:root {
  color-scheme: dark;
  --bg: radial-gradient(circle at 40% -10%, #0a1022 0%, #050712 35%, #02040a 70%, #000 100%);
  --panel-bg: rgba(7, 12, 24, 0.8);
  --panel-border: rgba(120, 166, 255, 0.3);
  --accent: #6cf3ff;
  --accent-2: #8d66ff;
  font-family: 'Segoe UI', Roboto, 'Inter', sans-serif;
}

* {
  box-sizing: border-box;
}

body, html {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background: var(--bg);
  color: #e8f1ff;
  overflow: hidden;
}

#app {
  position: relative;
  width: 100%;
  height: 100%;
}

#startScreen {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  background: linear-gradient(145deg, rgba(7, 10, 18, 0.94) 0%, rgba(9, 14, 28, 0.85) 50%, rgba(4, 6, 12, 0.94) 100%);
  backdrop-filter: blur(6px);
  z-index: 10;
}

.start-card {
  max-width: 560px;
  width: min(92vw, 560px);
  background: radial-gradient(circle at 30% 20%, rgba(108, 243, 255, 0.18), rgba(0, 0, 0, 0))
      , radial-gradient(circle at 80% 10%, rgba(141, 102, 255, 0.18), rgba(0, 0, 0, 0))
      , rgba(6, 9, 18, 0.9);
  border: 1px solid rgba(130, 170, 255, 0.35);
  border-radius: 18px;
  padding: clamp(1.1rem, 4vw, 1.6rem);
  box-shadow: 0 25px 80px rgba(0, 0, 0, 0.55), inset 0 0 0 1px rgba(255, 255, 255, 0.03);
  text-align: center;
}

.start-card h1 {
  margin: 0 0 0.3rem;
  font-size: clamp(2.4rem, 6vw, 3.2rem);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.start-card .subtitle {
  margin: 0 0 1rem;
  opacity: 0.8;
  font-weight: 500;
}

.start-card .eyebrow {
  letter-spacing: 0.16em;
  font-size: 0.85rem;
  text-transform: uppercase;
  opacity: 0.75;
  margin: 0.1rem 0 0.6rem;
}

.start-controls {
  display: flex;
  gap: 0.6rem;
  justify-content: center;
  margin-bottom: 0.8rem;
}

.start-controls button {
  cursor: pointer;
  border-radius: 999px;
  border: none;
  padding: 0.65rem 1.4rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: #02040a;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 12px 40px rgba(120, 166, 255, 0.4);
  transition: transform 0.12s ease, box-shadow 0.2s ease;
}

.start-controls .ghost {
  background: transparent;
  color: #d0e4ff;
  border: 1px solid rgba(145, 178, 255, 0.5);
  box-shadow: none;
}

.start-controls button:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 42px rgba(120, 166, 255, 0.45);
}

.start-meta {
  display: grid;
  gap: 0.35rem;
  font-size: 0.95rem;
  opacity: 0.9;
}

.start-meta span:first-child {
  color: var(--accent);
  font-weight: 600;
}

canvas {
  display: block;
}

#overlay {
  position: absolute;
  top: 0;
  left: 0;
  padding: 1.2rem;
  width: min(460px, 100%);
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  pointer-events: none;
  font-size: 0.95rem;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  padding: 0.6rem 0.9rem;
  border-radius: 10px;
  pointer-events: auto;
}

header h1 {
  margin: 0;
  font-size: 1.1rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

header h1 span {
  color: var(--accent-2);
  font-size: 0.85em;
}

#seedDisplay {
  font-size: 0.85rem;
  opacity: 0.85;
}

#hud {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.6rem;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  padding: 0.8rem;
  border-radius: 12px;
  pointer-events: auto;
}

.stat label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  opacity: 0.7;
}

.stat span {
  font-size: 1.2rem;
  font-weight: 600;
}

#controlsTooltip,
#leaderboard,
#settingsPanel {
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 12px;
  padding: 0.9rem;
  pointer-events: auto;
}

#controlsTooltip p {
  margin: 0.25rem 0;
  line-height: 1.4;
}

#leaderboard h2,
#settingsPanel h2 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

#leaderboard .entry,
.setting {
  display: flex;
  gap: 0.6rem;
  align-items: center;
  margin-bottom: 0.5rem;
}

#leaderboard .entry:last-child,
.setting:last-child {
  margin-bottom: 0;
}

#leaderboard input,
.setting input[type="range"],
.setting select {
  flex: 1;
  padding: 0.3rem 0.4rem;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.05);
  color: inherit;
}

#leaderboard button,
.setting button,
#pauseButton,
#saveName {
  cursor: pointer;
  border-radius: 999px;
  border: none;
  padding: 0.4rem 0.9rem;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #02040a;
  font-weight: 600;
  box-shadow: 0 6px 18px rgba(91, 158, 255, 0.32);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

#leaderboard button:hover,
.setting button:hover,
#pauseButton:hover,
#saveName:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 26px rgba(91, 158, 255, 0.35);
}

#pauseButton {
  position: absolute;
  right: 1.2rem;
  bottom: 1.2rem;
  pointer-events: auto;
}

#leaderboardList {
  list-style: decimal-leading-zero inside;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.2rem;
  font-size: 0.9rem;
}

#mobileControls {
  position: absolute;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 1.2rem;
  pointer-events: none;
}

#mobileControls .control {
  pointer-events: auto;
  font-size: 1.6rem;
  width: clamp(68px, 16vw, 110px);
  height: clamp(68px, 16vw, 110px);
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(14, 22, 33, 0.82);
  color: var(--accent);
  box-shadow: inset 0 0 12px rgba(80, 150, 255, 0.35);
}

#tiltStatus {
  font-size: 0.9rem;
  opacity: 0.8;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.hidden {
  display: none !important;
}

@media (max-width: 980px) {
  #overlay {
    width: 100%;
    padding: 0.8rem;
    gap: 0.6rem;
  }

  header,
  #hud,
  #controlsTooltip,
  #leaderboard,
  #settingsPanel {
    backdrop-filter: blur(12px);
  }

  #pauseButton {
    right: 0.8rem;
    bottom: 0.8rem;
  }
}

@media (max-width: 720px) {
  #overlay {
    font-size: 0.85rem;
  }

  header {
    flex-direction: column;
    align-items: flex-start;
  }

  #hud {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  #mobileControls {
    pointer-events: auto;
  }
}