:root {
  --color-bg: #f5f6fa;
  --color-surface: #ffffff;
  --color-border: #e3e5ec;
  --color-text: #2b2d3a;
  --color-text-muted: #6b6f80;

  --color-assistant: #4c6ef5;
  --color-assistant-bg: #eef1ff;
  --color-assistant-dark: #364fc7;

  --color-generate: #ff922b;
  --color-generate-bg: #fff4e8;
  --color-generate-dark: #e8590c;

  --radius-lg: 16px;
  --radius-md: 10px;
  --shadow-card: 0 2px 10px rgba(30, 34, 60, 0.06);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Hiragino Sans", "Yu Gothic UI", "Segoe UI", "Noto Sans JP", sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
}

/* Header */
.app-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.app-header__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 18px 24px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.app-header__logo {
  font-size: 26px;
}

.app-header__title {
  font-size: 20px;
  font-weight: 700;
  margin: 0;
  letter-spacing: 0.02em;
}

/* Main layout */
.main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 24px 64px;
}

.main__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 900px) {
  .main__grid {
    grid-template-columns: 1fr;
  }
}

/* Panel */
.panel {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-card);
  padding: 28px;
  position: relative;
  border-top: 4px solid transparent;
}

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

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

.panel__badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 12px;
}

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

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

.panel__title {
  font-size: 19px;
  font-weight: 700;
  margin: 0 0 8px;
}

.panel__desc {
  font-size: 14px;
  color: var(--color-text-muted);
  margin: 0 0 24px;
}

/* Fields */
.field {
  margin-bottom: 20px;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

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

.field__label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--color-text);
}

.select,
.textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-family: inherit;
  background: #fafbfc;
  color: var(--color-text);
  resize: vertical;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.select:focus,
.textarea:focus {
  outline: none;
  border-color: var(--color-assistant);
  box-shadow: 0 0 0 3px rgba(76, 110, 245, 0.12);
  background: #fff;
}

.panel--generate .select:focus,
.panel--generate .textarea:focus {
  border-color: var(--color-generate);
  box-shadow: 0 0 0 3px rgba(255, 146, 43, 0.14);
}

/* Upload box */
.upload-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 16px;
  cursor: pointer;
  background: #fafbfc;
  text-align: center;
  transition: border-color 0.15s, background 0.15s;
}

.upload-box:hover {
  border-color: var(--color-assistant);
  background: var(--color-assistant-bg);
}

.upload-box__icon {
  font-size: 28px;
}

.upload-box__text {
  font-size: 13px;
  color: var(--color-text-muted);
}

.upload-box__preview {
  margin-top: 12px;
  max-width: 100%;
  max-height: 160px;
  border-radius: var(--radius-md);
  object-fit: contain;
}

/* Buttons */
.btn {
  width: 100%;
  border: none;
  border-radius: var(--radius-md);
  padding: 14px 20px;
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  cursor: pointer;
  transition: transform 0.08s, box-shadow 0.15s, opacity 0.15s;
}

.btn:hover {
  opacity: 0.92;
}

.btn:active {
  transform: translateY(1px);
}

.btn--assistant {
  background: linear-gradient(135deg, var(--color-assistant), var(--color-assistant-dark));
  box-shadow: 0 4px 14px rgba(76, 110, 245, 0.3);
}

.btn--generate {
  background: linear-gradient(135deg, var(--color-generate), var(--color-generate-dark));
  box-shadow: 0 4px 14px rgba(255, 146, 43, 0.3);
}

/* Field note */
.field-note {
  font-size: 12px;
  color: var(--color-text-muted);
  margin: -8px 0 16px;
}

/* Notice box (generate area guidance) */
.notice-box {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  background: #fff8ec;
  border: 1px solid #ffe1bd;
  border-radius: var(--radius-md);
  padding: 12px 14px;
  font-size: 13px;
  color: #7a4a12;
  margin-bottom: 20px;
}

.notice-box__icon {
  flex-shrink: 0;
}

.notice-box--response {
  opacity: 0;
  transform: translateY(6px);
  animation: fade-in 0.35s ease forwards;
  margin-top: 20px;
  margin-bottom: 0;
}

.notice-box--error {
  background: #fff2f0;
  border-color: #ffc9c2;
  color: #a02a10;
}

/* Result box (assistant) */
.result-box {
  margin-top: 20px;
  background: var(--color-assistant-bg);
  border: 1px solid #d6ddff;
  border-radius: var(--radius-md);
  padding: 18px;
  opacity: 0;
  transform: translateY(6px);
  animation: fade-in 0.4s ease forwards;
  animation-delay: 0.1s;
}

.result-box__label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 700;
  color: var(--color-assistant-dark);
  margin-bottom: 10px;
  letter-spacing: 0.03em;
}

.result-box__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-assistant);
  display: inline-block;
}

.result-box__dot--generate {
  background: var(--color-generate);
}

.result-box__text {
  font-size: 13.5px;
  color: var(--color-text);
  margin: 0;
  white-space: pre-wrap;
}

.result-box--idle {
  background: #f4f5fa;
  border-color: var(--color-border);
}

.result-box--idle .result-box__label {
  color: var(--color-text-muted);
}

.result-box--idle .result-box__dot {
  background: var(--color-text-muted);
}

.result-box--loading .result-box__text {
  color: var(--color-text-muted);
}

.result-box--error {
  background: #fff2f0;
  border-color: #ffc9c2;
}

.result-box--error .result-box__label {
  color: #c9391a;
}

.result-box--error .result-box__dot {
  background: #e8590c;
}

.result-box--error .result-box__text {
  color: #a02a10;
}

/* Loading dots */
.loading-dots::after {
  content: "";
  animation: loading-dots 1.2s steps(4, end) infinite;
}

@keyframes loading-dots {
  0% { content: ""; }
  25% { content: "."; }
  50% { content: ".."; }
  75% { content: "..."; }
  100% { content: ""; }
}

/* Button disabled state */
.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Preview area (generate) */
.preview-area {
  margin-top: 20px;
  opacity: 0;
  transform: translateY(6px);
  animation: fade-in 0.4s ease forwards;
  animation-delay: 0.1s;
}

.preview-area__label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 700;
  color: var(--color-generate-dark);
  margin-bottom: 10px;
  letter-spacing: 0.03em;
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

@media (max-width: 1100px) {
  .preview-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

.preview-card {
  background: var(--color-generate-bg);
  border: 1px solid #ffe1bd;
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.preview-card__thumb {
  background: #fff;
  border-bottom: 1px dashed #ffd7a8;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  font-size: 26px;
  color: #c98a4b;
  padding: 24px 8px;
  text-align: center;
}

.preview-card__body {
  padding: 12px 14px 16px;
}

.preview-card__title {
  font-weight: 700;
  font-size: 14px;
  margin-bottom: 4px;
}

.preview-card__meta {
  font-size: 12px;
  color: var(--color-generate-dark);
  background: #fff;
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  margin-bottom: 8px;
}

.preview-card__note {
  font-size: 12px;
  color: var(--color-text-muted);
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Footer */
.app-footer {
  text-align: center;
  font-size: 12px;
  color: var(--color-text-muted);
  padding: 20px;
}