:root{
  --bg:#f6f7fb;
  --card:#ffffff;
  --line:#d9dfeb;
  --text:#1f2937;
  --muted:#6b7280;
  --accent:#2563eb;
  --accent-soft:#dbeafe;
  --shadow:0 10px 30px rgba(15, 23, 42, .08);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Hiragino Sans","Yu Gothic UI","Yu Gothic",Meiryo,sans-serif;
  color:var(--text);
  background:linear-gradient(180deg,#f9fbff 0%, var(--bg) 100%);
}
a{color:inherit;text-decoration:none}
.container{max-width:1120px;margin:0 auto;padding:32px 20px 56px}
.hero{margin-bottom:28px}
.hero h1{margin:0 0 10px;font-size:34px;line-height:1.2}
.hero p{margin:0;color:var(--muted);font-size:15px}
.card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:20px;
  box-shadow:var(--shadow);
}
.home-card{padding:26px}
.section-label{font-size:14px;font-weight:700;color:var(--muted);margin-bottom:12px}
.tab-row{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:24px}
.tab-input{display:none}
.tab-label{
  padding:12px 20px;border-radius:999px;border:1px solid var(--line);background:#fff;cursor:pointer;
  font-weight:700;transition:.18s ease;user-select:none;
}
.tab-input:checked + .tab-label{
  background:var(--accent-soft);border-color:#93c5fd;color:#1d4ed8;
}
.grid-links{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-top:20px}
.link-card{
  padding:18px;border:1px solid var(--line);border-radius:16px;background:#fff;transition:.18s ease;
}
.link-card:hover{transform:translateY(-1px);box-shadow:var(--shadow)}
.link-title{font-weight:800;margin-bottom:6px}
.link-meta{font-size:13px;color:var(--muted)}
.status-ready{display:inline-block;margin-top:10px;padding:4px 8px;border-radius:999px;background:#ecfdf5;color:#047857;font-size:12px;font-weight:700}
.status-wip{display:inline-block;margin-top:10px;padding:4px 8px;border-radius:999px;background:#fff7ed;color:#c2410c;font-size:12px;font-weight:700}
.primary-bar{display:flex;flex-wrap:wrap;gap:12px;align-items:center;justify-content:space-between;margin-top:24px}
.primary-button, button, select{
  font:inherit;
}
.primary-button, .secondary-button, button{
  border:none;border-radius:14px;padding:12px 18px;cursor:pointer;font-weight:800;
}
.primary-button, button.primary{background:var(--accent);color:#fff}
.secondary-button, button.secondary{background:#eef2ff;color:#3730a3}
.info-box{padding:16px 18px;border-radius:16px;background:#f8fafc;border:1px solid var(--line);font-size:14px;color:var(--muted)}
.header-row{display:flex;flex-wrap:wrap;gap:16px;align-items:flex-end;justify-content:space-between;margin-bottom:18px}
.header-actions{display:flex;gap:10px;flex-wrap:wrap}
.controls{
  padding:18px;display:flex;flex-wrap:wrap;gap:12px;align-items:end;margin-bottom:24px;
}
.control-group{display:flex;flex-direction:column;gap:8px;min-width:120px}
.control-group label{font-size:13px;color:var(--muted);font-weight:700}
select{
  border:1px solid var(--line);border-radius:12px;padding:10px 12px;background:#fff;min-width:120px;
}
.notice{margin-bottom:18px;padding:14px 16px;border-radius:14px;background:#eff6ff;border:1px solid #bfdbfe;color:#1d4ed8;font-size:14px}
.page{
  width:210mm;
  height:297mm;
  background:#fff;
  margin:0 auto 20px;
  padding:10mm 10mm 22mm;
  box-sizing:border-box;
  display:block;
  page-break-after:always;
  border:1px solid #e5e7eb;
  overflow:hidden;
}
.sheet-header{
  grid-column:1 / -1;display:flex;justify-content:space-between;align-items:center;
  border-bottom:1px solid #cbd5e1;padding-bottom:4mm;margin-bottom:1mm;font-size:14px;font-weight:700;color:#334155;
}
.problem{position:relative;width:100%;height:100%;padding-top:8px}
.number-top,.number-bottom{text-align:right;font-size:28px;letter-spacing:1px}
.operator{position:absolute;left:calc(100% - 92px);top:36px;font-size:28px;font-weight:700}
.line{border-bottom:2px solid #000;width:92px;margin-left:auto;margin-top:4px}
.problem-number{position:absolute;top:-4px;left:0;font-size:15px;color:#475569}
.page-actions{display:flex;flex-wrap:wrap;gap:10px}
.ready-panel, .placeholder-panel{padding:24px}
.placeholder-panel h2{margin-top:0;margin-bottom:10px}
.placeholder-panel p{color:var(--muted);line-height:1.8}
.coming-list{margin:14px 0 0;padding-left:1.2em;color:var(--muted)}
.footer-nav{margin-top:22px;display:flex;gap:12px;flex-wrap:wrap}
.small-note{font-size:13px;color:var(--muted)}
@media print{
  body{background:#fff}
  .no-print{display:none !important}
  .container{max-width:none;padding:0}
  .page{margin:0;border:none;box-shadow:none}
}
.page-preview{
  width:100%;
  display:flex;
  justify-content:center;
  margin:0 auto 20px;
}
.page-preview.is-scaled{
  overflow:visible;
}
.page-scale-box{
  position:relative;
  width:210mm;
  min-height:297mm;
}
.page-scale-box .page{
  position:absolute;
  left:0;
  top:0;
  margin:0;
  transform-origin:top left;
}
.problem-grid{
  grid-column:1 / -1;
  display:grid;
  grid-template-columns:repeat(3, 1fr);
  grid-template-rows:repeat(6, 1fr);
  grid-auto-flow:column;
  gap:8mm 15mm;
  height:calc(297mm - 10mm - 22mm);
}
@media (max-width:900px){
  .hero h1{font-size:28px}
}
@media (max-width:640px){
  .container{padding:18px 8px 28px}
  .header-row{gap:10px;margin-bottom:10px}
  .header-row h1{font-size:24px;margin:0}
  .section-label{font-size:12px;margin-bottom:6px}
  .small-note{font-size:12px}
  .notice{font-size:12px;padding:10px 12px;margin-bottom:12px}
  .controls{padding:10px 8px;gap:6px;align-items:center;justify-content:flex-start}
  .control-group{min-width:auto;gap:4px}
  .control-group label{font-size:11px}
  select{min-width:56px;padding:6px 8px;border-radius:8px;font-size:12px}
  .page-actions{gap:6px}
  button.primary, button.secondary, .secondary-button{padding:8px 10px;border-radius:8px;font-size:12px}
}
@media print{
  .page-preview{display:block;margin:0}
  .page-scale-box{width:auto !important;height:auto !important}
  .page-scale-box .page{position:static;transform:none !important}
}

/* ===================== 横式ページ ===================== */
.page-horizontal{
  display:block;
  padding:10mm 12mm 8mm;
}
.page-horizontal .sheet-header{
  display:flex;justify-content:space-between;align-items:center;
  border-bottom:1px solid #cbd5e1;padding-bottom:3mm;margin-bottom:5mm;
  font-size:13px;font-weight:700;color:#334155;
}
.problem-horizontal-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  grid-template-rows: repeat(10, 1fr);
  gap:0 8mm;
  height:calc(297mm - 10mm - 8mm - 3mm - 5mm - 10mm); /* A4高さからpadding・header引いた分 */
}
.problem-horizontal{
  display:flex;
  align-items:center;
  gap:5px;
  font-size:20px;
  white-space:nowrap;
  border-bottom:1px solid #e5e7eb;
  padding:0 4px;
}
.prob-num{
  font-size:13px;color:#475569;min-width:26px;flex-shrink:0;
}
.prob-expr{
  font-size:20px;letter-spacing:1px;
}
.prob-answer-box{
  display:inline-block;
  width:48px;
  border-bottom:2px solid #000;
  height:1.1em;
  vertical-align:middle;
  flex-shrink:0;
}
.prob-rem-label{
  font-size:13px;color:#475569;margin-left:2px;flex-shrink:0;
}

/* ===================== 割り算ひっ算 ===================== */
.problem-div-hissan{
  position:relative;
  width:100%;
  height:100%;
  padding-top:8px;
  display:flex;
  flex-direction:column;
  justify-content:flex-end;
}
.div-hissan-wrap{
  display:flex;
  align-items:flex-end;
  justify-content:flex-end;
}
.div-divisor{
  font-size:28px;
  line-height:1;
  margin-bottom:2px;
}
.div-right{
  display:flex;
  flex-direction:column;
  align-items:stretch;
}
.div-answer-line{
  display:block;
  border-top:2px solid #000;
  width:100%;
  margin-bottom:2px;
}
.div-bracket-dividend{
  display:flex;
  align-items:flex-end;
}
.div-bracket{
  font-size:34px;
  line-height:1;
  display:block;
  margin-bottom:-3px;
}
.div-dividend{
  font-size:28px;
  line-height:1;
  padding-left:3px;
  letter-spacing:3px;
  margin-bottom:1px;
}

/* ===================== 割り算ひっ算専用グリッド ===================== */
.problem-grid-division{
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(4, 1fr);
  height: calc(297mm - 10mm - 22mm);
}
.problem-grid-division .problem-div-hissan{
  padding-top: 6mm;
  justify-content: flex-start;
}
.problem-grid-division .div-hissan-wrap{
  margin-top: 10mm;
}

/* ===================== タブレットモード UI ===================== */
#tablet-bar{
  margin-bottom: 16px;
}
.tb-row{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}
.tb-toggle{
  font: inherit;
  font-weight: 800;
  font-size: 14px;
  padding: 10px 18px;
  border-radius: 14px;
  border: 2px solid #d1d5db;
  background: #f9fafb;
  color: #374151;
  cursor: pointer;
  transition: .15s ease;
  white-space: nowrap;
}
.tb-toggle.active{
  background: #eff6ff;
  border-color: #3b82f6;
  color: #1d4ed8;
}
.tb-tools{
  display: none;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.tb-tools.tb-tools-visible{
  display: flex;
}
.tb-group{
  display: flex;
  gap: 6px;
  align-items: center;
  background: #f1f5f9;
  border-radius: 12px;
  padding: 4px 8px;
}
.tb-tool{
  font: inherit;
  font-size: 13px;
  font-weight: 700;
  padding: 6px 12px;
  border-radius: 8px;
  border: none;
  background: transparent;
  color: #475569;
  cursor: pointer;
  transition: .12s ease;
}
.tb-tool.active{
  background: #fff;
  color: #1d4ed8;
  box-shadow: 0 1px 4px rgba(0,0,0,.12);
}
.tb-colors{
  gap: 6px;
}
.tb-color{
  width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 3px solid transparent;
  cursor: pointer;
  transition: .12s ease;
  padding: 0;
}
.tb-color.active{
  border-color: #fff;
  box-shadow: 0 0 0 2px #3b82f6;
}
.tb-size-group{
  gap: 8px;
}
.tb-size-label{
  font-size: 12px;
  color: #64748b;
  font-weight: 700;
  white-space: nowrap;
}
#tb-size{
  width: 80px;
  cursor: pointer;
  accent-color: #3b82f6;
}
.tb-clear{
  font: inherit;
  font-size: 13px;
  font-weight: 700;
  padding: 6px 12px;
  border-radius: 10px;
  border: none;
  background: #fee2e2;
  color: #dc2626;
  cursor: pointer;
  transition: .12s ease;
}
.tb-clear:hover{
  background: #fecaca;
}

/* タブレットモード中はテキスト選択を無効にして誤反応防止 */
.tablet-mode-active .page,
.tablet-mode-active .page *{
  user-select: none;
  -webkit-user-select: none;
}

/* Canvas が乗るので .page-scale-box を relative に */
.page-scale-box{
  position: relative;
}

@media (max-width:640px){
  .tb-toggle{ font-size:12px; padding:8px 12px; }
  .tb-tool{ font-size:12px; padding:5px 8px; }
  #tb-size{ width:60px; }
}

/* ===================== 分数表示 ===================== */
.frac{
  display:inline-flex;
  flex-direction:column;
  align-items:center;
  vertical-align:middle;
  margin:0 2px;
  line-height:1;
}
.frac-num{
  border-bottom:1.5px solid #000;
  padding:0 4px 2px;
  font-size:17px;
  font-weight:700;
  text-align:center;
  min-width:16px;
}
.frac-den{
  padding:2px 4px 0;
  font-size:17px;
  font-weight:700;
  text-align:center;
  min-width:16px;
}

/* ===================== 分数・小数 問題グリッド ===================== */
.problem-frac-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  grid-template-rows:repeat(10,1fr);
  height:calc(297mm - 10mm - 22mm);
}
.problem-frac-item{
  display:flex;
  align-items:center;
  gap:4px;
  padding:0 8px;
  border-bottom:1px solid #e5e7eb;
  min-height:0;
  overflow:hidden;
}
.prob-num-label{
  font-size:12px;
  color:#475569;
  min-width:24px;
  flex-shrink:0;
}
.prob-frac-expr{
  display:flex;
  align-items:center;
  gap:6px;
  white-space:nowrap;
}
.prob-op{
  font-size:18px;
  font-weight:700;
  flex-shrink:0;
}
.prob-eq{
  font-size:18px;
  flex-shrink:0;
}
.prob-blank-line{
  display:inline-block;
  width:56px;
  flex-shrink:0;
  vertical-align:middle;
}
.prob-dec-num{
  font-size:19px;
  font-weight:700;
}

/* ===================== タブレット設定パネル ===================== */
.tb-settings-btn{
  font:inherit;font-size:13px;font-weight:700;
  padding:6px 12px;border-radius:10px;
  border:1px solid var(--line);background:#f8fafc;
  color:#475569;cursor:pointer;transition:.13s;
}
.tb-settings-btn.active{background:#eff6ff;border-color:#93c5fd;color:#1d4ed8;}

.tb-settings-panel{
  display:none;
  background:#f8fafc;border:1px solid var(--line);
  border-radius:14px;padding:0;
  margin-top:8px;overflow:hidden;
  transition:.2s ease;
}
.tb-settings-panel.tb-settings-panel-open{
  display:block;
}
.tb-settings-inner{
  padding:14px 18px;
  display:flex;flex-direction:column;gap:14px;
}
.tb-setting-row{
  display:flex;align-items:center;gap:12px;flex-wrap:wrap;
}
.tb-setting-label{
  font-size:13px;font-weight:700;color:#475569;
  min-width:120px;flex-shrink:0;
}
.tb-setting-val{
  font-size:13px;font-weight:800;color:#1d4ed8;
  min-width:28px;text-align:right;
}
.tb-setting-note{
  font-size:12px;color:#94a3b8;
}
.tb-settings-inner input[type="range"]{
  width:160px;accent-color:#3b82f6;cursor:pointer;
}

/* ---- トグルスイッチ ---- */
.tb-toggle-switch{
  position:relative;display:inline-block;
  width:42px;height:24px;flex-shrink:0;cursor:pointer;
}
.tb-toggle-switch input{opacity:0;width:0;height:0;}
.tb-toggle-slider{
  position:absolute;inset:0;
  background:#d1d5db;border-radius:999px;transition:.2s;
}
.tb-toggle-slider::before{
  content:'';position:absolute;
  width:18px;height:18px;border-radius:50%;
  background:#fff;left:3px;top:3px;transition:.2s;
  box-shadow:0 1px 3px rgba(0,0,0,.2);
}
.tb-toggle-switch input:checked + .tb-toggle-slider{background:#3b82f6;}
.tb-toggle-switch input:checked + .tb-toggle-slider::before{transform:translateX(18px);}

@media(max-width:640px){
  .tb-settings-inner input[type="range"]{width:110px;}
  .tb-setting-label{min-width:90px;font-size:12px;}
}

/* タブレットモード中のテキスト選択・長押しメニューを無効化 */
.tablet-mode-active .page,
.tablet-mode-active .page *,
.tablet-mode-active .page-scale-box canvas {
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}

/* ===================== 答えページ ===================== */
.answer-page{
  padding: 12mm 14mm;
}
.answer-page-header{
  font-size: 16px;
  font-weight: 800;
  color: #334155;
  border-bottom: 2px solid #cbd5e1;
  padding-bottom: 4mm;
  margin-bottom: 6mm;
  letter-spacing: .5px;
}
.answer-section{
  margin-bottom: 8mm;
}
.answer-section-label{
  font-size: 12px;
  font-weight: 700;
  color: #64748b;
  margin-bottom: 4mm;
}
.answer-grid{
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4mm 6mm;
}
.answer-item{
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 15px;
}
.answer-num{
  font-size: 12px;
  color: #64748b;
  min-width: 24px;
}
.answer-val{
  font-size: 15px;
  font-weight: 800;
  color: #1e40af;
}

/* 答えページは高さauto（fixed heightを上書き） */
.page.answer-page{
  height: auto;
  min-height: 100mm;
}

/* ===== ページロゴ ===== */
.page-logo-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  margin-bottom: 8px;
  width: 100%;
  text-align: center;
}
.page-logo-area img {
  height: 64px;
  width: auto;
}
.page-logo-area .logo-text {
  font-size: 26px;
  font-weight: 900;
  color: #1e293b;
  letter-spacing: 0.05em;
  line-height: 1;
}
.page-logo-area .logo-sub {
  font-size: 12px;
  color: #94a3b8;
  font-weight: 500;
  letter-spacing: 0.1em;
}