:root {
  --color-bg: #f3f4f6;
  --color-surface: #ffffff;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-text: #111827;
  --color-text-muted: #6b7280;
  --color-border: #e5e7eb;
  --color-error: #dc2626;
  --color-error-bg: #fef2f2;
  --color-error-border: #fecaca;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.04);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 1rem;
  line-height: 1.5;
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

main {
  width: 100%;
  max-width: 520px;
}

/* Header */
.page-header {
  text-align: center;
  margin-bottom: 1.5rem;
}
.page-header h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-text);
}
.tagline {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  margin-top: 0.375rem;
}

/* Card */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Drop zone */
.drop-zone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s ease, background-color 0.15s ease;
  outline: none;
  user-select: none;
}
.drop-zone:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}
.drop-zone.drag-over {
  border-color: var(--color-primary);
  background-color: #eff6ff;
}
.drop-zone__icon {
  color: var(--color-text-muted);
  margin-bottom: 0.75rem;
}
.drop-zone__text {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
}
.link-style {
  color: var(--color-primary);
  text-decoration: underline;
  cursor: pointer;
}
.drop-zone__selected {
  font-weight: 500;
  color: var(--color-text);
  font-size: 0.9375rem;
  margin-top: 0.5rem;
}
.drop-zone input[type="file"] {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  overflow: hidden;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color 0.15s ease, opacity 0.15s ease;
  width: 100%;
}
.btn--primary {
  background-color: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}
.btn--primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
}
.btn--primary:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}
.btn--secondary {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-border);
}
.btn--secondary:hover {
  background-color: var(--color-bg);
}

/* Progress */
.progress-section {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.progress-bar {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  border: none;
  appearance: none;
  background: var(--color-border);
}
.progress-bar::-webkit-progress-bar {
  background: var(--color-border);
  border-radius: 3px;
}
.progress-bar::-webkit-progress-value {
  background: var(--color-primary);
  border-radius: 3px;
  transition: width 0.2s ease;
}
.progress-bar::-moz-progress-bar {
  background: var(--color-primary);
  border-radius: 3px;
}
.progress-text {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  text-align: center;
}

/* Error */
.error-section {
  background: var(--color-error-bg);
  border: 1px solid var(--color-error-border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.error-section p {
  color: var(--color-error);
  font-size: 0.9rem;
  line-height: 1.45;
}

/* Footer */
.page-footer {
  text-align: center;
  margin-top: 1.25rem;
  font-size: 0.8125rem;
}
.page-footer a {
  color: var(--color-text-muted);
  text-decoration: none;
}
.page-footer a:hover {
  text-decoration: underline;
}

/* Privacy page */
.prose {
  max-width: 680px;
  margin: 2rem auto;
  padding: 0 1.5rem;
}
.prose h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1rem;
}
.prose h2 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
}
.prose p, .prose ul {
  color: var(--color-text);
  margin-bottom: 0.75rem;
}
.prose ul {
  padding-left: 1.5rem;
}
.prose li {
  margin-bottom: 0.375rem;
}
.prose a {
  color: var(--color-primary);
}