/* 入力・行追加・再選択で紙面を動かさない。スクロールは利用者の操作のみ。 */
body{height:100svh;height:100dvh;min-height:0;overflow:hidden;display:flex;flex-direction:column}
body>.pair-header{flex-shrink:0}
.app{flex:1 1 auto;min-height:0;overflow:hidden}
.app>header{flex:none}
.brand{font-size:16px;letter-spacing:0;white-space:nowrap}
main#stream,.editing main#stream{display:block;flex:1 1 auto;min-height:0;width:100%;margin:0;padding:32px 20px calc(280px + env(safe-area-inset-bottom));overflow:auto;overscroll-behavior:contain;scroll-behavior:auto;overflow-anchor:none}
.rows{width:min(820px,100%);margin:0 auto;display:flex;flex-direction:column;align-items:center;gap:30px}
.row{width:100%;flex:none;display:flex;flex-direction:column;align-items:center}
.row:not(.active),.row:not(.active) button{cursor:pointer}
.formula-wrap{width:100%;--number-size:68px}
.formula{width:100%;display:grid;grid-template-columns:minmax(0,3fr) minmax(0,1.5fr);gap:24px;align-items:center}
.expression{display:grid;grid-template-columns:minmax(0,1fr) 60px minmax(0,1fr);gap:12px;align-items:center;min-width:0;width:100%}
.result-group{display:grid;grid-template-columns:60px minmax(0,1fr);gap:12px;align-items:center;min-width:0;margin:0}
.formula .num{display:flex;align-items:center;justify-content:center;width:100%;min-width:0;height:88px;min-height:0;padding:0 4px;white-space:nowrap;overflow:hidden;font-size:var(--number-size);line-height:1;letter-spacing:0}
.formula .op,.formula .equals{display:flex;align-items:center;justify-content:center;width:60px;height:88px;margin:0;padding:0;line-height:1;font-size:48px;letter-spacing:0}
.formula .op.unset{font-size:40px}
.paper .row-hit{width:100%;height:100%;border:0;padding:0;background:transparent;border-radius:10px;grid-column:2/-1}
.paper .row-hit.selected{background:var(--soft);box-shadow:inset 0 -1.5px 0 var(--ink)}
.paper .digit{pointer-events:none;position:relative;z-index:1}
.paper .digit.placeholder{color:#aaa}
.paper .operator{border:0;background:transparent;padding:0;width:100%;height:100%;font:inherit;font-size:46px;line-height:1;align-self:center;display:flex;align-items:center;justify-content:center}
.paper .operator.unset{color:#aaa;font-size:30px}
.paper .operator.selected{background:var(--soft);border-radius:10px}
button{-webkit-appearance:none;appearance:none}
/* 通常の数字・小数字・演算記号は、同じ下部領域に表示する。 */
.keypad,.operator-menu{position:fixed;z-index:5;left:50%;bottom:calc(14px + env(safe-area-inset-bottom));transform:translateX(-50%);width:min(410px,calc(100vw - 24px));height:242px;margin:0;padding:12px;background:#fff;border:1px solid var(--line);border-radius:22px;box-shadow:0 16px 40px rgba(0,0,0,.08)}
.keypad{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));grid-template-rows:repeat(4,48px);gap:8px}
.keypad button{height:48px;min-height:0;padding:0;display:flex;align-items:center;justify-content:center;line-height:1}
.operator-menu{display:flex;align-items:center;justify-content:center;gap:12px}
.operator-menu button{flex:none;width:64px;height:64px;padding:0;display:flex;align-items:center;justify-content:center;font-family:Arial,sans-serif;font-size:36px;line-height:1;letter-spacing:0}
@media(max-width:700px){
  .app>header{height:84px;grid-template-columns:minmax(0,1fr) auto;grid-template-rows:28px 48px;padding:4px 12px}
  .brand{grid-column:1/-1;font-size:14px;justify-self:center}
  .seg{justify-self:start}.tools{justify-self:end}
  .formula-wrap{--number-size:54px}
  .formula{max-width:420px;grid-template-columns:1fr;gap:16px}
  .expression{grid-template-columns:minmax(0,1fr) 48px minmax(0,1fr);gap:8px}
  .result-group{grid-template-columns:48px minmax(0,1fr);gap:8px;width:calc((100% - 64px)/2 + 56px);justify-self:end}
  .formula .num,.formula .op,.formula .equals{height:68px}
  .formula .op,.formula .equals{width:48px;font-size:42px}
}
@media(max-width:560px){
  main#stream,.editing main#stream{padding:20px 12px calc(280px + env(safe-area-inset-bottom))}
  .paper .operator{font-size:42px}
  .operator-menu{gap:8px}.operator-menu button{width:56px;height:56px}
}

/* 繰り下がりは手動の記入。斜線と小数字の値は独立して保持する。 */
.calc-wrap{width:100%;padding-right:44px}
.paper .borrow-digit{pointer-events:auto;cursor:pointer;border:0;background:transparent;padding:0;width:100%;height:100%;display:flex;align-items:center;justify-content:center;touch-action:manipulation}
.paper .crossed{position:relative}
.paper .crossed:after{content:"";position:absolute;left:50%;top:50%;width:1.1em;height:2px;background:currentColor;transform:translate(-50%,-50%) rotate(-55deg);pointer-events:none}
.number-edit{position:absolute;left:100%;transform:translateY(-50%);width:44px;height:44px;padding:0;border:0;background:transparent;color:var(--muted);font-size:14px;line-height:1;display:flex;align-items:center;justify-content:center}

html,body{touch-action:pan-x pan-y}
.number-edit svg{display:block;pointer-events:none}

/* 10問の入力記録。紙面を縮小して画面内に収め、スクロールを発生させない。 */
.tools #show-summary{width:auto;min-width:50px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1px;height:44px;border-radius:10px}
#summary-count{font-size:11px;line-height:1.1;font-variant-numeric:tabular-nums}
#show-summary.ready{background:#eaf6ee;color:#237846}
.summary-open>.app,.summary-open>.pair-header{display:none}
.summary-screen{position:fixed;inset:0;z-index:50;background:#fff;color:#181818;padding:8px 12px max(12px,env(safe-area-inset-bottom));display:flex;flex-direction:column;gap:8px;overflow:hidden}
.summary-heading{flex:none;display:flex;align-items:center;gap:12px;height:44px}
.summary-heading button{width:44px;height:44px;padding:0;display:flex;align-items:center;justify-content:center;background:#f1f1ee;border:0;border-radius:12px}
.summary-heading h1{font-size:20px;font-weight:500;margin:0}.summary-heading>span{margin-left:auto;font-size:12px;color:#777}
.summary-grid{flex:1;min-height:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));grid-template-rows:repeat(5,minmax(0,1fr));gap:8px}
.summary-entry{min-width:0;min-height:0;position:relative;border:1px solid #deded9;border-radius:10px;padding:20px 8px 6px}
.summary-number{position:absolute;top:5px;left:9px;font:14px/1 system-ui,sans-serif;color:#777}
.summary-content{position:relative;width:100%;height:100%;overflow:hidden}
.summary-content>div{position:absolute;left:50%;top:50%;transform-origin:center center;max-width:none}
.summary-formula{white-space:nowrap;font-size:48px;line-height:1.4;font-variant-numeric:tabular-nums;padding:2px}
.summary-paper button:disabled{opacity:1;color:inherit;cursor:default;pointer-events:none}
.summary-paper .digit{font-size:58px}.summary-paper .operator{font-size:46px}.summary-paper .answer{font-size:56px}.summary-paper .margin-anchor span{font-size:24px}.summary-paper .margin-anchor .multidigit{font-size:22px}
@media(min-aspect-ratio:6/5){.summary-grid{grid-template-columns:repeat(5,minmax(0,1fr));grid-template-rows:repeat(2,minmax(0,1fr))}}
@media(max-width:560px){.summary-heading{gap:8px}.summary-heading h1{font-size:18px}.summary-heading>span{font-size:10px}.summary-screen{padding-left:8px;padding-right:8px}.summary-grid{gap:5px}.summary-entry{padding:18px 4px 4px}}

.summary-score{flex:none;font:600 15px/1.5 system-ui,sans-serif;color:#252525;padding:0 4px}
.summary-entry{cursor:pointer;padding-top:34px}
.summary-entry:focus-visible{outline:3px solid #337bb5;outline-offset:-3px}
.summary-entry .summary-content{pointer-events:none}
.summary-mark{position:absolute;right:8px;top:3px;height:28px;display:flex;align-items:center;font:12px/1 system-ui,sans-serif;color:#666}
.summary-mark.correct{color:#d32f2f}.summary-mark.incorrect{color:#111}
.summary-mark svg{display:block}
@media(max-width:560px){.summary-entry{padding-top:32px}.summary-score{font-size:12px}}

/* Keep formula tokens together and center short input sheets above the keypad. */
main#stream:has(.formula-wrap),.editing main#stream:has(.formula-wrap){display:flex;flex-direction:column}
main#stream:has(.formula-wrap)>.rows{margin-block:auto}
.formula{max-width:560px;grid-template-columns:minmax(0,3fr) minmax(0,1.5fr);gap:12px}
.expression{grid-template-columns:minmax(0,1fr) 48px minmax(0,1fr);gap:6px}
.result-group{grid-template-columns:48px minmax(0,1fr);gap:6px}
.formula .op,.formula .equals{width:48px}
@media(max-width:700px){
.formula{max-width:360px;grid-template-columns:1fr;gap:12px}
.result-group{width:calc((100% - 60px)/2 + 54px)}
}

/* Shared soft, rounded empty-field marker; entered numbers keep their size. */
.input-placeholder{display:inline-block;width:.72em;height:.78em;border:2px solid #d5d8dc;border-radius:.12em;flex:none;vertical-align:middle;pointer-events:none}
.formula .num{border-bottom:0}
.paper .answer{border-bottom:0;border-radius:8px}
.paper .operator.unset{font-size:54px}
.paper .digit.placeholder{display:flex;align-items:center;justify-content:center}
.paper .row-hit.selected{box-shadow:none}
@media(max-width:560px){.paper .operator.unset{font-size:48px}}

/* One question at a time. Navigation stays outside the fixed input board. */
main#stream,.editing main#stream,main#stream:has(.formula-wrap),.editing main#stream:has(.formula-wrap){display:flex;flex-direction:column;padding-top:8px}
main#stream>.rows,main#stream:has(.formula-wrap)>.rows{margin-block:auto;gap:0;flex:none}
.question-nav{flex:none;display:flex;align-items:center;justify-content:center;gap:16px;min-height:48px;width:100%}
.question-nav button{min-height:44px;padding:8px 18px;border:0;border-radius:12px;background:transparent;color:#777773;font:inherit;font-size:14px;cursor:pointer}
.question-nav button:disabled{opacity:.25;cursor:default}
.question-nav button:focus-visible{outline:2px solid #2563eb;outline-offset:2px}
#question-position{font-size:13px;color:#777773;font-variant-numeric:tabular-nums}
.question-next{margin-top:8px}
.slide-next{animation:question-next .22s ease-out}
.slide-previous{animation:question-previous .22s ease-out}
@keyframes question-next{from{opacity:.3;transform:translateY(22px)}to{opacity:1;transform:translateY(0)}}
@keyframes question-previous{from{opacity:.3;transform:translateY(-22px)}to{opacity:1;transform:translateY(0)}}
@media(prefers-reduced-motion:reduce){.slide-next,.slide-previous{animation:none}}

/* A dial: neighboring expressions fade away from the active question. */
main#stream,.editing main#stream,main#stream:has(.formula-wrap),.editing main#stream:has(.formula-wrap){justify-content:center;touch-action:pan-x}
main#stream>.rows,main#stream:has(.formula-wrap)>.rows{margin-block:12px}
.question-nav{position:relative;min-height:76px;flex-direction:column;gap:0}
.question-nav button{display:flex;flex-direction:column;align-items:center;gap:5px;width:min(560px,100%);padding:4px 8px;min-height:70px;color:#777773}
.question-nav button:disabled{visibility:hidden}
.dial-preview{display:block;font-size:36px;line-height:1.2;white-space:nowrap;max-width:100%;overflow:hidden;font-variant-numeric:tabular-nums;opacity:.55;pointer-events:none}
.question-prev .dial-preview{-webkit-mask-image:linear-gradient(to bottom,transparent,#000);mask-image:linear-gradient(to bottom,transparent,#000)}
.question-next .dial-preview{-webkit-mask-image:linear-gradient(to bottom,#000,transparent);mask-image:linear-gradient(to bottom,#000,transparent)}
.dial-hint{font-size:11px;line-height:1.3;color:#92928e;pointer-events:none}
#question-position{position:absolute;right:8px;bottom:0;font-size:12px}
.question-next{margin-top:0}
@media(max-width:700px){.dial-preview{font-size:27px}.question-nav{min-height:62px}.question-nav button{min-height:58px}main#stream>.rows,main#stream:has(.formula-wrap)>.rows{margin-block:6px}}
@media(max-height:760px){.question-nav{min-height:48px}.question-nav button{min-height:44px}.dial-preview{font-size:24px}.dial-hint{font-size:10px}main#stream>.rows,main#stream:has(.formula-wrap)>.rows{margin-block:4px}}

/* Same-size reel: only position and fading distinguish neighboring expressions. */
.question-nav{display:none!important}
main#stream,.editing main#stream,main#stream:has(.formula-wrap),.editing main#stream:has(.formula-wrap){padding-top:0;overflow:hidden}
main#stream>.rows,main#stream:has(.formula-wrap)>.rows{position:relative;flex:1 1 auto;min-height:0;height:100%;margin:0;display:block;overflow:hidden;-webkit-mask-image:linear-gradient(to bottom,transparent 0%,#000 28%,#000 72%,transparent 100%);mask-image:linear-gradient(to bottom,transparent 0%,#000 28%,#000 72%,transparent 100%)}
.dial-track{position:absolute;inset:0;will-change:transform}
.dial-card{position:absolute;left:0;top:50%;width:100%;transform:translateY(calc(-50% + var(--dial-offset,0px)));animation:none!important}
.dial-neighbor{opacity:.32;cursor:pointer}
.dial-neighbor [inert]{pointer-events:none}
.dial-neighbor:focus-visible{outline:2px solid #2563eb;outline-offset:-2px}

main#stream>.rows,main#stream:has(.formula-wrap)>.rows{margin-inline:auto}


/* Viewport boards never inherit the reel transform. */
body>.operator-menu{position:fixed;z-index:6;left:50%;bottom:calc(14px + env(safe-area-inset-bottom));transform:translateX(-50%)}
/* Content sets field width; spare screen width is not shared among tokens. */
.formula{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;width:max-content;max-width:100%;gap:12px}
.expression,.result-group{display:flex;align-items:center;justify-content:center;width:auto;min-width:0;max-width:100%;gap:6px;margin:0}
.formula .num{width:auto;min-width:1.2em;max-width:none;flex:none;padding:0 8px;font-variant-numeric:tabular-nums}
.formula .op,.formula .equals{flex:none;margin:0}
.paper .margin-anchor span{display:grid;place-items:center;min-width:26px;min-height:28px;line-height:24px}
@media(max-width:700px){
.formula-wrap{--number-size:clamp(38px,9vw,54px)}
.formula{max-width:100%;gap:12px}
.expression,.result-group{width:auto}
}

/* Fade only neighbors. The entire active calculation, including answers, stays opaque. */
main#stream>.rows,main#stream:has(.formula-wrap)>.rows{-webkit-mask-image:none;mask-image:none}
.dial-neighbor[data-direction="-1"]{-webkit-mask-image:linear-gradient(to bottom,transparent,#000);mask-image:linear-gradient(to bottom,transparent,#000)}
.dial-neighbor[data-direction="1"]{-webkit-mask-image:linear-gradient(to bottom,#000,transparent);mask-image:linear-gradient(to bottom,#000,transparent)}
.row.active{-webkit-mask-image:none;mask-image:none;opacity:1}