:root {
  --ink: #1f2328; --sub: #5b636e; --line: #d8dde3; --bg: #f6f4ee; --card: #fff;
  --accent: #1d7a5f; --accent-2: #e8f3ee; --warn: #b4462b; --red: #d0342c;
  --z: 1;
  --font-ui: system-ui, -apple-system, "Hiragino Sans", "Noto Sans JP", "Yu Gothic UI", sans-serif;
  --font-sheet: "Klee One", "UD デジタル 教科書体 N-R", "UD Digi Kyokasho N-R", "YuKyokasho", "Hiragino Maru Gothic ProN", sans-serif;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font-family: var(--font-ui); line-height: 1.7; }
a { color: var(--accent); }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 16px; }
.site-head { background: var(--card); border-bottom: 1px solid var(--line); }
.site-head .wrap { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 56px; }
.logo { font-weight: 700; font-size: 18px; color: var(--ink); text-decoration: none; display: flex; align-items: center; gap: 8px; }
.logo b { display: inline-grid; place-items: center; width: 30px; height: 30px; border-radius: 8px; background: var(--accent); color: #fff; font-size: 15px; }
.site-head nav a { margin-left: 14px; font-size: 14px; color: var(--sub); text-decoration: none; }
.site-head nav a.pro { color: var(--accent); font-weight: 700; }
.crumb { font-size: 13px; color: var(--sub); margin: 14px 0 0; }
.crumb a { color: var(--sub); }
h1 { font-size: clamp(22px, 4vw, 30px); line-height: 1.35; margin: 10px 0 6px; }
.lead { color: var(--sub); margin: 0 0 16px; }
.site-foot { margin-top: 48px; padding: 24px 0 40px; border-top: 1px solid var(--line); font-size: 13px; color: var(--sub); }
.site-foot a { color: var(--sub); margin-right: 14px; }

/* トップ */
.hero { padding: 28px 0 8px; }
.hero h1 { font-size: clamp(24px, 5vw, 36px); }
.points { display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 0 0 20px; list-style: none; }
.points li { background: var(--card); border: 1px solid var(--line); border-radius: 999px; padding: 4px 12px; font-size: 14px; }
.tabs { display: flex; gap: 6px; overflow-x: auto; padding-bottom: 4px; position: sticky; top: 0; background: var(--bg); z-index: 2; padding-top: 8px; }
.tabs button { flex: 0 0 auto; font: inherit; font-weight: 700; border: 1px solid var(--line); background: var(--card); color: var(--ink); border-radius: 10px; padding: 8px 16px; min-height: 44px; cursor: pointer; }
.tabs button[aria-selected="true"] { background: var(--accent); color: #fff; border-color: var(--accent); }
.unit { margin: 18px 0; }
.unit h3 { font-size: 15px; color: var(--sub); margin: 0 0 8px; font-weight: 600; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 10px; }
.card { display: block; background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px; text-decoration: none; color: var(--ink); min-height: 44px; }
.card:hover { border-color: var(--accent); }
.card b { display: block; font-size: 16px; }
.card span { font-size: 13px; color: var(--sub); }

/* 操作パネル */
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 14px; margin: 12px 0 16px; display: grid; gap: 12px; }
.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.btn { font: inherit; font-weight: 700; border: 0; border-radius: 10px; padding: 10px 18px; min-height: 46px; cursor: pointer; background: var(--accent); color: #fff; }
.btn.sub { background: var(--accent-2); color: var(--accent); }
.btn.ghost { background: transparent; border: 1px solid var(--line); color: var(--ink); font-weight: 500; }
.chk { display: inline-flex; align-items: center; gap: 6px; min-height: 44px; }
.chk input { width: 20px; height: 20px; }
.pro-box { border-top: 1px dashed var(--line); padding-top: 12px; display: grid; gap: 10px; }
.pro-box h2 { font-size: 15px; margin: 0; display: flex; gap: 8px; align-items: center; }
.tag { font-size: 12px; background: #fff4d6; color: #7a5400; border-radius: 6px; padding: 1px 8px; font-weight: 700; }
.is-pro .tag { background: var(--accent-2); color: var(--accent); }
.pro-box label { display: inline-flex; gap: 6px; align-items: center; }
.pro-box input[type=text], .pro-box select { font: inherit; padding: 8px 10px; border: 1px solid var(--line); border-radius: 8px; min-height: 44px; }
.pro-box input:disabled, .pro-box select:disabled { background: #f1f1f1; }
.pro-note { font-size: 13px; color: var(--sub); margin: 0; }
.is-pro .pro-note.free { display: none; }
#msg { font-size: 14px; color: var(--accent); min-height: 1em; margin: 0; }

/* プレビュー（画面ではA4を縮小） */
.preview { overflow: hidden; }
#sheets { zoom: var(--z); }
.sheet { background: #fff; box-shadow: 0 1px 4px rgba(0,0,0,.15); margin: 0 auto 16px; }
.info { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 6px 18px 12px; margin-top: 16px; font-size: 15px; }
.info h2 { font-size: 17px; }
.info dt { font-weight: 700; margin-top: 10px; }
.info dd { margin: 0; color: var(--sub); }
.related { display: flex; flex-wrap: wrap; gap: 8px; }
.related a { background: var(--card); border: 1px solid var(--line); border-radius: 999px; padding: 6px 12px; text-decoration: none; font-size: 14px; }
.wk { position: absolute; right: 2mm; top: 1mm; font: 13px var(--font-ui); color: var(--warn); background: #fff8f5; border: 1px solid #f0c8bd; border-radius: 6px; padding: 0 6px; display: inline-flex; gap: 4px; align-items: center; cursor: pointer; }

/* ====== プリント本体（mm 指定・A4） ====== */
.sheet { width: 210mm; height: 296.5mm; padding: 11mm 13mm 8mm; display: flex; flex-direction: column; overflow: hidden; font-family: var(--font-sheet); color: #111; position: relative; }
.sh-head { border-bottom: 0.5mm solid #111; padding-bottom: 2mm; margin-bottom: 4mm; }
.sh-title { display: flex; align-items: center; gap: 3mm; }
.sh-title h2 { font-size: 6.4mm; margin: 0; font-weight: 600; line-height: 1.3; }
.grade { border: 0.4mm solid #111; border-radius: 1.5mm; padding: 0 2mm; font-size: 4mm; font-weight: 600; }
.sh-meta { display: flex; justify-content: flex-end; gap: 6mm; margin-top: 2mm; font-size: 4.2mm; }
.sh-meta .f { border-bottom: 0.3mm solid #111; padding: 0 1mm; min-width: 26mm; }
.sh-meta .name { min-width: 62mm; }
.sh-meta .nm { font-size: 5mm; margin-left: 2mm; }
.sh-meta .score { min-width: 22mm; text-align: right; }
.sh-meta .score i { display: inline-block; width: 12mm; }
.answer .sh-head { border-bottom-color: var(--red); }
.answer .sh-title h2 { color: var(--red); }
.sh-body { flex: 1; min-height: 0; display: grid; column-gap: 8mm; }
.sh-foot { display: flex; justify-content: space-between; font: 2.8mm var(--font-ui); color: #777; padding-top: 2mm; }
.red { color: var(--red); }
.it { position: relative; display: flex; align-items: center; gap: 2mm; min-width: 0; }
.no { font-size: 3.6mm; color: #555; flex: 0 0 auto; }
/* 分数 */
.mx { display: inline-flex; align-items: center; vertical-align: middle; }
.mx .w { margin-right: 0.6mm; }
.fr { display: inline-flex; flex-direction: column; align-items: center; vertical-align: middle; font-size: 0.78em; line-height: 1.12; margin: 0 0.6mm; }
.fr .fn { border-bottom: 0.3mm solid currentColor; padding: 0 0.8mm; }
.bx { display: inline-block; width: 1.4em; height: 1.2em; border: 0.35mm solid #111; vertical-align: middle; margin: 0 0.5mm; }

/* 横式 */
.L-h { grid-template-columns: repeat(var(--cols), 1fr); grid-auto-flow: column; grid-template-rows: repeat(var(--rows), 1fr); }
.L-h .it { font-size: 7.2mm; border-bottom: 0.2mm dotted #bbb; }
.L-h.cols-3 .it { font-size: 6.2mm; }
.L-h .eq { margin: 0 1.5mm; }
.L-h .ans { flex: 1; }
.L-h .ans.red { font-size: 0.95em; }
.L-h .it.t { font-size: 5.4mm; flex-wrap: wrap; }
.L-h .it.t .q { flex: 1 1 auto; }
.L-h .it.t .ans { flex: 0 0 auto; min-width: 40mm; }
.L-h .it.t .ans.line { border-bottom: 0.3mm solid #111; height: 7mm; }
.L-h .arrow { font-size: 3.6mm; color: var(--red); }
.L-h.cols-1 .it { font-size: 5.6mm; }
.L-h.cols-1 .it.t .ans { min-width: 60mm; }
/* 筆算 */
.L-v { grid-template-columns: repeat(var(--cols), 1fr); grid-template-rows: repeat(var(--rows), 1fr); }
.L-v .it { align-items: flex-start; padding-top: 2mm; }
.hs { border-collapse: collapse; font-size: 7.5mm; margin-left: 2mm; }
.hs td { width: 9mm; height: 10.5mm; text-align: center; border: 0.15mm dashed #ccc; padding: 0; }
.hs tr.bar td { border-bottom: 0.45mm solid #111; }
.L-v.cols-3 .hs td { width: 10mm; height: 11mm; }
/* わり算の筆算 */
.L-ld { grid-template-columns: repeat(var(--cols), 1fr); grid-template-rows: repeat(var(--rows), 1fr); }
.L-ld .it { align-items: flex-start; padding-top: 2mm; }
.ldw { font-size: 7.4mm; margin-left: 2mm; }
.ldw .c { display: inline-block; width: 8.5mm; text-align: center; }
.ldq { padding-left: 13mm; height: 10mm; }
.ldr { display: flex; align-items: stretch; }
.ldy { width: 11mm; text-align: right; padding-right: 2mm; }
.ldx { border-top: 0.45mm solid #111; border-left: 0.45mm solid #111; border-top-left-radius: 4mm 9mm; padding-left: 1mm; }
.ldrem { font-size: 4.6mm; margin-top: 2mm; padding-left: 13mm; }
/* 時計 */
.L-clock { grid-template-columns: repeat(var(--cols), 1fr); grid-template-rows: repeat(var(--rows), 1fr); }
.L-clock .it { flex-direction: column; align-items: center; justify-content: center; }
.L-clock .no { align-self: flex-start; }
.clock { width: 52mm; height: 52mm; }
.ckans { font-size: 5mm; margin-top: 1mm; }
/* 漢字（たて書き） */
.L-kw, .L-kr { display: flex; flex-direction: row-reverse; justify-content: space-between; }
.L-kw .it, .L-kr .it { writing-mode: vertical-rl; display: flex; flex-direction: row; justify-content: flex-start; align-items: center; height: 100%; width: 18mm; gap: 4mm; border-left: 0.2mm dotted #bbb; padding: 2mm 0; }
.L-kw .it:last-child, .L-kr .it:last-child { border-left: 0; }
.L-kw .no, .L-kr .no { font-size: 4mm; text-combine-upright: all; }
.L-kw .wd { font-size: 9mm; line-height: 1; display: flex; flex-direction: row; align-items: center; }
.L-kw ruby { ruby-position: over; }
.L-kw rt { font-size: 3.6mm; }
.kb { display: inline-block; width: 14mm; height: 14mm; border: 0.4mm solid #111; margin: 0.3mm 0; text-align: center; line-height: 13mm; font-size: 10mm; background: linear-gradient(#ddd, #ddd) center/100% 0.2mm no-repeat, linear-gradient(90deg, #ddd, #ddd) center/0.2mm 100% no-repeat; }
.L-kw .kn { font-size: 8mm; }
.L-kr .wd { font-size: 9mm; line-height: 1.15; }
.L-kr .kk { display: inline-flex; flex-direction: column-reverse; align-items: stretch; }
.L-kr .ul { text-decoration: underline; text-decoration-thickness: 0.3mm; text-underline-offset: 1mm; }
.L-kr .blank { display: block; border: 0.3mm solid #111; block-size: 6.5mm; margin-block-end: 1mm; font-size: 4.2mm; line-height: 6.5mm; text-align: center; }
.answer .L-kr .blank, .L-kr .blank.none { border-color: transparent; }
.L-kr .it { gap: 6mm; }
/* なぞり練習 */
.L-kt { display: flex; flex-direction: column; justify-content: space-between; }
.L-kt .it { gap: 1.2mm; }
.tb { width: 18.5mm; height: 18.5mm; border: 0.35mm solid #111; display: inline-grid; place-items: center; font-size: 14.5mm; line-height: 1; flex: 0 0 auto; background: linear-gradient(90deg, transparent calc(50% - 0.1mm), #ccc calc(50% - 0.1mm), #ccc calc(50% + 0.1mm), transparent calc(50% + 0.1mm)), linear-gradient(transparent calc(50% - 0.1mm), #ccc calc(50% - 0.1mm), #ccc calc(50% + 0.1mm), transparent calc(50% + 0.1mm)); }
.tb.model { background: #fff; font-weight: 600; }
.tb.trace { color: #c9c9c9; }
.exw { font-size: 4.2mm; padding-left: 1mm; flex: 1; min-width: 0; }
.exw rt { font-size: 2.6mm; }

/* ====== 印刷 ====== */
@page { size: A4 portrait; margin: 0; }
@media print {
  html, body { background: #fff; }
  .no-print, .site-head, .site-foot, .panel, .crumb, h1, .lead, .info, .related-wrap, .ad { display: none !important; }
  .wrap { max-width: none; padding: 0; }
  #sheets { zoom: 1 !important; }
  .sheet { box-shadow: none; margin: 0; break-after: page; page-break-after: always; }
  .sheet:last-child { break-after: auto; page-break-after: auto; }
  .red { color: var(--red); -webkit-print-color-adjust: exact; print-color-adjust: exact; }
}
@media (max-width: 640px) {
  .site-head nav a:not(.pro) { display: none; }
  .btn { flex: 1 1 auto; }
}

/* Pro ページ */
.plans { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 12px; margin: 16px 0; }
.plan { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px; }
.plan h3 { margin: 0 0 6px; }
.license { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px; display: grid; gap: 10px; max-width: 560px; }
.license input { font: inherit; padding: 10px; border: 1px solid var(--line); border-radius: 8px; min-height: 46px; width: 100%; }
#pro-state { font-weight: 700; }
#pro-state.on { color: var(--accent); }
a.btn { display: inline-block; text-decoration: none; text-align: center; }
a.btn.disabled { background: #bbb; pointer-events: none; }
.doc { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 4px 20px 16px; }
.doc h2 { font-size: 18px; margin-top: 22px; }