:root {
  --font-sans: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", -apple-system,
    BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;

  --color-bg: #f5f6fa;
  --color-card: #ffffff;
  --color-border: #e4e6ec;
  --color-text: #24262b;
  --color-text-muted: #5c6270;

  --color-assistant: #6c5ce7;
  --color-assistant-bg: #f2effd;
  --color-assistant-dark: #5a4bd1;

  --color-generate: #ff7a59;
  --color-generate-bg: #fff1ec;
  --color-generate-dark: #ea6647;

  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 4px 16px rgba(20, 20, 40, 0.07);
  --shadow-hover: 0 8px 22px rgba(20, 20, 40, 0.1);
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.app-header {
  text-align: center;
  padding: 48px 20px 32px;
}

.app-header__icon {
  display: inline-block;
  font-size: 1.6rem;
  margin-right: 8px;
  transform: translateY(2px);
}

.app-header h1 {
  margin: 0;
  display: inline-block;
  font-size: 2.1rem;
  font-weight: 800;
  letter-spacing: 0.01em;
  background: linear-gradient(90deg, var(--color-assistant), var(--color-generate));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.app-header__sub {
  margin: 10px 0 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

@media (max-width: 480px) {
  .app-header {
    padding: 36px 20px 24px;
  }

  .app-header h1 {
    font-size: 1.6rem;
  }
}

.main-grid {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px 64px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 900px) {
  .main-grid {
    grid-template-columns: 1fr;
    padding: 0 16px 48px;
    gap: 20px;
  }
}

.panel {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
  position: relative;
}

@media (max-width: 480px) {
  .panel {
    padding: 22px 18px;
  }
}

.panel--assistant {
  border-top: 4px solid var(--color-assistant);
}

.panel--generate {
  border-top: 4px solid var(--color-generate);
}

.panel__badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--color-assistant-bg);
  color: var(--color-assistant-dark);
  margin-bottom: 12px;
}

.panel__badge--generate {
  background: var(--color-generate-bg);
  color: var(--color-generate-dark);
}

.panel__title {
  margin: 0 0 8px;
  font-size: 1.3rem;
  font-weight: 700;
}

.panel__desc {
  margin: 0 0 24px;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form__row {
  display: flex;
  gap: 16px;
}

@media (max-width: 480px) {
  .form__row {
    flex-direction: column;
  }
}

.form__group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form__group--half {
  flex: 1;
}

.form__label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text);
}

.form__select,
.form__textarea {
  width: 100%;
  min-height: 46px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-size: 0.92rem;
  font-family: inherit;
  background: #fafbfc;
  color: var(--color-text);
  resize: vertical;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.form__select {
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='none' stroke='%236b7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 7l5 5 5-5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  background-size: 16px;
  padding-right: 40px;
  cursor: pointer;
}

.form__textarea {
  line-height: 1.6;
}

.form__select:focus,
.form__textarea:focus {
  outline: none;
  border-color: var(--color-assistant);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.14);
}

.panel--generate .form__select:focus,
.panel--generate .form__textarea:focus {
  border-color: var(--color-generate);
  box-shadow: 0 0 0 3px rgba(255, 122, 89, 0.14);
}

.upload-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 2px dashed var(--color-border);
  border-radius: 12px;
  padding: 32px 18px;
  background: #fafbfc;
  cursor: pointer;
  text-align: center;
  transition: border-color 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
}

.upload-box:hover {
  border-color: var(--color-assistant);
  background: var(--color-assistant-bg);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.1);
}

.upload-box__icon {
  font-size: 1.9rem;
}

.upload-box__text {
  font-size: 0.9rem;
  font-weight: 600;
}

.upload-box__hint {
  font-size: 0.76rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

.btn {
  border: none;
  border-radius: var(--radius-sm);
  min-height: 50px;
  padding: 14px 22px;
  font-size: 0.96rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: #fff;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.15s ease, opacity 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
  opacity: 0.95;
}

.btn:active {
  transform: translateY(0);
}

.btn:focus-visible,
.upload-box:focus-visible {
  outline: 2px solid var(--color-assistant);
  outline-offset: 2px;
}

.btn--assistant {
  background: linear-gradient(90deg, var(--color-assistant), var(--color-assistant-dark));
  box-shadow: 0 4px 12px rgba(108, 92, 231, 0.3);
}

.btn--generate {
  background: linear-gradient(90deg, var(--color-generate), var(--color-generate-dark));
  box-shadow: 0 4px 12px rgba(255, 122, 89, 0.3);
}

.result-box {
  border-radius: var(--radius-sm);
  background: var(--color-assistant-bg);
  border: 1px solid #e1daf9;
  padding: 18px 20px;
}

.result-box__label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-assistant-dark);
  letter-spacing: 0.04em;
  margin-bottom: 10px;
}

.result-box__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--color-text);
  white-space: pre-line;
}

.result-box--loading {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-assistant-dark);
  font-size: 0.85rem;
  font-weight: 600;
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid #d9d0f7;
  border-top-color: var(--color-assistant);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

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

.result-box--error {
  background: #fdecec;
  border: 1px solid #f6c6c6;
}

.result-box--error .result-box__label {
  color: #b3261e;
}

.result-box--error .result-box__text {
  color: #b3261e;
  font-weight: 600;
}

.result-box--notice {
  background: var(--color-generate-bg);
  border: 1px solid #ffd9c8;
}

.result-box--notice .result-box__label {
  color: var(--color-generate-dark);
}

.result-box--notice .result-box__text {
  color: var(--color-generate-dark);
  font-weight: 600;
}

.panel__notice {
  margin: -12px 0 24px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  background: var(--color-generate-bg);
  border: 1px solid #ffd9c8;
  color: var(--color-generate-dark);
  font-size: 0.82rem;
  font-weight: 600;
  line-height: 1.6;
}

.preview-area__label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-generate-dark);
  letter-spacing: 0.04em;
  margin-bottom: 12px;
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 16px;
}

@media (max-width: 480px) {
  .preview-grid {
    grid-template-columns: 1fr;
  }
}

.preview-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: #fafbfc;
  display: flex;
  flex-direction: column;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.preview-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.preview-card__thumb {
  position: relative;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  text-align: center;
  padding: 12px;
  background:
    repeating-linear-gradient(45deg, #efe3dd, #efe3dd 8px, #f6ece7 8px, #f6ece7 16px);
}

.preview-card__thumb > .preview-card__thumb-icon,
.preview-card__thumb > .preview-card__thumb-text {
  transition: opacity 0.15s ease;
}

.preview-card__thumb--loaded > .preview-card__thumb-icon,
.preview-card__thumb--loaded > .preview-card__thumb-text,
.preview-card__thumb--error > .preview-card__thumb-icon,
.preview-card__thumb--error > .preview-card__thumb-text {
  display: none;
}

.preview-card__img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.preview-card__thumb--loaded .preview-card__img {
  opacity: 1;
}

.preview-card__thumb--error .preview-card__img {
  display: none;
}

.preview-card__thumb-fallback {
  display: none;
  position: absolute;
  inset: 0;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  text-align: center;
  padding: 12px;
  background: var(--color-card);
}

.preview-card__thumb--error .preview-card__thumb-fallback {
  display: flex;
}

.preview-card__thumb-icon {
  font-size: 1.6rem;
  opacity: 0.7;
}

.preview-card__thumb-text {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  font-weight: 600;
  line-height: 1.5;
}

.preview-card__body {
  padding: 12px 14px;
}

.preview-card__title {
  font-size: 0.86rem;
  font-weight: 700;
  margin: 0 0 4px;
}

.preview-card__meta {
  font-size: 0.76rem;
  color: var(--color-text-muted);
  margin: 0;
}

.preview-card__tag {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--color-generate-dark);
  background: var(--color-generate-bg);
  padding: 3px 9px;
  border-radius: 999px;
}

.app-footer {
  text-align: center;
  padding: 28px 16px 44px;
  margin-top: 8px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.8rem;
}