:root {
  color-scheme: light;
  --ink: #07576a;
  --muted: #66838a;
  --teal: #2fc4cf;
  --teal-dark: #087e90;
  --teal-deep: #07596a;
  --cream: #fff8e7;
  --cream-2: #ffedbd;
  --yellow: #ffc542;
  --orange: #ff8e38;
  --green: #59c950;
  --blue: #2e96e8;
  --red: #ef655b;
  --purple: #8c6be6;
  --surface: rgba(255,255,255,.94);
  --outline: rgba(7,89,106,.18);
  --shadow: 0 16px 0 rgba(7,89,106,.06), 0 26px 48px rgba(31,103,114,.16);
}

* { box-sizing: border-box; }
html, body, #app { min-height: 100%; margin: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 6%, rgba(255,208,70,.34), transparent 20%),
    radial-gradient(circle at 91% 8%, rgba(47,196,207,.29), transparent 25%),
    radial-gradient(circle at 84% 93%, rgba(138,219,177,.25), transparent 22%),
    linear-gradient(145deg, #fffaf0 0%, #f5fff9 52%, #e7f9f8 100%);
  overflow-x: hidden;
}
body::before, body::after {
  content: "";
  position: fixed;
  z-index: -1;
  border-radius: 50%;
  opacity: .45;
}
body::before { width: 260px; height: 260px; left: -100px; bottom: -90px; background: #c8f1d9; }
body::after { width: 220px; height: 220px; right: -60px; bottom: -70px; background: #ffedaa; }
button, select { font: inherit; }
button { -webkit-tap-highlight-color: transparent; }

.site-footer {
  position: fixed;
  z-index: 100;
  right: 0;
  bottom: 0;
  left: 0;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 max(24px, calc((100vw - 1100px) / 2));
  background: transparent;
  color: #d0d0d0;
  font-size: 11px;
  font-weight: 400;
  line-height: 1.5;
  opacity: .82;
}
.site-footer a { color: inherit; text-decoration: none; white-space: nowrap; }
.site-footer a + a { display: inline-flex; align-items: center; gap: 3px; }
.site-footer a + a { margin-left: 24px; }
.site-footer img { width: 10px; height: 11px; object-fit: contain; opacity: .6; }
.site-footer.site-footer--subtle { opacity: .48; }
.site-footer:hover { opacity: .78; }
.site-footer a:hover { color: #b8b8b8; text-decoration: underline; }

.app-shell {
  width: min(1740px, calc(100vw - 24px));
  margin: 0 auto;
  padding: 14px 0 24px;
}

.topbar {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 0 12px 12px;
}
.brand-wrap { display: flex; align-items: center; gap: 14px; }
.brand-mascot {
  width: 62px;
  height: 62px;
  display: grid;
  place-items: center;
  font-size: 36px;
  border-radius: 22px;
  background: linear-gradient(180deg, #fffef8, #ffe9a7);
  border: 3px solid #fff;
  outline: 2px solid rgba(196,132,34,.36);
  box-shadow: 0 8px 0 rgba(142,86,18,.10), 0 14px 25px rgba(98,73,26,.13);
}
.eyebrow {
  display: inline-flex;
  padding: 5px 12px;
  border-radius: 999px;
  background: #fff0ca;
  color: #b66120;
  font-size: 13px;
  font-weight: 900;
  letter-spacing: .08em;
  border: 1px solid rgba(238,137,44,.3);
}
h1 {
  margin: 5px 0 0;
  font-size: clamp(27px, 2.6vw, 42px);
  line-height: 1;
  color: var(--teal-deep);
  text-shadow: 0 3px 0 #fff;
}
.top-actions { display: flex; align-items: center; gap: 12px; }
.difficulty-picker {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px 9px 16px;
  border-radius: 22px;
  background: rgba(255,255,255,.88);
  border: 2px solid #24b7c5;
  box-shadow: 0 7px 0 rgba(7,126,144,.10);
  font-weight: 900;
}
.difficulty-picker span { font-size: 14px; color: var(--muted); }
.difficulty-picker select {
  border: 0;
  color: var(--teal-deep);
  background: #e7faf8;
  border-radius: 13px;
  padding: 7px 11px;
  font-weight: 900;
  outline: none;
}
.round-button {
  width: 52px;
  height: 52px;
  border-radius: 18px;
  border: 3px solid #fff;
  outline: 2px solid rgba(7,126,144,.38);
  background: linear-gradient(180deg, #50d9e0, #22afbe);
  box-shadow: 0 7px 0 rgba(7,89,106,.18);
  cursor: pointer;
  font-size: 23px;
}

.workspace {
  display: grid;
  grid-template-columns: 278px minmax(720px, 1fr) 250px;
  gap: 16px;
  align-items: start;
}
.card-surface {
  background: var(--surface);
  border: 3px solid #22b7c5;
  border-radius: 34px;
  box-shadow: var(--shadow), inset 0 3px 0 rgba(255,255,255,.86);
}

.mode-panel {
  position: sticky;
  top: 12px;
  max-height: calc(100vh - 28px);
  overflow: hidden;
  background: linear-gradient(180deg, #31c4d0, #16a6b5);
  border-color: #087a8b;
  padding: 14px 10px 14px;
}
.mode-panel-title {
  margin: 0 5px 10px;
  padding: 12px 14px;
  border-radius: 20px;
  color: #fff;
  font-size: 21px;
  font-weight: 950;
  text-shadow: 0 2px 0 rgba(0,0,0,.15);
  background: rgba(255,255,255,.13);
  border: 1px solid rgba(255,255,255,.3);
}
.mode-panel-title span { display: block; margin-top: 2px; font-size: 12px; opacity: .82; }
.mode-nav {
  max-height: calc(100vh - 116px);
  overflow-y: auto;
  padding: 0 5px 6px;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,.6) transparent;
}
.mode-group h2 {
  margin: 14px 8px 7px;
  color: rgba(255,255,255,.78);
  font-size: 12px;
  letter-spacing: .12em;
}
.mode-item {
  width: 100%;
  min-height: 58px;
  display: grid;
  grid-template-columns: 42px 1fr;
  align-items: center;
  gap: 9px;
  margin: 7px 0;
  padding: 8px 10px;
  text-align: left;
  color: var(--teal-deep);
  border: 0;
  border-radius: 19px;
  background: rgba(255,255,255,.82);
  cursor: pointer;
  transition: transform .15s ease, filter .15s ease, box-shadow .15s ease;
}
.mode-item:hover { transform: translateX(3px); filter: brightness(1.03); }
.mode-item.active {
  background: linear-gradient(180deg, #fffef9, #fff0bf);
  outline: 3px solid rgba(255,255,255,.8);
  box-shadow: 0 7px 0 rgba(5,89,103,.18);
  transform: translateX(4px);
}
.mode-icon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: color-mix(in srgb, var(--mode-color), white 76%);
  font-size: 23px;
  border: 2px solid color-mix(in srgb, var(--mode-color), white 45%);
}
.mode-item b { display: block; font-size: 14px; }
.mode-item small { display: block; margin-top: 2px; color: #678188; font-size: 11px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.activity-card {
  min-width: 0;
  padding: 15px;
  background:
    radial-gradient(circle at 12% 0%, rgba(255,255,255,.72), transparent 25%),
    linear-gradient(180deg, #42d1da 0%, #20b2c0 100%);
  border-color: #087a8b;
}
.activity-card.correct { animation: correctPulse .5s ease; }
.activity-card.wrong { animation: wrongNudge .42s ease; }
@keyframes correctPulse { 50% { filter: saturate(1.15) brightness(1.04); transform: translateY(-2px); } }
@keyframes wrongNudge { 25% { transform: translateX(-4px); } 75% { transform: translateX(4px); } }

.activity-heading {
  min-height: 86px;
  display: grid;
  grid-template-columns: 58px 1fr auto;
  align-items: center;
  gap: 13px;
  padding: 12px 16px;
  border-radius: 26px;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(255,246,214,.98));
  border: 3px solid #fff;
  outline: 2px solid rgba(7,89,106,.28);
  box-shadow: 0 7px 0 rgba(7,89,106,.11);
}
.activity-icon {
  width: 56px;
  height: 56px;
  display: grid;
  place-items: center;
  border-radius: 19px;
  font-size: 31px;
  background: color-mix(in srgb, var(--mode-color), white 73%);
  border: 2px solid color-mix(in srgb, var(--mode-color), white 35%);
}
.activity-kicker { color: #c06c23; font-size: 12px; font-weight: 900; }
.activity-heading h2 { margin: 2px 0 1px; font-size: 24px; color: var(--teal-deep); }
.activity-heading p { margin: 0; color: var(--muted); font-size: 13px; font-weight: 700; }
.question-count {
  padding: 9px 12px;
  border-radius: 999px;
  background: #e5f9f3;
  color: #237d61;
  border: 2px solid rgba(52,154,116,.2);
  font-size: 13px;
  font-weight: 900;
}

.activity-stage {
  position: relative;
  min-height: 600px;
  margin-top: 13px;
  padding: 16px;
  border-radius: 30px;
  background:
    radial-gradient(circle at 50% 16%, rgba(255,255,255,.95), rgba(255,246,218,.92) 48%, rgba(229,247,239,.93) 100%);
  border: 4px solid #fff;
  outline: 2px solid rgba(7,89,106,.35);
  overflow: hidden;
}
.prompt-card {
  position: absolute;
  z-index: 3;
  left: 30px;
  top: 30px;
  width: 215px;
  min-height: 160px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 17px;
  border-radius: 25px;
  background: linear-gradient(180deg, #fffef9, #ffe9a9);
  border: 3px solid #fff;
  outline: 2px solid rgba(192,128,27,.38);
  box-shadow: 0 9px 0 rgba(164,100,18,.11), 0 18px 28px rgba(91,66,25,.16);
  text-align: center;
}
.prompt-card span { color: #aa681d; font-size: 13px; font-weight: 900; }
.prompt-card strong { margin: 6px 0; color: #075b6c; font-size: 55px; line-height: 1; }
.prompt-card p { margin: 4px 0 0; color: #745d3d; font-size: 13px; line-height: 1.5; font-weight: 750; }
.prompt-card.listen-prompt strong { font-size: 70px; color: #e28031; }
.prompt-card.compact {
  position: relative;
  left: auto;
  top: auto;
  width: min(720px, calc(100% - 24px));
  min-height: 108px;
  margin: 0 auto 18px;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  column-gap: 14px;
  row-gap: 2px;
}
.prompt-card.compact strong { font-size: 32px; margin: 0; }
.prompt-card.compact p { flex-basis: 100%; }
.prompt-card.equation-prompt strong { font-size: 37px; }
.prompt-card.detective-prompt { background: linear-gradient(180deg, #fffdf8, #f1e1ff); outline-color: rgba(122,78,186,.35); }

.abacus-shell {
  position: relative;
  width: 100%;
  max-width: 1030px;
  margin: 0 auto;
  padding-top: 4px;
}
#abacusCanvas {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1000 / 630;
  touch-action: none;
  cursor: grab;
}
#abacusCanvas.is-dragging { cursor: grabbing; }
#abacusCanvas.is-locked { cursor: default; }
.abacus-readout {
  position: absolute;
  z-index: 4;
  right: 30px;
  top: 28px;
  min-width: 135px;
  padding: 10px 16px;
  border-radius: 20px;
  text-align: center;
  background: rgba(255,255,255,.95);
  border: 3px solid #35b9c5;
  box-shadow: 0 7px 0 rgba(7,89,106,.1);
}
.abacus-readout span { display: block; color: var(--muted); font-size: 11px; font-weight: 900; }
.abacus-readout strong { display: block; color: var(--teal-deep); font-size: 29px; line-height: 1.05; }
.canvas-hint {
  position: absolute;
  z-index: 5;
  right: 34px;
  bottom: 34px;
  max-width: 340px;
  padding: 12px 15px;
  border-radius: 18px;
  background: #fff8cf;
  border: 3px solid #f2b73e;
  color: #80581c;
  font-size: 13px;
  font-weight: 900;
  box-shadow: 0 8px 0 rgba(165,103,21,.1);
}

.feedback-bar {
  min-height: 58px;
  display: flex;
  align-items: center;
  gap: 11px;
  margin-top: 13px;
  padding: 10px 17px;
  border-radius: 21px;
  background: rgba(255,255,255,.91);
  border: 3px solid rgba(255,255,255,.86);
  color: var(--teal-deep);
}
.feedback-bar.correct { background: #edffe7; color: #2c7a34; outline: 2px solid rgba(68,166,73,.25); }
.feedback-bar.wrong { background: #fff3df; color: #a25d23; outline: 2px solid rgba(219,126,42,.25); }
.feedback-face { font-size: 27px; }
.feedback-bar strong { font-size: 15px; line-height: 1.4; }
.control-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 9px;
  margin-top: 12px;
}
.secondary-button, .primary-button, .next-button {
  min-height: 47px;
  padding: 0 15px;
  border-radius: 17px;
  border: 3px solid #fff;
  cursor: pointer;
  font-weight: 900;
  transition: transform .13s ease, filter .13s ease;
}
.secondary-button:hover, .primary-button:hover, .next-button:hover { transform: translateY(-2px); filter: brightness(1.03); }
.secondary-button { color: #08778a; background: rgba(255,255,255,.84); box-shadow: 0 6px 0 rgba(7,89,106,.11); }
.primary-button { min-width: 135px; color: #fff; background: linear-gradient(180deg, #6add62, #3fb83d); box-shadow: 0 7px 0 rgba(43,124,39,.21); }
.next-button { min-width: 125px; color: #7a460d; background: linear-gradient(180deg, #ffe469, #ffc03a); box-shadow: 0 7px 0 rgba(170,105,19,.2); }

.progress-panel {
  position: sticky;
  top: 12px;
  padding: 18px 15px;
  background: linear-gradient(180deg, #fffefa, #fff4d8);
  border-color: #21b1c0;
}
.progress-title {
  width: fit-content;
  margin: 0 auto 12px;
  padding: 9px 16px;
  border-radius: 999px;
  background: linear-gradient(180deg, #35cbd4, #159ba9);
  color: #fff;
  border: 3px solid #fff;
  outline: 2px solid rgba(7,126,144,.33);
  font-weight: 950;
  box-shadow: 0 6px 0 rgba(7,89,106,.10);
}
.score-orbit { display: grid; place-items: center; padding: 8px 0 13px; }
.score-ring {
  width: 126px;
  height: 126px;
  display: grid;
  place-content: center;
  text-align: center;
  border-radius: 50%;
  background:
    radial-gradient(circle, #fff 57%, transparent 59%),
    conic-gradient(#56c94a var(--score), #dceeed 0);
  box-shadow: inset 0 0 0 6px rgba(255,255,255,.68), 0 10px 25px rgba(38,95,89,.13);
}
.score-ring strong { font-size: 31px; color: #23835f; }
.score-ring span { font-size: 11px; color: var(--muted); font-weight: 900; }
.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; }
.stats-grid div {
  min-width: 0;
  padding: 10px 3px;
  border-radius: 17px;
  text-align: center;
  background: #fff;
  border: 2px solid rgba(34,177,192,.17);
}
.stats-grid b { display: block; font-size: 22px; color: var(--teal-deep); }
.stats-grid span { display: block; font-size: 10px; color: var(--muted); font-weight: 800; }
.learning-goal, .principle-card {
  margin-top: 12px;
  padding: 13px;
  border-radius: 19px;
  background: #eafbf5;
  border: 2px solid rgba(47,169,132,.18);
}
.learning-goal span, .principle-card span { display: block; color: #4d8074; font-size: 11px; font-weight: 900; }
.learning-goal strong { display: block; margin-top: 4px; color: #23775d; font-size: 14px; }
.principle-card { background: #fff7df; border-color: rgba(219,159,51,.2); }
.principle-card p { margin: 6px 0 0; color: #7c6543; font-size: 12px; line-height: 1.5; font-weight: 700; }
.badge-shelf { display: flex; justify-content: space-between; gap: 4px; margin-top: 14px; }
.badge {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  background: #edf3f2;
  filter: grayscale(1);
  opacity: .48;
  border: 2px solid #fff;
}
.badge.earned { filter: none; opacity: 1; background: #fff3bd; transform: rotate(-3deg); }

.answer-options {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin: 14px auto 0;
}
.answer-button {
  min-width: 105px;
  height: 64px;
  padding: 0 24px;
  border-radius: 24px;
  border: 4px solid #fff;
  outline: 2px solid rgba(7,89,106,.28);
  background: linear-gradient(180deg, #fffef9, #ffe9a5);
  color: var(--teal-deep);
  font-size: 26px;
  font-weight: 950;
  cursor: pointer;
  box-shadow: 0 8px 0 rgba(155,97,20,.13), 0 15px 24px rgba(76,64,30,.12);
  transition: transform .14s ease;
}
.answer-button:hover { transform: translateY(-3px); }
.answer-button.selected { background: linear-gradient(180deg, #8ce5ef, #42becd); color: #fff; outline-color: #08798b; transform: translateY(-3px); }

/* 小算盘 */
.mini-abacus-wrap { text-align: center; }
.mini-abacus {
  position: relative;
  width: 250px;
  height: 250px;
  display: flex;
  justify-content: center;
  gap: 48px;
  padding: 26px 36px 20px;
  border-radius: 32px;
  background: linear-gradient(180deg, #43d3dc, #18a5b4);
  border: 5px solid #087383;
  box-shadow: inset 0 4px 0 rgba(255,255,255,.5), 0 12px 0 rgba(7,89,106,.08);
}
.mini-abacus::before {
  content: "";
  position: absolute;
  inset: 24px;
  border-radius: 22px;
  background: linear-gradient(180deg, #fffdf4, #ffe8ad);
  border: 2px solid rgba(127,92,28,.24);
}
.mini-rod { position: relative; z-index: 1; width: 62px; height: 205px; }
.mini-stick { position: absolute; left: 27px; top: 7px; width: 8px; height: 167px; border-radius: 5px; background: linear-gradient(90deg, #8c6421, #f2da8e, #956721); }
.mini-beam { position: absolute; left: -18px; top: 88px; width: 98px; height: 17px; border-radius: 8px; background: linear-gradient(180deg, #efd070, #9b6724); border: 1px solid #70491c; }
.mini-bead { position: absolute; left: 0; width: 62px; height: 25px; border-radius: 14px; box-shadow: 0 4px 5px rgba(15,65,71,.15); }
.mini-bead.upper { top: 22px; background: linear-gradient(180deg, #ff9e8c, #d7443c); }
.mini-bead.upper.active { top: 60px; box-shadow: 0 0 14px rgba(255,182,61,.65); }
.mini-lower-group { position: absolute; inset: 0; }
.mini-bead.lower { top: calc(170px - (3 - var(--slot)) * 27px); background: linear-gradient(180deg, #78e0ef, #1c88a7); }
.mini-bead.lower.active { top: calc(110px + var(--slot) * 27px); box-shadow: 0 0 12px rgba(255,184,55,.48); }
.mini-rod b { position: absolute; bottom: 0; left: 12px; width: 38px; height: 29px; display: grid; place-items: center; border-radius: 10px; background: #fff3c5; border: 2px solid #c98f2c; color: var(--teal-deep); }
.mini-label { margin-top: 8px; font-weight: 950; color: var(--teal-deep); }

.compose-board {
  display: grid;
  grid-template-columns: 260px 130px 56px 130px 56px 100px;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-height: 330px;
}
.number-spinner {
  display: grid;
  grid-template-columns: 40px 1fr 40px;
  align-items: center;
  gap: 5px;
  padding: 10px;
  border-radius: 25px;
  background: #fff;
  border: 3px solid #37b9c7;
  box-shadow: 0 8px 0 rgba(7,89,106,.09);
}
.number-spinner button {
  width: 40px; height: 44px; border: 0; border-radius: 14px; background: #e7f8f6; color: var(--teal-deep); font-size: 22px; font-weight: 950; cursor: pointer;
}
.number-spinner strong { text-align: center; font-size: 36px; }
.math-symbol { text-align: center; font-size: 42px; font-weight: 950; color: #c47a25; }
.sum-cloud {
  min-width: 88px; height: 76px; display: grid; place-items: center; border-radius: 36px; background: #ffe574; color: #80500e; border: 4px solid #fff; outline: 2px solid rgba(181,112,25,.3); font-size: 35px; font-weight: 950;
}
.representation-row { display: flex; justify-content: center; gap: 20px; margin-top: 10px; }

.compare-board { min-height: 380px; display: grid; grid-template-columns: 1fr 165px 1fr; align-items: center; justify-items: center; gap: 10px; }
.compare-choice { display: grid; gap: 12px; }
.compare-choice .answer-button { min-width: 92px; height: 61px; font-size: 33px; }

.train-track {
  min-height: 380px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 30px 20px 80px;
  background: linear-gradient(180deg, transparent 0 75%, #d3aa69 75% 79%, #8b693b 79% 83%, transparent 83%);
}
.train-engine { font-size: 76px; filter: drop-shadow(0 9px 0 rgba(63,70,62,.12)); }
.train-car {
  position: relative;
  width: 118px;
  height: 92px;
  border: 4px solid #fff;
  outline: 2px solid rgba(7,89,106,.32);
  border-radius: 25px 25px 18px 18px;
  background: linear-gradient(180deg, #58d3de, #239aac);
  color: #fff;
  font-size: 37px;
  font-weight: 950;
  cursor: grab;
  box-shadow: 0 9px 0 rgba(7,89,106,.14);
}
.train-car:nth-child(odd) { background: linear-gradient(180deg, #ffbd5e, #ef8432); }
.train-car.swap-selected { transform: translateY(-14px); outline: 5px solid #ffe064; }
.train-car i { position: absolute; bottom: -23px; width: 27px; height: 27px; border-radius: 50%; background: #46575b; border: 4px solid #c5d6d7; }
.train-car i:first-of-type { left: 14px; }
.train-car i:last-of-type { right: 14px; }

.ten-frame-stack { display: flex; flex-wrap: wrap; justify-content: center; gap: 15px; }
.ten-frame {
  width: 300px;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  border: 5px solid #087b8c;
  border-radius: 18px;
  overflow: hidden;
  background: #fff;
  box-shadow: 0 9px 0 rgba(7,89,106,.08);
}
.ten-cell {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border: 2px solid #a7d6d6;
  color: #2ca8c2;
  font-size: 36px;
}
.ten-cell.filled:nth-child(-n+5) { color: #ef655b; }
.visual-question { min-height: 310px; display: grid; place-items: center; }
.visual-question .ten-frame { width: min(440px, 80vw); }
.visual-question .ten-cell { font-size: 47px; }
.dot-card {
  width: 430px;
  min-height: 260px;
  display: grid;
  grid-template-columns: repeat(5, 58px);
  grid-auto-rows: 58px;
  place-content: center;
  gap: 14px;
  padding: 28px;
  border-radius: 34px;
  background: linear-gradient(180deg, #fffefb, #f1e6ff);
  border: 5px solid #9a78cc;
  box-shadow: 0 12px 0 rgba(102,69,151,.09);
}
.dot { width: 54px; height: 54px; border-radius: 50%; background: radial-gradient(circle at 34% 28%, #9fe9f2, #2b99ba 62%, #17647c); box-shadow: inset 0 3px 0 rgba(255,255,255,.4), 0 7px 8px rgba(31,77,91,.17); }

.number-line-wrap { position: relative; min-height: 400px; display: grid; align-content: center; padding: 90px 35px 40px; }
.jump-animal { position: absolute; left: calc(42px + var(--start) * .84); top: 105px; font-size: 50px; transform: translateX(-50%); filter: drop-shadow(0 7px 0 rgba(35,83,71,.12)); }
.number-line { position: relative; display: flex; justify-content: space-between; align-items: center; padding-top: 55px; }
.number-line::before { content: ""; position: absolute; left: 2%; right: 2%; top: 76px; height: 9px; border-radius: 5px; background: linear-gradient(90deg, #49baca, #f3b94f); }
.number-node { position: relative; z-index: 1; width: 44px; height: 94px; display: flex; align-items: flex-end; justify-content: center; border: 0; background: transparent; cursor: pointer; }
.number-node::before { content: ""; position: absolute; left: 18px; top: 48px; width: 8px; height: 35px; border-radius: 5px; background: #087889; }
.number-node span { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 13px; background: #fff; border: 3px solid #22aebd; color: var(--teal-deep); font-weight: 950; box-shadow: 0 5px 0 rgba(7,89,106,.08); }
.number-node.start span { background: #fff0ad; border-color: #e5a62e; }
.number-node.selected span { transform: translateY(-16px) scale(1.13); background: #75d866; color: #fff; border-color: #3a9d35; }

.shop-shelf { min-height: 240px; display: flex; justify-content: center; align-items: center; gap: 20px; padding: 20px 260px 5px 20px; }
.product-card {
  width: 150px;
  min-height: 170px;
  display: grid;
  place-items: center;
  padding: 14px;
  border-radius: 28px;
  background: #fff;
  border: 4px solid #f0b953;
  box-shadow: 0 10px 0 rgba(169,105,20,.10);
}
.product-card span { font-size: 58px; }
.product-card b { color: #80511c; }
.product-card strong { padding: 6px 10px; border-radius: 12px; background: #fff0c4; color: #bd6d1e; }
.basket { font-size: 62px; }
.shop-shelf + .abacus-shell { margin-top: -80px; }

.feed-board { min-height: 430px; display: grid; grid-template-columns: 230px 1fr; gap: 28px; align-items: center; padding: 10px 40px 30px; }
.animal-card { position: relative; text-align: center; }
.animal-card > span { font-size: 125px; filter: drop-shadow(0 10px 0 rgba(73,102,53,.1)); }
.speech-cloud { padding: 12px; border-radius: 22px; background: #fff; border: 3px solid #6bc35c; color: #39772f; font-weight: 900; }
.carrot-field { display: flex; flex-wrap: wrap; justify-content: center; gap: 9px; padding: 24px; border-radius: 30px; background: #f2f9dc; border: 4px dashed #8ac565; }
.carrot { width: 64px; height: 70px; border: 0; border-radius: 20px; background: rgba(255,255,255,.8); font-size: 39px; cursor: pointer; filter: grayscale(.85); opacity: .56; }
.carrot.selected { filter: none; opacity: 1; background: #fff0bd; transform: translateY(-5px); box-shadow: 0 7px 0 rgba(139,95,29,.1); }
.count-basket { grid-column: 1 / -1; width: fit-content; margin: 0 auto; padding: 10px 18px; border-radius: 18px; background: #fff; color: #7c5523; border: 3px solid #e5ae47; font-weight: 900; }
.count-basket strong { font-size: 25px; }

.repair-board { min-height: 320px; display: grid; grid-template-columns: 1fr 130px 1fr; align-items: center; gap: 15px; padding: 10px 30px; }
.repair-board > div { text-align: center; }
.repair-board small { display: block; margin-bottom: 12px; color: var(--muted); font-weight: 900; }
.object-row { min-height: 140px; display: flex; flex-wrap: wrap; justify-content: center; align-content: center; gap: 8px; padding: 20px; border-radius: 28px; background: #fff; border: 4px solid #4eb6c2; }
.object-row span { font-size: 39px; }
.object-row.target { border-color: #e4ad43; background: #fff7da; }
.repair-arrow { font-size: 27px; color: #b77422; font-weight: 950; }

.treasure-cave {
  min-height: 400px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-content: center;
  gap: 17px;
  padding: 35px;
  border-radius: 36px;
  background: radial-gradient(circle at 50% 20%, #5c5777, #2f3958 62%, #1f2946);
  box-shadow: inset 0 0 45px rgba(0,0,0,.22);
}
.treasure-gem {
  width: 90px;
  height: 100px;
  display: grid;
  place-items: center;
  border: 3px solid rgba(255,255,255,.45);
  border-radius: 26px;
  background: rgba(255,255,255,.11);
  color: #fff;
  cursor: pointer;
  transition: transform .14s ease;
}
.treasure-gem span { font-size: 40px; filter: grayscale(.8); opacity: .62; }
.treasure-gem b { font-size: 25px; }
.treasure-gem.selected { transform: translateY(-8px) scale(1.05); background: #fff1ad; color: #70470e; border-color: #fff; box-shadow: 0 0 25px rgba(255,221,80,.7); }
.treasure-gem.selected span { filter: none; opacity: 1; }

@media (max-width: 1420px) {
  .workspace { grid-template-columns: 245px minmax(650px, 1fr); }
  .progress-panel { position: static; grid-column: 1 / -1; display: grid; grid-template-columns: 160px 180px 1fr 1fr 240px; align-items: center; gap: 12px; }
  .progress-title { margin: 0; }
  .score-orbit { padding: 0; }
  .score-ring { width: 105px; height: 105px; }
  .badge-shelf { margin: 0; }
}
@media (max-width: 1080px) {
  .workspace { grid-template-columns: 1fr; }
  .mode-panel { position: static; max-height: none; }
  .mode-nav { display: flex; gap: 8px; overflow-x: auto; overflow-y: hidden; max-height: none; }
  .mode-group { display: flex; gap: 8px; }
  .mode-group h2 { writing-mode: vertical-rl; margin: 8px 2px; }
  .mode-item { width: 195px; flex: 0 0 195px; }
  .progress-panel { grid-column: auto; grid-template-columns: repeat(2, 1fr); }
  .progress-title, .score-orbit, .stats-grid, .badge-shelf { grid-column: auto; }
  .compose-board { grid-template-columns: 1fr 130px 48px 130px; }
  .compose-board .mini-abacus-wrap { grid-column: 1 / -1; }
  .sum-cloud { grid-column: 1 / -1; justify-self: center; }
  .compare-board { grid-template-columns: 1fr; }
  .compare-choice { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 760px) {
  .app-shell { width: min(100% - 12px, 720px); padding-top: 7px; }
  .topbar { align-items: flex-start; flex-direction: column; }
  .top-actions { width: 100%; justify-content: space-between; }
  .activity-card { padding: 9px; border-radius: 25px; }
  .activity-heading { grid-template-columns: 48px 1fr; }
  .question-count { display: none; }
  .activity-stage { min-height: 520px; padding: 10px; }
  .prompt-card:not(.compact) { position: relative; left: auto; top: auto; width: calc(100% - 20px); min-height: 110px; margin: 0 auto -10px; flex-direction: row; flex-wrap: wrap; align-items: center; gap: 8px; }
  .prompt-card:not(.compact) strong { font-size: 35px; }
  .prompt-card:not(.compact) p { flex-basis: 100%; }
  .abacus-readout { top: 20px; right: 20px; transform: scale(.82); transform-origin: top right; }
  .control-row { justify-content: center; }
  .secondary-button, .primary-button, .next-button { flex: 1 1 130px; }
  .progress-panel { grid-template-columns: 1fr; }
  .compose-board { grid-template-columns: 1fr 45px 1fr; }
  .compose-board .mini-abacus-wrap { grid-column: 1 / -1; transform: scale(.85); margin: -15px 0; }
  .compose-board .math-symbol:nth-of-type(2), .sum-cloud { display: none; }
  .representation-row { transform: scale(.76); margin: -35px -70px; }
  .train-track { justify-content: flex-start; overflow-x: auto; }
  .train-engine { font-size: 58px; }
  .train-car { width: 92px; flex: 0 0 92px; }
  .dot-card { width: 100%; grid-template-columns: repeat(5, 44px); grid-auto-rows: 44px; gap: 10px; }
  .dot { width: 42px; height: 42px; }
  .number-line-wrap { overflow-x: auto; padding-inline: 10px; }
  .number-line { min-width: 720px; }
  .shop-shelf { padding: 15px; flex-wrap: wrap; }
  .shop-shelf + .abacus-shell { margin-top: 0; }
  .feed-board { grid-template-columns: 1fr; padding: 5px; }
  .count-basket { grid-column: 1; }
  .repair-board { grid-template-columns: 1fr; }
  .repair-arrow { transform: rotate(90deg); }
}
.primary-button:disabled {
  cursor: default;
  filter: saturate(.8);
  background: linear-gradient(180deg, #8ad981, #54b851);
  opacity: .82;
}

/* 最终可读性修正 */
.shop-shelf {
  min-height: 205px;
  padding: 10px 235px 0 20px;
  align-items: flex-start;
}
.product-card {
  min-height: 150px;
  padding: 10px;
  grid-template-rows: 55px 24px 34px;
}
.product-card span { font-size: 46px; }
.product-card b { line-height: 1; }
.product-card strong { display: block; min-width: 68px; text-align: center; }
.shop-shelf + .abacus-shell {
  margin-top: -42px;
  transform: scale(.92);
  transform-origin: top center;
  margin-bottom: -50px;
}
.number-node span { position: relative; z-index: 2; }
.number-node::after {
  content: "";
  position: absolute;
  left: 20px;
  top: 70px;
  width: 4px;
  height: 16px;
  border-radius: 2px;
  background: #087889;
}
@media (max-width: 760px) {
  .shop-shelf { padding: 10px; }
  .shop-shelf + .abacus-shell { margin-top: 0; transform: none; margin-bottom: 0; }
}

/* v1.2.0-alpha.2：默认“先拨一拨”自由入口 */
.free-switch-button{border:0;border-radius:18px;padding:13px 18px;background:#fff;color:var(--teal-deep);font-weight:950;box-shadow:0 7px 0 rgba(7,89,106,.12);cursor:pointer}.free-switch-button.primary{background:linear-gradient(180deg,#ffd866,#ffb837);color:#75420e}.free-abacus-hero{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:24px 32px;margin-bottom:16px;background:linear-gradient(135deg,#fffef8,#e7fbf3);border-color:#52cbb7}.free-abacus-hero span{display:block;color:#66838a;font-weight:900}.free-abacus-hero strong{display:block;font-size:clamp(64px,9vw,120px);line-height:.95;color:#ef714d}.free-abacus-hero p{margin:7px 0 0;font-weight:900;color:#2b7d70}.free-message{max-width:480px;padding:18px 22px;border-radius:22px;background:#fff1c6}.free-message b,.free-message small{display:block}.free-message b{font-size:20px}.free-message small{margin-top:7px;color:#6d786f;line-height:1.6;font-weight:700}.free-abacus-layout{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:16px}.free-canvas-card{padding:14px;border-color:#23b8c5}.free-canvas-card canvas{display:block;width:100%;height:auto;touch-action:none;border-radius:24px}.free-abacus-controls{padding:22px;align-self:start;position:sticky;top:12px}.free-abacus-controls h2{margin:0 0 6px}.free-abacus-controls>p{color:var(--muted);font-weight:700;line-height:1.6}.free-tool-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:18px 0}.free-tool-grid button{min-height:52px;border:0;border-radius:16px;background:#e7faf8;color:var(--teal-deep);font-weight:950;cursor:pointer;box-shadow:0 5px 0 rgba(7,89,106,.10)}.free-number-meaning{padding:15px;border-radius:18px;background:#fff1cc}.free-number-meaning span,.free-number-meaning b{display:block}.free-number-meaning span{font-size:12px;color:#b66120;font-weight:900}.free-number-meaning b{margin-top:6px;line-height:1.55}.training-invite{width:100%;margin:16px 0 10px;padding:15px;border:0;border-radius:18px;background:linear-gradient(180deg,#50d3a5,#25a977);color:white;font-weight:950;cursor:pointer;box-shadow:0 7px 0 #1f8160}.free-abacus-controls>small{display:block;color:#718488;line-height:1.6}
@media(max-width:1050px){.free-abacus-layout{grid-template-columns:1fr}.free-abacus-controls{position:static}.free-abacus-hero{align-items:flex-start;flex-direction:column}}@media(max-width:650px){.free-abacus-hero{padding:18px}.free-tool-grid{grid-template-columns:1fr 1fr}.free-abacus-page .topbar{align-items:flex-start;flex-direction:column}}

/* 桌面端一屏工作台：页面本身不滚动，主要功能始终完整可见。 */
@media (min-width: 700px) {
  html, body, #app { height: 100%; overflow: hidden; }

  .app-shell {
    height: 100vh;
    padding: 8px 0 49px;
    display: flex;
    flex-direction: column;
  }
  .topbar {
    flex: 0 0 64px;
    min-height: 64px;
    padding-bottom: 8px;
  }
  .brand-mascot { width: 50px; height: 50px; border-radius: 17px; font-size: 29px; }
  h1 { font-size: clamp(24px, 2.1vw, 34px); }
  .workspace {
    flex: 1;
    min-height: 0;
    grid-template-columns: 190px minmax(0, 1fr);
  }
  .mode-panel { height: 100%; max-height: none; }
  .mode-nav { display: block; max-height: calc(100% - 66px); overflow-x: hidden; overflow-y: auto; }
  .mode-group { display: block; }
  .mode-group h2 { writing-mode: horizontal-tb; margin: 10px 8px 5px; }
  .mode-item { width: 100%; min-height: 48px; margin: 5px 0; }
  .progress-panel { display: none; }
  .activity-card {
    height: 100%;
    min-height: 0;
    display: flex;
    flex-direction: column;
    padding: 9px;
    overflow: hidden;
  }
  .activity-heading { min-height: 66px; padding: 7px 13px; }
  .activity-icon { width: 48px; height: 48px; font-size: 26px; }
  .activity-heading h2 { font-size: 20px; }
  .activity-stage {
    flex: 1;
    min-height: 0;
    margin-top: 8px;
    padding: 8px;
  }
  .abacus-shell { height: 100%; padding: 0; }
  #abacusCanvas {
    width: auto;
    max-width: 100%;
    height: 100%;
    max-height: 100%;
    margin: 0 auto;
  }
  .feedback-bar { flex: 0 0 46px; min-height: 46px; margin-top: 7px; padding: 6px 13px; }
  .feedback-face { font-size: 22px; }
  .control-row { flex: 0 0 43px; margin-top: 6px; gap: 7px; }
  .secondary-button, .primary-button, .next-button {
    min-height: 41px;
    padding: 0 12px;
    border-radius: 14px;
  }

  .free-abacus-page {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 300px;
    grid-template-rows: 64px 142px minmax(0, 1fr);
    gap: 10px 14px;
  }
  .free-abacus-page .topbar { grid-column: 1 / -1; grid-row: 1; }
  .free-abacus-hero {
    grid-column: 2;
    grid-row: 2;
    display: block;
    min-width: 0;
    margin: 0;
    padding: 12px 17px;
    overflow: hidden;
  }
  .free-abacus-hero strong { font-size: clamp(52px, 6.5vh, 72px); }
  .free-abacus-hero p { margin-top: 4px; font-size: 13px; white-space: nowrap; }
  .free-message { display: none; }
  .free-abacus-layout { display: contents; }
  .free-canvas-card {
    grid-column: 1;
    grid-row: 2 / 4;
    min-height: 0;
    display: grid;
    place-items: center;
    padding: 8px;
    overflow: hidden;
  }
  .free-canvas-card canvas {
    width: auto;
    max-width: 100%;
    height: auto;
    max-height: 100%;
  }
  .free-abacus-controls {
    grid-column: 2;
    grid-row: 3;
    min-height: 0;
    position: static;
    padding: 13px;
    overflow: auto;
  }
  .free-abacus-controls > p,
  .free-abacus-controls > small { display: none; }
  .free-tool-grid { gap: 7px; margin: 9px 0; }
  .free-tool-grid button { min-height: 42px; border-radius: 13px; }
  .free-number-meaning { padding: 10px; border-radius: 14px; }
  .free-number-meaning b { margin-top: 3px; font-size: 13px; line-height: 1.35; }
  .training-invite { margin: 9px 0 0; padding: 11px; border-radius: 14px; }
}

@media (min-width: 700px) and (max-height: 600px) {
  .app-shell { width: min(100% - 10px, 1740px); padding: 5px 0 47px; }
  .topbar { flex-basis: 50px; min-height: 50px; padding: 0 5px 5px; }
  .brand-wrap { gap: 8px; }
  .brand-mascot { width: 42px; height: 42px; border-radius: 14px; font-size: 24px; }
  .eyebrow { display: none; }
  h1 { margin: 0; font-size: 22px; }
  .free-switch-button { padding: 8px 12px; border-radius: 13px; font-size: 12px; }

  .workspace { grid-template-columns: 160px minmax(0, 1fr); gap: 8px; }
  .mode-panel { padding: 7px 5px; border-radius: 20px; }
  .mode-panel-title { margin-bottom: 5px; padding: 7px 9px; border-radius: 13px; font-size: 15px; }
  .mode-nav { max-height: calc(100% - 52px); }
  .mode-group h2 { margin: 7px 6px 3px; font-size: 10px; }
  .mode-item { grid-template-columns: 32px 1fr; min-height: 39px; padding: 4px 6px; border-radius: 12px; }
  .mode-icon { width: 30px; height: 30px; border-radius: 10px; font-size: 17px; }
  .mode-item b { font-size: 11px; }
  .mode-item small { display: none; }

  .activity-card { border-radius: 20px; padding: 6px; }
  .activity-heading { min-height: 50px; padding: 4px 8px; border-radius: 17px; }
  .activity-icon { width: 38px; height: 38px; border-radius: 12px; font-size: 21px; }
  .activity-heading h2 { font-size: 17px; }
  .activity-heading p { display: none; }
  .activity-stage { margin-top: 5px; padding: 5px; border-radius: 19px; }
  .prompt-card:not(.compact) {
    left: 14px;
    top: 14px;
    width: 150px;
    min-height: 100px;
    padding: 9px;
    border-radius: 16px;
  }
  .prompt-card strong { font-size: 34px; }
  .abacus-readout { right: 14px; top: 12px; transform: scale(.76); transform-origin: top right; }
  .feedback-bar { flex-basis: 36px; min-height: 36px; margin-top: 4px; padding: 3px 9px; border-width: 2px; border-radius: 13px; }
  .feedback-face { font-size: 18px; }
  .feedback-bar strong { font-size: 12px; }
  .control-row { flex-basis: 35px; margin-top: 4px; gap: 4px; }
  .secondary-button, .primary-button, .next-button {
    min-width: 0;
    min-height: 33px;
    padding: 0 8px;
    border-width: 2px;
    border-radius: 11px;
    font-size: 11px;
  }

  .free-abacus-page {
    grid-template-columns: minmax(0, 1fr) 220px;
    grid-template-rows: 50px 88px minmax(0, 1fr);
    gap: 7px 8px;
  }
  .free-abacus-hero { padding: 7px 11px; border-radius: 19px; border-width: 2px; }
  .free-abacus-hero span { font-size: 11px; }
  .free-abacus-hero strong { font-size: 42px; }
  .free-abacus-hero p { margin-top: 2px; font-size: 10px; }
  .free-canvas-card { padding: 5px; border-width: 2px; border-radius: 20px; }
  .free-canvas-card canvas { border-radius: 15px; }
  .free-abacus-controls { padding: 9px; border-width: 2px; border-radius: 19px; }
  .free-abacus-controls h2 { margin-bottom: 3px; font-size: 17px; }
  .free-tool-grid { gap: 5px; margin: 6px 0; }
  .free-tool-grid button { min-height: 33px; border-radius: 10px; font-size: 11px; }
  .free-number-meaning { padding: 7px; border-radius: 10px; }
  .free-number-meaning span { font-size: 9px; }
  .free-number-meaning b { font-size: 10px; line-height: 1.2; }
  .training-invite { margin-top: 6px; padding: 8px 5px; border-radius: 10px; font-size: 10px; }
}