/* Schriftlich rechnen (Grundschule, ganz kostenlos): Stufen, Klick-Erklärung, Üben in Runden zu 10 Aufgaben.
   Die Rechnung steht in einer Stellenwert-Tafel: oben die Stellen (E, Z, H, T), dann die Zahlen, die Überträge, der Strich und das Ergebnis. */
main { padding-block: 28px 56px; }
.col { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 16px; }
.kick { margin: 0; font-size: 13px; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--moss); }
.lead { margin: 0; color: var(--muted); font-size: 17px; max-width: 60ch; }
.note { font-size: 14px; color: var(--muted); margin: 0; } .note a { color: var(--moss); }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.btn.big { padding: 13px 24px; font-size: 17px; }
/* Stufen */
.stufen { display: flex; flex-direction: column; gap: 10px; }
.stufe { display: grid; grid-template-columns: 44px minmax(0, 1fr); gap: 4px 14px; align-items: center; background: var(--surface); border: 1.5px solid var(--line); border-radius: 16px; padding: 14px 16px; }
.stufe .sn { grid-row: span 2; width: 44px; height: 44px; border-radius: 50%; display: grid; place-items: center; font-family: var(--display); font-weight: 800; font-size: 20px; background: var(--raised); }
.stufe.done .sn { background: var(--ok); color: var(--bg); }
.stufe h3 { margin: 0; font-size: 17px; }
.stufe p { margin: 0; color: var(--muted); font-size: 14.5px; }
.stufe .row { grid-column: 2; margin-top: 6px; }
/* Stellenwert-Tafel */
.sr { display: inline-grid; gap: 4px; font-variant-numeric: tabular-nums; margin: 4px auto; }
.sr .h { font-size: 13px; color: var(--muted); text-align: center; font-weight: 600; }
.sr .d, .sr .op { width: 44px; height: 46px; display: grid; place-items: center; font-size: 28px; font-weight: 600; }
.sr .op { color: var(--muted); }
.sr .cy { width: 44px; height: 24px; display: grid; place-items: center; font-size: 16px; font-weight: 600; color: var(--warn); }
.sr .cy.in { border: 1.5px dashed var(--line); border-radius: 6px; cursor: pointer; background: transparent; }
.sr .line { height: 0; border-top: 3px solid var(--ink); }
.sr .r { width: 44px; height: 50px; display: grid; place-items: center; font-size: 28px; font-weight: 700; border-radius: 10px; }
.sr .r.in { border: 2px solid var(--line); background: var(--bg); cursor: pointer; }
.sr .on { border-color: var(--chalk) !important; box-shadow: 0 0 0 2px var(--chalk); }
.sr .r.ok { border-color: var(--ok); color: var(--ok); }
.sr .r.bad { border-color: var(--warn); color: var(--warn); }
.sr .new { color: var(--chalk); }
.sr .d.x { text-decoration: line-through; text-decoration-thickness: 2px; color: var(--muted); }
.sr .cur { background: color-mix(in srgb, var(--chalk) 18%, transparent); border-radius: 8px; }
.srwrap { display: flex; justify-content: center; overflow-x: auto; }
/* Ziffern-Tasten */
.pad { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; max-width: 360px; width: 100%; margin: 0 auto; }
.pad button { min-height: 52px; border: 1.5px solid var(--line); background: var(--surface); color: var(--ink); border-radius: 12px; font-size: 22px; font-weight: 600; }
.pad .wide { grid-column: span 2; }
.pad .go { background: var(--chalk); color: var(--chalk-ink); border-color: var(--chalk); font-size: 17px; }
.prog { display: flex; gap: 4px; } .prog i { flex: 1; height: 6px; border-radius: 3px; background: var(--line); } .prog i.ok { background: var(--ok); } .prog i.bad { background: var(--warn); } .prog i.cur { background: var(--chalk); }
.qhead { display: flex; justify-content: space-between; gap: 10px; color: var(--muted); font-size: 14px; }
.fb { margin: 0; font-size: 17px; text-align: center; min-height: 24px; }
.fb.good { color: var(--ok); } .fb.bad { color: var(--warn); }
.howto { font-size: 14px; color: var(--muted); text-align: center; margin: 0; }
/* Erklärung */
.rule { border-left: 5px solid var(--chalk); background: var(--surface); border-radius: 0 14px 14px 0; padding: 12px 16px; display: flex; flex-direction: column; gap: 8px; }
.rule p { margin: 0; }
.rule .why { color: var(--muted); }
.achtung { border: 1.5px solid var(--warn); border-radius: 14px; padding: 12px 16px; }
.achtung b { color: var(--warn); }
.achtung p { margin: 0; }
.stk { background: var(--surface); border: 1.5px solid var(--line); border-radius: 16px; padding: 12px 14px; display: flex; flex-direction: column; gap: 8px; }
.stk .sr { gap: 2px 4px; }
.stk .sr .d, .stk .sr .op { height: 32px; font-size: 24px; }
.stk .sr .r { height: 38px; font-size: 24px; }
.stk .sr .cy { height: 20px; }
.stk .gs { margin: 0; font-weight: 600; }
.stk .tx { margin: 0; min-height: 92px; font-size: 16px; }
.stk .nav { display: flex; justify-content: space-between; align-items: center; gap: 8px; }
.stk .nav span { color: var(--muted); font-size: 14px; }
.fml { display: block; white-space: nowrap; font-weight: 600; }
/* Ergebnis */
.wrongbox { border: 1.5px solid var(--warn); border-radius: 16px; padding: 14px 16px; display: flex; flex-direction: column; gap: 6px; }
.wrongbox.ok { border-color: var(--ok); }
.wrongbox h3 { margin: 0; font-size: 18px; }
.wrongbox p { margin: 0; }
.big-msg { font-family: var(--display); font-weight: 800; font-size: clamp(34px, 8vw, 52px); margin: 0; color: var(--chalk); }
.steps-list { margin: 0; padding-left: 20px; display: flex; flex-direction: column; gap: 4px; }
/* Division: schmale Spalten, damit Aufgabe, Ergebnis und Rechenweg nebeneinander passen; Eingabe in eigener Zeile */
.sr.div { gap: 0 0; }
.sr.div .d { width: 24px; height: 28px; font-size: 20px; }
.sr.div .line { border-top-width: 2px; }
.sr.divin { display: flex; gap: 6px; align-items: center; }
.sr.divin .op { font-size: 26px; padding-right: 4px; }