:root {
  --black: #000000;
  --gray: #9ea3a8;
  --white: #ffffff;
  --accent: #00a676;
  --border-thick: 6px;
  --gap: 18px;
  --radius: 8px;
}

html,
body {
  height: 100%;
  margin: 0;
}
body {
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial;
  background: var(--white);
  color: var(--black);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 28px;
}

.app {
  width: min(920px, 96vw);
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--gap);
  padding: 20px;
  border: var(--border-thick) solid var(--black);
  border-radius: var(--radius);
  background: var(--white);
  box-sizing: border-box;
}

header {
  grid-column: 1 / -1;
  display: flex;
  gap: 16px;
  align-items: center;
  position: relative;
}

.sound-toggle {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sound-toggle svg {
  width: 24px;
  height: 24px;
  fill: var(--black);
}

.sound-toggle[data-muted="true"] .unmuted,
.sound-toggle[data-muted="false"] .muted {
  display: none;
}

@media (max-width: 520px) {
  .sound-toggle {
    position: static;
    transform: none;
    margin-left: auto;
  }
}

.logo {
  width: 60px;
  height: 60px;
  border: var(--border-thick) solid var(--black);
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 18px;
  background: var(--white);
  border-radius: 6px;
}

h1 {
  margin: 0;
  font-size: 20px;
}
p.lead {
  margin: 0;
  color: var(--gray);
  font-size: 13px;
}

.skip-link {
  position: absolute;
  top: -48px;
  left: 8px;
  background: var(--black);
  color: var(--white);
  padding: 8px 12px;
  text-decoration: none;
  font-weight: 700;
  z-index: 1000;
}
.skip-link:focus {
  top: 8px;
  outline: 4px solid var(--gray);
  outline-offset: 2px;
}

.board-wrap {
  border: var(--border-thick) solid var(--black);
  padding: 20px;
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: center;
  background: var(--white);
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  width: 100%;
  max-width: 420px;
}

.cell {
  aspect-ratio: 1 / 1;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: var(--border-thick) solid var(--black);
  background: var(--white);
  font-weight: 800;
  font-size: 36px;
  cursor: pointer;
  user-select: none;
  padding: 0;
  border-radius: 6px;
  transition: transform 80ms linear;
}

.cell:active {
  transform: scale(0.96);
}

.cell:focus,
button:focus,
select:focus,
.skip-link:focus {
  outline: 4px solid var(--gray);
  outline-offset: 2px;
}

.cell.win {
  outline: 6px solid var(--accent);
  outline-offset: -6px;
  animation: winPulse 1s ease infinite;
}

@keyframes winPulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

.cell-click {
  animation: cellClick 0.3s ease;
}

@keyframes cellClick {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(0.9);
  }
  100% {
    transform: scale(1);
  }
}

.celebration {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1000;
  animation: celebrate 1s ease-out;
  opacity: 0;
}

@keyframes celebrate {
  0% {
    opacity: 0.8;
    background: radial-gradient(circle, var(--accent) 0%, transparent 70%);
  }
  100% {
    opacity: 0;
    background: radial-gradient(circle, var(--accent) 0%, transparent 100%);
  }
}

.panel {
  border: var(--border-thick) solid var(--black);
  padding: 18px;
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--white);
}

.score-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
}
.score-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  font-weight: 700;
}
.score-badge {
  min-width: 46px;
  text-align: center;
  padding: 8px 6px;
  border: 4px solid var(--black);
  background: var(--white);
  font-weight: 800;
}

.controls {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
}

.controls button {
  border: var(--border-thick) solid var(--black);
  padding: 8px 10px;
  background: var(--white);
  cursor: pointer;
  border-radius: 6px;
  font-weight: 700;
  transition: all 0.2s ease;
}

.controls button:hover {
  transform: translateY(-2px);
  box-shadow: 2px 2px 0 var(--black);
}

.controls button:active {
  transform: translateY(0);
  box-shadow: none;
}

.mode-btn {
  position: relative;
  overflow: hidden;
}

.mode-btn.active {
  background: var(--black);
  color: var(--white);
}

.mode-btn:not(.active) {
  opacity: 0.8;
}

#status {
  min-height: 1.4em;
  font-weight: 800;
  text-align: center;
  color: var(--black);
}

#banner {
  position: fixed;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2000;
  background: var(--black);
  color: var(--white);
  padding: 8px 12px;
  font-weight: 800;
  border: 4px solid var(--black);
  display: none;
}

@media (max-width: 520px) {
  body {
    padding: 16px;
    min-height: 100vh;
    align-items: flex-start;
  }

  .app {
    grid-template-columns: 1fr;
    width: 100%;
    padding: 12px;
  }

  header {
    flex-direction: column;
    text-align: center;
    gap: 8px;
    padding-bottom: 12px;
  }

  .logo {
    width: 50px;
    height: 50px;
    margin: 0 auto;
  }

  h1 {
    font-size: 18px;
  }

  .lead {
    font-size: 12px;
  }

  .board {
    max-width: 320px;
    gap: 8px;
  }

  .cell {
    font-size: 24px;
    border-width: 4px;
  }

  .panel {
    padding: 12px;
  }

  .controls {
    justify-content: center;
  }

  .controls button,
  select[type="select"] {
    padding: 6px 8px;
    font-size: 14px;
  }

  .score-badge {
    min-width: 40px;
    padding: 6px 4px;
  }
}

@media (max-width: 360px) {
  body {
    padding: 8px;
  }

  .app {
    padding: 8px;
  }

  .board {
    max-width: 280px;
    gap: 6px;
  }

  .cell {
    font-size: 22px;
  }

  .controls button {
    padding: 6px;
  }
}
/* Universal Home Button Styling */
.home-button {
  position: fixed;
  top: 20px;
  left: 20px;
  background: #ffffff;
  color: #000000;
  text-decoration: none;
  padding: 12px 18px;
  border: 4px solid #000000;
  box-shadow: 6px 6px 0 #808080;
  font-family: "Arial Black", Arial, sans-serif;
  font-size: 0.9rem;
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  z-index: 1000;
  transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  cursor: pointer;
  user-select: none;
}

.home-button:hover {
  background: #000000;
  color: #ffffff;
  transform: translate(-2px, -2px);
  box-shadow: 8px 8px 0 #808080;
}

.home-button:active {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 #808080;
}