:root {
  --color-bg: #f5f6fa;
  --color-surface: #ffffff;
  --color-border: #e4e6ee;
  --color-text: #23252b;
  --color-text-muted: #5c6273;

  --color-assistant: #7c5cff;
  --color-assistant-bg: #f4f1ff;
  --color-assistant-dark: #5c3dfa;

  --color-generate: #ff7a59;
  --color-generate-bg: #fff1ec;
  --color-generate-dark: #e85f3a;

  --radius-lg: 16px;
  --radius-md: 10px;
  --shadow-card: 0 2px 10px rgba(20, 20, 40, 0.06);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Segoe UI", -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

/* Header */
.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 14px 24px;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 14px;
}

.logo-chip {
  flex-shrink: 0;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  background: linear-gradient(135deg, var(--color-assistant), var(--color-generate));
  box-shadow: 0 4px 12px rgba(124, 92, 255, 0.25);
}

.header-titles {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.app-header h1 {
  font-size: 1.3rem;
  font-weight: 800;
  margin: 0;
  letter-spacing: -0.01em;
}

.header-subtitle {
  margin: 0;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* Layout */
.main-layout {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 24px 64px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  align-items: start;
}

@media (max-width: 900px) {
  .main-layout {
    grid-template-columns: 1fr;
    padding: 20px 16px 48px;
    gap: 24px;
  }
}

/* Panel */
.panel {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  padding: 24px;
  box-shadow: var(--shadow-card);
}

.panel-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 12px;
}

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

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

.panel h2 {
  margin: 0 0 8px;
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.panel-desc {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  margin: 0 0 20px;
}

/* Card (form container) — a top divider keeps the panel flat instead of stacking a box inside a box */
.card {
  padding-top: 22px;
  border-top: 1px solid var(--color-border);
}

.field { margin-bottom: 18px; }
.field:last-of-type { margin-bottom: 20px; }

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

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

label {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-text);
}

select, textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: var(--color-surface);
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--color-text);
  resize: vertical;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

select:focus, textarea:focus {
  outline: none;
  border-color: var(--color-assistant);
  box-shadow: 0 0 0 3px rgba(124, 92, 255, 0.15);
}

.panel-generate select:focus, .panel-generate textarea:focus {
  border-color: var(--color-generate);
  box-shadow: 0 0 0 3px rgba(255, 122, 89, 0.15);
}

textarea::placeholder { color: #9a9dab; }

/* 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;
  text-align: center;
  cursor: pointer;
  background: var(--color-surface);
  transition: border-color 0.15s ease, background 0.15s ease;
}

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

.upload-icon { font-size: 1.8rem; }
.upload-text { font-size: 0.88rem; font-weight: 600; }
.upload-sub { font-size: 0.76rem; color: var(--color-text-muted); }

/* Buttons */
.btn {
  display: block;
  width: 100%;
  padding: 14px 20px;
  border: none;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, opacity 0.15s ease;
}

.btn:hover { opacity: 0.96; transform: translateY(-1px); }
.btn:active { transform: translateY(0) scale(0.98); }

.btn:focus-visible {
  outline: 3px solid rgba(124, 92, 255, 0.4);
  outline-offset: 2px;
}

.btn-generate:focus-visible {
  outline-color: rgba(255, 122, 89, 0.4);
}

.btn-assistant {
  background: linear-gradient(135deg, var(--color-assistant), var(--color-assistant-dark));
  box-shadow: 0 4px 14px rgba(124, 92, 255, 0.35);
}

.btn-assistant:hover {
  box-shadow: 0 6px 20px rgba(124, 92, 255, 0.4);
}

.btn-generate {
  background: linear-gradient(135deg, var(--color-generate), var(--color-generate-dark));
  box-shadow: 0 4px 14px rgba(255, 122, 89, 0.35);
}

.btn-generate:hover {
  box-shadow: 0 6px 20px rgba(255, 122, 89, 0.4);
}

/* Result box */
.result-box {
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px dashed var(--color-border);
}

.result-label {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
  margin-bottom: 10px;
}

.result-text {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 18px;
  font-size: 0.95rem;
  margin: 0;
  white-space: pre-wrap;
  box-shadow: var(--shadow-card);
}

.result-error {
  color: #c0392b !important;
  background: #fdecea !important;
  border-color: #f5c6c0 !important;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

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

@media (max-width: 900px) {
  .preview-grid { grid-template-columns: repeat(2, 1fr); }
}

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

.preview-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 14px;
  text-align: center;
  box-shadow: var(--shadow-card);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.preview-card:has(.preview-img):hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(20, 20, 40, 0.12);
}

.preview-thumb {
  font-size: 2.1rem;
  background: linear-gradient(135deg, var(--color-generate-bg), #ffe3d6);
  border-radius: 8px;
  padding: 20px 0;
  margin-bottom: 10px;
}

.preview-title { font-weight: 700; font-size: 0.92rem; }
.preview-meta { font-size: 0.78rem; color: var(--color-text-muted); margin: 2px 0 8px; }
.preview-status {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--color-generate-dark);
  background: var(--color-generate-bg);
  display: inline-block;
  padding: 3px 8px;
  border-radius: 999px;
  margin-bottom: 8px;
}
.preview-placeholder {
  font-size: 0.76rem;
  color: var(--color-text-muted);
  border-top: 1px dashed var(--color-border);
  padding-top: 8px;
}

.preview-status-error {
  color: #c0392b;
  background: #fdecea;
}

.preview-img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  display: block;
}

.preview-thumb {
  padding: 0;
  overflow: hidden;
}

.preview-thumb:empty::before,
.preview-thumb:not(:has(img)) {
  padding: 20px 0;
}

/* Footer */
.app-footer {
  text-align: center;
  padding: 28px 20px;
  color: var(--color-text-muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--color-border);
}