:root {
  --primary: #19336e;
  --primary-light: #1e2a6f;
  --accent: #ff9800;
  --success: #4CAF50;
  --disabled-bg: #555;
  --disabled-text: #aaa;
  --text: #fff;
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  font-family: 'Arial', sans-serif;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  padding: 80px 16px 60px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: var(--text);
  text-align: center;
}

.site-logo {
  position: fixed;
  top: 10px;
  left: 10px;
  width: 60px;
  height: auto;
  z-index: 9999;
}

#counter {
  font-size: 3rem;
  margin-bottom: 50px;
}

#clickButton {
  font-size: 2rem;
  background-color: var(--accent);
  color: white;
  padding: 20px 40px;
  border: none;
  border-radius: 50px;
  margin-bottom: 50px;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.2s ease;
}

#clickButton:active {
  transform: scale(0.95);
}

#upgrades {
  display: flex;
  flex-direction: column;
  gap: 15px;
  width: 250px;
}

#upgrades button {
  font-size: 1.25rem;
  padding: 15px 25px;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  margin: 0;
  transition: opacity 0.2s ease;
}

#upgrades button.enabled {
  background-color: var(--success);
  color: white;
}

#upgrades button.disabled {
  background-color: var(--disabled-bg);
  color: var(--disabled-text);
  cursor: not-allowed;
}

footer {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  z-index: 9999;
  text-align: center;
  font-size: 14px;
  color: gray;
  background: white;
  padding: 4px 0;
}

@media (max-width: 500px) {
  #clickButton {
    width: 80%;
  }

  #upgrades {
    width: 90%;
  }
}