:root {
  --font-sans: "Inter", "Noto Sans JP", "Hiragino Sans", "Yu Gothic", "Segoe UI", system-ui, sans-serif;

  --color-bg: #f5f6fa;
  --color-surface: #ffffff;
  --color-border: #e4e6ee;
  --color-text: #1f2430;
  --color-text-muted: #6b7280;

  --color-assistant: #4f6df5;
  --color-assistant-bg: #eef1ff;
  --color-generate: #e0479e;
  --color-generate-bg: #fdeef8;

  --radius-lg: 20px;
  --radius-md: 14px;
  --shadow-card: 0 6px 24px rgba(20, 24, 40, 0.07);
  --shadow-card-hover: 0 10px 32px rgba(20, 24, 40, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: linear-gradient(180deg, #fafbff 0%, #f2f3f9 100%) fixed;
  color: var(--color-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a,
button,
input,
select,
textarea,
[tabindex] {
  -webkit-tap-highlight-color: transparent;
}

.btn:focus-visible,
.select-input:focus-visible,
.text-input:focus-visible,
.dropzone:focus-visible {
  outline: 3px solid var(--color-assistant);
  outline-offset: 2px;
}

.panel--generate .btn:focus-visible {
  outline-color: var(--color-generate);
}

/* ---------- Header ---------- */
.app-header {
  background: var(--color-surface);
  box-shadow: 0 1px 0 rgba(20, 24, 40, 0.05), 0 6px 20px rgba(20, 24, 40, 0.03);
  position: sticky;
  top: 0;
  z-index: 10;
}

.app-header__inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.app-logo {
  flex: none;
  width: 40px;
  height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  background: var(--color-assistant-bg);
  border-radius: 12px;
}

.app-title {
  font-size: clamp(1.05rem, 1rem + 0.5vw, 1.3rem);
  font-weight: 800;
  margin: 0;
  letter-spacing: -0.01em;
}

/* ---------- Layout ---------- */
.main-grid {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 24px 72px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}

@media (max-width: 899px) {
  .main-grid {
    grid-template-columns: 1fr;
    padding: 24px 16px 56px;
    gap: 20px;
  }
}

/* ---------- Panel (card) ---------- */
.panel {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: 32px;
  border-top: 5px solid transparent;
}

@media (max-width: 520px) {
  .panel {
    padding: 24px 20px;
  }
}

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

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

.panel__badge {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 700;
  padding: 5px 14px;
  border-radius: 999px;
  margin-bottom: 14px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

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

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

.panel__title {
  font-size: clamp(1.15rem, 1rem + 0.6vw, 1.4rem);
  margin: 0 0 10px;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.35;
}

.panel__desc {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--color-text-muted);
  margin: 0 0 28px;
}

/* ---------- Fields ---------- */
.field {
  margin-bottom: 22px;
}

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

@media (max-width: 520px) {
  .field-row {
    grid-template-columns: 1fr;
  }
}

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

.select-input,
.text-input {
  width: 100%;
  min-height: 48px;
  padding: 13px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  font-size: 15px;
  font-family: inherit;
  color: var(--color-text);
  resize: vertical;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.select-input:focus,
.text-input:focus {
  outline: none;
  border-color: var(--color-assistant);
  box-shadow: 0 0 0 3px var(--color-assistant-bg);
}

.panel--generate .select-input:focus,
.panel--generate .text-input:focus {
  border-color: var(--color-generate);
  box-shadow: 0 0 0 3px var(--color-generate-bg);
}

/* ---------- Dropzone ---------- */
.dropzone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 8px;
  padding: 32px 16px;
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
}

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

.dropzone__icon {
  font-size: 28px;
}

.dropzone__text {
  font-size: 14px;
  font-weight: 600;
}

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

.preview-thumb {
  margin-top: 12px;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  max-width: 220px;
}

.preview-thumb img {
  display: block;
  width: 100%;
  height: auto;
}

/* ---------- Buttons ---------- */
.btn {
  width: 100%;
  min-height: 52px;
  padding: 14px 20px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 15.5px;
  font-weight: 700;
  font-family: inherit;
  letter-spacing: 0.01em;
  color: #fff;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(20, 24, 40, 0.08);
  transition: transform 0.1s ease, box-shadow 0.15s ease, opacity 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-card-hover);
}

.btn:active {
  transform: translateY(0);
  opacity: 0.9;
}

.btn:disabled {
  cursor: not-allowed;
  opacity: 0.7;
  transform: none;
}

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

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

/* ---------- Result box (assistant) ---------- */
.result-box {
  margin-top: 22px;
  padding: 20px 22px;
  background: var(--color-assistant-bg);
  border: 1px solid #d8deff;
  border-radius: var(--radius-md);
  transition: opacity 0.2s ease;
}

.result-box__label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 700;
  color: var(--color-assistant);
  margin-bottom: 10px;
  letter-spacing: 0.02em;
}

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

.result-box__text {
  font-size: 14.5px;
  line-height: 1.75;
  margin: 0;
  color: var(--color-text);
  white-space: pre-line;
}

/* ---------- Error box ---------- */
.error-box {
  margin-top: 16px;
  padding: 14px 18px;
  background: #fdeceb;
  border: 1px solid #f3b7b0;
  border-radius: var(--radius-md);
  color: #b3261e;
  font-size: 13.5px;
  font-weight: 600;
  line-height: 1.6;
}

/* ---------- Preview area (generate) ---------- */
.preview-area {
  margin-top: 24px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

@media (max-width: 899px) {
  .preview-area {
    grid-template-columns: 1fr;
  }
}

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

.preview-card__thumb {
  aspect-ratio: 3 / 4;
  background: repeating-linear-gradient(
    45deg,
    var(--color-generate-bg),
    var(--color-generate-bg) 10px,
    #fff 10px,
    #fff 20px
  );
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: var(--color-generate);
  text-align: center;
  padding: 12px;
}

.preview-card__thumb-icon {
  font-size: 30px;
  opacity: 0.7;
}

.preview-card__thumb-label {
  font-size: 12px;
  font-weight: 700;
}

.preview-card__thumb-sub {
  font-size: 11px;
  color: var(--color-text-muted);
  padding: 0 8px;
}

.preview-card__thumb--image {
  background: #000;
  padding: 0;
}

.preview-card__thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.preview-card__thumb-icon.is-spinning {
  display: inline-block;
  animation: spin 1.2s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.preview-card__info {
  padding: 14px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13.5px;
  background: var(--color-surface);
}

.preview-card__page {
  font-weight: 700;
}

.preview-card__panels {
  font-size: 12px;
  color: var(--color-generate);
  background: var(--color-generate-bg);
  padding: 3px 10px;
  border-radius: 999px;
  font-weight: 600;
}

/* ---------- Footer ---------- */
.app-footer {
  text-align: center;
  font-size: 12.5px;
  color: var(--color-text-muted);
  padding: 28px 16px 36px;
}