/* 2311 MOON_SUDOKU — style (kit-swiss 변형 · 다크 우선 · 단색 인디고 액센트)
 * §6 준수: 평면 솔리드 · 무채 계조 · 1px 헤어라인 · 액센트 1색. 그라디언트/글래스/글로우/다색 없음. */

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: 'tnum' 1, 'cv05' 1;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { line-height: 1.25; font-weight: 700; letter-spacing: -0.01em; }

.sr-only, .sr-title {
  position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 20px; }

/* ---------- Header ---------- */
.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--surface);
  position: sticky; top: 0; z-index: 20;
}
.header-in { display: flex; align-items: center; gap: 16px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: -0.02em; color: var(--ink); font-size: 17px; white-space: nowrap; }
.brand svg { width: 26px; height: 26px; display: block; }
.brand .mark { width: 24px; height: 24px; border: 2px solid var(--accent); border-radius: 4px; display: grid; place-items: center; font-size: 12px; font-weight: 800; color: var(--accent-ink); }
.header-nav { display: flex; gap: 4px; margin-left: 8px; }
.header-nav a { color: var(--ink-2); font-size: 14px; font-weight: 600; padding: 6px 10px; border-radius: 6px; }
.header-nav a:hover { color: var(--ink); background: var(--surface-2); text-decoration: none; }
.header-tools { margin-left: auto; display: flex; align-items: center; gap: 6px; }
.icon-btn {
  appearance: none; border: 1px solid var(--line); background: var(--surface-2); color: var(--ink-2);
  height: 34px; min-width: 34px; padding: 0 10px; border-radius: 7px; font: inherit; font-size: 13px; font-weight: 600;
  cursor: pointer; display: inline-flex; align-items: center; gap: 6px;
}
.icon-btn:hover { color: var(--ink); border-color: var(--line-strong); }
.icon-btn[aria-pressed="true"] { color: var(--accent-ink); border-color: var(--accent-line); }
.lang-select { appearance: none; border: 1px solid var(--line); background: var(--surface-2); color: var(--ink-2);
  height: 34px; padding: 0 26px 0 10px; border-radius: 7px; font: inherit; font-size: 13px; font-weight: 600; cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%239AA1AD' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 8px center; }

/* ---------- Layout ---------- */
main { padding: 26px 0 56px; }
.game { display: grid; grid-template-columns: minmax(0, 1fr); gap: 22px; align-items: start; }
.board-col { min-width: 0; }
@media (min-width: 940px) {
  .game { grid-template-columns: 504px 1fr; gap: 34px; }
}

/* ---------- HUD ---------- */
.hud { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
.tabs { display: inline-flex; border: 1px solid var(--line); border-radius: 9px; overflow: hidden; background: var(--surface); }
.tab {
  appearance: none; border: 0; background: transparent; color: var(--ink-2);
  font: inherit; font-size: 13px; font-weight: 600; padding: 8px 13px; cursor: pointer;
  border-right: 1px solid var(--line);
}
.tab:last-child { border-right: 0; }
.tab:hover { color: var(--ink); background: var(--surface-2); }
.tab.active { color: var(--accent-fg); background: var(--accent); }
:root[data-theme="light"] .tab.active { color: var(--accent-fg); }
.hud-meta { display: flex; align-items: center; gap: 8px; }
.timer { font-variant-numeric: tabular-nums; font-weight: 700; font-size: 18px; color: var(--ink); min-width: 52px; text-align: right; }

/* ---------- Board ---------- */
.board-wrap { position: relative; width: 100%; max-width: 504px; }
.board {
  width: 100%;
  aspect-ratio: 1 / 1;
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(9, 1fr);
  background: var(--line);
  border: 1px solid var(--line-strong);
  border-radius: 0;
  gap: 1px;
  touch-action: manipulation;
  user-select: none;
}
.cell {
  appearance: none; position: relative; border: 0; margin: 0; padding: 0;
  min-width: 0; min-height: 0; width: auto; height: auto;
  background: var(--cell-bg); color: var(--entry);
  font: inherit; font-size: clamp(15px, 4.6vw, 26px); font-weight: 600;
  font-variant-numeric: tabular-nums; cursor: pointer;
  display: grid; place-items: center;
}
.cell.given { background: var(--cell-fixed-bg); color: var(--given); font-weight: 700; cursor: default; }
.cell.bl { border-left: 2px solid var(--line-strong); }
.cell.bt { border-top: 2px solid var(--line-strong); }
.cell.rel { background: var(--rel); }
.cell.given.rel { background: var(--cell-fixed-bg); }
.cell.same { background: var(--accent-soft); }
.cell.sel { background: var(--accent-soft); box-shadow: inset 0 0 0 2px var(--accent); z-index: 2; }
.cell.error { color: var(--danger); background: var(--danger-soft); }
.cell .val { pointer-events: none; }
.cell .notes {
  position: absolute; inset: 3px; display: grid; grid-template-columns: repeat(3, 1fr); grid-template-rows: repeat(3, 1fr);
  font-size: clamp(7px, 2vw, 11px); font-weight: 600; color: var(--ink-3); line-height: 1;
}
.cell .notes i { display: grid; place-items: center; font-style: normal; }
.cell.filled .notes { display: none; }

/* 일시정지 가림 (블러 없이 솔리드) */
.board-cover {
  position: absolute; inset: 0; background: var(--surface); border: 1px solid var(--line-strong); border-radius: 0;
  display: grid; place-items: center; text-align: center; color: var(--ink-2); font-weight: 600; font-size: 14px; cursor: pointer; z-index: 5;
}
.board-cover[hidden] { display: none; }

/* ---------- Controls ---------- */
.controls { max-width: 420px; min-width: 0; }
@media (min-width: 940px) { .controls { padding-top: 2px; } }
.numpad { display: grid; grid-template-columns: repeat(9, minmax(0, 1fr)); gap: 6px; margin-bottom: 12px; }
.num {
  appearance: none; position: relative; border: 1px solid var(--line); background: var(--surface); color: var(--ink);
  font: inherit; font-size: 20px; font-weight: 700; font-variant-numeric: tabular-nums;
  aspect-ratio: 1 / 1; border-radius: 8px; cursor: pointer; display: grid; place-items: center; min-width: 0;
}
.num:hover { border-color: var(--accent-line); color: var(--accent-ink); }
.num:active { background: var(--surface-2); }
.num.done { color: var(--ink-3); background: var(--surface-2); border-style: dashed; }
.num .rem { position: absolute; top: 3px; right: 5px; font-size: 9px; font-weight: 600; color: var(--ink-3); }
.numpad.note-mode .num { border-color: var(--accent-line); color: var(--accent-ink); }
@media (max-width: 519px) {
  .numpad { grid-template-columns: repeat(9, minmax(0, 1fr)); gap: 3px; }
  .num { font-size: 15px; border-radius: 6px; }
  .num .rem { display: none; }
}

.tools { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 6px; }
.tool-btn {
  appearance: none; border: 1px solid var(--line); background: var(--surface); color: var(--ink-2);
  font: inherit; font-size: 12px; font-weight: 600; padding: 10px 4px 8px; border-radius: 8px; cursor: pointer;
  display: flex; flex-direction: column; align-items: center; gap: 4px; line-height: 1.2; min-width: 0;
}
.tool-btn:hover { color: var(--ink); border-color: var(--line-strong); }
.tool-btn.active { color: var(--accent-ink); border-color: var(--accent-line); background: var(--accent-soft); }
.tool-btn svg { width: 20px; height: 20px; stroke: currentColor; }
.tool-btn[data-act="new"] { color: var(--accent-fg); background: var(--accent); border-color: var(--accent); }
.tool-btn[data-act="new"]:hover { filter: brightness(1.06); color: var(--accent-fg); }

.second-row { display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
.ghost-btn { appearance: none; border: 1px solid var(--line); background: transparent; color: var(--ink-2);
  font: inherit; font-size: 13px; font-weight: 600; padding: 8px 14px; border-radius: 8px; cursor: pointer; }
.ghost-btn:hover { color: var(--ink); border-color: var(--line-strong); }

/* ---------- Stats ---------- */
.stats { margin-top: 18px; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.stats h2 { margin: 0; font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-3);
  padding: 10px 14px; border-bottom: 1px solid var(--line); background: var(--surface); }
.stat-row { display: grid; grid-template-columns: 1fr auto auto; gap: 10px; align-items: center; padding: 9px 14px; border-bottom: 1px solid var(--line); font-size: 13px; }
.stat-row:last-child { border-bottom: 0; }
.stat-row .d { font-weight: 600; color: var(--ink); }
.stat-row .n { color: var(--ink-2); font-variant-numeric: tabular-nums; }
.stat-row .n b { color: var(--ink); font-weight: 700; }

/* ---------- 완료 오버레이 ---------- */
.overlay { position: fixed; inset: 0; background: rgba(10,12,16,0.6); display: grid; place-items: center; z-index: 60; padding: 20px; }
:root[data-theme="light"] .overlay { background: rgba(20,22,30,0.4); }
.overlay[hidden] { display: none; }
.overlay-card { background: var(--surface); border: 1px solid var(--line-strong); border-radius: 4px; max-width: 360px; width: 100%; padding: 30px 26px; text-align: center; }
.overlay-card .badge { width: 46px; height: 46px; margin: 0 auto 14px; border: 2px solid var(--accent); border-radius: 10px; display: grid; place-items: center; color: var(--accent-ink); }
.overlay-card h2 { margin: 0 0 6px; font-size: 22px; }
.overlay-card .big-time { font-size: 34px; font-weight: 800; font-variant-numeric: tabular-nums; margin: 8px 0 4px; letter-spacing: -0.02em; }
.overlay-card .ov-meta { color: var(--ink-2); font-size: 13px; margin-bottom: 20px; }
.overlay-card .btn-primary { appearance: none; border: 0; background: var(--accent); color: var(--accent-fg); font: inherit; font-weight: 700; font-size: 15px; padding: 12px 20px; border-radius: 9px; cursor: pointer; width: 100%; }
.overlay-card .btn-primary:hover { filter: brightness(1.06); }

/* ---------- Ads ---------- */
.ad-wrap { margin: 30px auto 0; }
.ad-label { text-align: center; font-size: 10px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-3); margin-bottom: 8px; }
.ad-grid { display: flex; flex-direction: column; align-items: center; gap: 14px; width: 100%; max-width: 672px; margin: 0 auto; }
.ad-grid[data-ad-layout="mixed"] { max-width: 760px; }
.ad-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; width: 100%; }
.ad-cell { min-height: 50px; }

/* ---------- 콘텐츠 페이지(about/기법/가이드) 공통 ---------- */
.doc { max-width: 760px; margin: 0 auto; }
.doc h1 { font-size: 30px; margin: 8px 0 6px; letter-spacing: -0.02em; }
.doc .lead { color: var(--ink-2); font-size: 17px; margin: 0 0 26px; }
.doc h2 { font-size: 20px; margin: 34px 0 12px; padding-bottom: 8px; border-bottom: 1px solid var(--line); }
.doc h3 { font-size: 16px; margin: 22px 0 8px; }
.doc p { color: var(--ink); margin: 0 0 14px; }
.doc ul, .doc ol { color: var(--ink); margin: 0 0 16px; padding-left: 22px; }
.doc li { margin: 5px 0; }
.doc blockquote { margin: 0 0 16px; padding: 10px 16px; border-left: 3px solid var(--accent-line); background: var(--surface); color: var(--ink-2); }
.doc code { background: var(--surface-2); border: 1px solid var(--line); border-radius: 4px; padding: 1px 5px; font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.9em; }
.breadcrumb { font-size: 13px; color: var(--ink-3); margin-bottom: 14px; }
.breadcrumb a { color: var(--ink-2); }

/* 허브 카드 그리드 */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 14px; margin: 20px 0; }
.card { display: block; border: 1px solid var(--line); border-radius: 10px; padding: 16px; background: var(--surface); color: var(--ink); }
.card:hover { border-color: var(--accent-line); text-decoration: none; }
.card .tag { display: inline-block; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; color: var(--accent-ink); margin-bottom: 6px; }
.card h3 { margin: 0 0 4px; font-size: 15px; }
.card p { margin: 0; color: var(--ink-2); font-size: 13px; }

/* 미니 예시 격자(기법 페이지) */
.mini-board { display: inline-grid; grid-template-columns: repeat(9, 1fr); border: 2px solid var(--line-strong); background: var(--line-strong); gap: 1px; margin: 8px 0 18px; }
.mini-board .mc { width: 30px; height: 30px; background: var(--cell-bg); display: grid; place-items: center; font-size: 14px; font-weight: 600; color: var(--given); font-variant-numeric: tabular-nums; }
.mini-board .mc.hl { background: var(--accent-soft); color: var(--accent-ink); }
.mini-board .mc.cand { color: var(--ink-3); font-size: 9px; }
.mini-board .mc.bl { border-left: 2px solid var(--line-strong); }
.mini-board .mc.bt { border-top: 2px solid var(--line-strong); }

.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 34px; padding-top: 18px; border-top: 1px solid var(--line); font-size: 14px; }
.pager a { font-weight: 600; }

/* FAQ */
.faq { margin: 20px 0; }
.faq details { border: 1px solid var(--line); border-radius: 9px; margin-bottom: 8px; background: var(--surface); }
.faq summary { padding: 13px 16px; font-weight: 600; cursor: pointer; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq details[open] summary { border-bottom: 1px solid var(--line); }
.faq .a { padding: 12px 16px; color: var(--ink-2); }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); background: var(--surface); margin-top: 50px; }
.footer-in { padding: 30px 0; display: grid; gap: 18px; }
.footer-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 22px; }
.footer-cols h4 { margin: 0 0 10px; font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-3); }
.footer-cols a { display: block; color: var(--ink-2); font-size: 13px; padding: 3px 0; }
.footer-cols a:hover { color: var(--ink); text-decoration: none; }
.copyright { color: var(--ink-3); font-size: 12px; border-top: 1px solid var(--line); padding-top: 16px; }

/* 모바일 헤더: 네비 숨김(동일 링크 푸터에 존재) */
@media (max-width: 600px) {
  .header-nav { display: none; }
  .header-in { gap: 10px; height: 54px; }
}

.start-link { display: inline-block; background: var(--accent); color: var(--accent-fg); padding: 11px 20px; border-radius: 8px; font-weight: 700; margin-top: 6px; }
.start-link:hover { filter: brightness(1.06); text-decoration: none; color: var(--accent-fg); }

/* ===== 게임(index) 심플 레이아웃 ===== */
.play-main { padding: 22px 0 74px; }
.play-area { max-width: 600px; margin: 0 auto; display: flex; flex-direction: column; align-items: center; gap: 16px; }
/* 보드·컨트롤 폭 = 가로/세로 중 작은 쪽에 맞춰 한 화면에 담기 */
.play-top,
.play-area .board-wrap,
.play-area .numpad,
.play-area .tools { width: 100%; max-width: clamp(280px, calc(100vh - 384px), 552px); }
.play-top { display: flex; align-items: center; justify-content: center; gap: 14px; }
.play-top .timer { font-size: 22px; min-width: auto; text-align: center; }
.play-top .diff-label { font-size: 13px; font-weight: 600; color: var(--ink-2); padding: 4px 13px; border: 1px solid var(--line); border-radius: 20px; }

/* FAB 스택 (우하단 고정: 기록 위 · 설정 아래) */
.fab-stack { position: fixed; right: 18px; bottom: 54px; display: flex; flex-direction: column; align-items: flex-end; gap: 10px; z-index: 40; }
.fab { appearance: none; border: 1px solid var(--line-strong); background: var(--surface); color: var(--ink);
  height: 46px; padding: 0 18px; border-radius: 23px; display: inline-flex; align-items: center; gap: 8px;
  font: inherit; font-size: 14px; font-weight: 600; cursor: pointer; }
.fab svg { width: 19px; height: 19px; stroke: currentColor; flex: 0 0 auto; }
.fab:hover { border-color: var(--accent-line); color: var(--accent-ink); }
.fab-primary { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
.fab-primary:hover { filter: brightness(1.07); color: var(--accent-fg); }

/* 설정·기록 패널 */
.panel-backdrop { position: fixed; inset: 0; background: rgba(8,10,14,0.32); z-index: 44; }
.panel-backdrop[hidden] { display: none; }
.side-panel { position: fixed; right: 18px; bottom: 54px; width: 300px; max-width: calc(100vw - 36px);
  background: var(--surface); border: 1px solid var(--line-strong); border-radius: 4px; z-index: 45;
  max-height: calc(100vh - 120px); overflow-y: auto; }
.side-panel[hidden] { display: none; }
.panel-head { display: flex; align-items: center; justify-content: space-between; padding: 13px 16px; border-bottom: 1px solid var(--line); }
.panel-head h3 { margin: 0; font-size: 15px; }
.panel-close { appearance: none; border: 0; background: transparent; color: var(--ink-3); font-size: 15px; cursor: pointer; width: 28px; height: 28px; border-radius: 6px; line-height: 1; }
.panel-close:hover { background: var(--surface-2); color: var(--ink); }
.panel-body { padding: 16px; display: flex; flex-direction: column; gap: 18px; }
.set-block { display: flex; flex-direction: column; gap: 8px; }
.set-label { font-size: 13px; font-weight: 600; color: var(--ink-2); }
.set-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.row-btns { display: flex; gap: 8px; }
.row-btns .ghost-btn { flex: 1; text-align: center; }

/* 세그먼트 난이도 (2×2) */
.seg { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 6px; }
.seg .tab { appearance: none; border: 1px solid var(--line); border-radius: 8px; padding: 9px 8px; font: inherit; font-size: 13px; font-weight: 600; background: var(--surface); color: var(--ink-2); cursor: pointer; }
.seg .tab:hover { border-color: var(--accent-line); color: var(--ink); }
.seg .tab.active { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }

/* 스위치 (오답 보기) */
.switch { appearance: none; border: 0; width: 44px; height: 26px; border-radius: 13px; background: var(--line-strong); position: relative; cursor: pointer; padding: 0; flex: 0 0 auto; transition: background .15s; }
.switch .knob { position: absolute; top: 3px; left: 3px; width: 20px; height: 20px; border-radius: 50%; background: var(--accent-fg); transition: left .15s; }
.switch.on { background: var(--accent); }
.switch.on .knob { left: 21px; }

/* 미니 푸터 (게임 전용 · 하단 고정) */
.site-footer.mini { position: fixed; left: 0; right: 0; bottom: 0; margin: 0; border-top: 1px solid var(--line); background: var(--surface); z-index: 30; }
.site-footer.mini .copyright { border: 0; padding: 10px 20px; text-align: center; }

/* RTL: FAB·패널 왼쪽 하단 */
[dir="rtl"] .fab-stack, [dir="rtl"] .side-panel { right: auto; left: 18px; }
[dir="rtl"] .fab-stack { align-items: flex-start; }

@media (max-width: 560px) {
  .fab-stack { right: 12px; bottom: 48px; }
  .side-panel { right: 12px; left: 12px; width: auto; }
  [dir="rtl"] .side-panel { left: 12px; right: 12px; }
  /* 모바일: FAB 아이콘 원형(텍스트 숨김)으로 툴 버튼과 겹침 완화 */
  .fab { width: 46px; height: 46px; padding: 0; justify-content: center; }
  .fab-txt { display: none; }
}

/* 소형 유틸 */
.center { text-align: center; }
.muted { color: var(--ink-2); font-size: 13px; }