/* Terme-Trainer – hell: Matheheft mit Füllertinte, dunkel: Schultafel mit Kreide */
:root {
  --paper: #f7f5ee;
  --grid: rgb(60 110 190 / 13%);
  --card: #ffffff;
  --ink: #1b2440;
  --muted: #5d6680;
  --line: #d9dbe3;
  --pen: #1f4fbf;          /* Füllerblau: Terme, Hauptaktionen */
  --pen-ink: #ffffff;
  --pen-soft: #e8eefc;
  --margin: #e0566b;       /* Heftrand */
  --ok: #17794a;
  --ok-bg: #e4f4ea;
  --warn: #8a5a00;
  --warn-bg: #fdf0cf;
  --bad: #b3261e;
  --bad-bg: #fbe6e3;
  --star: #e2a200;
  --key: #ffffff;
  --key-op: #e8eefc;
  --shadow: 0 1px 2px rgb(27 36 64 / 8%), 0 6px 18px rgb(27 36 64 / 6%);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #14332b;
    --grid: rgb(255 255 255 / 5%);
    --card: #1b4238;
    --ink: #f1efe4;
    --muted: #a9bdb4;
    --line: #2f5a4e;
    --pen: #ffe58a;        /* gelbe Kreide */
    --pen-ink: #1d2a12;
    --pen-soft: #25503f;
    --margin: #ff9aa8;
    --ok: #8fe3b0;
    --ok-bg: #1d5138;
    --warn: #ffd37a;
    --warn-bg: #4a4320;
    --bad: #ffa59c;
    --bad-bg: #55302d;
    --star: #ffd24a;
    --key: #24503f;
    --key-op: #2e6150;
    --shadow: none;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 22px 22px;
  font: 17px/1.5 ui-rounded, "SF Pro Rounded", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh;
  min-height: 100dvh;
}
main {
  max-width: 640px;
  margin: 0 auto;
  padding: calc(18px + env(safe-area-inset-top)) 16px calc(32px + env(safe-area-inset-bottom));
}
h1, h2, h3, p { margin: 0; }
a { color: inherit; }
.m, .term {
  font-family: "STIX Two Text", "Cambria Math", Cambria, "Times New Roman", Georgia, serif;
  font-variant-numeric: lining-nums;
  white-space: nowrap;
}
.m i, .term i { font-style: italic; padding-right: .04em; }
.muted { color: var(--muted); }
:focus-visible { outline: 3px solid var(--pen); outline-offset: 2px; }

/* ---------- Übersicht ---------- */
.hero { border-left: 3px solid var(--margin); padding: 4px 0 4px 16px; margin: 6px 0 22px; }
.hero h1 { font-size: 34px; line-height: 1.1; letter-spacing: -.01em; }
.hero h1 .m { color: var(--pen); font-size: 1.05em; }
.hero p { color: var(--muted); margin-top: 6px; text-wrap: pretty; }
.stats { display: flex; flex-wrap: wrap; gap: 6px 18px; margin-top: 10px; font-weight: 650; font-size: 15px; }
.stats b { color: var(--pen); font-variant-numeric: tabular-nums; }

.topics { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.topic {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 14px 14px 12px; box-shadow: var(--shadow);
}
.topic.mix { border-style: dashed; border-color: var(--pen); }
.thead { display: flex; align-items: baseline; gap: 10px; }
.thead .no { font-weight: 800; color: var(--muted); font-variant-numeric: tabular-nums; min-width: 1.1em; }
.thead h2 { font-size: 19px; line-height: 1.25; flex: 1; }
.thead .rule-link {
  font-size: 14px; font-weight: 650; color: var(--pen); text-decoration: none;
  padding: 6px 2px; margin: -6px 0; white-space: nowrap;
}
.thead .rule-link:hover { text-decoration: underline; }
.topic .ex { color: var(--muted); font-size: 15px; margin: 2px 0 10px calc(1.1em + 10px); }
.topic .ex .exm { display: inline-block; }
.topic .ex .m { color: var(--pen); font-size: 17px; }
.levels { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.lvl {
  display: flex; flex-direction: column; align-items: center; gap: 1px;
  text-decoration: none; font-weight: 700; font-size: 15px;
  background: var(--pen-soft); border: 1px solid transparent; border-radius: 12px;
  padding: 8px 4px 7px; min-height: 56px; touch-action: manipulation;
}
.lvl:hover { border-color: var(--pen); }
.lvl:active { transform: translateY(1px); }
.stars { letter-spacing: 2px; font-size: 15px; color: var(--star); line-height: 1.2; }
.stars .off { color: var(--muted); opacity: .45; }
.foot { margin-top: 22px; color: var(--muted); font-size: 14px; text-align: center; }

/* ---------- Regel ---------- */
.back {
  display: inline-flex; align-items: center; gap: 6px; text-decoration: none;
  font-weight: 650; color: var(--muted); padding: 8px 0; min-height: 44px;
}
.sheet {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 18px 18px 18px 22px; box-shadow: var(--shadow); border-left: 3px solid var(--margin);
}
.sheet h1 { font-size: 24px; line-height: 1.2; }
.sheet .sub { color: var(--muted); margin-bottom: 10px; }
.rules { margin: 0; padding: 0; list-style: none; display: grid; gap: 10px; }
.rules li { padding-left: 22px; position: relative; text-wrap: pretty; }
.rules li::before { content: "→"; position: absolute; left: 0; color: var(--margin); font-weight: 700; }
.rules .m, .fb .m, .steps .m { color: var(--pen); font-size: 1.1em; }
.actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }

/* ---------- Üben ---------- */
.qbar { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.qbar .close {
  text-decoration: none; font-size: 20px; line-height: 1; color: var(--muted);
  width: 44px; height: 44px; display: grid; place-items: center; margin-left: -10px; border-radius: 12px;
}
.qbar .what { flex: 1; min-width: 0; font-weight: 700; font-size: 15px; line-height: 1.25; }
.qbar .what span { display: block; color: var(--muted); font-weight: 500; font-size: 13px; }
.dots { display: flex; gap: 4px; flex-wrap: wrap; justify-content: flex-end; max-width: 150px; }
.dot { width: 10px; height: 10px; border-radius: 50%; border: 1.5px solid var(--muted); opacity: .5; }
.dot.now { border-color: var(--pen); background: var(--pen); opacity: 1; transform: scale(1.25); }
.dot.first { background: var(--ok); border-color: var(--ok); opacity: 1; }
.dot.second { background: var(--star); border-color: var(--star); opacity: 1; }
.dot.miss { background: var(--bad); border-color: var(--bad); opacity: 1; }
.dot.rep { border-style: dashed; }

.q {
  background: var(--card); border: 1px solid var(--line); border-radius: 18px;
  box-shadow: var(--shadow); padding: 16px 16px 14px;
}
.q .prompt { font-weight: 650; color: var(--muted); font-size: 15px; display: flex; gap: 8px; align-items: baseline; }
.q .prompt .rep { color: var(--warn); background: var(--warn-bg); border-radius: 99px; padding: 0 9px; font-size: 13px; }
.q .text { font-size: 20px; line-height: 1.4; margin: 8px 0 2px; text-wrap: pretty; }
.q .text .m { color: var(--pen); font-size: 1.1em; }
.q .term {
  color: var(--pen); font-size: clamp(24px, 7.2vw, 36px); line-height: 1.3;
  margin: 10px 0 2px; white-space: normal; overflow-wrap: anywhere;
}
.q .term.long { font-size: clamp(20px, 5.6vw, 30px); }
.q .given { font-size: 19px; color: var(--ink); }
.q .given .m { font-size: 1.1em; }

.answer { display: flex; align-items: center; gap: 10px; margin-top: 12px; }
.answer .eq { font-size: 28px; color: var(--muted); font-family: Georgia, serif; }
.answer input {
  flex: 1; min-width: 0; width: 100%;
  font-family: "STIX Two Text", "Cambria Math", Cambria, "Times New Roman", Georgia, serif;
  font-size: 26px; line-height: 1.2; color: var(--ink);
  background: transparent; border: 0; border-bottom: 2.5px solid var(--pen); border-radius: 0;
  padding: 6px 2px; caret-color: var(--pen);
}
.answer input:focus { outline: none; border-bottom-color: var(--margin); }
.answer input:read-only { border-bottom-style: dashed; color: var(--muted); }
.answer input::placeholder { color: var(--muted); opacity: .55; font-size: 18px; }
.shake { animation: shake .3s; }
@keyframes shake { 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }

.fb { margin-top: 12px; border-radius: 12px; padding: 10px 12px; font-size: 16px; text-wrap: pretty; }
.fb:empty { display: none; }
.fb.ok { background: var(--ok-bg); color: var(--ok); }
.fb.warn { background: var(--warn-bg); color: var(--warn); }
.fb.bad { background: var(--bad-bg); color: var(--bad); }
.fb.info { background: var(--pen-soft); color: var(--ink); }
.fb strong { display: block; font-size: 17px; }
.fb .sol { font-size: 24px; display: block; margin: 2px 0; white-space: normal; }
.fb.ok .m, .fb.bad .m, .fb.warn .m { color: inherit; }
.steps { margin: 8px 0 0; padding: 8px 0 0; border-top: 1px dashed currentColor; list-style: none; display: grid; gap: 6px; color: var(--ink); }
.steps .m { display: block; font-size: 20px; white-space: normal; }
.fb .steps .m { color: var(--ink); }

.btnrow { display: flex; gap: 8px; margin-top: 12px; }
button, .btn {
  font: inherit; font-weight: 700; border: 0; border-radius: 12px; padding: 11px 16px; cursor: pointer;
  min-height: 48px; touch-action: manipulation; text-decoration: none;
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  background: var(--pen); color: var(--pen-ink);
}
button.ghost, .btn.ghost { background: transparent; color: var(--pen); border: 1.5px solid var(--pen); }
button.grow { flex: 1; }
button:active, .btn:active { transform: translateY(1px); }

.pad { display: grid; grid-template-columns: repeat(6, 1fr); gap: 6px; margin-top: 14px; user-select: none; -webkit-user-select: none; }
.pad button {
  min-height: 50px; padding: 0; font-size: 22px; font-weight: 500;
  font-family: "STIX Two Text", "Cambria Math", Cambria, "Times New Roman", Georgia, serif;
  background: var(--key); color: var(--ink); border: 1px solid var(--line); border-bottom-width: 2px;
}
.pad button.op { background: var(--key-op); }
.pad button.var { font-style: italic; color: var(--pen); font-size: 24px; }
.pad button.del { font-family: inherit; font-size: 20px; }
.pad button:active { background: var(--pen-soft); transform: translateY(1px); }
.ruletoggle { margin-top: 14px; }
.ruletoggle summary { cursor: pointer; font-weight: 650; color: var(--muted); padding: 8px 0; font-size: 15px; }
.ruletoggle .rules { font-size: 16px; padding: 4px 0 8px; }

/* ---------- Ergebnis ---------- */
.result { text-align: center; padding: 26px 18px 20px; }
.result .big { font-size: 56px; letter-spacing: 8px; color: var(--star); line-height: 1.1; }
.result .big .off { color: var(--muted); opacity: .35; }
.result h1 { font-size: 26px; margin-top: 6px; }
.result .score { font-size: 18px; margin-top: 6px; }
.result .score b { color: var(--pen); }
.result .actions { justify-content: center; }
.missed { margin-top: 16px; }
.missed h2 { font-size: 15px; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 0 0 8px; }
.missed ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.missed li { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px; }
.missed .m { white-space: normal; font-size: 19px; }
.missed .sol { color: var(--ok); }

@media (min-width: 560px) {
  .q { padding: 22px 24px 18px; }
  .pad button { min-height: 46px; }
}
@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; } }