:root {
  color-scheme: dark;
  --bg: #07111f;
  --bg-deep: #030711;
  --panel: rgba(9, 20, 38, 0.9);
  --panel-border: rgba(100, 190, 255, 0.18);
  --text: #ebf5ff;
  --muted: #91a7c2;
  --accent: #56d6ff;
  --accent-strong: #2bf5c0;
  --accent-soft: rgba(86, 214, 255, 0.18);
  --danger: #ff7f98;
  --success: #8af4a0;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
  --board-light: #dce8f6;
  --board-dark: #38617f;
  --board-frame: #071524;
  --board-highlight: rgba(43, 245, 192, 0.42);
  --board-selected: rgba(86, 214, 255, 0.56);
  --board-last: rgba(184, 82, 255, 0.34);
  --font-display: "Segoe UI Variable", "Aptos", "Trebuchet MS", sans-serif;
  --font-body: "Segoe UI", "Aptos", "Tahoma", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  background:
    radial-gradient(circle at top left, rgba(45, 174, 255, 0.18), transparent 28%),
    radial-gradient(circle at 90% 15%, rgba(55, 255, 177, 0.14), transparent 20%),
    linear-gradient(180deg, #0b1528 0%, var(--bg-deep) 100%);
  color: var(--text);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(86, 214, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(86, 214, 255, 0.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.45), transparent 80%);
}

.app-shell {
  width: min(1400px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.5rem 0 2rem;
}

.topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0 1.5rem;
}

.eyebrow {
  margin: 0 0 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.24em;
  color: var(--accent-strong);
  font-size: 0.72rem;
}

h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3.6rem);
  line-height: 0.98;
}

.subtitle {
  max-width: 48rem;
  margin: 0.8rem 0 0;
  color: var(--muted);
  font-size: 1rem;
}

.status-pills {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.65rem;
}

.pill {
  padding: 0.8rem 1.05rem;
  border-radius: 999px;
  background: rgba(8, 21, 39, 0.78);
  border: 1px solid rgba(43, 245, 192, 0.2);
  box-shadow: inset 0 0 0 1px rgba(86, 214, 255, 0.08);
  font-weight: 600;
  letter-spacing: 0.03em;
}

.pill.muted {
  color: var(--muted);
  border-color: rgba(255, 255, 255, 0.08);
}

.layout {
  display: grid;
  grid-template-columns: minmax(320px, 760px) minmax(300px, 420px);
  gap: 1.5rem;
  align-items: start;
}

.board-panel,
.card {
  position: relative;
}

.board-frame,
.card {
  background: linear-gradient(180deg, rgba(10, 24, 45, 0.92), rgba(4, 10, 22, 0.96));
  border: 1px solid var(--panel-border);
  border-radius: 28px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.board-frame {
  padding: 1rem;
}

.board-frame::before,
.card::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(135deg, rgba(86, 214, 255, 0.12), transparent 30%);
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 0;
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 20px;
  overflow: hidden;
  background: var(--board-frame);
  aspect-ratio: 1;
}

.square {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1;
  border: 0;
  padding: 0;
  cursor: pointer;
  transition: transform 120ms ease, filter 120ms ease;
  font-size: clamp(1.8rem, 3vw, 3rem);
  line-height: 1;
}

.square:hover {
  filter: brightness(1.06);
}

.square.light {
  background: linear-gradient(160deg, #edf4fc, var(--board-light));
  color: #10233a;
}

.square.dark {
  background: linear-gradient(160deg, #4d7a9c, var(--board-dark));
  color: #eef8ff;
}

.square.selected {
  box-shadow: inset 0 0 0 3px var(--board-selected);
  z-index: 2;
}

.square.legal::after {
  content: "";
  width: 28%;
  aspect-ratio: 1;
  border-radius: 999px;
  background: var(--board-highlight);
  box-shadow: 0 0 0 8px rgba(43, 245, 192, 0.08);
}

.square.capture::after {
  width: 72%;
  background: transparent;
  border: 0.28rem solid rgba(255, 127, 152, 0.7);
  box-shadow: none;
}

.square.last-move {
  box-shadow: inset 0 0 0 3px var(--board-last);
}

.square.in-check {
  animation: pulse-check 1.2s ease-in-out infinite;
}

@keyframes pulse-check {
  0%,
  100% {
    box-shadow: inset 0 0 0 3px rgba(255, 127, 152, 0.65);
  }

  50% {
    box-shadow: inset 0 0 0 6px rgba(255, 127, 152, 0.35);
  }
}

.piece {
  position: relative;
  z-index: 1;
  user-select: none;
  text-shadow: 0 5px 14px rgba(0, 0, 0, 0.22);
  -webkit-font-smoothing: antialiased;
}

.piece.white {
  color: #ffffff;
  -webkit-text-stroke: 1px rgba(8, 22, 39, 0.48);
  text-shadow:
    0 4px 12px rgba(0, 0, 0, 0.28),
    0 0 8px rgba(255, 255, 255, 0.18);
}

.piece.black {
  color: #10263d;
  -webkit-text-stroke: 1px rgba(228, 245, 255, 0.22);
  text-shadow:
    0 4px 12px rgba(255, 255, 255, 0.1),
    0 2px 10px rgba(0, 0, 0, 0.18);
}

.coord-rank,
.coord-file {
  position: absolute;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  opacity: 0.78;
}

.coord-rank {
  top: 0.35rem;
  left: 0.45rem;
}

.coord-file {
  right: 0.45rem;
  bottom: 0.32rem;
}

.control-panel {
  display: grid;
  gap: 1rem;
}

.card {
  padding: 1.1rem 1.1rem 1rem;
}

.card.compact {
  padding-bottom: 1.15rem;
}

.card h2 {
  margin: 0 0 0.9rem;
  font-size: 1.05rem;
  font-family: var(--font-display);
  letter-spacing: 0.03em;
}

.large-text {
  min-height: 2.7rem;
  margin: 0 0 0.9rem;
  color: var(--text);
  font-size: 1.03rem;
}

.field-label {
  display: inline-block;
  margin-bottom: 0.45rem;
  color: var(--muted);
  font-size: 0.9rem;
}

textarea {
  width: 100%;
  border: 1px solid rgba(128, 204, 255, 0.18);
  border-radius: 16px;
  padding: 0.9rem 0.95rem;
  resize: vertical;
  min-height: 3.2rem;
  background: rgba(2, 8, 18, 0.75);
  color: var(--text);
  font: inherit;
  outline: none;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}

textarea:focus {
  border-color: rgba(86, 214, 255, 0.6);
  box-shadow: 0 0 0 4px rgba(86, 214, 255, 0.12);
}

.copy-field {
  margin-bottom: 0.9rem;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 0.9rem;
}

.button {
  border: 0;
  border-radius: 14px;
  padding: 0.82rem 1rem;
  font: inherit;
  font-weight: 700;
  letter-spacing: 0.03em;
  cursor: pointer;
  transition: transform 120ms ease, box-shadow 120ms ease, opacity 120ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button:active {
  transform: translateY(0);
}

.button.primary {
  background: linear-gradient(135deg, #1f8cff, #20d9bf);
  color: #05111f;
  box-shadow: 0 10px 26px rgba(43, 245, 192, 0.18);
}

.button.secondary {
  background: rgba(86, 214, 255, 0.16);
  color: var(--text);
  border: 1px solid rgba(86, 214, 255, 0.2);
}

.button.ghost {
  background: rgba(255, 255, 255, 0.04);
  color: var(--muted);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.button.tiny {
  padding: 0.65rem 0.85rem;
  border-radius: 12px;
}

.message {
  margin: 0.9rem 0 0;
  min-height: 1.5rem;
  color: var(--muted);
}

.message.error {
  color: var(--danger);
}

.message.success {
  color: var(--success);
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.9rem;
}

.section-heading span {
  color: var(--muted);
  font-size: 0.92rem;
}

.history-card {
  min-height: 340px;
}

.history-list {
  display: grid;
  gap: 0.75rem;
  max-height: 420px;
  overflow: auto;
  padding-right: 0.25rem;
}

.history-item {
  display: flex;
  justify-content: space-between;
  gap: 0.8rem;
  align-items: center;
  padding: 0.85rem 0.95rem;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.history-title,
.history-subtitle {
  margin: 0;
}

.history-title {
  font-weight: 700;
}

.history-subtitle {
  margin-top: 0.22rem;
  color: var(--muted);
  font-size: 0.9rem;
  word-break: break-all;
}

@media (max-width: 1060px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .status-pills {
    justify-content: flex-start;
  }
}

@media (max-width: 720px) {
  .app-shell {
    width: min(100% - 1rem, 100%);
    padding-top: 1rem;
  }

  .topbar {
    flex-direction: column;
  }

  .board-frame,
  .card {
    border-radius: 22px;
  }

  .board-frame {
    padding: 0.75rem;
  }

  .square {
    font-size: clamp(1.65rem, 8vw, 2.4rem);
  }

  .coord-rank,
  .coord-file {
    font-size: 0.65rem;
  }
}