:root {
  color-scheme: dark;
  --bg: #080913;
  --panel: #0e1026;
  --line: #20244c;
  --muted: #626994;
  --text: #eef1f8;
  --pink: #f0257e;
  --cyan: #00e5ff;
  --violet: #8e2de2;
  --emerald: #1ad173;
  --gold: #ffd635;
  --glass: rgba(11, 13, 31, 0.55);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
  margin: 0;
  background:
    radial-gradient(circle at 50% 15%, rgba(0, 229, 255, 0.08), transparent 45%),
    radial-gradient(circle at 10% 80%, rgba(240, 37, 126, 0.05), transparent 40%),
    var(--bg);
}

body {
  min-height: 100svh;
  color: var(--text);
  overscroll-behavior: none;
}

button {
  color: inherit;
  font: inherit;
  cursor: pointer;
}

.shell {
  width: min(100%, 540px);
  min-height: 100svh;
  margin: 0 auto;
  padding: max(16px, env(safe-area-inset-top)) 20px max(18px, env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
}

/* Nav */
.top-nav {
  position: relative;
  z-index: 10;
  padding: 0 2px 12px;
  display: flex;
  align-items: center;
}

.back-link {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: color 0.2s ease, transform 0.2s ease;
}

.back-link:hover, .back-link:focus {
  color: var(--cyan);
  transform: translateX(-2px);
  outline: none;
}

/* Header */
.masthead {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 4px 2px 18px;
}

.eyebrow {
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.2em;
  color: var(--pink);
  margin: 0 0 6px;
}

h1 {
  font-size: 1.62rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0;
  background: linear-gradient(135deg, #fff 40%, #a5b4fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.icon-button {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--panel);
  font-size: 1rem;
  font-weight: bold;
  color: var(--cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, border-color 0.2s, transform 0.2s;
}

.icon-button:hover, .icon-button:focus {
  background: var(--line);
  border-color: var(--cyan);
  transform: scale(1.05);
  outline: none;
}

/* HUD metrics */
.hud {
  position: relative;
  z-index: 10;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 10px 14px;
  margin-bottom: 18px;
}

.metric {
  display: flex;
  flex-direction: column;
}

.metric-center {
  align-items: center;
}

.metric-right {
  align-items: flex-end;
}

.metric-label {
  font-size: 0.6rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  color: var(--muted);
  margin-bottom: 3px;
}

.metric strong {
  font-size: 1.15rem;
  font-weight: 800;
  color: #fff;
  font-variant-numeric: tabular-nums;
}

#score {
  color: var(--cyan);
}

#combo {
  color: var(--pink);
}

#high-score {
  color: var(--gold);
}

/* Board Canvas */
.board-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  width: 100%;
  max-width: 440px;
  aspect-ratio: 1;
}

#game-canvas {
  display: block;
  max-width: 100%;
  background: radial-gradient(circle at 50% 50%, #0d0f2b, #04050d);
  border: 1px solid var(--line);
  border-radius: 50%; /* Make the canvas frame itself beautifully circular! */
  box-shadow: 0 8px 36px rgba(0, 0, 0, 0.5), 0 0 15px rgba(14, 16, 38, 0.6);
  touch-action: none;
}

/* On-screen Rotation Controls */
.controls-container {
  position: relative;
  z-index: 10;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 18px;
}

.action-button {
  background: var(--glass);
  backdrop-filter: blur(6px);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 14px 10px;
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.25);
  transition: all 0.25s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.btn-icon {
  font-size: 1.1rem;
  display: inline-block;
}

#rotate-left-btn {
  border-color: rgba(240, 37, 126, 0.25);
}
#rotate-left-btn:hover, #rotate-left-btn:focus {
  border-color: var(--pink);
  box-shadow: 0 0 15px rgba(240, 37, 126, 0.35);
  transform: translateY(-2px);
  color: var(--pink);
  outline: none;
}

#rotate-right-btn {
  border-color: rgba(0, 229, 255, 0.25);
}
#rotate-right-btn:hover, #rotate-right-btn:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 15px rgba(0, 229, 255, 0.35);
  transform: translateY(-2px);
  color: var(--cyan);
  outline: none;
}

.action-button:active {
  transform: translateY(1px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* Status Chip */
.status-chip-container {
  position: relative;
  z-index: 10;
  display: flex;
  justify-content: center;
  margin-bottom: 18px;
}

.status-chip {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 6px 16px;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: #fff;
  text-align: center;
  text-shadow: 0 0 8px rgba(0, 229, 255, 0.4);
  animation: float 2.5s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* Footer */
.footer {
  position: relative;
  z-index: 10;
  text-align: center;
  padding: 4px 0;
  margin-top: auto;
}

.footer p {
  font-size: 0.68rem;
  color: var(--muted);
  margin: 0 0 10px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  justify-content: center;
}

.pulse-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--pink);
  animation: pulse-ring 1.8s infinite;
}

@keyframes pulse-ring {
  0% { transform: scale(0.95); opacity: 0.5; }
  50% { transform: scale(1.2); opacity: 1; box-shadow: 0 0 10px var(--pink); }
  100% { transform: scale(0.95); opacity: 0.5; }
}

.text-button {
  background: none;
  border: none;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-decoration: underline;
  padding: 4px 8px;
  transition: color 0.2s;
}

.text-button:hover, .text-button:focus {
  color: var(--pink);
  outline: none;
}

/* Dialog Modals */
dialog {
  padding: 0;
  border: none;
  background: transparent;
}

dialog::backdrop {
  background: rgba(4, 5, 12, 0.82);
  backdrop-filter: blur(8px);
}

.dialog-inner {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  width: min(90vw, 420px);
  padding: 26px;
  color: var(--text);
  position: relative;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.6), 0 0 20px rgba(0, 229, 255, 0.15);
  backdrop-filter: blur(12px);
}

.dialog-close {
  position: absolute;
  top: 18px;
  right: 18px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.05);
  font-size: 1.15rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  transition: color 0.2s, background 0.2s;
}

.dialog-close:hover {
  color: #fff;
  background: var(--line);
}

h2 {
  font-size: 1.45rem;
  font-weight: 900;
  letter-spacing: -0.01em;
  margin: 0 0 16px;
  color: #fff;
}

ol {
  padding-left: 18px;
  margin: 0 0 24px;
}

li {
  font-size: 0.78rem;
  line-height: 1.5;
  color: #c2c6d4;
  margin-bottom: 10px;
}

.primary-button {
  width: 100%;
  padding: 12px;
  border-radius: 12px;
  border: none;
  background: linear-gradient(135deg, var(--cyan), #0099ff);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  color: #000;
  box-shadow: 0 4px 15px rgba(0, 229, 255, 0.35);
  transition: transform 0.2s, box-shadow 0.2s;
}

.primary-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 229, 255, 0.5);
}

.secondary-button {
  width: 100%;
  padding: 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  color: #fff;
  transition: background 0.2s, border-color 0.2s;
}

.secondary-button:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--muted);
}

/* Results dialog specific */
.result-inner {
  text-align: center;
}

pre {
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px;
  font-family: monospace;
  font-size: 0.72rem;
  line-height: 1.4;
  color: var(--cyan);
  text-align: left;
  margin: 0 0 24px;
  white-space: pre-wrap;
  word-wrap: break-word;
}

.result-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

/* Toast alert */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--pink);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  padding: 10px 20px;
  border-radius: 30px;
  box-shadow: 0 8px 24px rgba(255, 46, 147, 0.45);
  transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  pointer-events: none;
  z-index: 1000;
}

.toast.visible {
  transform: translateX(-50%) translateY(0);
}

.icon-button:focus-visible,
.action-button:focus-visible,
.text-button:focus-visible,
.dialog-close:focus-visible,
.primary-button:focus-visible,
.secondary-button:focus-visible,
.back-link:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 3px;
}

dialog {
  max-height: calc(100svh - 24px);
  max-width: calc(100vw - 24px);
}

.dialog-inner {
  max-height: calc(100svh - 24px);
  overflow-y: auto;
}

@media (max-height: 820px) {
  .shell {
    padding-top: max(10px, env(safe-area-inset-top));
  }

  .masthead {
    padding-bottom: 10px;
  }

  .hud {
    margin-bottom: 10px;
  }

  .board-wrap {
    max-width: min(54svh, 440px);
    margin-bottom: 10px;
  }

  .controls-container,
  .status-chip-container {
    margin-bottom: 10px;
  }
}

@media (max-width: 380px) {
  .shell {
    padding-inline: 14px;
  }

  .controls-container,
  .result-actions {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}