:root {
  --text: #f4f7ff;
  --board: #8ea388;
  --ink: #2c3428;
  --panel: #f6f2ea;
  --bg-top: #050a24;
  --bg-mid: #060c2b;
  --bg-bottom: #050920;
  --bg-glow: rgba(80, 106, 192, 0.2);
  --sparkle-opacity: 0.24;
  --frame-shadow: rgba(5, 12, 28, 0.45);
  --hud-color: rgba(239, 234, 220, 0.9);
  --hud-shadow: none;
  --timer-color: rgba(239, 234, 220, 0.9);
  --timer-track: rgba(239, 234, 220, 0.22);
  --timer-core: rgba(58, 70, 78, 0.42);
  --button-bg: #f2eee3;
  --button-border: #7d7868;
  --button-hover: #faf5ea;
  --overlay-backdrop: rgba(6, 12, 30, 0.45);
  --panel-shadow: rgba(10, 18, 38, 0.28);
  --font-sans:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial,
    sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html,
body {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font-sans);
  color: var(--text);
  background:
    radial-gradient(120% 82% at 50% -18%, var(--bg-glow) 0%, transparent 62%),
    linear-gradient(
      180deg,
      var(--bg-top) 0%,
      var(--bg-mid) 54%,
      var(--bg-bottom) 100%
    );
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: var(--sparkle-opacity);
  background:
    radial-gradient(
      2px 2px at 8vw 16vh,
      rgba(255, 255, 255, 0.95),
      transparent
    ),
    radial-gradient(
      2.5px 2.5px at 21vw 67vh,
      rgba(255, 255, 255, 0.85),
      transparent
    ),
    radial-gradient(
      2px 2px at 36vw 22vh,
      rgba(255, 255, 255, 0.95),
      transparent
    ),
    radial-gradient(
      2px 2px at 46vw 78vh,
      rgba(255, 255, 255, 0.9),
      transparent
    ),
    radial-gradient(
      2.5px 2.5px at 63vw 12vh,
      rgba(255, 255, 255, 0.9),
      transparent
    ),
    radial-gradient(
      2px 2px at 74vw 61vh,
      rgba(255, 255, 255, 0.95),
      transparent
    ),
    radial-gradient(
      2px 2px at 91vw 30vh,
      rgba(255, 255, 255, 0.9),
      transparent
    ),
    radial-gradient(
      2px 2px at 82vw 90vh,
      rgba(255, 255, 255, 0.92),
      transparent
    ),
    radial-gradient(
      2.5px 2.5px at 54vw 48vh,
      rgba(255, 255, 255, 0.78),
      transparent
    ),
    radial-gradient(
      2px 2px at 14vw 43vh,
      rgba(255, 255, 255, 0.88),
      transparent
    );
}

#app {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 820px;
  margin: 0 auto;
  height: 100%;
  padding: calc(env(safe-area-inset-top) + 12px) 12px
    calc(env(safe-area-inset-bottom) + 10px);
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 8px;
}

header {
  text-align: center;
}

header h1 {
  font-size: 36px;
  line-height: 1;
  letter-spacing: 0.2px;
  color: var(--text);
  text-shadow: 0 2px 10px rgba(6, 14, 30, 0.45);
  transition: color 260ms ease;
}

#game-container {
  position: relative;
  display: grid;
  place-items: start center;
  min-height: 0;
}

#canvas-wrap {
  position: relative;
  height: min(700px, calc(100vh - 100px));
  aspect-ratio: 39 / 70;
  width: auto;
  max-width: 100%;
  overflow: hidden;
  border: none;
  border-radius: 8px;
  background: var(--board);
  box-shadow: 0 22px 44px -26px var(--frame-shadow);
  transition: box-shadow 360ms ease;
  touch-action: none;
}

#canvas-wrap[data-tide-stage="sky"] {
  --button-bg: #e8f2ff;
  --button-border: #4c6f99;
  --button-hover: #f4f8ff;
  --panel: #eaf2ff;
  --ink: #1a2d4a;
  --overlay-backdrop: rgba(8, 20, 44, 0.44);
  --panel-shadow: rgba(17, 38, 71, 0.3);
}

#canvas-wrap[data-tide-stage="space"] {
  --button-bg: #dae4ff;
  --button-border: #546da4;
  --button-hover: #e7efff;
  --panel: #dde6ff;
  --ink: #1c2744;
  --overlay-backdrop: rgba(10, 18, 40, 0.48);
  --panel-shadow: rgba(10, 17, 44, 0.34);
}

#canvas-wrap[data-tide-stage="deep-space"] {
  --button-bg: #e7def8;
  --button-border: #7060a0;
  --button-hover: #f0e8ff;
  --panel: #e8ddfa;
  --ink: #2c1f44;
  --overlay-backdrop: rgba(14, 10, 31, 0.5);
  --panel-shadow: rgba(30, 12, 56, 0.34);
}

#game-canvas {
  display: block;
  width: 100%;
  height: 100%;
}
#score-display {
  position: absolute;
  top: auto;
  bottom: calc((58px - 1em) / 2);
  right: 14px;
  font-size: 30px;
  line-height: 1;
  font-weight: 600;
  color: var(--hud-color);
  text-shadow: none;
  transition: color 260ms ease;
  pointer-events: none;
}

#timer-display {
  --timer-progress: 0;
  --timer-size: 28px;
  position: absolute;
  top: auto;
  bottom: calc((58px - var(--timer-size)) / 2);
  left: 14px;
  width: var(--timer-size);
  height: var(--timer-size);
  border-radius: 50%;
  background: conic-gradient(
    from -90deg,
    var(--timer-color) calc(var(--timer-progress) * 1turn),
    var(--timer-track) 0
  );
  box-shadow: inset 0 0 0 1px rgba(239, 234, 220, 0.28);
  opacity: 0.95;
  transition:
    background 120ms linear,
    opacity 180ms ease;
  pointer-events: none;
}

#timer-display::after {
  content: "";
  position: absolute;
  inset: 6px;
  border-radius: 50%;
  background: var(--timer-core);
}

button {
  border: 2px solid var(--button-border);
  border-radius: 6px;
  background: var(--button-bg);
  color: var(--ink);
  font-weight: 700;
  font-size: 14px;
  padding: 9px 22px;
  min-width: 110px;
  box-shadow: 0 8px 18px -14px rgba(7, 14, 30, 0.5);
  transition:
    background 180ms ease,
    border-color 180ms ease;
}

button:hover {
  background: var(--button-hover);
}

button:active {
  transform: translateY(1px);
}

.overlay {
  position: absolute;
  inset: 0;
  background: var(--overlay-backdrop);
  display: grid;
  place-items: center;
}

.overlay.hidden {
  display: none;
}

.hidden {
  display: none !important;
}

.overlay-card {
  width: min(360px, calc(100% - 28px));
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: var(--panel);
  color: var(--ink);
  padding: 20px 16px;
  text-align: center;
  box-shadow: 0 18px 32px -16px var(--panel-shadow);
}

.overlay-card h2 {
  margin-bottom: 6px;
}

.overlay-card h2:empty {
  display: none;
}

.overlay-card .overlay-description {
  margin-bottom: 14px;
  font-size: 14px;
}

.overlay-card .overlay-score {
  margin-bottom: 8px;
  font-size: 16px;
  font-weight: 500;
}

@media (max-height: 760px) {
  header h1 {
    font-size: 32px;
  }
}

@media (max-width: 540px) {
  header h1 {
    font-size: 30px;
  }

  #canvas-wrap {
    height: min(700px, calc(100vh - 96px));
  }

  #score-display {
    font-size: 24px;
  }
  #timer-display {
    --timer-size: 24px;
  }
}