:root {
  /* Light Theme */
  --bg-color: oklch(0.98 0.01 240);
  --text-color: oklch(0.2 0.01 240);
  --card-bg: oklch(1 0 0 / 0.8);
  --accent-color: oklch(0.6 0.2 250);
  --button-hover: oklch(0.5 0.2 250);
  --shadow: 0 10px 30px oklch(0 0 0 / 0.1);
  --ball-text: #fff;
}

[data-theme="dark"] {
  /* Dark Theme */
  --bg-color: oklch(0.15 0.02 240);
  --text-color: oklch(0.95 0.01 240);
  --card-bg: oklch(0.2 0.03 240 / 0.8);
  --accent-color: oklch(0.7 0.15 250);
  --button-hover: oklch(0.8 0.15 250);
  --shadow: 0 10px 30px oklch(0 0 0 / 0.3);
}

* {
  box-sizing: border-box;
  transition: background-color 0.3s ease, color 0.3s ease;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  background-color: var(--bg-color);
  color: var(--text-color);
  padding: 40px 20px;
}

#app {
  width: 100%;
  max-width: 500px;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

header {
  text-align: center;
  margin-bottom: 1rem;
}

header h1 {
  font-size: 2.2rem;
  font-weight: 900;
  letter-spacing: -0.04em;
  margin: 0;
  background: linear-gradient(135deg, var(--accent-color), oklch(0.7 0.2 330));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

header p {
  opacity: 0.6;
  font-weight: 500;
  margin-top: 0.5rem;
}

.theme-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  background: var(--card-bg);
  border: 1px solid var(--accent-color);
  color: var(--text-color);
  padding: 10px;
  border-radius: 50%;
  cursor: pointer;
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 45px;
  height: 45px;
  font-size: 1.2rem;
  z-index: 1000;
}