:root {
  --bg: #f6f9fc;
  --card: #ffffff;
  --primary: #1976d2;
  --primary-strong: #0f5aa5;
  --text: #1f2d3d;
  --muted: #5f6c80;
  --border: #d9e2ec;
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

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

.brand-logo {
  width: 46px;
  height: 46px;
  object-fit: contain;
}

.brand-title {
  font-weight: 700;
  font-size: 18px;
}

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

.ghost-btn {
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  border-radius: 10px;
  padding: 10px 14px;
  cursor: pointer;
  transition: transform 0.1s ease, box-shadow 0.15s ease;
  font-weight: 600;
}

.ghost-btn.small {
  padding: 6px 10px;
  font-size: 13px;
}

.ghost-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.06);
}

.lang-switch select {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  background: #fff;
  font-weight: 600;
}

.page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 32px 16px 48px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.hero {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
}

h1 {
  margin: 0 0 6px;
  font-size: 28px;
}

.hero p {
  margin: 0;
  color: var(--muted);
}

.hero-actions {
  display: flex;
  gap: 10px;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.04);
}

.card.info ol {
  margin: 8px 0 12px 16px;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}

.card-title {
  font-weight: 700;
}

.hint {
  color: var(--muted);
  font-size: 14px;
}

.dropzone {
  border: 1.5px dashed var(--border);
  border-radius: 12px;
  padding: 18px;
  display: flex;
  gap: 12px;
  align-items: center;
  cursor: pointer;
  background: #fdfefe;
  transition: border-color 0.15s ease, background 0.15s ease;
}

.dropzone:hover {
  border-color: var(--primary);
  background: #f1f6ff;
}

.dz-icon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  font-size: 20px;
  background: #e9f1ff;
  color: var(--primary);
  border-radius: 10px;
}

.dz-title {
  font-weight: 600;
}

.dz-sub {
  color: var(--muted);
  font-size: 14px;
}

.linklike {
  color: var(--primary);
  font-weight: 600;
}

.preview {
  margin-top: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.preview img {
  max-height: 180px;
  max-width: 100%;
  border-radius: 10px;
  border: 1px solid var(--border);
  object-fit: contain;
}

.action-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.primary-btn {
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 10px 16px;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}

.primary-btn:hover {
  background: var(--primary-strong);
  transform: translateY(-1px);
}

.checkbox {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  color: var(--muted);
}

textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px;
  font-size: 15px;
  resize: vertical;
  background: #fdfefe;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 14px;
}

.hidden {
  display: none;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

#status {
  min-height: 20px;
  color: var(--muted);
  font-size: 14px;
}

/* Upload card layout */
.upload-card {
  max-width: 960px;
  margin: 0 auto;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.06);
  overflow: hidden;
}

.upload-zone {
  text-align: center;
  border-bottom: 1px solid var(--border);
  padding: 40px 28px;
  border: 2px dashed var(--border);
  margin: 16px;
  border-radius: 14px;
  cursor: pointer;
  transition: border-color 0.2s ease, background 0.2s ease, transform 0.1s ease;
}

.upload-zone:hover,
.upload-zone:focus-visible {
  border-color: var(--primary);
  background: #f1f6ff;
  outline: none;
  transform: translateY(-1px);
}

.upload-icon {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: #e5f0ff;
  color: var(--primary);
  display: grid;
  place-items: center;
  font-size: 30px;
  margin: 0 auto 12px;
}

.upload-title {
  font-weight: 700;
  font-size: 18px;
  color: var(--text);
}

.upload-sub {
  color: var(--muted);
  margin-top: 6px;
}

.loading-state {
  text-align: center;
  padding: 28px;
}

.spinner {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 5px solid #e5e7eb;
  border-top-color: var(--primary);
  margin: 0 auto 12px;
  animation: spin 1s linear infinite;
}

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

.result-state {
  padding: 0 0 12px 0;
}

.preview-top {
  background: #f5f7fb;
  display: grid;
  place-items: center;
  padding: 18px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.preview-top img {
  max-width: 100%;
  max-height: 320px;
  object-fit: contain;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fff;
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.05);
}

.result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
  padding: 16px;
}

.result-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.04);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.label {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 12px;
  color: var(--muted);
  font-weight: 700;
}

.latex-box {
  min-height: 96px;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
  background: #f7f9fc;
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
  overflow-x: auto;
}

.spoken-text {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
  background: #fff;
  min-height: 60px;
  margin: 0;
}

.controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.controls-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.status-line {
  min-height: 20px;
  color: var(--muted);
  font-size: 14px;
  margin-top: -4px;
  margin-bottom: 8px;
}

@media (max-width: 720px) {
  .hero {
    flex-direction: column;
    gap: 6px;
  }
  .hero-actions {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
  }
  .result-wrap {
    flex-direction: column;
  }
  .preview-pane {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
}