/* ============================================================
   24 게임 전용 스타일
   - 콘셉트: 트럼프 카드. 숫자 타일을 카드처럼(모서리 숫자, 각진
     흰 카드) 만들고, 포인트는 사이트 공통 주묵색을 그대로 쓴다.
   - 연산자는 실제 기호 ＋ − × ÷ 를 큰 알약 버튼으로.
   - 모바일 우선: 카드/버튼을 손가락에 맞춰 크게.
   ============================================================ */

:root {
  --tf-ok: #2e7d3c;
  --tf-bad: #c0392b;
  --tf-card: #fffdf8;
  --tf-card-line: #e0d7c4;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --tf-ok: #7fd694;
    --tf-bad: #ff8f7d;
    --tf-card: #262019;
    --tf-card-line: #3d342a;
  }
}
:root[data-theme="dark"] {
  --tf-ok: #7fd694;
  --tf-bad: #ff8f7d;
  --tf-card: #262019;
  --tf-card-line: #3d342a;
}

/* ---- 도입부: 옅은 점 격자(카드 무늬 없이 중립적으로) ---- */
.tool-intro { position: relative; overflow: hidden; padding: clamp(30px, 5vw, 56px) 0 clamp(18px, 3vw, 30px); }
.tool-intro > * { position: relative; }
.tool-intro::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(var(--color-grid) 1.3px, transparent 1.5px);
  background-size: 22px 22px;
  opacity: .4;
  -webkit-mask-image: linear-gradient(115deg, rgba(0,0,0,.55), transparent 58%);
          mask-image: linear-gradient(115deg, rgba(0,0,0,.55), transparent 58%);
  pointer-events: none;
}
.tool-intro h1 { margin: 0 0 var(--space-4); }
.tool-intro .lead {
  font-size: 1.08rem;
  line-height: 1.75;
  color: var(--color-text-sub);
  max-width: 52ch;
  margin: 0;
}
.tool-intro .lead strong { color: var(--color-text); }
.tool-intro .lead-note {
  margin: var(--space-3) 0 0;
  font-size: .88rem;
  color: var(--color-text-sub);
}

/* ---- 설정 줄 ---- */
.tf-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3) var(--space-5);
  padding: var(--space-4) var(--space-5);
  margin-bottom: var(--space-4);
}
.tf-field { display: flex; align-items: center; gap: var(--space-3); flex-wrap: wrap; }
.tf-lab { font-size: .95rem; font-weight: 700; color: var(--color-text-sub); }
.tf-field-note { flex-basis: 100%; font-size: .85rem; color: var(--color-text-sub); }
.tf-chips { display: flex; gap: var(--space-2); flex-wrap: wrap; }
.tf-chip {
  font: inherit;
  font-size: 1rem;
  cursor: pointer;
  touch-action: manipulation;
  padding: 10px 18px;
  border-radius: 999px;
  border: 1.5px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
}
.tf-chip small { font-size: .78em; font-weight: 400; opacity: .75; margin-left: 2px; }
.tf-chip:hover { border-color: var(--color-primary); }
.tf-chip[aria-pressed="true"] {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
  font-weight: 700;
}
.tf-btn-restart {
  font: inherit;
  font-size: 1rem;
  cursor: pointer;
  touch-action: manipulation;
  padding: 10px 18px;
  border-radius: 999px;
  border: 1.5px solid var(--color-border);
  background: transparent;
  color: var(--color-text-sub);
}
.tf-btn-restart:hover { border-color: var(--color-primary); color: var(--color-text); }

/* ---- 게임판 ---- */
.tf-stage { max-width: 560px; margin: 0 auto; }

.tf-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}
.tf-stat {
  font-size: 1.02rem;
  color: var(--color-text-sub);
  font-variant-numeric: tabular-nums;
  min-width: 92px;
}
.tf-stat:last-child { text-align: right; }
.tf-mid {
  flex: 1;
  text-align: center;
  font-size: 1.1rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  color: var(--color-text-sub);
}
.tf-mid.is-live { color: var(--color-text); }
.tf-mid.is-hurry { color: var(--tf-bad); border-color: var(--tf-bad); }

/* ---- 문제판 ---- */
.tf-board-wrap { display: grid; }
.tf-board-wrap > * { grid-area: 1 / 1; }
.tf-board {
  position: relative;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 20px;
  box-shadow: var(--shadow-sm);
  padding: clamp(18px, 4vw, 28px);
  overflow: hidden;
}
/* 남은 시간 막대 */
.tf-timer { position: absolute; top: 0; left: 0; right: 0; height: 7px; background: transparent; }
.tf-timer-fill {
  height: 100%;
  background: var(--color-primary);
  opacity: .85;
  transform-origin: left;
  transform: scaleX(0);
  will-change: transform;
}
.tf-timer-fill.is-low { background: var(--tf-bad); opacity: 1; }

/* 난이도 뱃지 */
.tf-badge-row { display: flex; justify-content: center; margin-bottom: clamp(10px, 2vw, 16px); }
.tf-badge {
  font-size: .74rem;
  font-weight: 700;
  letter-spacing: .12em;
  padding: 4px 12px;
  border-radius: 999px;
  border: 1.5px solid var(--color-border);
  color: var(--color-text-sub);
  background: var(--color-bg);
}
.tf-target {
  text-align: center;
  margin: 0 0 clamp(12px, 2.5vw, 18px);
  font-size: .92rem;
  color: var(--color-text-sub);
}
.tf-target b { color: var(--color-primary); font-size: 1.05rem; }

/* ---- 숫자 카드 타일 ---- */
.tf-tiles {
  display: flex;
  justify-content: center;
  gap: clamp(8px, 2.4vw, 16px);
  min-height: clamp(96px, 24vw, 132px);
  align-items: center;
}
.tf-tile {
  position: relative;
  flex: 0 0 auto;
  width: clamp(64px, 18vw, 92px);
  height: clamp(90px, 25vw, 128px);
  font: inherit;
  cursor: pointer;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  -webkit-user-select: none;
  user-select: none;
  background: var(--tf-card);
  border: 1.5px solid var(--tf-card-line);
  border-radius: 10px;
  box-shadow: 0 2px 6px rgba(0,0,0,.08);
  color: var(--color-text);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform .1s ease, box-shadow .12s ease, border-color .12s ease;
}
.tf-tile:hover { border-color: var(--color-primary); transform: translateY(-2px); }
.tf-tile:active { transform: translateY(0) scale(.97); }
.tf-tile:focus-visible { outline: 3px solid var(--color-text); outline-offset: 2px; }
.tf-tile.is-sel {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-weak), 0 4px 10px rgba(0,0,0,.12);
  transform: translateY(-3px);
}
.tf-tile-val {
  font-size: clamp(1.9rem, 7vw, 2.9rem);
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  color: var(--color-primary);
  line-height: 1;
}
.tf-tile-val.is-small { font-size: clamp(1.15rem, 4.6vw, 1.7rem); }
.tf-tile-corner {
  position: absolute;
  font-size: clamp(.62rem, 2.4vw, .82rem);
  font-weight: 700;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
  line-height: 1;
  opacity: .8;
}
.tf-tl { top: 6px; left: 7px; }
.tf-br { bottom: 6px; right: 7px; transform: rotate(180deg); }
/* 합쳐져 비어버린 자리 */
.tf-tile.is-ghost {
  background: transparent;
  border: 1.5px dashed var(--color-border);
  box-shadow: none;
  cursor: default;
  opacity: .5;
}

/* ---- 연산자 알약 버튼 ---- */
.tf-ops {
  display: flex;
  justify-content: center;
  gap: clamp(8px, 2.4vw, 14px);
  margin: clamp(16px, 3.5vw, 24px) 0 clamp(12px, 2.5vw, 18px);
}
.tf-op {
  font: inherit;
  font-size: clamp(1.5rem, 6vw, 2rem);
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  width: clamp(52px, 15vw, 66px);
  height: clamp(52px, 15vw, 66px);
  border-radius: 50%;
  border: 1.5px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  transition: transform .08s ease, border-color .1s ease, background .1s ease;
}
.tf-op:hover { border-color: var(--color-primary); }
.tf-op:active { transform: scale(.94); }
.tf-op:focus-visible { outline: 3px solid var(--color-text); outline-offset: 2px; }
.tf-op[aria-pressed="true"] {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

/* ---- 하단 조작(되돌리기/리셋/넘기기) ---- */
.tf-actions {
  display: flex;
  justify-content: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}
.tf-act {
  font: inherit;
  font-size: .98rem;
  cursor: pointer;
  touch-action: manipulation;
  padding: 9px 16px;
  border-radius: 999px;
  border: 1.5px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-sub);
}
.tf-act:hover:not(:disabled) { border-color: var(--color-primary); color: var(--color-text); }
.tf-act:disabled { opacity: .4; cursor: default; }
.tf-act-skip { margin-left: auto; }

/* ---- 안내 문구 ---- */
.tf-msg {
  min-height: 1.8em;
  margin: var(--space-3) 0 0;
  text-align: center;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-text);
}
.tf-msg b { color: var(--color-primary); }

/* 정답 순간 카드 강조 */
.tf-stage[data-phase="play"] .tf-tiles:only-child {}

/* ---- 오버레이(시작/종료) ---- */
.tf-overlay {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 20px;
  background: color-mix(in srgb, var(--color-bg) 82%, transparent);
  -webkit-backdrop-filter: blur(3px);
          backdrop-filter: blur(3px);
}
@supports not (background: color-mix(in srgb, red 50%, transparent)) {
  .tf-overlay { background: rgba(243, 240, 232, .9); }
  :root[data-theme="dark"] .tf-overlay { background: rgba(23, 19, 14, .9); }
}
.tf-overlay-panel { text-align: center; padding: var(--space-5); max-width: 100%; }
.tf-overlay-note {
  margin: 0 0 var(--space-4);
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.6;
  color: var(--color-text);
}
.tf-btn-big {
  font: inherit;
  font-size: 1.35rem;
  font-weight: 700;
  cursor: pointer;
  touch-action: manipulation;
  padding: 18px 44px;
  border-radius: 999px;
  border: 0;
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow);
}
.tf-btn-big:hover { filter: brightness(1.06); }
.tf-btn-big:active { transform: scale(.97); }

/* ---- 종료 화면 ---- */
.tf-over-eyebrow {
  margin: 0 0 var(--space-2);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--color-text-sub);
}
.tf-over-score { font-family: var(--font-serif); font-size: 2rem; font-weight: 700; color: var(--color-text); }
.tf-over-score b { font-size: 3.4rem; color: var(--color-primary); font-variant-numeric: tabular-nums; }
.tf-over-score small { font-size: 1.2rem; margin-left: 2px; }
.tf-over-grade { margin: var(--space-2) 0 0; font-size: 1.05rem; font-weight: 700; color: var(--color-text); }
.tf-over-best { margin: var(--space-1) 0 var(--space-3); font-size: 1rem; color: var(--color-text-sub); }
.tf-over-best .tf-new-record { color: var(--color-primary); font-weight: 700; }

/* 못 푼 문제 리뷰 */
.tf-review { margin: 0 auto var(--space-4); max-width: 360px; text-align: left; }
.tf-review-title { margin: 0 0 var(--space-2); font-size: .88rem; font-weight: 700; color: var(--color-text-sub); }
.tf-review-list {
  max-height: 176px;
  overflow-y: auto;
  display: grid;
  gap: 6px;
  padding-right: 4px;
}
.tf-rev-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
  padding: 8px 12px;
  border-radius: 10px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  font-variant-numeric: tabular-nums;
}
.tf-rev-nums { font-weight: 700; color: var(--color-text); white-space: nowrap; }
.tf-rev-sol { font-size: .9rem; color: var(--color-primary); white-space: nowrap; }

/* ---- 본문 ---- */
.prose { max-width: 720px; margin: clamp(40px, 6vw, 64px) auto 0; }
.prose h2 { margin: 0 0 var(--space-3); }
.prose h3 { margin: var(--space-4) 0 var(--space-2); font-size: 1.08rem; }
.prose p { margin: 0 0 var(--space-3); color: var(--color-text); }
.prose ul { margin: 0; padding-left: 1.2em; }
.prose li { margin-bottom: var(--space-2); }
.prose li strong { color: var(--color-text); }

@media (prefers-reduced-motion: reduce) {
  .tf-tile, .tf-op, .tf-btn-big { transition: none; }
  .tf-tile:hover { transform: none; }
}

@media (max-width: 420px) {
  .tf-stat { min-width: 76px; font-size: .92rem; }
  .tf-mid { font-size: 1rem; padding: 9px 10px; }
  .tf-act-skip { margin-left: 0; }
}