:root {
  --color-bg: #f3f4f9;
  --color-surface: #ffffff;
  --color-border: #e5e7ee;
  --color-text: #1c2029;
  --color-text-sub: #6b7180;

  --color-assistant: #6c5ce7;
  --color-assistant-bg: #f2effd;
  --color-assistant-dark: #5a48d6;

  --color-generate: #00b894;
  --color-generate-bg: #e9fbf5;
  --color-generate-dark: #049d7d;

  --radius-lg: 20px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --shadow-card: 0 1px 2px rgba(20, 20, 40, 0.04), 0 8px 24px rgba(20, 20, 40, 0.07);
  --shadow-btn: 0 6px 16px rgba(20, 20, 40, 0.12);

  --font-base: "Inter", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: linear-gradient(180deg, #f7f8fc 0%, #eef0f6 100%);
  background-attachment: fixed;
  color: var(--color-text);
  font-family: var(--font-base);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Header ---------- */
.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  padding: 18px 24px;
}

.header-inner {
  max-width: 1160px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-mark {
  font-size: 26px;
}

.app-header h1 {
  font-size: 20px;
  font-weight: 800;
  margin: 0;
  letter-spacing: -0.01em;
}

/* ---------- Layout ---------- */
.main-layout {
  max-width: 1160px;
  margin: 0 auto;
  padding: 36px 24px 72px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
  align-items: start;
}

@media (max-width: 900px) {
  .main-layout {
    grid-template-columns: 1fr;
    gap: 20px;
    padding: 24px 16px 56px;
  }
}

/* ---------- Panel (card) ---------- */
.panel {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  border-top: 4px solid transparent;
  overflow: hidden;
  transition: box-shadow 0.2s ease;
}

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

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

.panel-header {
  padding: 28px 28px 6px;
}

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

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

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

.panel-header h2 {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
}

.panel-desc {
  font-size: 13.5px;
  color: var(--color-text-sub);
  line-height: 1.7;
  margin: 0 0 4px;
}

.panel-body {
  padding: 20px 28px 32px;
}

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

.field-row {
  display: flex;
  gap: 14px;
}

.field-half {
  flex: 1;
  min-width: 0;
}

.field-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 6px;
}

.select-input,
.textarea-input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 14.5px;
  font-family: inherit;
  color: var(--color-text);
  background: #fbfbfd;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.select-input {
  min-height: 46px;
}

.select-input:focus,
.textarea-input:focus {
  outline: none;
  border-color: var(--color-assistant);
  background: #fff;
  box-shadow: 0 0 0 4px var(--color-assistant-bg);
}

.panel-generate .select-input:focus,
.panel-generate .textarea-input:focus {
  border-color: var(--color-generate);
  box-shadow: 0 0 0 4px var(--color-generate-bg);
}

.textarea-input {
  resize: vertical;
  line-height: 1.6;
}

.textarea-input.has-error {
  border-color: #d6423c;
}

.field-error {
  margin: 6px 0 0;
  font-size: 12.5px;
  color: #b3261e;
  font-weight: 600;
}

/* ---------- Upload box ---------- */
.upload-box {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 16px;
  text-align: center;
  cursor: pointer;
  background: #fbfbfd;
  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: 30px;
  margin-bottom: 6px;
}

.upload-text {
  font-size: 13.5px;
  margin: 0 0 4px;
  color: var(--color-text);
}

.upload-sub {
  font-size: 12px;
  color: var(--color-text-sub);
  margin: 0;
}

.upload-preview {
  margin-top: 10px;
}

.file-chip {
  display: inline-block;
  font-size: 12.5px;
  background: var(--color-assistant-bg);
  color: var(--color-assistant-dark);
  padding: 5px 12px;
  border-radius: 999px;
}

.upload-note {
  font-size: 12px;
  color: var(--color-text-sub);
  margin: 8px 0 0;
}

/* ---------- Buttons ---------- */
.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 50px;
  padding: 13px 16px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 15.5px;
  font-weight: 700;
  font-family: inherit;
  color: #fff;
  cursor: pointer;
  box-shadow: var(--shadow-btn);
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, opacity 0.15s ease;
}

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

.btn:active {
  transform: translateY(0) scale(0.99);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

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

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

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

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

/* ---------- Result box ---------- */
.result-box {
  margin-top: 22px;
  background: var(--color-assistant-bg);
  border: 1px solid #e2dbfb;
  border-radius: var(--radius-md);
  padding: 18px 20px;
}

.result-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--color-text-sub);
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}

.result-text {
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--color-text);
  margin: 0;
  white-space: pre-wrap;
}

.result-box.is-loading .result-text {
  color: var(--color-text-sub);
}

.result-box.is-error {
  background: #fdecec;
  border-color: #f5c2c2;
}

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

.loading-dot {
  display: inline-block;
  animation: pulse 1.2s infinite ease-in-out;
}

@keyframes pulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 1; }
}

.notice-box {
  margin-top: 18px;
  background: #fff8e6;
  border: 1px solid #f3dca3;
  border-radius: var(--radius-md);
  padding: 16px 18px;
  font-size: 13px;
  line-height: 1.7;
  color: #8a6417;
}

/* ---------- Preview grid ---------- */
.preview-section {
  margin-top: 20px;
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 10px;
}

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

.preview-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: #fbfbfd;
  transition: box-shadow 0.15s ease, transform 0.15s ease;
}

.preview-card:hover {
  box-shadow: 0 6px 18px rgba(20, 20, 40, 0.08);
  transform: translateY(-2px);
}

.preview-thumb {
  aspect-ratio: 3 / 4;
  background: repeating-linear-gradient(
    45deg,
    #eef9f5,
    #eef9f5 10px,
    #e3f4ec 10px,
    #e3f4ec 20px
  );
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 6px;
  color: var(--color-generate-dark);
  text-align: center;
  padding: 12px;
}

.preview-thumb .icon {
  font-size: 26px;
}

.preview-thumb .caption {
  font-size: 12px;
  color: #4a5a54;
  line-height: 1.5;
}

.preview-meta {
  padding: 10px 12px;
  border-top: 1px solid var(--color-border);
}

.preview-meta .page-title {
  font-size: 13.5px;
  font-weight: 700;
  margin: 0 0 2px;
}

.preview-meta .page-sub {
  font-size: 12px;
  color: var(--color-text-sub);
  margin: 0;
}

.preview-meta .page-flag {
  display: inline-block;
  margin-top: 6px;
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: #8a6417;
  background: #fff3d6;
  padding: 2px 8px;
  border-radius: 999px;
}

/* ---------- Footer ---------- */
.app-footer {
  text-align: center;
  padding: 24px 20px 32px;
  color: var(--color-text-sub);
  font-size: 12px;
}