/* 数字花园：纸色、森林绿与少量收获黄；题目和数字优先。 */
:root {
  color-scheme: light;
  --panel: #243f33;
  --muted: #617265;
  --paper: #f7f8f2;
  --card: #fffef8;
  --accent: #35664b;
  --accent-deep: #264d38;
  --line: #dce3d5;
  --soft: #edf2e7;
  --warning: #a33e30;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  margin: 0;
  height: 100dvh;
  background: var(--paper);
  color: var(--panel);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.6;
  padding: max(10px, env(safe-area-inset-top)) max(12px, env(safe-area-inset-right)) max(10px, env(safe-area-inset-bottom)) max(12px, env(safe-area-inset-left));
  overscroll-behavior-y: contain;
}
.app { max-width: 1000px; height: 100%; margin: auto; display: flex; flex-direction: column; gap: 8px; }
.app-header { flex: none; margin: 0; }
h1 { font-size: 26px; line-height: 1.2; margin: 0; }
.title-dot { color: #c09638; }
.player-bar { display: flex; align-items: center; gap: 10px; padding: 4px 10px; flex: none; border: 1px solid var(--line); border-radius: 14px; background: var(--card); font-size: 13px; }
#btn-menu { margin-left: auto; border: 0; background: transparent; padding: 8px 10px; }
.avatar-art { display: inline-block; width: 36px; height: 36px; flex-shrink: 0; }
.avatar-art svg { width: 100%; height: 100%; }
.avatar-art.large { width: 150px; height: 150px; margin: 16px auto; display: block; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
button {
  font: inherit;
  font-size: 14px;
  font-weight: 650;
  padding: 11px 18px;
  min-height: 48px;
  border: 1px solid #ced8c7;
  border-radius: 12px;
  background: var(--card);
  color: var(--panel);
  cursor: pointer;
  touch-action: manipulation;
  transition: background .15s, transform .15s;
}
button:active { transform: translateY(2px); }
button.primary { background: var(--accent); border-color: var(--accent); color: #fffef8; box-shadow: 0 3px 0 var(--accent-deep); }
button:disabled { opacity: .45; cursor: not-allowed; transform: none; box-shadow: none; }
button:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible, canvas:focus-visible { outline: 3px solid #a16d19; outline-offset: 4px; }
@media (hover: hover) { button:not(:disabled):hover { background: var(--soft); } button.primary:not(:disabled):hover { background: var(--accent-deep); } }
#main-nav { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); margin: 16px 0 24px; gap: 12px; }
#main-nav button { text-align: center; padding: 10px 6px; background: transparent; border-color: var(--line); }
#main-nav button > span { display: inline-grid; place-items: center; width: 28px; height: 28px; margin-right: 8px; background: #e7eddf; border-radius: 7px; font-size: 20px; vertical-align: middle; }
#main-nav small { display: block; font-size: 11px; font-weight: 400; color: var(--muted); margin-top: 9px; }
.screen { flex: 1; min-height: 0; }
.screen h2 { font-size: 23px; line-height: 1.4; margin: 0 0 14px; }
.screen:not(#screen-select):not(#screen-game) { padding: 20px; overflow: auto; background: var(--card); border: 1px solid var(--line); border-radius: 22px; }
.hint { color: var(--muted); font-size: 13px; margin: 8px 0; }
#screen-select { display: flex; flex-direction: column; gap: 8px; }
.home-layout { flex: 1; min-height: 0; display: grid; grid-template-columns: 1fr 1fr; border: 1px solid var(--line); border-radius: 24px; overflow: hidden; background: var(--card); }
.garden-intro { display: flex; align-items: center; justify-content: center; padding: 20px; background: #eaf0df; min-height: 0; }
.garden-art { display: block; max-width: 100%; max-height: 100%; aspect-ratio: 400 / 220; }
.grade-panel { padding: 20px; display: flex; flex-direction: column; justify-content: center; min-height: 0; }
.grade-panel h2 { font-size: 22px; }
.grades { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; padding: 0; margin: 20px 0; border: 0; }
.grades legend { font-size: 12px; color: var(--muted); padding: 0; margin-bottom: 10px; }
.grades label { display: flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 8px; min-height: 54px; background: #fafbf6; border: 1px solid var(--line); border-radius: 12px; font-size: 14px; cursor: pointer; }
.grades input { width: 18px; height: 18px; margin: 0; accent-color: var(--accent); }
.grades label:has(input:checked) { border-color: var(--accent); background: #e9f0e1; box-shadow: inset 0 0 0 1px var(--accent); font-weight: 700; }
.grade-panel .actions { margin-top: 22px; }
#btn-to-availability { width: 100%; }
.records { border-bottom: 1px solid var(--line); margin-top: 20px; padding: 15px 4px; }
.records summary { cursor: pointer; font-size: 14px; font-weight: 650; min-height: 48px; align-content: center; }
.records summary span { float: right; color: var(--muted); font-size: 12px; font-weight: 400; }
.records-list { list-style: none; padding: 0; margin: 12px 0; }
.records-list li { padding: 12px; border-bottom: 1px solid var(--line); font-size: 13px; }
.status { margin: 0; flex: none; padding: 8px 12px; border: 1px solid var(--line); border-radius: 12px; background: var(--soft); font-size: 14px; overflow-wrap: anywhere; }
.status-warning { color: var(--warning); border-color: #dca99a; background: #fff0e9; }
.offline-notice { font-size: 11px; color: var(--muted); border: 0; padding: 0 2px; background: transparent; }
.restore-offer { flex: none; display: flex; justify-content: space-between; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 0; padding: 8px 12px; background: #f7efda; border: 1px solid #e2d3aa; border-radius: 16px; }
.restore-text { margin: 0; font-size: 14px; }
.restore-offer .actions { margin: 0; }
.round-guide { display: flex; flex-wrap: wrap; gap: 20px; margin: 28px 0; }
.round-guide span { font-size: 14px; }
.round-guide b { display: inline-grid; place-items: center; width: 32px; height: 32px; margin-right: 8px; border-radius: 50%; color: var(--accent); background: var(--soft); font: 700 12px system-ui; }
.preview-banner { padding: 10px; background: #fbf0d7; color: #77531b; border: 1px dashed #a7792c; border-radius: 10px; text-align: center; font-size: 13px; }
/* 局内仅显示必要状态；道具在棋盘之后，主任务始终优先。 */
body[data-screen="game"] { padding: max(6px, env(safe-area-inset-top)) 8px max(6px, env(safe-area-inset-bottom)); }
body[data-screen="game"] .app { max-width: 460px; }
body[data-screen="game"] .app-header { display: none; }
body[data-screen="game"] .player-bar { display: none; }
body[data-screen="game"] #offline-notice:not(.status-warning) { display: none; }
.screen-game { display: flex; flex-direction: column; position: relative; gap: 6px; }
.chip { padding: 5px 10px; font-size: 12px; min-height: 48px; background: transparent; border: 0; }
.game-status { flex: none; display: flex; justify-content: space-between; gap: 8px; align-items: center; padding: 0 8px; }
#game-mode { font-size: 11px; margin: 4px 0; }
.countdown { margin: 4px 0; font-size: 14px; font-weight: 750; font-variant-numeric: tabular-nums; white-space: nowrap; color: var(--accent); }
.countdown[data-urgent="true"] { color: var(--warning); background: #fce8df; border-radius: 7px; padding: 2px 6px; }
.board-wrap { flex: 1; min-height: 0; position: relative; display: flex; justify-content: center; align-items: center; padding: 8px; border: 0; border-radius: 18px; background: #e9efdf; }
.board-canvas { display: block; border: 0; border-radius: 15px; background: #edf2e6; cursor: pointer; touch-action: none; }
.pause-overlay { position: absolute; inset: 8px; z-index: 2; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; background: #edf2e6; border-radius: 15px; padding: 24px; text-align: center; }
.pause-overlay::before { content: 'Ⅱ'; display: grid; place-items: center; width: 64px; height: 64px; background: #d6e4cb; color: var(--accent); font-size: 28px; border-radius: 20px; margin-bottom: 8px; }
.pause-title { font-size: 23px; font-weight: 750; margin: 0; }
.pause-hint { color: var(--muted); font-size: 13px; margin: 0 0 16px; }
.challenge-tools { flex: none; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-top: 0; }
.challenge-tools .actions { margin: 0; flex: 1; display: grid; grid-template-columns: 1fr 1fr; }
.challenge-tools button { padding: 9px; background: #fffef8; font-size: 13px; }
#btn-ready { width: 100%; order: -1; }
.game-actions { flex: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-top: 0; padding-top: 0; border-top: 1px solid var(--line); }
.game-actions button { font-size: 13px; padding-inline: 4px; border-color: transparent; background: transparent; }
.game-actions #btn-pause:disabled { display: none; }
.game-actions:has(#btn-restart[hidden]) { grid-template-columns: 1fr; }
#practice-tools .actions { margin-top: 10px; }
#screen-result { text-align: center; }
#screen-result .actions { justify-content: center; }
.result-emblem { display: grid; place-items: center; width: 76px; height: 76px; margin: 0 auto 20px; background: #f4df9e; border: 1px solid #ddc579; border-radius: 25px; font-size: 44px; color: #83601d; }
.result-line { font-size: 15px; color: var(--muted); }
#result-score { font-size: 38px; font-weight: 800; color: var(--panel); margin: 14px 0; }
#result-coins { max-width: 520px; margin: 24px auto; }
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); gap: 16px; margin: 22px 0; }
.product-card { padding: 20px; background: #f4f6ec; border: 1px solid var(--line); border-radius: 16px; }
.product-card h3 { font-size: 18px; margin: 10px 0; }
.product-card p { font-size: 13px; color: var(--muted); }
.product-card button { margin: 5px 5px 5px 0; font-size: 13px; }
#nickname, #review-filter { font: inherit; padding: 12px; max-width: 100%; min-height: 48px; border: 1px solid #bccbb5; border-radius: 10px; background: var(--card); color: var(--panel); }
#nickname { display: block; width: 100%; margin: 10px 0; }
#nickname-form { max-width: 420px; }
.example { white-space: pre-line; line-height: 1.8; padding: 16px; background: #e9efdd; border-radius: 12px; }
#app-notice { white-space: pre-line; }
dialog { color: var(--panel); background: var(--card); border: 1px solid #c9d6bf; border-radius: 22px; padding: 28px; width: min(460px, calc(100% - 32px)); max-height: 85dvh; overflow: auto; }
dialog::backdrop { background: rgb(25 44 32 / 55%); }
dialog h2 { font-size: 22px; margin-top: 0; }
dialog p { line-height: 1.8; font-size: 14px; }
.skin-preview canvas { display: block; width: min(100%, 240px); height: auto; margin: auto; border-radius: 14px; }
body[data-skin="autumn"] { --paper: #faf6ec; --soft: #f3ead8; --accent: #7e5c32; --accent-deep: #604324; }
body[data-skin="snow"] { --paper: #f1f7f7; --soft: #e2eeef; --accent: #3c6970; --accent-deep: #2d5057; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }

.menu-heading { position: sticky; top: 0; z-index: 1; background: var(--card); display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.menu-heading h2 { margin: 0; }
#main-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
#main-nav small { display: none; }
#main-nav button[aria-current="page"] { background: #e6eddb; border-color: var(--accent); }
#screen-availability, #screen-result { position: relative; }
#screen-availability > .actions, #screen-result > .actions { position: sticky; bottom: 0; background: var(--card); padding: 8px 0; }
#courses-list:has(> h3) { display: block; }
#courses-list:has(> h3) > button { display: block; margin: 12px 0; }
#screen-shop, #screen-courses, #screen-review { display: flex; flex-direction: column; gap: 8px; overflow: hidden; }
:is(#screen-shop, #screen-courses, #screen-review) > .card-grid { flex: 1; min-height: 0; overflow: auto; margin: 0; align-content: start; }
:is(#screen-shop, #screen-courses, #screen-review) > :not(.card-grid) { flex: none; }
#practice-tools .actions { margin: 0; }
#practice-tools .actions button { flex: 1; padding-inline: 8px; font-size: 13px; }
#explanation-dialog > button { margin-top: 12px; }
@media (max-width: 640px) {
  .home-layout { grid-template-columns: 1fr; grid-template-rows: minmax(0, 1fr) auto; border-radius: 18px; }
  .garden-intro { padding: 0; }
  .garden-art { width: auto; height: 100%; }
  .grade-panel { padding: 16px; }
  .grade-panel h2 { font-size: 20px; margin-bottom: 4px; }
  .grades { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; margin: 10px 0; }
  .grades label { flex-direction: column; gap: 4px; padding: 8px 2px; font-size: 13px; }
  .grade-panel .actions { margin-top: 12px; }
  .round-guide { gap: 12px; margin: 16px 0; }
  .round-guide span { font-size: 12px; }
  .round-guide b { margin: 0 4px 0 0; }
  .result-emblem { width: 48px; height: 48px; font-size: 28px; margin-bottom: 8px; border-radius: 15px; }
  #result-score { font-size: 26px; margin: 8px 0; }
  #result-coins { margin: 12px 0; }
}
@media (max-height: 740px) {
  .garden-intro { display: none; }
  .home-layout { grid-template-columns: 1fr; grid-template-rows: 1fr; }
  .grade-panel { padding: 12px 16px; }
  .grade-panel .hint { margin: 4px 0; }
  .app-header h1 { font-size: 23px; }
  .restore-text { font-size: 12px; }
  #select-empty-hint { display: none; }
}
@media (orientation: landscape) and (max-height: 500px) {
  .app { max-width: 1000px; gap: 4px; }
  .app-header { display: none; }
  .player-bar { padding-block: 0; }
  .avatar-art { width: 24px; height: 24px; }
  #screen-select { flex-direction: row; }
  .grade-panel { padding: 8px 16px; }
  .grade-panel h2 { font-size: 18px; margin-bottom: 2px; }
  .grades { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; margin: 4px 0; }
  .grades legend { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .grades label { flex-direction: row; min-height: 44px; padding: 4px; }
  .grade-panel .actions { margin-top: 4px; }
  .restore-offer { width: 150px; flex-direction: column; justify-content: center; gap: 4px; padding: 8px; }
  .restore-offer .actions { gap: 6px; }
  body[data-screen="game"] .app { max-width: 1000px; }
  .screen-game { display: grid; grid-template-columns: minmax(0, 1fr) 132px; grid-template-rows: auto minmax(0, 1fr) auto; gap: 4px 8px; }
  .board-wrap { grid-column: 1; grid-row: 1 / 4; }
  .game-status { grid-column: 2; grid-row: 1; padding: 0; flex-wrap: wrap; justify-content: center; gap: 0; }
  .challenge-tools, #practice-tools { grid-column: 2; grid-row: 2; align-content: center; }
  .challenge-tools .actions { grid-template-columns: 1fr; }
  .game-actions { grid-column: 2; grid-row: 3; grid-template-columns: repeat(2, 1fr); gap: 0; }
  .game-actions button { min-height: 44px; }
  #btn-restart { grid-column: 1 / -1; grid-row: 2; }
  .screen:not(#screen-select):not(#screen-game) { padding: 12px; }
  .round-guide { display: none; }
  .screen h2 { font-size: 20px; margin-bottom: 6px; }
}
@media (prefers-reduced-motion: reduce) { button { transition: none; } }

/* 选择题沿用纸色题卡，候选与提交区共享可用高度。 */
.choice-board { width: 100%; max-width: 620px; height: 100%; min-height: 0; display: flex; flex-direction: column; gap: 8px; padding: 8px; }
.choice-board p, .choice-board h2 { margin: 0; }
.choice-board h2 { font-size: clamp(18px, 3vw, 24px); line-height: 1.35; }
.choice-options { flex: 1; min-height: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); grid-auto-rows: minmax(44px, 1fr); gap: 8px; }
.choice-options button { font-size: clamp(20px, 4vw, 30px); min-width: 0; padding: 4px; position: relative; }
.choice-options button[aria-pressed="true"] { background: #dcebd5; border: 2px solid var(--accent); }
.choice-mark { display: inline-block; width: 1.2em; font-size: 18px; }
.choice-options button[data-hint="true"] { border: 3px solid #795016; }
.choice-options button[data-hint="true"]::after { content: '提示'; position: absolute; right: 4px; top: 2px; font-size: 12px; }
.choice-board[data-resolving="true"] .choice-options button[data-correct="true"] { opacity: .25; transform: scale(.9); transition: opacity .3s, transform .3s; }
.choice-board #btn-choice-submit { flex: none; min-height: 44px; }
#choice-feedback:empty { display: none; }
@media (orientation: landscape) and (max-height: 500px) {
  .choice-board { gap: 4px; padding: 2px; }
  .choice-board h2 { font-size: 18px; }
  .choice-board .hint { font-size: 12px; }
  .choice-options { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 4px; }
}
@media (prefers-reduced-motion: reduce) {
  .choice-board[data-resolving="true"] .choice-options button[data-correct="true"] { transition: none; transform: none; }
}

.choice-diagram { display: flex; justify-content: center; gap: 8px; flex-wrap: wrap; }
.choice-dot-group { display: flex; align-items: center; gap: 5px; border: 1px solid var(--line); border-radius: 8px; padding: 8px; }
.choice-dot { width: 10px; height: 10px; border-radius: 50%; background: var(--accent); }
.choice-options:has(button[data-expression="true"]) button { font-size: clamp(17px, 3vw, 24px); }