* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: radial-gradient(circle at top, #10142d 0%, #05060d 55%, #020308 100%);
  color: #eaf2ff;
  font-family: Arial, Helvetica, sans-serif;
  min-height: 100%;
}

body {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 24px;
  touch-action: manipulation;
}

.page {
  width: 100%;
  max-width: 980px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.help-drawer {
  width: 100%;
  max-width: 900px;
  color: #eaf2ff;
}

.help-drawer summary {
  list-style: none;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 14px;
  padding: 12px 16px;
  backdrop-filter: blur(6px);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  user-select: none;
}

.help-drawer summary::-webkit-details-marker {
  display: none;
}

.help-drawer[open] summary {
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.help-drawer summary::after {
  content: "+";
  float: right;
  opacity: 0.7;
}

.help-drawer[open] summary::after {
  content: "-";
}

.help-panel {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-top: 0;
  border-bottom-left-radius: 14px;
  border-bottom-right-radius: 14px;
  padding: 14px 18px;
  backdrop-filter: blur(6px);
}

.help-panel h1 {
  margin: 0 0 8px;
  font-size: 24px;
}

.help-panel p {
  margin: 4px 0;
  opacity: 0.9;
}

#game-container {
  width: 900px;
  max-width: 100%;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
  border: 1px solid rgba(255, 255, 255, 0.08);
  touch-action: none;
}

canvas {
  display: block;
  max-width: 100%;
  height: auto;
  touch-action: none;
}

@media (max-width: 640px) {
  body {
    padding: 12px;
  }

  .page {
    gap: 12px;
  }

  .help-drawer summary {
    padding: 11px 14px;
    font-size: 14px;
  }

  .help-panel {
    padding: 12px 14px;
  }

  .help-panel h1 {
    font-size: 20px;
  }
}