:root {
  --primary-color: #6a7eff;
  --primary-hover-color: #8c9eff;
  --background-color: #1a1b26;
  --card-background-color: #24283b;
  --text-color: #c0caf5;
  --border-color: #414868;

  font-family: 'Inter', 'Noto Sans JP', sans-serif;
  line-height: 1.6;
  font-weight: 400;
  color-scheme: light dark;
  color: var(--text-color);
  background-color: var(--background-color);

  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  overflow-x: hidden;
}

#app {
  width: 100%;
  max-width: 640px;
  margin: 0 auto;
  padding: 0 1rem;
  text-align: center;
}

.app-header {
  background-color: var(--background-color);
  padding: 2rem 1rem;
  position: sticky;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  border-bottom: 1px solid var(--border-color);
}

.app-main {
  padding-top: 1rem;
  padding-bottom: 2rem;
}

h1 {
  font-family: 'M PLUS Rounded 1c', 'Inter', 'Noto Sans JP', sans-serif;
  font-size: 2.5em;
  font-weight: 800;
  color: var(--primary-color);
  margin-bottom: 0.5em;
  letter-spacing: 0.05em;
}

p {
  color: #a9b1d6;
  font-size: 1.1em;
}

.card {
  padding: 2em;
  border-radius: 12px;
  background-color: var(--card-background-color);
  border: 1px solid var(--border-color);
  margin-top: 2em;
  text-align: left;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

textarea {
  box-sizing: border-box;
  width: 100%;
  padding: 0.8em;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background-color: #1e2133;
  color: var(--text-color);
  font-family: inherit;
  font-size: 16px;
  margin-bottom: 1.5em;
  resize: vertical;
  transition: border-color 0.3s, box-shadow 0.3s;
}

textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(106, 126, 255, 0.3);
}

#generate-btn {
  border-radius: 8px;
  border: 1px solid transparent;
  padding: 0.8em 1.5em;
  font-size: 1.1em;
  font-weight: 500;
  font-family: inherit;
  background-color: var(--primary-color);
  color: #fff;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
  display: block;
  width: 100%;
  margin-top: 1em;
}

#generate-btn:hover {
  background-color: var(--primary-hover-color);
  transform: translateY(-2px);
}

#result-area h2 {
    font-size: 1.2em;
    font-weight: 500;
    color: #a9b1d6;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5em;
    margin-bottom: 1em;
}

#result-area h3 {
  margin-top: 0;
  color: var(--primary-color);
  font-size: 2em;
  font-weight: 640;
}

#result-area p {
  font-size: 1.2em;
  color: var(--text-color);
  margin-top: 0.5em;
}

h4 {
  font-size: 1.1em;
  font-weight: 500;
  color: #a9b1d6;
  margin-bottom: 1em;
  margin-top: 2em;
}

#member-selection-area {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.member-button {
  background-color: #2a2f4a;
  border: 1px solid var(--border-color);
  color: var(--text-color);
  padding: 8px 14px;
  border-radius: 20px;
  cursor: pointer;
  font-family: inherit;
  font-size: 16px;
  transition: background-color 0.2s, border-color 0.2s, color 0.2s;
}

.member-button:hover {
  background-color: #3b426e;
}

.member-button.selected {
  background-color: var(--primary-color);
  color: #fff;
  border-color: var(--primary-color);
}

#loading {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2em 0;
}

.spinner {
  border: 4px solid rgba(255, 255, 255, 0.2);
  border-left-color: var(--primary-color);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

#error {
  background-color: #581b2d;
  color: #ff757f;
  padding: 1em;
  border-radius: 8px;
  border: 1px solid #ff757f;
  margin: 1em 0;
}

.hidden {
  display: none !important;
}

/* Responsive styles for mobile */
@media (max-width: 640px) {
  .app-header {
    padding: 1rem;
  }

  h1 {
    font-size: 2em;
  }

  .card {
    padding: 1.5em;
  }
}

input, select, textarea, button {
  font-size: 16px;
}

/* Styles for the button loading state */
#generate-btn.generating {
  cursor: wait;
  background-color: var(--primary-hover-color);
}

#generate-btn .spinner-inline {
  display: none; /* Hidden by default */
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-left-color: #fff;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  animation: spin 1s linear infinite;
  vertical-align: middle;
}

#generate-btn.generating .spinner-inline {
  display: inline-block;
}

#generate-btn.generating .btn-text {
  display: none;
}

.line-share-button {
  display: inline-block;
  text-decoration: none;
  background-color: #06C755;
  color: white;
  padding: 0.8em 1.5em;
  border-radius: 8px;
  font-weight: 500;
  margin-top: 1.5em;
  text-align: center;
  transition: background-color 0.3s, transform 0.2s;
}

.line-share-button:hover {
  background-color: #07dd5e;
  transform: translateY(-2px);
}

/* Styles for History/Results List */
#results-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem; /* Space between history items */
}

.result-item {
  background-color: #2a2f4a;
  padding: 1.5rem;
  border-radius: 10px;
  border: 1px solid var(--border-color);
  transition: transform 0.2s ease-out, box-shadow 0.2s ease-out;
  text-align: left;
}

.result-item:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

/* Style for the most recent result */
.result-item.latest {
  border-color: var(--primary-color);
  box-shadow: 0 0 15px rgba(106, 126, 255, 0.2);
  animation: popup 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}

@keyframes popup {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.result-item h3 {
  margin-top: 0;
  color: var(--primary-color);
  font-size: 1.75em;
  font-weight: 600;
}

.result-item p {
  font-size: 1.1em;
  color: var(--text-color);
  margin-top: 0.5em;
  margin-bottom: 0;
}