:root { --cian: #5ff2ff; --ambar: #ffe14d; --fondo: #02030a; --tinta: #eaf6ff; }
* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { margin: 0; height: 100%; overflow: hidden; background: var(--fondo); color: var(--tinta);
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif; overscroll-behavior: none; touch-action: none; user-select: none; -webkit-user-select: none; }
#lienzo { position: fixed; inset: 0; width: 100%; height: 100%; display: block; }

/* ---------- paneles ---------- */
.panel { position: fixed; inset: 0; z-index: 10; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 18px;
  padding: calc(env(safe-area-inset-top) + 130px) 24px calc(env(safe-area-inset-bottom) + 24px); text-align: center;
  background: radial-gradient(circle at 50% 40%, rgba(10, 18, 48, .72), rgba(2, 3, 10, .9)); }
.panel[hidden] { display: none; }
.logo { width: min(44vw, 170px); height: auto; filter: drop-shadow(0 0 18px rgba(95, 242, 255, .45)); animation: flotar 5s ease-in-out infinite; }
@keyframes flotar { 50% { transform: translateY(-8px); } }
#panel-inicio { padding-top: calc(env(safe-area-inset-top) + 24px); }
.fila { display: flex; gap: 12px; width: min(100%, 360px); }
.panel .fila button { flex: 1; min-width: 0; width: auto; padding: 10px 6px; font-size: 17px; }
#panel-menu, #panel-pausa { gap: 11px; }
#panel-menu button:not(.principal), #panel-pausa button:not(.principal) { min-height: 56px; }
#panel-menu button.principal { min-height: 72px; }
h1, h2 { margin: 0; font-weight: 900; letter-spacing: .08em; text-shadow: 0 0 18px rgba(95, 242, 255, .6); }
h1 { font-size: clamp(34px, 11vw, 60px); }
h1 span { color: var(--cian); }
h2 { font-size: clamp(26px, 8vw, 44px); }
.panel p { margin: 0; max-width: 30em; font-size: 17px; line-height: 1.4; text-wrap: balance; }
.panel .nota { font-size: 13px; opacity: .65; }
button { font: inherit; color: var(--tinta); cursor: pointer; }
.panel button { width: min(100%, 360px); min-height: 68px; padding: 10px 18px; font-size: 19px; font-weight: 700; border-radius: 16px;
  border: 2px solid rgba(95, 242, 255, .55); background: rgba(14, 26, 54, .85); }
.panel button.principal { min-height: 84px; font-size: 24px; letter-spacing: .06em; color: #021018; background: var(--cian); border-color: #fff; box-shadow: 0 0 24px rgba(95, 242, 255, .5); }
.esquina { position: fixed; z-index: 9; top: calc(env(safe-area-inset-top) + 8px); right: 8px; width: 64px; height: 64px; border-radius: 16px;
  font-size: 20px; border: 2px solid rgba(255, 255, 255, .35); background: rgba(10, 16, 34, .55); }
.esquina[hidden] { display: none; }
#aviso { position: fixed; z-index: 30; left: 50%; bottom: calc(env(safe-area-inset-bottom) + 20px); transform: translateX(-50%); width: max-content; max-width: 90vw;
  padding: 12px 18px; border-radius: 14px; background: rgba(8, 12, 26, .92); border: 1px solid rgba(95, 242, 255, .5); font-size: 16px; text-align: center; pointer-events: none; }
#aviso[hidden] { display: none; }

/* ---------- control con la cabeza ---------- */
#cabeza-cursor { position: fixed; left: 0; top: 0; width: 0; height: 0; z-index: 90; pointer-events: none; }
#cabeza-cursor[hidden] { display: none; }
#cabeza-cursor span { position: absolute; left: -23px; top: -23px; width: 46px; height: 46px; border-radius: 50%;
  background: conic-gradient(var(--ambar) var(--progreso, 0deg), rgba(255, 255, 255, .5) 0);
  -webkit-mask: radial-gradient(circle, transparent 16px, #000 17px); mask: radial-gradient(circle, transparent 16px, #000 17px);
  filter: drop-shadow(0 0 3px rgba(0, 0, 0, .9)); }
#cabeza-cursor::after { content: ''; position: absolute; left: -4px; top: -4px; width: 8px; height: 8px; border-radius: 50%; background: #fff; box-shadow: 0 0 8px var(--cian), 0 0 2px #000; }
#cabeza-cursor.sin-cara { opacity: .35; }
.cabeza-objetivo { outline: 4px solid var(--ambar) !important; outline-offset: 3px; }
.cabeza-pulsado { filter: brightness(1.4); }
/* El vídeo tiene que seguir pintándose para que el detector reciba imágenes: en la partida se deja casi invisible en vez de ocultarlo. */
#cabeza-video { position: fixed; z-index: 20; left: 50%; top: calc(env(safe-area-inset-top) + 12px); width: 84px; height: 108px; margin-left: -42px;
  border-radius: 14px; border: 2px solid rgba(95, 242, 255, .6); background: #000; object-fit: cover; transform: scaleX(-1); opacity: 0; pointer-events: none; }
html.con-cabeza #cabeza-video { opacity: 1; }
html.jugando #cabeza-video, html.con-raton #cabeza-video { width: 2px; height: 2px; opacity: .01; border: 0; }