.spacing-trainer-intro { max-width: 920px; }
.spacing-rules {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: -8px 0 16px;
}
.spacing-rules span {
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--panel);
  color: var(--muted);
  font-size: .79rem;
  line-height: 1.35;
}
.spacing-rules strong { display: block; margin-bottom: 2px; color: var(--text); font-size: .86rem; }

.spacing-mode-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 16px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fbfcf8;
}
.spacing-mode-panel strong { display: block; margin-top: 3px; font-size: .84rem; }
.spacing-mode-switch { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 7px; min-width: min(420px, 52%); }
.spacing-mode-switch button {
  min-height: 40px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
  font: inherit;
  font-size: .75rem;
  font-weight: 850;
  cursor: pointer;
}
.spacing-mode-switch button:hover { background: #f4f6ef; }
.spacing-mode-switch button.is-selected { border-color: #737e67; background: #edf1e7; }

.spacing-trainer-shell {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}
.spacing-trainer-topbar {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-bottom: 1px solid var(--line);
}
.spacing-stat,
.spacing-timer-stat {
  min-height: 72px;
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 6px;
  padding: 15px;
  border-right: 1px solid var(--line);
}
.spacing-timer-stat { background: #f8f9f3; }
.spacing-stat:last-child { border-right: 0; }
.spacing-stat span,
.spacing-timer-stat span {
  color: var(--muted);
  font-size: .72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .055em;
}
.spacing-stat strong,
.spacing-timer-stat strong { font-size: 1.55rem; letter-spacing: -.04em; }
.spacing-timer-stat em { color: var(--muted); font-size: .69rem; font-style: normal; font-weight: 800; }
.spacing-timer-track { height: 5px; background: #eceee7; }
.spacing-timer-track span { display: block; width: 100%; height: 100%; background: #6f775f; transition: width .1s linear; }
.spacing-timer-track span.is-low { background: #9c493f; }

.spacing-game-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(300px, .55fr);
  min-height: 620px;
}
.spacing-plan-panel { min-width: 0; padding: 22px; border-right: 1px solid var(--line); }
.spacing-plan-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; }
.spacing-plan-head h2 { margin: 3px 0 0; font-size: 1.25rem; }
.spacing-round-tools { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: .74rem; white-space: nowrap; }
.spacing-reset { min-height: 34px; padding: 7px 10px; font-size: .68rem; }

.spacing-canvas-wrap {
  margin-top: 15px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
}
.spacing-svg { display: block; width: 100%; height: auto; aspect-ratio: 720 / 390; }
.spacing-svg .spacing-wall { fill: #eceee7; stroke: #6d7368; stroke-width: 2.2; }
.spacing-svg .spacing-wall-hatch { stroke: #c2c7bc; stroke-width: 1.25; }
.spacing-svg .spacing-rail { fill: #daddd4; stroke: #6a7062; stroke-width: 2; }
.spacing-svg .spacing-member { fill: #f6f7f2; stroke: #252a21; stroke-width: 2.5; }
.spacing-svg .spacing-unknown-panel { fill: #fafbf7; stroke: #aeb5a7; stroke-width: 1.6; stroke-dasharray: 7 6; }
.spacing-svg .spacing-unknown-text { fill: #62695c; font-size: 23px; font-weight: 900; text-anchor: middle; letter-spacing: -.02em; }
.spacing-svg .spacing-unknown-sub { fill: #858c7f; font-size: 11px; font-weight: 850; text-anchor: middle; letter-spacing: .06em; }
.spacing-svg .spacing-dim { stroke: #737a6c; stroke-width: 1.5; }
.spacing-svg .spacing-dim-extension { stroke: #b5baaf; stroke-width: 1; stroke-dasharray: 3 3; }
.spacing-svg .spacing-dim-tick { stroke: #737a6c; stroke-width: 1.5; }
.spacing-svg .spacing-dim-text { fill: #2b3027; font-size: 14px; font-weight: 800; text-anchor: middle; }
.spacing-svg .spacing-gap-dim { stroke: #667257; stroke-width: 2; }
.spacing-svg .spacing-gap-text { fill: #59634d; font-size: 13px; font-weight: 900; text-anchor: middle; letter-spacing: .04em; }
.spacing-svg .spacing-caption { fill: #737a6c; font-size: 11px; font-weight: 900; letter-spacing: .08em; }
.spacing-svg .spacing-member-label { fill: #737a6c; font-size: 12px; font-weight: 800; }
.spacing-svg .spacing-thickness-box { fill: #f3f6ef; stroke: #8e9984; stroke-width: 1.2; }
.spacing-svg .spacing-thickness-swatch { fill: #f6f7f2; stroke: #252a21; stroke-width: 2; }
.spacing-svg .spacing-thickness-title { fill: #687260; font-size: 9px; font-weight: 900; letter-spacing: .07em; }
.spacing-svg .spacing-thickness-value { fill: #242a20; font-size: 14px; font-weight: 950; }
.spacing-svg .spacing-thickness-leader { stroke: #7c876f; stroke-width: 1.4; stroke-dasharray: 3 3; }
.spacing-svg .spacing-thickness-dot { fill: #687260; }
.spacing-svg .spacing-wall-label { fill: #858c7f; font-size: 10px; font-weight: 850; letter-spacing: .06em; }
.spacing-svg .spacing-max-label-box { fill: #f1f4ec; stroke: #9ea895; stroke-width: 1.2; }
.spacing-svg .spacing-max-label { fill: #4f5946; font-size: 13px; font-weight: 900; text-anchor: middle; }

.spacing-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin-top: 10px;
}
.spacing-facts div { min-width: 0; padding: 10px 11px; border: 1px solid var(--line); border-radius: 11px; background: #fbfcf8; }
.spacing-facts span { display: block; color: var(--muted); font-size: .65rem; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; }
.spacing-facts strong { display: block; margin-top: 4px; font-size: .95rem; white-space: nowrap; }

.spacing-answer-panel { padding: 22px; background: #fbfcf8; }
.spacing-answer-display {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 8px 0 17px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
}
.spacing-answer-display strong { font-size: 2rem; letter-spacing: -.04em; }
.spacing-desktop-entry label { display: block; margin-bottom: 7px; color: var(--muted); font-size: .68rem; font-weight: 900; letter-spacing: .06em; }
.spacing-answer-input { display: grid; grid-template-columns: 1fr auto; align-items: center; overflow: hidden; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.spacing-answer-input input { width: 100%; min-width: 0; min-height: 48px; border: 0; outline: 0; padding: 11px 12px; background: transparent; font: inherit; font-weight: 780; }
.spacing-answer-input span { padding-right: 12px; color: var(--muted); font-size: .78rem; font-weight: 800; }
.spacing-desktop-entry > p { margin: 8px 0 0; color: var(--muted); font-size: .7rem; line-height: 1.4; }
.spacing-desktop-fraction-tools { margin-top: 13px; }
.spacing-desktop-fraction-tools.is-hidden,
#spacingMobileFractionTools.is-hidden { display: none; }
.spacing-pad-heading { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 7px; }
.spacing-pad-heading span { color: var(--muted); font-size: .65rem; font-weight: 900; letter-spacing: .06em; }
.spacing-pad-heading small { color: var(--muted); font-size: .65rem; }
.spacing-desktop-fraction-pad,
.spacing-fraction-pad { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 6px; }
.spacing-desktop-fraction-pad button,
.spacing-fraction-pad button,
.spacing-whole-pad button {
  min-width: 0;
  min-height: 38px;
  padding: 7px 4px;
  border: 1px solid var(--line);
  border-radius: 9px;
  color: var(--text);
  background: #fff;
  font: inherit;
  font-size: .72rem;
  font-weight: 800;
  cursor: pointer;
}
.spacing-desktop-fraction-pad button:hover,
.spacing-fraction-pad button:hover,
.spacing-whole-pad button:hover { background: #f4f6ef; }
.spacing-desktop-fraction-pad button.is-selected,
.spacing-fraction-pad button.is-selected { border-color: #737e67; background: #edf1e7; }
.spacing-desktop-fraction-pad button:disabled { cursor: not-allowed; opacity: .45; }
.spacing-mobile-entry { display: none; }

.spacing-calculator-open { width: 100%; margin-top: 16px; min-height: 42px; }
.spacing-calculator-note { margin: 6px 0 0; color: var(--muted); font-size: .68rem; text-align: center; }
.spacing-feedback { margin-top: 14px; padding: 12px; border: 1px solid var(--line); border-radius: 11px; background: #fff; font-size: .79rem; line-height: 1.45; }
.spacing-feedback.hidden { display: none; }
.spacing-feedback.is-correct { border-color: #b8c5ad; background: #f5f8f1; }
.spacing-feedback.is-wrong { border-color: #ddc6bd; background: #fbf5f2; }
.spacing-feedback.is-summary { background: #f4f6ef; }
.spacing-why { margin-top: 8px; border-top: 1px solid rgba(0,0,0,.08); padding-top: 7px; }
.spacing-why summary { cursor: pointer; font-weight: 850; }
.spacing-why p { margin: 7px 0 0; color: var(--muted); }
.spacing-primary { width: 100%; margin-top: 12px; }

.spacing-calculator-backdrop {
  position: fixed;
  z-index: 90;
  inset: 0;
  background: rgba(24, 29, 22, .32);
  backdrop-filter: blur(1px);
}
.spacing-calculator-backdrop.hidden { display: none; }
.spacing-calculator-sheet {
  position: fixed;
  z-index: 100;
  right: 24px;
  bottom: 24px;
  width: min(390px, calc(100vw - 32px));
  max-height: calc(100vh - 48px);
  overflow: auto;
  border: 1px solid #c9cdc3;
  border-radius: 18px;
  background: #fbfcf8;
  box-shadow: 0 22px 60px rgba(20, 24, 18, .24);
  transform: translateY(calc(100% + 40px));
  opacity: 0;
  pointer-events: none;
  transition: transform .18s ease, opacity .18s ease;
}
.spacing-calculator-sheet.is-open { transform: translateY(0); opacity: 1; pointer-events: auto; }
.spacing-calculator-head { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 13px 15px; border-bottom: 1px solid var(--line); }
.spacing-calculator-head span { display: block; color: var(--muted); font-size: .64rem; font-weight: 900; letter-spacing: .07em; }
.spacing-calculator-head strong { display: block; margin-top: 2px; font-size: .79rem; }
.spacing-calculator-close { width: 34px; height: 34px; border: 1px solid var(--line); border-radius: 10px; background: #fff; color: var(--text); font-size: 1.3rem; cursor: pointer; }
.spacing-calculator-display { min-height: 78px; display: flex; flex-direction: column; align-items: flex-end; justify-content: center; padding: 12px 16px; border-bottom: 1px solid var(--line); background: #fff; }
.spacing-calculator-display small { min-height: 18px; color: var(--muted); font-size: .71rem; text-align: right; }
.spacing-calculator-display strong { max-width: 100%; overflow: hidden; text-overflow: ellipsis; font-size: 1.9rem; letter-spacing: -.04em; }
.spacing-calculator-input-label { padding: 9px 12px 0; color: var(--muted); font-size: .6rem; font-weight: 900; letter-spacing: .07em; }
.spacing-calculator-keys { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 6px; padding: 7px 11px 8px; }
.spacing-calculator-keys button { min-height: 42px; border: 1px solid var(--line); border-radius: 9px; background: #fff; color: var(--text); font: inherit; font-size: .88rem; font-weight: 820; cursor: pointer; }
.spacing-calculator-keys button:hover { background: #f4f6ef; }
.spacing-calculator-keys button[data-calc-operator],
.spacing-calculator-keys .spacing-calc-equals { background: #eef1e8; }
.spacing-calculator-keys .spacing-calc-zero { grid-column: span 2; }
.spacing-calculator-keys button[data-calc-action="fraction-clear"] { font-size: .66rem; }
.spacing-calculator-fraction-wrap { padding: 0 11px 10px; }
.spacing-calculator-fraction-wrap .spacing-calculator-input-label { padding: 2px 1px 7px; }
.spacing-calculator-fraction-pad { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 5px; }
.spacing-calculator-fraction-pad button {
  min-width: 0;
  min-height: 33px;
  padding: 5px 3px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  font: inherit;
  font-size: .67rem;
  font-weight: 800;
  cursor: pointer;
}
.spacing-calculator-fraction-pad button.is-selected { border-color: #737e67; background: #edf1e7; }
.spacing-calculator-footer { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 10px 12px 12px; border-top: 1px solid var(--line); background: #f8f9f4; }
.spacing-calculator-footer span { color: var(--muted); font-size: .64rem; line-height: 1.3; }
.spacing-calculator-use { min-height: 36px; padding: 7px 11px; white-space: nowrap; }
.spacing-calculator-use.is-hidden { display: none; }

@media (max-width: 900px) {
  .spacing-rules { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .spacing-mode-panel { align-items: flex-start; }
  .spacing-mode-switch { min-width: 48%; }
  .spacing-game-grid { grid-template-columns: 1fr; }
  .spacing-plan-panel { border-right: 0; border-bottom: 1px solid var(--line); }
  .spacing-answer-panel { max-width: none; }
}

@media (max-width: 680px) {
  .spacing-trainer-page { padding-top: 14px; }
  .spacing-trainer-intro { margin-bottom: 18px; }
  .spacing-trainer-intro .lede { font-size: .9rem; }
  .spacing-rules { grid-template-columns: 1fr 1fr; gap: 7px; margin-bottom: 10px; }
  .spacing-rules span { padding: 9px 10px; font-size: .67rem; }
  .spacing-rules strong { font-size: .73rem; }
  .spacing-mode-panel { display: block; padding: 10px; margin-bottom: 12px; }
  .spacing-mode-panel > div:first-child strong { font-size: .72rem; }
  .spacing-mode-switch { min-width: 0; width: 100%; margin-top: 9px; }
  .spacing-mode-switch button { min-height: 38px; padding: 7px 5px; font-size: .68rem; }
  .spacing-trainer-topbar { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .spacing-stat,
  .spacing-timer-stat { min-height: 54px; padding: 9px 4px; gap: 3px; flex-direction: column; align-items: center; justify-content: center; }
  .spacing-stat span,
  .spacing-timer-stat span { font-size: .55rem; }
  .spacing-stat strong,
  .spacing-timer-stat strong { font-size: 1.12rem; }
  .spacing-timer-stat em { display: none; }
  .spacing-plan-panel { padding: 13px; }
  .spacing-plan-head { align-items: center; }
  .spacing-plan-head h2 { font-size: .98rem; }
  .spacing-round-tools { gap: 6px; font-size: .62rem; }
  .spacing-reset { min-height: 30px; padding: 5px 7px; font-size: .58rem; }
  .spacing-canvas-wrap { margin-top: 10px; }
  .spacing-facts { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; margin-top: 7px; }
  .spacing-facts div { padding: 8px 9px; }
  .spacing-facts span { font-size: .52rem; }
  .spacing-facts strong { font-size: .82rem; }
  .spacing-answer-panel { padding: 13px; }
  .spacing-answer-display { min-height: 58px; margin: 5px 0 10px; }
  .spacing-answer-display strong { font-size: 1.55rem; }
  .spacing-desktop-entry { display: none; }
  .spacing-mobile-entry { display: block; }
  .spacing-mobile-pad { transition: opacity .12s ease; }
  .spacing-mobile-pad.is-disabled { opacity: .46; pointer-events: none; }
  .spacing-whole-pad { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 5px; }
  .spacing-whole-pad button { min-height: 39px; font-size: .73rem; }
  .spacing-fraction-heading { margin-top: 10px; }
  .spacing-fraction-pad { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 5px; }
  .spacing-fraction-pad button { min-height: 36px; font-size: .65rem; }
  .spacing-calculator-open { margin-top: 12px; }
  .spacing-calculator-note { margin-top: 5px; }
  .spacing-feedback { margin-top: 10px; }
  .spacing-primary { margin-top: 10px; }
  .spacing-calculator-sheet {
    right: 0;
    bottom: 0;
    width: 100%;
    max-height: 88vh;
    border-radius: 18px 18px 0 0;
    border-left: 0;
    border-right: 0;
    border-bottom: 0;
  }
  .spacing-calculator-head { padding: 10px 12px; }
  .spacing-calculator-display { min-height: 64px; padding: 9px 13px; }
  .spacing-calculator-display strong { font-size: 1.65rem; }
  .spacing-calculator-keys button { min-height: 38px; }
  .spacing-calculator-fraction-pad button { min-height: 31px; font-size: .62rem; }
  .spacing-calculator-footer { padding-bottom: max(11px, env(safe-area-inset-bottom)); }
}

@media (max-width: 390px) {
  .spacing-rules { grid-template-columns: 1fr; }
  .spacing-plan-head { align-items: flex-start; }
  .spacing-round-tools { flex-direction: column; align-items: flex-end; }
  .spacing-svg .spacing-dim-text { font-size: 12px; }
  .spacing-svg .spacing-gap-text { font-size: 11px; }
  .spacing-svg .spacing-unknown-text { font-size: 19px; }
}


/* Inline trainer workbench calculator */
.spacing-calculator-workbench {
  display: none;
  margin-top: 10px;
  overflow: hidden;
  border: 1px solid #c9cdc3;
  border-radius: 14px;
  background: #fbfcf8;
  box-shadow: none;
}
.spacing-calculator-workbench.is-open { display: block; }
.spacing-answer-panel.is-calculator-open .spacing-calculator-open,
.spacing-answer-panel.is-calculator-open .spacing-calculator-note { display: none; }
.spacing-answer-panel.is-calculator-open .spacing-desktop-entry,
.spacing-answer-panel.is-calculator-open .spacing-mobile-entry { display: none; }
.spacing-calculator-close { width: auto; height: auto; min-height: 32px; padding: 6px 10px; border-radius: 9px; font-size: .68rem; font-weight: 850; line-height: 1; }
.spacing-calculator-values { padding: 9px 11px; border-bottom: 1px solid var(--line); background: #f8f9f4; }
.spacing-calculator-values-head { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; margin-bottom: 6px; }
.spacing-calculator-values-head span { color: var(--muted); font-size: .58rem; font-weight: 900; letter-spacing: .065em; }
.spacing-calculator-values-head small { color: var(--muted); font-size: .58rem; }
.spacing-calculator-value-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.spacing-calculator-value-chips button { min-height: 32px; padding: 6px 8px; border: 1px solid #cfd3ca; border-radius: 9px; background: #fff; color: var(--text); font: inherit; font-size: .68rem; font-weight: 800; cursor: pointer; }
.spacing-calculator-value-chips button:hover:not(:disabled) { background: #f2f5eb; border-color: #aeb5a6; }
.spacing-calculator-value-chips button:disabled { opacity: .48; cursor: default; }
.spacing-calculator-value-chips button span { display: block; color: var(--muted); font-size: .52rem; font-weight: 850; letter-spacing: .04em; }
.spacing-calculator-value-chips button strong { display: block; margin-top: 1px; font-size: .76rem; }

@media (max-width: 680px) {
  .spacing-answer-panel.is-calculator-open .spacing-mobile-entry { display: none; }
  .spacing-answer-panel.is-calculator-open .spacing-answer-display { margin-bottom: 4px; }
  .spacing-calculator-workbench { margin-top: 7px; border-radius: 11px; }
  .spacing-calculator-head { padding: 8px 9px; }
  .spacing-calculator-head strong { font-size: .68rem; line-height: 1.3; }
  .spacing-calculator-values { padding: 7px 8px; }
  .spacing-calculator-value-chips { gap: 5px; }
  .spacing-calculator-value-chips button { min-height: 30px; padding: 5px 7px; }
  .spacing-calculator-display { min-height: 56px; padding: 7px 10px; }
  .spacing-calculator-display strong { font-size: 1.48rem; }
  .spacing-calculator-keys { gap: 5px; padding: 7px 8px; }
  .spacing-calculator-keys button { min-height: 35px; }
  .spacing-calculator-fraction-wrap { padding: 0 8px 8px; }
  .spacing-calculator-fraction-pad { gap: 4px; }
  .spacing-calculator-fraction-pad button { min-height: 30px; font-size: .61rem; }
  .spacing-calculator-footer { padding: 8px; }
}

.spacing-calculator-workbench .spacing-calculator-keys button[data-calc-action="fraction-clear"] { grid-column: span 2; }