:root {
  color-scheme: dark;
  --text: #e7f7f5;
  --muted: #a9d2cf;
  --panel: rgba(6, 24, 36, 0.68);
  --line: rgba(255, 255, 255, 0.16);
  --button: rgba(148, 221, 213, 0.22);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: radial-gradient(circle at 50% 10%, #2a95a8, #15384d 45%, #081622 100%);
  color: var(--text);
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
}

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

#game {
  display: block;
  width: 100%;
  height: 100%;
}

.hud {
  position: absolute;
  top: 14px;
  left: 14px;
  width: min(320px, calc(100vw - 28px));
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--panel);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.hud h1 {
  margin: 0 0 10px;
  font-size: 1.05rem;
  font-weight: 600;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
}

.stats div {
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.05);
  padding: 8px;
}

.stats span {
  display: block;
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.stats strong {
  display: block;
  margin-top: 4px;
  font-size: 1.05rem;
}

.pulse-wrap {
  margin-top: 10px;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
}

.pulse-ring {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 2px solid rgba(203, 255, 246, 0.9);
  box-shadow: 0 0 18px rgba(166, 255, 243, 0.8);
  transform: scale(1);
}

.hint {
  margin: 9px 0 0;
  font-size: 0.8rem;
  color: var(--muted);
}

.combo-banner {
  position: absolute;
  top: 18px;
  left: 50%;
  transform: translateX(-50%);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  padding: 7px 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  background: rgba(7, 27, 40, 0.78);
  text-shadow: 0 0 12px rgba(208, 255, 252, 0.5);
}

.card {
  position: absolute;
  inset: 0;
  margin: auto;
  width: min(430px, calc(100vw - 28px));
  height: fit-content;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(4, 14, 24, 0.88);
  padding: 18px;
  text-align: center;
}

.card.hidden {
  display: none;
}

.hidden {
  display: none;
}

.card h2 {
  margin: 0 0 12px;
  font-size: 1.3rem;
  font-weight: 600;
}

button {
  appearance: none;
  font: inherit;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--button);
  padding: 8px 14px;
  cursor: pointer;
}

button:hover,
button:focus-visible {
  background: rgba(190, 255, 248, 0.3);
  outline: none;
}