:root {
  --bg: #0b0c10;
  --card: #15171d;
  --text: #edf0f5;
  --muted: #8a91a3;
  --accent: #6366f1;
  --accent-hover: #4f46e5;
  --surface: #22252d;
  --radius: 18px;
  --shadow: 0 12px 32px rgba(0,0,0,0.45);
  --ease: cubic-bezier(0.34, 1.56, 0.64, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  -webkit-tap-highlight-color: transparent;
  -webkit-font-smoothing: antialiased;
}

.card {
  background: var(--card);
  border: 1px solid #252830;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 24px 28px;
  width: 100%;
  max-width: 380px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.title {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 20px;
}

.counter {
  font-size: 72px;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 28px;
  transition: transform 250ms var(--ease);
  display: inline-block;
  will-change: transform;
}

.counter.pulse {
  transform: scale(1.18);
}

.btn {
  position: relative;
  width: 100%;
  padding: 16px 20px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 12px;
  cursor: pointer;
  overflow: hidden;
  transition: background 200ms, transform 100ms;
  outline: none;
}

.btn:hover { background: var(--accent-hover); }
.btn:active { transform: scale(0.96); }
.btn:focus-visible { box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.45); }

.btn-ripple {
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(255,255,255,0.25) 0%, transparent 70%);
  opacity: 0;
  transform: scale(0);
  transition: transform 400ms var(--ease), opacity 300ms;
  pointer-events: none;
}

.btn:active .btn-ripple {
  opacity: 1;
  transform: scale(2.2);
}

.pause-overlay {
  position: absolute;
  inset: 0;
  background: rgba(11, 12, 16, 0.88);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 200ms;
}

.pause-overlay:not(.hidden) {
  opacity: 1;
  pointer-events: auto;
}

.pause-overlay span {
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  letter-spacing: 0.05em;
}

.hidden { display: none !important; }

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f8fafc;
    --card: #ffffff;
    --text: #0f172a;
    --muted: #64748b;
    --accent: #4f46e5;
    --accent-hover: #4338ca;
    --surface: #f1f5f9;
    --shadow: 0 10px 24px rgba(15, 23, 42, 0.12);
  }
  .pause-overlay { background: rgba(255, 255, 255, 0.85); }
}