:root {
  --bg: #0a0a0a;
  --surface: #141414;
  --surface-2: #1c1c1c;
  --border: #2a2a2a;
  --text: #f5f5f5;
  --text-muted: #8a8a8a;
  --accent: #ffffff;
  --radius: 16px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
  background-color: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  letter-spacing: -0.01em;
}

.container {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2rem;
}

.send-btn {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  cursor: pointer;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), background 0.25s, box-shadow 0.25s, border-color 0.25s;
  position: relative;
  outline: none;
  display: flex;
  align-items: center;
  justify-content: center;
}

.send-btn::before {
  content: "";
  position: absolute;
  inset: 14px;
  border-radius: 50%;
  border: 1px solid var(--border);
  transition: border-color 0.25s, transform 0.25s;
}

.send-btn:hover {
  background: var(--surface-2);
  border-color: #444;
  box-shadow: 0 0 0 8px rgba(255, 255, 255, 0.03);
  transform: scale(1.03);
}

.send-btn:hover::before {
  border-color: #555;
  transform: scale(1.02);
}

.send-btn:active {
  transform: scale(0.97);
}

.send-btn.sending {
  background: var(--surface-2);
  border-color: #555;
  animation: pulse 1.2s ease-in-out infinite;
}

.send-btn.sending::before {
  border-color: #777;
}

.send-btn.success {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}

.send-btn.success::before {
  border-color: rgba(0, 0, 0, 0.15);
}

.status-msg {
  font-size: 0.95rem;
  color: var(--text-muted);
  min-height: 24px;
  letter-spacing: 0;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.06); }
  50% { box-shadow: 0 0 0 14px rgba(255, 255, 255, 0); }
  100% { box-shadow: 0 0 0 0 rgba(255, 255, 255, 0); }
}