html, body {
  margin: 0;
  padding: 0;
  overflow: hidden;
}
canvas {
  display: block;
}

/* ---- Info button (top-left) ---- */
#infoBtn {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 10;

  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.55);
  background: rgba(0,0,0,0.35);
  color: #fff;

  font: italic 700 18px/1 Georgia, "Times New Roman", serif;
  cursor: pointer;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  transition: background .18s ease, transform .18s ease, border-color .18s ease;
}
#infoBtn:hover { background: rgba(0,0,0,0.6); border-color:#fff; transform: scale(1.06); }
#infoBtn:active { transform: scale(0.96); }
#infoBtn:focus-visible { outline: 2px solid #fff; outline-offset: 2px; }

/* ---- Modal ---- */
.modal {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: grid;
  place-items: center;

  opacity: 0;
  pointer-events: none;
  transition: opacity .22s ease;

}
.modal.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.modal-panel {
  position: relative;
  max-width: min(520px, calc(100vw - 40px));
  max-height: calc(100vh - 40px);
  overflow-y: auto;

  padding: 24px 26px 26px;
  border-radius: 14px;

  background: rgba(20, 20, 24, 0.92);
  color: #f2f2f2;
  border: 1px solid rgba(255,255,255,0.12);
  box-shadow: 0 20px 60px rgba(0,0,0,0.6);

  font: 15px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 1.1em;

  transform: translateY(8px) scale(0.98);
  transition: transform .22s ease;
}
.modal.open .modal-panel { transform: translateY(0) scale(1); }

.modal-panel h2 {
  margin: 0 24px 12px 0;
  font-size: 1.5em;
  font-weight: 600;
  letter-spacing: .01em;
}
.modal-panel p { margin: 0 0 12px; }
.modal-panel p:last-child { margin-bottom: 0; }

.modal-panel a {
  color: #7fd1ff;
  text-decoration: none;
  border-bottom: 1px solid rgba(127,209,255,0.4);
  word-break: break-word;
}
.modal-panel a:hover { color: #b6e4ff; border-bottom-color: #b6e4ff; }

.modal-close {
  position: absolute;
  top: 10px;
  right: 12px;
  width: 30px;
  height: 30px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: #cfcfcf;
  font-size: 2em;
  line-height: 1;
  cursor: pointer;
  transition: background .15s ease, color .15s ease;
}
.modal-close:hover { background: rgba(255,255,255,0.08); color: #fff; }