*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #f9f8f5;
  --bg2: #f1f0eb;
  --bg3: #ffffff;
  --text: #1a1a18;
  --text2: #5f5e5a;
  --border: rgba(0,0,0,0.12);
  --border2: rgba(0,0,0,0.22);
  --radius: 8px;
  --radius-lg: 12px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1c1a;
    --bg2: #242422;
    --bg3: #2c2c2a;
    --text: #e8e6dc;
    --text2: #888780;
    --border: rgba(255,255,255,0.10);
    --border2: rgba(255,255,255,0.20);
  }
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 16px 48px;
}

h1 { font-size: 20px; font-weight: 500; text-align: center; margin-bottom: 4px; }
.subtitle { font-size: 13px; color: var(--text2); text-align: center; margin-bottom: 20px; }

.card {
  background: var(--bg3);
  border: 0.5px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  width: 100%;
  max-width: 620px;
}

.tab-row { display: flex; border-bottom: 1px solid var(--border); margin-bottom: 18px; }
.tab {
  padding: 8px 18px; font-size: 13px; cursor: pointer; color: var(--text2);
  border-bottom: 2px solid transparent; margin-bottom: -1px;
  background: none; border-top: none; border-left: none; border-right: none;
  transition: color .15s;
}
.tab.active { color: var(--text); border-bottom-color: #7F77DD; font-weight: 500; }

.panel { display: none; flex-direction: column; align-items: center; gap: 12px; }
.panel.show { display: flex; }

:root { --cell: 52px; }
.grid-wrap { display: flex; flex-direction: column; align-items: center; gap: 3px; }
.grid-row { display: flex; gap: 3px; }
.cell {
  width: var(--cell); height: var(--cell);
  border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; font-weight: 500;
  cursor: pointer;
  transition: background .25s, transform .15s, box-shadow .15s;
  border: 1.5px solid transparent;
  user-select: none;
  position: relative;
}
.cell.water   { background: #E6F1FB; color: #185FA5; border-color: #85B7EB; }
.cell.land    { background: #EAF3DE; color: #3B6D11; border-color: #97C459; }
.cell.visited { background: #9FE1CB; color: #085041; border-color: #1D9E75; }
.cell.current { background: #EF9F27; color: #412402; border-color: #BA7517; transform: scale(1.12); box-shadow: 0 0 0 3px #FAC77544; }
.cell.island1 { background: #AFA9EC; color: #26215C; border-color: #7F77DD; }
.cell.island2 { background: #F0997B; color: #4A1B0C; border-color: #D85A30; }
.cell.island3 { background: #F4C0D1; color: #4B1528; border-color: #D4537E; }
.cell.island4 { background: #FAC775; color: #412402; border-color: #BA7517; }
.coord { position: absolute; top: 3px; left: 5px; font-size: 9px; opacity: .45; font-weight: 400; }

.legend { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.leg { display: flex; align-items: center; gap: 5px; font-size: 12px; color: var(--text2); }
.leg-dot { width: 14px; height: 14px; border-radius: 3px; flex-shrink: 0; }

.steps-bar { display: flex; flex-direction: column; gap: 5px; width: 100%; max-width: 520px; }
.step-item {
  background: var(--bg2); border-radius: 6px; padding: 7px 12px;
  font-size: 12px; color: var(--text2);
  border-left: 3px solid transparent;
  transition: border-color .3s, background .3s;
}
.step-item.active { border-left-color: #EF9F27; background: var(--bg3); color: var(--text); }
.step-item.done { border-left-color: #1D9E75; }

.controls { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
button.ctrl {
  padding: 6px 16px; border-radius: 6px;
  border: 0.5px solid var(--border2);
  background: var(--bg3); color: var(--text);
  font-size: 13px; cursor: pointer;
  transition: background .15s;
}
button.ctrl:hover { background: var(--bg2); }
button.ctrl:disabled { opacity: .4; cursor: default; }

.counter { font-size: 28px; font-weight: 500; color: var(--text); text-align: center; }
.counter span { font-size: 13px; color: var(--text2); font-weight: 400; display: block; margin-top: -2px; }

.queue-label { font-size: 12px; color: var(--text2); }
.queue-row { display: flex; gap: 4px; flex-wrap: wrap; justify-content: center; min-height: 28px; }
.q-cell { background: #FAEEDA; color: #412402; border: 1px solid #EF9F27; border-radius: 4px; padding: 2px 8px; font-size: 12px; }

.example-btns { display: flex; gap: 6px; }
.ex-btn { font-size: 11px; padding: 4px 12px; }
.ex-btn.sel { background: #EEEDFE; border-color: #7F77DD; color: #3C3489; }

.phase-row { display: grid; grid-template-columns: 190px 1fr; gap: 10px; align-items: start; }
.phase-card {
  border-radius: var(--radius); border: 1.5px solid var(--border);
  padding: 10px 12px; cursor: pointer;
  transition: border-color .2s, background .2s;
  background: var(--bg2); text-align: left;
}
.phase-card:hover { border-color: var(--border2); }
.phase-card.active { border-color: var(--active-c, #7F77DD); background: var(--active-bg, #EEEDFE); }
.phase-lbl { font-size: 10px; font-weight: 500; letter-spacing:.06em; text-transform:uppercase; color:var(--text2); margin-bottom:3px; }
.phase-ttl { font-size: 12px; font-weight: 500; color: var(--text); margin-bottom:4px; line-height:1.35; }
.phase-code { font-size: 11px; color: var(--text2); font-family: monospace; line-height: 1.6; }
.phase-demo { display: flex; flex-direction: column; gap: 8px; }
.mini-grid { display: flex; flex-direction: column; gap: 2px; }
.mini-row { display: flex; gap: 2px; }
.mcell {
  width: 30px; height: 30px; border-radius: 4px;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 500;
  transition: background .3s, transform .2s;
  border: 1.5px solid transparent; position: relative;
}
.mcell.water   { background:#E6F1FB; color:#185FA5; border-color:#85B7EB; }
.mcell.land    { background:#EAF3DE; color:#3B6D11; border-color:#97C459; }
.mcell.visited { background:#9FE1CB; color:#085041; border-color:#1D9E75; }
.mcell.current { background:#EF9F27; color:#412402; border-color:#BA7517; transform:scale(1.15); z-index:2; }
.mcell.island1 { background:#AFA9EC; color:#26215C; border-color:#7F77DD; }
.mcell.island2 { background:#F0997B; color:#4A1B0C; border-color:#D85A30; }
.mcell.island3 { background:#F4C0D1; color:#4B1528; border-color:#D4537E; }