:root {
  --bg-color: #f0f2f5;
  --container-bg: #ffffff;
  --text-primary: #1a73e8;
  --text-secondary: #5f6368;
  --btn-bg: #1a73e8;
  --btn-hover: #1557b0;
  --set-bg: #f8f9fa;
  --set-border: #e8eaed;
  --transition-speed: 0.3s;
}

[data-theme="dark"] {
  --bg-color: #121212;
  --container-bg: #1e1e1e;
  --text-primary: #8ab4f8;
  --text-secondary: #bdc1c6;
  --btn-bg: #8ab4f8;
  --btn-hover: #aecbfa;
  --set-bg: #2d2d2d;
  --set-border: #3c4043;
}

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
  background-color: var(--bg-color);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  transition: background-color var(--transition-speed);
}

.container {
  background: var(--container-bg);
  padding: 2rem;
  border-radius: 20px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  text-align: center;
  width: 90%;
  max-width: 500px;
  transition: background-color var(--transition-speed);
}

.theme-toggle {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 1rem;
}

#theme-btn {
  background: none;
  border: 1px solid var(--set-border);
  color: var(--text-secondary);
  padding: 8px 12px;
  font-size: 0.8rem;
  margin-bottom: 0;
}

h1 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  transition: color var(--transition-speed);
}

p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  transition: color var(--transition-speed);
}

button {
  background-color: var(--btn-bg);
  color: white;
  border: none;
  padding: 12px 24px;
  font-size: 1rem;
  font-weight: bold;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color var(--transition-speed), color var(--transition-speed);
  margin-bottom: 2rem;
}

[data-theme="dark"] button#generate-btn {
    color: #202124;
}

button:hover {
  background-color: var(--btn-hover);
}

.results-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.lotto-set {
  display: flex;
  justify-content: space-between;
  background: var(--set-bg);
  padding: 10px;
  border-radius: 12px;
  border: 1px solid var(--set-border);
  transition: background-color var(--transition-speed), border-color var(--transition-speed);
}

.ball {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  color: white;
  font-weight: bold;
  font-size: 0.9rem;
  box-shadow: inset -3px -3px 5px rgba(0,0,0,0.2);
}

/* 로또 번호대별 색상 */
.ball-1 { background-color: #fbc02d; } /* 1-10 yellow */
.ball-11 { background-color: #1976d2; } /* 11-20 blue */
.ball-21 { background-color: #d32f2f; } /* 21-30 red */
.ball-31 { background-color: #7b1fa2; } /* 31-40 purple */
.ball-41 { background-color: #388e3c; } /* 41-45 green */