction{flex-shrink:0;margin:0 .09em;}

/* v0.22: 10×10の100マス。単元の境界だけを少し太く囲む。 */
.hundred-grid{
  display:grid;grid-template-columns:repeat(10,minmax(0,1fr));
  width:min(100%,470px);margin:13px auto 21px;
  gap:0;
}
.hundred-cell{display:block;aspect-ratio:1;min-width:0;border:1px solid #fff;box-sizing:border-box}
.hundred-cell.status-upcoming{background:#e0e8e4}
.hundred-cell.status-practicing{background:#afd5ef}
.hundred-cell.status-checking{background:#f1d58d}
.hundred-cell.status-mastered{background:#a8dbb9}
.hundred-cell.edge-top{border-top:2px solid #53786e}
.hundred-cell.edge-bottom{border-bottom:2px solid #53786e}
.hundred-cell.edge-left{border-left:2px solid #53786e}
.hundred-cell.edge-right{border-right:2px solid #53786e}

/* v0.23: 方眼の具体例と印刷入口。余計な説明を計算画面へ追加しない。 */
.worksheet-example{margin:12px 0 18px;padding:17px 8px;background:#f8faf8;border:1px solid var(--line);border-radius:12px;text-align:center}
.worksheet-example-grid{display:grid;grid-template-columns:repeat(4,38px);width:max-content;margin:0 auto;color:var(--ink)}
.worksheet-example-cell{height:38px;display:flex;align-items:center;justify-content:center;border-right:1px solid #a5c4bd;border-bottom:1px solid #a5c4bd;font-size:24px;font-weight:750;font-variant-numeric:tabular-nums;background:#fff}
.worksheet-example-cell:nth-child(-n+4){border-top:1px solid #a5c4bd}
.worksheet-example-cell:nth-child(4n+1){border-left:1px solid #a5c4bd}
.worksheet-example-cell.example-answer{border-top:2px solid var(--ink)}
.worksheet-example-cell.example-carry{align-items:end;font-size:16px;color:var(--accent);padding-bottom:2px}
.worksheet-example-cell.example-sign{font-size:22px}
.worksheet-example figcaption{font-size:12px;line-height:1.7;margin:10px auto 0;color:var(--muted)}
.worksheet-print{display:flex;flex-direction:column;align-items:flex-start;gap:9px;margin:13px 0 20px}
.worksheet-print-main{border-radius:11px;padding:12px 15px;background:var(--accent);color:#fff;text-decoration:none;line-height:1.6}
.worksheet-print-other{display:flex;align-items:center;flex-wrap:wrap;gap:9px;font-size:12px;color:var(--muted)}
.worksheet-print-other a{color:var(--accent);text-decoration:underline;text-underline-offset:2px;padding:5px 2px;font-weight:700}
/* 不規則な領域をもつ100マスをマイページへ。4色は学習状態のみを表す。 */
.hundred-section{margin:10px 0 27px}
.hundred-section h2{font-size:18px;margin:22px 0 10px}
.hundred-section .hundred-grid{margin:0 auto;width:min(100%,470px)}
.hundred-cell.edge-top{border-top-width:2.5px}
.hundred-cell.edge-bottom{border-bottom-width:2.5px}
.hundred-cell.edge-left{border-left-width:2.5px}
.hundred-cell.edge-right{border-right-width:2.5px}
.footer-nav{flex-wrap:wrap}