:root {
  --primary-color: #4CAF50;
  --bg-color: #f4f7f6;
  --container-bg: #ffffff;
  --text-color: #333;
  --h1-color: #2c3e50;
  --ball-size: 50px;
  --shadow-color: rgba(0,0,0,0.1);
  --placeholder-color: #95a5a6;
}

[data-theme="dark"] {
  --bg-color: #1a1a1a;
  --container-bg: #2d2d2d;
  --text-color: #e0e0e0;
  --h1-color: #ffffff;
  --shadow-color: rgba(0,0,0,0.4);
  --placeholder-color: #7f8c8d;
}

body {
  font-family: 'Noto Sans KR', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 100vh;
  padding: 2rem 0;
  margin: 0;
  transition: background-color 0.3s, color 0.3s;
}

.container {
  background: var(--container-bg);
  padding: 2.5rem;
  border-radius: 20px;
  box-shadow: 0 10px 30px var(--shadow-color);
  text-align: center;
  max-width: 450px;
  width: 90%;
  position: relative;
  transition: background-color 0.3s, box-shadow 0.3s;
}

.theme-toggle {
  position: absolute;
  top: 15px;
  right: 15px;
}

#theme-btn {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 5px;
  box-shadow: none;
  transition: transform 0.2s;
}

#theme-btn:hover {
  transform: scale(1.1);
  background: none;
}

h1 {
  margin-top: 0;
  color: var(--h1-color);
  font-size: 1.8rem;
}

#lotto-container {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin: 2rem 0;
  min-height: var(--ball-size);
  flex-wrap: wrap;
}

.placeholder {
  color: var(--placeholder-color);
  font-style: italic;
}

.ball {
  width: var(--ball-size);
  height: var(--ball-size);
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  font-size: 1.2rem;
  color: white;
  box-shadow: 0 4px 6px rgba(0,0,0,0.15);
  animation: pop 0.4s ease-out forwards;
  text-shadow: 1px 1px 2px rgba(0,0,0,0.3);
}

@keyframes pop {
  0% { transform: scale(0); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

/* 로또 공 색상 규정 */
.color-1-10 { background-color: #fbc02d; }
.color-11-20 { background-color: #1976d2; }
.color-21-30 { background-color: #e53935; }
.color-31-40 { background-color: #757575; }
.color-41-45 { background-color: #43a047; }

#generate-btn {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 12px 30px;
  font-size: 1.1rem;
  font-weight: 700;
  border-radius: 30px;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: 0 4px 6px rgba(76, 175, 80, 0.3);
}

#generate-btn:hover {
  background-color: #45a049;
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(76, 175, 80, 0.4);
}

#generate-btn:active {
  transform: translateY(0);
}

/* 제휴 문의 섹션 스타일 */
.contact-section {
  margin-top: 2rem;
  text-align: left;
}

hr {
  border: none;
  border-top: 1px solid var(--shadow-color);
  margin: 1.5rem 0;
}

h3 {
  color: var(--h1-color);
  font-size: 1.2rem;
  margin-bottom: 1rem;
  text-align: center;
}

.input-group {
  margin-bottom: 0.8rem;
}

input, textarea {
  width: 100%;
  padding: 10px;
  border: 1px solid var(--placeholder-color);
  border-radius: 8px;
  background-color: var(--container-bg);
  color: var(--text-color);
  font-family: inherit;
  box-sizing: border-box;
  transition: border-color 0.2s;
}

input:focus, textarea:focus {
  outline: none;
  border-color: var(--primary-color);
}

textarea {
  height: 80px;
  resize: none;
}

.submit-btn {
  width: 100%;
  background-color: #34495e;
  color: white;
  border: none;
  padding: 10px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 700;
  transition: background-color 0.2s;
}

[data-theme="dark"] .submit-btn {
  background-color: #4a627a;
}

.submit-btn:hover {
  background-color: #2c3e50;
}

.form-hint {
  font-size: 0.75rem;
  color: var(--placeholder-color);
  margin-top: 0.5rem;
  text-align: center;
}