:root {
  --bg: #f3f2ee;
  --ink: #1a1a1a;
  --muted: #5a5a5a;
  --line: #c8c4ba;
  --board: #d2c0a2;
  --board-line: #5c4a36;
  --last: #c4ad86;
  --sel: #b89a6e;
  --legal: #3d3d3d;
  --white: #f2f0ea;
  --black: #1e1e1e;
  --red: #a43b35;
  --board-size: min(92vw, calc(100vh - 8rem), 760px);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.4 "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.25rem 1.5rem 0.5rem;
  border-bottom: 1px solid var(--line);
}

h1 {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.sub {
  margin: 0.15rem 0 0.55rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.tabs {
  display: flex;
  gap: 0.3rem;
  margin: 0 0 0.75rem;
}
.tab {
  border-color: transparent;
  background: transparent;
  color: var(--muted);
  padding: 0.2rem 0.55rem;
}
.tab:hover { background: #e8e6df; }
.tab[aria-selected="true"] {
  color: var(--ink);
  border-color: var(--line);
  background: #e8e6df;
}
.tab-count {
  font-size: 0.8rem;
  font-variant-numeric: tabular-nums;
}

code {
  font-family: ui-monospace, Menlo, monospace;
  font-size: 0.85em;
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.1rem;
  height: 2.1rem;
  padding: 0;
  border: 1px solid transparent;
  background: transparent;
  color: var(--muted);
}
.icon-btn:hover,
.icon-btn[aria-expanded="true"] {
  color: var(--ink);
  border-color: var(--line);
  background: #e8e6df;
}
.cog { width: 1.2rem; height: 1.2rem; display: block; overflow: visible; }

.settings-wrap { position: relative; flex: 0 0 auto; }
.settings {
  position: absolute;
  right: 0;
  top: calc(100% + 0.35rem);
  width: 16.5rem;
  z-index: 40;
  background: var(--bg);
  border: 1px solid var(--line);
  padding: 0.7rem 0.8rem 0.8rem;
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.12);
}
.nnue-name {
  margin: 0 0 0.15rem;
  font-family: ui-monospace, Menlo, monospace;
  font-size: 0.78rem;
  word-break: break-all;
}
.nnue-msg { margin: 0.45rem 0 0; font-size: 0.8rem; color: #8a2f2a; }
.nnue-msg.ok { color: var(--muted); }

main {
  display: flex;
  gap: 1.25rem;
  padding: 1.25rem 1.5rem 2rem;
  align-items: flex-start;
  flex-wrap: wrap;
}

.eval-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
}

.eval-bar {
  width: 22px;
  height: var(--board-size);
  background: var(--black);
  border: 1px solid var(--ink);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}

.eval-white {
  width: 100%;
  height: 50%;
  background: var(--white);
}

.eval-label {
  font-size: 0.75rem;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

.board-wrap { position: relative; }

.board {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  width: var(--board-size);
  height: var(--board-size);
  background: var(--board);
  border: 1px solid var(--board-line);
  user-select: none;
}

.sq {
  border: 1px solid var(--board-line);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sq.last { background: var(--last); }
.sq.sel { background: var(--sel); }
.sq.preview-from { outline: 2px solid var(--ink); outline-offset: -2px; }

.coord {
  position: absolute;
  font-size: 0.65rem;
  color: var(--board-line);
  pointer-events: none;
}
.coord.file { bottom: 2px; right: 3px; }
.coord.rank { top: 2px; left: 3px; }

.marble {
  width: 72%;
  height: 72%;
  border-radius: 50%;
  border: 0;
  box-shadow: 1px 2px 3px rgba(0, 0, 0, 0.25);
}
.marble.W {
  background: radial-gradient(circle at 32% 28%, #ffffff 0%, #d4d1cb 58%, #b0aca4 100%);
  box-shadow:
    inset -2px -3px 5px rgba(0, 0, 0, 0.18),
    inset 2px 3px 4px rgba(255, 255, 255, 0.45),
    1px 2px 3px rgba(0, 0, 0, 0.22);
}
.marble.B {
  background: radial-gradient(circle at 32% 28%, #5c5c5c 0%, #1a1a1a 55%, #050505 100%);
  box-shadow:
    inset -2px -3px 6px rgba(0, 0, 0, 0.55),
    inset 2px 3px 5px rgba(255, 255, 255, 0.12),
    1px 2px 3px rgba(0, 0, 0, 0.28);
}
.marble.R {
  background: radial-gradient(circle at 32% 28%, #ff7a72 0%, #a43b35 55%, #6a1814 100%);
  box-shadow:
    inset -2px -3px 5px rgba(0, 0, 0, 0.28),
    inset 2px 3px 4px rgba(255, 180, 170, 0.28),
    1px 2px 3px rgba(0, 0, 0, 0.22);
}

.legal-dot {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--legal);
  pointer-events: none;
}

.offboard {
  position: absolute;
  width: 9px;
  height: 9px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: var(--legal);
  cursor: pointer;
}
.offboard:hover { background: var(--ink); }
.offboard.N { top: 3px; left: 50%; transform: translateX(-50%); }
.offboard.S { bottom: 3px; left: 50%; transform: translateX(-50%); }
.offboard.E { right: 3px; top: 50%; transform: translateY(-50%); }
.offboard.W { left: 3px; top: 50%; transform: translateY(-50%); }

.pv-arrow {
  position: absolute;
  pointer-events: none;
  inset: 0;
}

.pv-mini {
  position: fixed;
  z-index: 30;
  pointer-events: none;
  padding: 5px;
  background: var(--bg);
  border: 1px solid var(--line);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.18);
}
.pv-mini .mini-board {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  width: 112px;
  height: 112px;
  background: var(--board);
  border: 1px solid var(--board-line);
}
.pv-mini .sq {
  border-width: 0.5px;
}
.pv-mini .marble {
  width: 78%;
  height: 78%;
  box-shadow: 0.5px 1px 1.5px rgba(0, 0, 0, 0.28);
}

aside {
  flex: 1;
  min-width: 240px;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

#play-panel,
#puzzle-panel {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.status { margin: 0; font-weight: 600; }
#caps { margin: 0; color: var(--muted); font-size: 0.95rem; }

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  align-items: center;
}

label { font-size: 0.9rem; color: var(--muted); }

select, input, button {
  font: inherit;
  color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--line);
  padding: 0.25rem 0.45rem;
}

button { cursor: pointer; }
button:hover { background: #e8e6df; }
button.active { background: var(--ink); color: var(--white); }
button:disabled { opacity: 0.45; cursor: default; }

#movetime { width: 5.5rem; }

.pv-box, .moves-box {
  border: 1px solid var(--line);
  padding: 0.55rem 0.65rem;
}

.k { margin: 0 0 0.25rem; font-size: 0.75rem; letter-spacing: 0.04em; text-transform: uppercase; color: var(--muted); }

.pv {
  margin: 0;
  min-height: 2.4em;
  font-variant-numeric: tabular-nums;
  word-break: break-word;
}

.pv span {
  cursor: pointer;
  padding: 0 0.1em;
  border-radius: 2px;
}
.pv span:hover { background: #e4e0d6; }

.info { margin: 0.35rem 0 0; font-size: 0.8rem; color: var(--muted); }

#moves, #puzzle-moves {
  margin: 0;
  padding-left: 1.3rem;
  max-height: 12rem;
  overflow: auto;
  font-variant-numeric: tabular-nums;
}

.kfen-lab { display: flex; flex-direction: column; gap: 0.25rem; font-size: 0.8rem; color: var(--muted); }
#kfen { width: 100%; font-family: ui-monospace, Menlo, monospace; font-size: 0.75rem; }

.guide {
  flex: 1 1 100%;
  max-width: 40rem;
}

.guide h2 {
  margin: 0 0 0.35rem;
  font-size: 1.45rem;
  font-weight: 600;
}

.guide-lead {
  margin: 0 0 1rem;
}

.steps {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.steps > li {
  counter-increment: step;
  border: 1px solid var(--line);
  background: #faf9f6;
  padding: 0.75rem 0.9rem 0.85rem;
}

.steps > li h3 {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
  font-weight: 600;
}

.steps > li h3::before {
  content: counter(step) ". ";
}

.steps p {
  margin: 0 0 0.45rem;
}

.steps > li > p:last-child,
.steps ul {
  margin-bottom: 0;
}

.steps ul {
  margin: 0.15rem 0 0;
  padding-left: 1.2rem;
}

.steps ul li {
  margin: 0.15rem 0;
}

.demo { margin: 0.15rem 0 0.55rem; }

.demo-board {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  width: min(100%, 220px);
  aspect-ratio: 1;
  background: var(--board);
  border: 1px solid var(--board-line);
}

.demo-board .sq {
  border-width: 1px;
}

.demo-board .marble {
  width: 68%;
  height: 68%;
  display: block;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1rem;
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.legend span {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.legend .marble {
  width: 0.95rem;
  height: 0.95rem;
  display: inline-block;
}

.guide-cta { margin: 1rem 0 0; }

.guide-go {
  background: var(--ink);
  color: var(--white);
  padding: 0.4rem 0.85rem;
}

.guide-go:hover {
  background: #333;
  color: var(--white);
}

[hidden] { display: none !important; }

#puzzle-caps { margin: 0; color: var(--muted); font-size: 0.95rem; }
#puzzle-status.bad { color: #8a2f2a; }

@keyframes board-shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}
.board.shake { animation: board-shake 0.28s ease; }