/* ── Apple-inspired design ── */
:root {
  --bg:          #f5f5f7;
  --surface:     #ffffff;
  --elev:        #fbfbfd;
  --hover:       #f0f0f3;
  --separator:   rgba(60, 60, 67, 0.12);
  --separator-strong: rgba(60, 60, 67, 0.24);
  --text:        #1d1d1f;
  --text-sec:    #6e6e73;
  --text-ter:    #86868b;
  --accent:      #007aff;
  --accent-hov:  #0969da;
  --accent-soft: rgba(0, 122, 255, 0.10);
  --filled:      #1d1d1f;
  --marked:      #ff3b30;
  --radius-sm:   8px;
  --radius:      12px;
  --radius-lg:   16px;
  --shadow-sm:   0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:   0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg:   0 12px 32px rgba(0,0,0,0.12);
  --ease:        cubic-bezier(0.25, 0.1, 0.25, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; -webkit-font-smoothing: antialiased; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Pretendard', 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  letter-spacing: -0.01em;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

/* ── 헤더 ── */
.app-header {
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  padding: 14px 28px;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--separator);
  position: sticky;
  top: 0;
  z-index: 50;
}
.app-header h1 {
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.logo { font-size: 1.4rem; }

/* ── 스크린 전환 ── */
.main {
  max-width: 820px;
  margin: 0 auto;
  padding: 20px 16px;
}
.screen { display: none; }
.screen.active { display: block; }

/* ── 카드 ── */
.card {
  background: var(--surface);
  border: 1px solid var(--separator);
  border-radius: var(--radius-lg);
  padding: 22px;
  box-shadow: var(--shadow-sm);
}
.card h2 {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

/* ── 업로드 영역 ── */
.upload-zone {
  border: 1.5px dashed var(--separator-strong);
  border-radius: var(--radius);
  padding: 30px 16px;
  text-align: center;
  cursor: pointer;
  background: var(--elev);
  transition: all 0.2s var(--ease);
  position: relative;
  min-height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.upload-zone:hover, .upload-zone.drag-over {
  border-color: var(--accent);
  background: var(--accent-soft);
}
.upload-icon {
  font-size: 2.2rem;
  margin-bottom: 10px;
  opacity: 0.7;
}
.upload-hint p { font-size: 0.88rem; line-height: 1.6; }
.upload-hint .sub { color: var(--text-sec); font-size: 0.82rem; margin-top: 4px; }
.source-wrap {
  position: relative;
  display: inline-block;
  user-select: none;
}
#sourcePreview {
  display: block;
  max-width: 100%;
  max-height: 280px;
  border-radius: var(--radius);
  pointer-events: none;
}
.crop-box {
  position: absolute;
  border: 2px solid #ffffff;
  box-shadow: 0 0 0 9999px rgba(0, 0, 0, 0.45);
  cursor: move;
  touch-action: none;
  box-sizing: border-box;
}
.crop-box::before, .crop-box::after {
  content: '';
  position: absolute;
  left: 0; right: 0; top: 0; bottom: 0;
  pointer-events: none;
  border: 1px dashed rgba(255,255,255,0.7);
  margin: 33%;
}
.crop-box::before { margin: 0; border-top: 1px dashed rgba(255,255,255,0.4); border-bottom: 1px dashed rgba(255,255,255,0.4); top: 33.3%; bottom: 33.3%; }
.crop-box::after  { margin: 0; border-left: 1px dashed rgba(255,255,255,0.4); border-right: 1px dashed rgba(255,255,255,0.4); left: 33.3%; right: 33.3%; }
.crop-handle {
  position: absolute;
  width: 12px; height: 12px;
  background: var(--accent);
  border: 2px solid #fff;
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
}
.crop-handle.tl { top: -7px; left: -7px; cursor: nw-resize; }
.crop-handle.tr { top: -7px; right: -7px; cursor: ne-resize; }
.crop-handle.bl { bottom: -7px; left: -7px; cursor: sw-resize; }
.crop-handle.br { bottom: -7px; right: -7px; cursor: se-resize; }

.crop-actions {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-top: 8px;
}

/* ── 옵션 그룹 ── */
.option-group {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.option-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.option-row > label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-sec);
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.option-row label.inline {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex: 1;
  color: var(--text);
  font-size: 0.88rem;
}
.option-row .val { color: var(--text); font-variant-numeric: tabular-nums; }

.choice-row {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}
.choice-btn {
  padding: 9px 4px;
  background: var(--surface);
  border: 1px solid var(--separator);
  border-radius: var(--radius-sm);
  font-size: 0.86rem;
  font-weight: 500;
  color: var(--text);
  transition: all 0.15s var(--ease);
}
.choice-btn:hover { background: var(--hover); border-color: var(--separator-strong); }
.choice-btn.active {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

input[type=range] {
  width: 100%;
  accent-color: var(--accent);
  height: 4px;
}
input[type=checkbox] { accent-color: var(--accent); }

.preview-wrap {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
  padding: 14px;
  background: var(--elev);
  border: 1px solid var(--separator);
  border-radius: var(--radius);
}
.preview-header {
  display: flex;
  align-items: center;
  gap: 10px;
  justify-content: space-between;
  width: 100%;
}
.preview-label {
  font-size: 0.82rem;
  color: var(--text-sec);
  font-weight: 600;
}
.preview-label em {
  font-style: normal;
  color: var(--accent);
  font-weight: 500;
  font-size: 0.76rem;
}
.preview-hint {
  font-size: 0.72rem;
  color: var(--text-ter);
  text-align: center;
}
.ghost-btn.small {
  padding: 5px 10px;
  font-size: 0.78rem;
}
#binaryPreview {
  image-rendering: pixelated;
  background: #fff;
  border-radius: 6px;
  box-shadow: var(--shadow-sm);
  touch-action: none;
  cursor: crosshair;
}

/* ── 버튼 ── */
.primary-btn {
  padding: 13px;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: -0.01em;
  transition: all 0.15s var(--ease);
  box-shadow: 0 1px 2px rgba(0,122,255,0.2);
}
.primary-btn:hover {
  background: var(--accent-hov);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,122,255,0.25);
}
.primary-btn:active { transform: translateY(0); }
.primary-btn:disabled { opacity: 0.4; cursor: default; transform: none; box-shadow: none; }

.ghost-btn {
  padding: 7px 12px;
  background: transparent;
  border: 1px solid var(--separator);
  color: var(--text);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  transition: all 0.15s var(--ease);
}
.ghost-btn:hover { background: var(--hover); }

/* ── 게임 화면 ── */
.game-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 4px;
  flex-wrap: wrap;
}
.toolbar-info {
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 0.9rem;
}
.toolbar-info #sizeLabel { color: var(--text-sec); font-weight: 500; }
.timer {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  color: var(--text);
  background: var(--surface);
  padding: 4px 10px;
  border-radius: 14px;
  box-shadow: var(--shadow-sm);
}
.toolbar-actions { display: flex; gap: 4px; }
.toolbar-actions .ghost-btn { padding: 7px 10px; font-size: 0.95rem; }

.board-wrap {
  display: flex;
  justify-content: center;
  padding: 8px;
  overflow: auto;
}

/* 네모로직 보드: 상단 열 힌트, 좌측 행 힌트, 그리드 */
.board {
  display: grid;
  grid-template-columns: auto auto;
  grid-template-rows: auto auto;
  gap: 2px;
  background: var(--surface);
  padding: 10px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  max-width: 100%;
}
.corner { /* 좌상단 빈 칸 */
  grid-column: 1; grid-row: 1;
}
.col-clues {
  grid-column: 2; grid-row: 1;
  display: grid;
}
.row-clues {
  grid-column: 1; grid-row: 2;
  display: grid;
  align-content: end;
}
.cells {
  grid-column: 2; grid-row: 2;
  display: grid;
  border: 1.5px solid var(--text);
  user-select: none;
  touch-action: none;
}

.col-hint, .row-hint {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  font-size: 0.58rem;
  font-weight: 400;
  color: var(--text);
  background: var(--elev);
  box-sizing: border-box;
  width: var(--cell-size);
  height: 100%;
  padding: 1px;
  text-align: center;
  overflow: hidden;
  letter-spacing: -0.02em;
}
.col-hint {
  flex-direction: column;
  gap: 0;
  align-items: center;
  justify-content: flex-end;
  border-top: 1px solid var(--separator);
  width: var(--cell-size);
  height: 100%;
}
.row-hint {
  flex-direction: row;
  gap: 0;
  justify-content: flex-end;
  align-items: center;
  padding-right: 3px;
  border-left: 1px solid var(--separator);
  width: 100%;
  height: var(--cell-size);
}
.col-hint .num, .row-hint .num {
  line-height: 1;
  padding: 0 2px;
  white-space: nowrap;
}
.col-hint .num { padding: 0; }
.col-hint .num.done,
.row-hint .num.done { color: var(--text-ter); text-decoration: line-through; }

/* 5칸마다 강조 구분선 */
.col-clues { position: relative; }
.row-clues { position: relative; }
.cells .cell[data-r][data-c] { }

.cell {
  aspect-ratio: 1;
  background: var(--surface);
  border: 1px solid var(--separator);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.08s ease;
  position: relative;
}
.cell.fill {
  background: var(--filled);
  border-color: var(--filled);
}
.cell.mark::before {
  content: '';
  width: 45%; height: 2px;
  background: var(--marked);
  position: absolute;
  transform: rotate(45deg);
}
.cell.mark::after {
  content: '';
  width: 45%; height: 2px;
  background: var(--marked);
  position: absolute;
  transform: rotate(-45deg);
}
/* 5칸마다 두껍게 */
.cell[data-c-mod5="0"] { border-left-color: var(--text); }
.cell[data-r-mod5="0"] { border-top-color: var(--text); }
.cell[data-c-last="1"] { border-right-color: var(--text); }
.cell[data-r-last="1"] { border-bottom-color: var(--text); }

/* ── 도구 선택 ── */
.controls {
  display: flex;
  gap: 6px;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  padding: 10px 0 24px;
}
.tool-btn {
  padding: 9px 14px;
  background: var(--surface);
  border: 1px solid var(--separator);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text);
  transition: all 0.15s var(--ease);
}
.tool-btn.active {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}
.controls .hint {
  font-size: 0.76rem;
  color: var(--text-ter);
  width: 100%;
  text-align: center;
  margin-top: 4px;
}

/* ── 모달 ── */
.modal {
  position: fixed; inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
}
.modal[hidden] { display: none; }
.modal-backdrop {
  position: absolute; inset: 0;
  background: rgba(0,0,0,0.4);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.modal-content {
  position: relative;
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 24px;
  min-width: 280px;
  max-width: 88vw;
  text-align: center;
  box-shadow: var(--shadow-lg);
  animation: modalPop 0.25s var(--ease);
}
@keyframes modalPop {
  from { opacity: 0; transform: scale(0.92); }
  to   { opacity: 1; transform: scale(1); }
}
.modal-content h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.modal-content p {
  color: var(--text-sec);
  font-size: 0.9rem;
  margin-bottom: 18px;
}
.modal-content p strong { color: var(--text); }
.modal-actions {
  display: flex;
  gap: 8px;
  justify-content: center;
}

/* ══ 인쇄용 스타일 ══ */
@media print {
  @page { margin: 12mm; }
  body { background: #fff !important; padding: 0 !important; }
  .app-header, .game-toolbar, .controls, .modal { display: none !important; }
  .main { padding: 0 !important; max-width: none !important; }
  .board-wrap { padding: 0 !important; overflow: visible !important; }
  .board {
    background: #fff !important;
    box-shadow: none !important;
    border: none !important;
    page-break-inside: avoid;
  }
  .cell { background: #fff !important; }
  .cell.fill, .cell.mark { background: #fff !important; }
  .cell.fill::before, .cell.mark::before, .cell.mark::after { display: none !important; }
  .col-hint, .row-hint { background: #fff !important; }
}

/* 모바일 */
@media (max-width: 540px) {
  .app-header { padding: 10px 16px; }
  .app-header h1 { font-size: 1rem; }
  .card { padding: 16px; }
  .choice-row { grid-template-columns: repeat(3, 1fr); }
  .col-hint, .row-hint { font-size: 0.6rem; min-width: 1.4em; }
  .toolbar-info { order: 3; width: 100%; justify-content: center; }
}