:root {
  --primary-color: #4CAF50;
  --primary-dark: #388E3C;
  --danger-color: #F44336;
  --danger-dark: #D32F2F;
  --bg-color: #F5F5F5;
  --text-color: #333333;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  touch-action: manipulation; /* ダブルタップズーム防止など */
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  background-color: #ffffff;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

#header-logo {
  height: 40px;
  object-fit: contain;
}

#settings-btn {
  font-size: 1.5rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

main {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 1rem;
}

.character-container {
  text-align: center;
  margin-bottom: 2rem;
}

#kappa-img {
  width: 150px;
  height: 150px;
  object-fit: contain;
  transition: transform 0.3s ease;
}

#kappa-img.happy {
  animation: bounce 0.5s ease infinite alternate;
}

@keyframes bounce {
  from { transform: translateY(0); }
  to { transform: translateY(-20px); }
}

#status-message {
  font-size: 1.5rem;
  font-weight: bold;
  margin-top: 1rem;
  min-height: 2.5rem;
}

.main-action {
  display: flex;
  justify-content: center;
  width: 100%;
}

.giant-btn {
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background-color: var(--primary-color);
  color: white;
  font-size: 3.5rem;
  font-weight: bold;
  border: none;
  box-shadow: 0 8px 16px rgba(0,0,0,0.2), inset 0 -8px 0 rgba(0,0,0,0.1);
  cursor: pointer;
  transition: transform 0.1s, box-shadow 0.1s;
  display: flex;
  justify-content: center;
  align-items: center;
  user-select: none;
}

.giant-btn:active {
  transform: translateY(8px);
  box-shadow: 0 0px 0px rgba(0,0,0,0.2), inset 0 -4px 0 rgba(0,0,0,0.1);
}

.giant-btn:disabled {
  background-color: #BDBDBD;
  box-shadow: none;
  transform: none;
  cursor: not-allowed;
}

footer {
  padding: 1rem;
  display: flex;
  justify-content: center;
  background-color: #ffffff;
  box-shadow: 0 -2px 4px rgba(0,0,0,0.1);
}

.danger-btn {
  width: 100%;
  max-width: 400px;
  padding: 1.5rem;
  background-color: var(--danger-color);
  color: white;
  font-size: 2rem;
  font-weight: bold;
  border: none;
  border-radius: 12px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  cursor: pointer;
}

.danger-btn:active {
  background-color: var(--danger-dark);
  transform: translateY(2px);
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

/* Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.modal.hidden {
  display: none;
}

.modal-content {
  background-color: white;
  padding: 2rem;
  border-radius: 12px;
  width: 90%;
  max-width: 400px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}

.modal-content h2 {
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
  text-align: center;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 0.5rem;
}

.form-group input {
  width: 100%;
  padding: 0.8rem;
  font-size: 1.2rem;
  border: 2px solid #ccc;
  border-radius: 8px;
}

.modal-actions {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
}

.modal-actions button {
  flex: 1;
  padding: 1rem;
  font-size: 1.2rem;
  font-weight: bold;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

.primary-btn {
  background-color: var(--primary-color);
  color: white;
}

.secondary-btn {
  background-color: #E0E0E0;
  color: #333;
}

/* TOS Modal Styles */
.tos-content {
  max-width: 500px;
}

.tos-text {
  max-height: 40vh;
  overflow-y: auto;
  background: #f9f9f9;
  padding: 1rem;
  border: 1px solid #ddd;
  border-radius: 8px;
  font-size: 0.95rem;
  line-height: 1.5;
  margin-bottom: 1.5rem;
  text-align: left;
}

.tos-text h3 {
  font-size: 1.1rem;
  margin-top: 1rem;
  margin-bottom: 0.5rem;
}

.tos-text p {
  margin-bottom: 0.5rem;
}

.tos-agree-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
  justify-content: center;
}

.tos-agree-group input[type="checkbox"] {
  width: 24px;
  height: 24px;
  cursor: pointer;
}

.tos-agree-group label {
  font-size: 1.1rem;
  font-weight: bold;
  cursor: pointer;
}

#tos-start-btn:disabled {
  background-color: #BDBDBD;
  cursor: not-allowed;
}