:root {
  --surface: rgba(19, 31, 42, 0.82);
  --surface-strong: rgba(14, 24, 32, 0.96);
  --line: rgba(255, 255, 255, 0.08);
  --text: #f6f1e8;
  --muted: #b5c0cb;
  --accent: #ffb84d;
  --board-light: #efe5d1;
  --board-dark: #6f8a74;
  --board-highlight: rgba(255, 184, 77, 0.32);
  --board-select: rgba(90, 208, 199, 0.42);
  --danger: rgba(255, 124, 107, 0.36);
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  height: 100vh;
  overflow: hidden;
  font-family: "Space Grotesk", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(255, 184, 77, 0.12), transparent 34%),
    radial-gradient(circle at top right, rgba(90, 208, 199, 0.12), transparent 28%),
    linear-gradient(160deg, #081117 0%, #0f1720 36%, #1b2834 100%);
}

button,
select {
  font: inherit;
}

.app-shell {
  width: min(1480px, calc(100% - 20px));
  height: 100vh;
  margin: 0 auto;
  padding: 10px 0 16px;
}

.top-links {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 18px;
  height: 28px;
  margin-bottom: 8px;
}

.top-link-button {
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--muted);
  font-size: 0.85rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  cursor: pointer;
}

.top-link-button:hover,
.top-link-button:focus-visible {
  color: var(--text);
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 14px;
  align-items: start;
  height: calc(100vh - 62px);
}

.section-label,
.seat-label,
.status-label {
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.72rem;
  color: var(--muted);
}

.board-panel,
.sidebar-card,
.status-card,
.seat-card {
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
}

.board-panel {
  border-radius: 32px;
  padding: 14px;
  min-height: 0;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.sidebar-card,
.status-card {
  border-radius: 22px;
  padding: 14px;
}

.board-header,
.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.board-header h2 {
  margin: 6px 0 0;
  font-size: clamp(1.3rem, 2.6vw, 2rem);
}

.status-pill {
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--muted);
  font-size: 0.82rem;
}

.board-stage {
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1;
}

.files,
.ranks {
  color: var(--muted);
  font-size: 0.8rem;
}

.files {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  width: min(calc(100vh - 160px), calc(100vw - 432px), 940px);
  margin-left: 42px;
  margin-bottom: 6px;
  text-align: center;
}

.board-frame {
  display: grid;
  grid-template-columns: 32px auto;
  gap: 10px;
  align-items: stretch;
  justify-content: center;
}

.ranks {
  display: grid;
  grid-template-rows: repeat(8, 1fr);
  align-items: center;
  justify-items: center;
}

.board-wrap {
  position: relative;
  width: min(calc(100vh - 160px), calc(100vw - 432px), 940px);
  aspect-ratio: 1;
  flex: 0 0 auto;
}

.board,
.move-layer {
  position: absolute;
  inset: 0;
}

.board {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-template-rows: repeat(8, 1fr);
  width: 100%;
  height: 100%;
  border-radius: 28px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.move-layer {
  pointer-events: none;
  overflow: hidden;
  border-radius: 28px;
}

.square {
  position: relative;
  display: grid;
  place-items: center;
  cursor: pointer;
  user-select: none;
  transition: filter 120ms ease;
}

.square.light { background: var(--board-light); }
.square.dark { background: var(--board-dark); }

.square.selected::after,
.square.legal::after,
.square.in-check::after,
.square.latest-from::after,
.square.latest-to::after {
  content: "";
  position: absolute;
  inset: 10%;
  border-radius: 18px;
  pointer-events: none;
}

.square.selected::after { background: var(--board-select); }
.square.legal::after { background: var(--board-highlight); }
.square.in-check::after { background: var(--danger); }
.square.latest-from::after { background: rgba(255, 255, 255, 0.12); }
.square.latest-to::after { background: rgba(255, 184, 77, 0.22); }

.piece {
  position: relative;
  z-index: 1;
  font-size: clamp(2rem, 4vw, 4.8rem);
  line-height: 1;
  text-shadow: 0 4px 16px rgba(0, 0, 0, 0.22);
}

.piece.black { color: #192126; }
.piece.white { color: #fff9ef; }

.move-piece {
  position: absolute;
  display: grid;
  place-items: center;
  font-size: clamp(2rem, 4vw, 4.8rem);
  line-height: 1;
  text-shadow: 0 4px 16px rgba(0, 0, 0, 0.22);
  will-change: transform, opacity;
}

.move-piece.black { color: #192126; }
.move-piece.white { color: #fff9ef; }
.move-piece.is-captured { animation: capture-fade 320ms ease forwards; }

.side-panel,
.score-grid,
.mini-metrics {
  display: grid;
  gap: 14px;
}

.side-panel {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 10px;
  height: 100%;
  min-height: 0;
}

.sidebar-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.seat-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  border-radius: 20px;
  padding: 14px;
}

.compact-seat {
  padding: 0;
  background: transparent;
  border: 0;
  box-shadow: none;
  backdrop-filter: none;
}

.seat-card strong {
  display: block;
  margin-top: 0;
  font-size: 1.05rem;
}

.seat-button {
  padding: 9px 13px;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  background: linear-gradient(135deg, var(--accent), #ff8f5b);
  color: #1a1611;
  font-weight: 700;
  flex: 0 0 auto;
}

.status-card p {
  margin: 0;
  line-height: 1.35;
  font-size: 0.97rem;
}

.score-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 8px;
}

.score-grid span,
.mini-metrics span {
  display: block;
  color: var(--muted);
  font-size: 0.85rem;
}

.score-grid strong {
  display: block;
  margin-top: 6px;
  font-size: 1.35rem;
}

.mini-metrics {
  margin-top: 8px;
}

.mini-metrics strong {
  display: block;
  margin-top: 6px;
  font-size: 0.96rem;
}

.ai-control {
  display: block;
}

.ai-control select {
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
}

.ai-control select option {
  color: #111827;
  background: #f6f1e8;
}

.move-log {
  margin: 8px 0 0;
  padding: 0 6px 0 0;
  flex: 1;
  min-height: 0;
  overflow: auto;
  color: var(--muted);
  line-height: 1.38;
  font-size: 0.88rem;
  list-style: none;
}

.move-log li {
  padding-left: 0;
  margin-bottom: 6px;
}

.log-card {
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.compact-card {
  padding: 0;
  background: transparent;
  border: 0;
  box-shadow: none;
  backdrop-filter: none;
}

.compact-score-grid {
  margin-top: 4px;
}

.compact-metrics {
  grid-template-columns: 1fr;
}

.move-log li strong { color: var(--text); }

.promotion-modal {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  background: rgba(7, 12, 17, 0.68);
  backdrop-filter: blur(8px);
}

.promotion-modal.hidden { display: none; }

.info-modal {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  background: rgba(7, 12, 17, 0.68);
  backdrop-filter: blur(8px);
  z-index: 20;
}

.info-modal.hidden {
  display: none;
}

.info-card {
  width: min(620px, calc(100% - 24px));
  padding: 24px;
  border-radius: 28px;
  background: var(--surface-strong);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.info-card h3 {
  margin: 10px 0 18px;
  font-size: 1.7rem;
}

.settings-card {
  width: min(560px, calc(100% - 24px));
}

.info-close {
  border: 0;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}

.settings-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.settings-field,
.settings-toggle-row {
  display: grid;
  gap: 8px;
}

.settings-field span,
.settings-toggle-row span {
  color: var(--muted);
  font-size: 0.88rem;
}

.settings-field select {
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
}

.settings-field select option {
  color: #111827;
  background: #f6f1e8;
}

.settings-toggle-row {
  align-items: start;
}

.settings-toggle-row input {
  width: 18px;
  height: 18px;
  margin: 0;
}

.settings-toggle-row:last-child {
  align-self: end;
}

.faq-list {
  margin: 0;
  display: grid;
  gap: 16px;
}

.faq-list dt {
  margin: 0 0 6px;
  font-weight: 700;
  color: var(--text);
}

.faq-list dd {
  margin: 0;
  color: var(--muted);
  line-height: 1.45;
}

.promotion-card {
  width: min(440px, calc(100% - 24px));
  padding: 24px;
  border-radius: 28px;
  background: var(--surface-strong);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.promotion-card h3 {
  margin: 10px 0 18px;
  font-size: 1.7rem;
}

.promotion-options {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.promotion-button {
  padding: 16px 10px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  cursor: pointer;
}

.promotion-button span {
  display: block;
  font-size: 2rem;
  margin-bottom: 8px;
}

@keyframes capture-fade {
  from { opacity: 1; transform: scale(1); }
  to { opacity: 0; transform: scale(0.72); }
}

@media (max-width: 1120px) {
  body {
    height: auto;
    overflow: auto;
  }

  .app-shell {
    height: auto;
  }

  .layout {
    grid-template-columns: 1fr;
    height: auto;
  }

  .side-panel {
    grid-template-rows: auto;
    height: auto;
  }

  .board-panel {
    min-height: auto;
    height: auto;
  }

  .files,
  .board-wrap {
    width: min(calc(100vw - 72px), 900px);
  }
}

@media (max-width: 720px) {
  .app-shell {
    width: min(100% - 12px, 1480px);
    padding-top: 8px;
  }

  .settings-grid {
    grid-template-columns: 1fr;
  }

  .sidebar-grid {
    grid-template-columns: 1fr;
  }

  .files,
  .board-wrap {
    width: min(calc(100vw - 44px), 760px);
  }

  .files {
    margin-left: 30px;
  }

  .board-frame {
    grid-template-columns: 24px auto;
    gap: 6px;
  }

  .score-grid {
    grid-template-columns: 1fr;
  }

  .seat-card {
    flex-direction: row;
    align-items: center;
  }

  .piece,
  .move-piece {
    font-size: clamp(1.7rem, 10vw, 3.2rem);
  }
}