:root {
  --blue-700: #1e40af;
  --white: #ffffff;
  --gray-50: #f8fafc;
  --gray-100: #eef2f7;
  --gray-300: #cbd5e1;
  --text-900: #0f172a;
  --text-700: #334155;
  --shadow: 0 8px 20px rgba(2, 6, 23, 0.08);
  --radius: 14px;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--text-900);
  background: var(--gray-50);
}

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

.app-header {
  background: var(--white);
  border-bottom: 1px solid var(--gray-100);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--blue-700);
  color: var(--white);
  font-weight: 700;
}

.brand-text {
  font-weight: 700;
  letter-spacing: 0.2px;
}

.main-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 24px;
  padding: 24px 0;
}

.card {
  background: var(--white);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.form-card {
  padding: 20px;
}

.section-title {
  margin: 0 0 16px;
  font-size: 20px;
  color: var(--blue-700);
}

.subsection-title {
  margin: 16px 0 8px;
  font-size: 16px;
  color: var(--text-700);
}

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

.form-grid.thirds {
  grid-template-columns: repeat(3, 1fr);
}

.form-row {
  display: flex;
  align-items: center;
  gap: 16px;
}

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

label {
  font-size: 13px;
  color: var(--text-700);
}

input[type="text"],
input[type="number"],
input[type="file"],
textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--gray-300);
  border-radius: 10px;
  outline: none;
  font-size: 14px;
  color: var(--text-900);
  background: var(--white);
}

input[type="file"] {
  padding: 8px;
}

textarea {
  resize: vertical;
}

.checkbox {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
}

.divider {
  height: 1px;
  background: var(--gray-100);
  margin: 12px 0 16px;
}

.logo-preview {
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: flex-start;
}

.logo-preview img {
  height: 48px;
  width: auto;
  border-radius: 8px;
  border: 1px solid var(--gray-100);
  display: none;
}

.status {
  margin-top: 16px;
  padding: 10px 12px;
  border: 1px solid var(--gray-100);
  border-radius: 10px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.status.hidden {
  display: none;
}

.spinner {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid var(--gray-300);
  border-top-color: var(--blue-700);
  animation: spin 1s linear infinite;
}

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

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

.preview-header {
  padding: 16px;
  background: linear-gradient(90deg, var(--blue-700), #2b55ce);
  color: var(--white);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.preview-title {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
}

.preview-body {
  padding: 0;
  overflow-y: auto;
  max-height: calc(100vh - 200px);
}

.paper-preview {
  font-family: Arial, "Microsoft JhengHei", sans-serif;
  font-size: 14px;
  line-height: 1.6;
  padding: 20px;
  background: #ffffff;
}

.paper-preview h1 {
  font-size: 20px;
  font-weight: bold;
  text-align: center;
  margin: 0 0 20px 0;
}

.paper-preview h2 {
  font-size: 16px;
  font-weight: bold;
  background: #1e40af;
  color: white;
  padding: 8px 12px;
  margin: 20px 0 12px 0;
}

.paper-preview ol {
  margin: 0;
  padding-left: 25px;
}

.paper-preview li {
  margin-bottom: 16px;
}

.paper-preview ul {
  list-style-type: none;
  padding-left: 20px;
  margin: 8px 0;
}

.paper-preview ul li {
  margin: 4px 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 38px;
  padding: 0 16px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: var(--gray-100);
  color: var(--text-900);
  font-weight: 600;
  cursor: pointer;
}

.btn-primary {
  background: var(--blue-700);
  color: var(--white);
}

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

.app-footer {
  margin-top: 24px;
  border-top: 1px solid var(--gray-100);
  background: var(--white);
}

.footer-inner {
  padding: 16px 0;
  font-size: 13px;
  color: var(--text-700);
}

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

  .form-grid {
    grid-template-columns: 1fr;
  }

  .form-grid.thirds {
    grid-template-columns: 1fr;
  }
}