:root {
  --color-ink: #14110d;
  --color-paper: #fff2d6;
  --color-surface: #ffffff;
  --color-text: #14110d;
  --color-text-muted: #5a5340;
  --color-border: var(--color-ink);
  --color-accent: #ff5a36;
  --color-accent-contrast: #14110d;
  --color-safe: #14110d;
  --color-safe-bg: #7ad1c4;
  --color-stretch: #14110d;
  --color-stretch-bg: #ffb5e8;
  --color-error: #7a1d0a;
  --color-error-bg: #ffd1c2;
  --color-cover-1: #ffb5e8;
  --color-cover-2: #7ad1c4;
  --color-cover-3: #ffd166;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2.5rem;

  --radius: 4px;
  --border-w: 3px;
  --shadow-offset: 8px;
  --hard-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--color-ink);

  --font-display: 'Archivo Black', system-ui, sans-serif;
  --font-sans: 'Space Grotesk', system-ui, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-ink: #fff2d6;
    --color-paper: #14110d;
    --color-surface: #201b13;
    --color-text: #fff2d6;
    --color-text-muted: #b9ad8c;
    --color-accent: #ff7a54;
    --color-accent-contrast: #14110d;
    --color-safe: #14110d;
    --color-safe-bg: #6fc3b4;
    --color-stretch: #14110d;
    --color-stretch-bg: #f0a8e0;
    --color-error: #ffd1c2;
    --color-error-bg: #4a231a;
    --color-cover-1: #b5488c;
    --color-cover-2: #3a8e7c;
    --color-cover-3: #c99a34;
  }
}

* {
  box-sizing: border-box;
}

/* The UA rule for [hidden] is display:none, but ANY author `display`
   declaration outranks it, so a class like .loading-screen { display: flex }
   silently un-hides the element. Everything here toggles visibility through
   the hidden attribute, so make it win outright. */
[hidden] {
  display: none !important;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  overflow-wrap: break-word;
  background: var(--color-paper);
  color: var(--color-text);
  line-height: 1.5;
}

main {
  max-width: 72rem;
  margin: 0 auto;
  padding: var(--space-4);
}

.site-header {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: var(--space-4) var(--space-5);
  background: var(--color-ink);
  color: var(--color-paper);
}

.site-header h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 7vw, 2rem);
  letter-spacing: -0.01em;
  text-transform: uppercase;
  text-align: center;
}

.tagline {
  margin: 0;
  color: inherit;
  opacity: 0.75;
  text-align: center;
  text-wrap: balance;
}

.setup-screen {
  display: grid;
  gap: var(--space-4);
  max-width: 34rem;
  margin: var(--space-5) auto 0;
}

/* Un item de grid no baja de su min-content salvo que se lo permita, y ahi
   un titulo o un boton largo empuja toda la pagina fuera del viewport. */
.setup-screen > * {
  min-width: 0;
}

.step-card {
  background: var(--color-surface);
  border: var(--border-w) solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--hard-shadow);
  padding: var(--space-4);
  color: var(--color-text);
}

.step-card h2 {
  margin-top: 0;
  font-family: var(--font-display);
  font-size: 1.1rem;
  text-transform: uppercase;
  letter-spacing: -0.01em;
}

.hint {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.upload-instructions-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.upload-instructions-row .hint {
  margin: 0;
}

.mini-btn {
  display: inline-block;
  padding: 0.2rem 0.7rem;
  background: var(--color-cover-3);
  color: var(--color-ink);
  border: 2px solid var(--color-border);
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  text-decoration: none;
  white-space: nowrap;
}

.file-picker {
  display: inline-block;
  padding: var(--space-2) var(--space-3);
  background: var(--color-cover-3);
  color: var(--color-ink);
  border: var(--border-w) solid var(--color-border);
  border-radius: var(--radius);
  font-weight: 700;
  cursor: pointer;
}

.key-help {
  margin-top: var(--space-3);
  border: var(--border-w) solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-surface);
  padding: var(--space-2) var(--space-3);
}

.key-help summary {
  cursor: pointer;
  font-weight: 700;
  list-style-position: inside;
}

.key-help[open] summary {
  margin-bottom: var(--space-2);
}

.key-help-steps {
  margin: 0 0 var(--space-2);
  padding-left: 1.25rem;
  display: grid;
  gap: var(--space-1);
  font-size: 0.9rem;
}

.key-help .hint + .hint {
  margin-top: var(--space-1);
}

.key-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-2);
}

.key-row input {
  flex: 1 1 12rem;
  min-width: 0;
  padding: var(--space-2);
  border: var(--border-w) solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-paper);
  color: var(--color-text);
  font-family: inherit;
}

button {
  font-family: inherit;
  font-size: 1rem;
}

.primary-btn {
  width: 100%;
  padding: var(--space-3);
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  border: var(--border-w) solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--hard-shadow);
  font-family: var(--font-display);
  text-transform: uppercase;
  letter-spacing: -0.01em;
  cursor: pointer;
}

.primary-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  box-shadow: none;
}

.link-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  text-decoration: none;
}

.footer-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.social-link .icon {
  flex: none;
}

.footer-danger-zone {
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.danger-btn {
  color: var(--color-error);
  font-weight: 700;
}

.key-row button {
  padding: var(--space-2) var(--space-3);
  background: var(--color-safe-bg);
  color: var(--color-ink);
  border: var(--border-w) solid var(--color-border);
  border-radius: var(--radius);
  cursor: pointer;
  white-space: nowrap;
  font-weight: 700;
}

.link-btn {
  background: none;
  border: none;
  color: var(--color-text);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 700;
  cursor: pointer;
  padding: 0;
}

.key-saved-actions {
  display: flex;
  gap: var(--space-3);
}

.status-line {
  color: var(--color-safe-bg);
  font-weight: 700;
  font-size: 0.9rem;
}

.error-line {
  color: var(--color-error);
  background: var(--color-error-bg);
  border: var(--border-w) solid var(--color-border);
  padding: var(--space-2);
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
}

.loading-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  text-align: center;
  padding: var(--space-5);
  color: var(--color-text-muted);
  font-family: var(--font-display);
  text-transform: uppercase;
}

.loading-screen p {
  margin: 0;
}

.spinner {
  flex: none;
  width: 1.25rem;
  height: 1.25rem;
  border: 3px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* Still turning, just calmly: a frozen spinner would read as a hang. */
@media (prefers-reduced-motion: reduce) {
  .spinner {
    animation-duration: 2.4s;
  }
}

.results-screen.is-busy {
  opacity: 0.4;
  pointer-events: none;
}

.results-screen {
  margin-top: var(--space-5);
}

.results-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}

.results-header h2 {
  margin: 0;
  flex: 1;
  font-family: var(--font-display);
  text-transform: uppercase;
  letter-spacing: -0.01em;
}

.filter-row {
  display: flex;
  gap: var(--space-2);
}

.filter-btn {
  padding: var(--space-1) var(--space-3);
  background: var(--color-surface);
  border: var(--border-w) solid var(--color-border);
  border-radius: 999px;
  color: var(--color-text);
  font-weight: 700;
  cursor: pointer;
}

.filter-btn.active {
  background: var(--color-ink);
  color: var(--color-paper);
  border-color: var(--color-ink);
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--space-4);
}

.book-card {
  background: var(--color-surface);
  border: var(--border-w) solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--hard-shadow);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.book-card .cover {
  width: 100%;
  aspect-ratio: 2 / 3;
  object-fit: cover;
  background: var(--color-cover-1);
  border-bottom: var(--border-w) solid var(--color-border);
}

.book-card .cover-placeholder {
  width: 100%;
  aspect-ratio: 2 / 3;
  background: var(--color-cover-2);
  border-bottom: var(--border-w) solid var(--color-border);
  background-image: repeating-linear-gradient(
    135deg,
    rgba(20, 17, 13, 0.12) 0 10px,
    transparent 10px 20px
  );
}

.results-grid .book-card:nth-child(3n + 1) .cover-placeholder {
  background-color: var(--color-cover-1);
}

.results-grid .book-card:nth-child(3n + 2) .cover-placeholder {
  background-color: var(--color-cover-2);
}

.results-grid .book-card:nth-child(3n) .cover-placeholder {
  background-color: var(--color-cover-3);
}

.card-body {
  padding: var(--space-3);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  flex: 1;
}

.badge {
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.2rem 0.6rem;
  border: 2px solid var(--color-border);
  border-radius: 999px;
}

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

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

.book-card .title {
  margin: var(--space-1) 0 0;
  font-family: var(--font-display);
  font-size: 1rem;
  line-height: 1.2;
}

.book-card .author {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.book-card .reason {
  font-size: 0.85rem;
  flex: 1;
}

.stale-note {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  font-style: italic;
}

.card-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  font-size: 0.85rem;
  font-weight: 700;
}

.card-links a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

.card-actions {
  display: flex;
  gap: var(--space-1);
  margin-top: var(--space-2);
}

.card-actions button {
  flex: 1;
  padding: var(--space-2) var(--space-1);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  cursor: pointer;
}

.card-actions .mark-read-btn {
  background: var(--color-accent);
  color: var(--color-accent-contrast);
}

.site-footer {
  text-align: center;
  padding: var(--space-4);
  color: var(--color-text-muted);
  font-size: 0.85rem;
  border-top: var(--border-w) solid var(--color-border);
}

.faq {
  max-width: 46rem;
  margin: var(--space-3) auto;
  text-align: left;
}

.faq summary {
  cursor: pointer;
  font-weight: 700;
  text-align: center;
}

.faq-list {
  margin: var(--space-3) 0 0;
}

.faq-list dt {
  font-weight: 700;
  color: var(--color-text);
}

.faq-list dd {
  margin: var(--space-1) 0 var(--space-3);
}

.faq-list dd:last-child {
  margin-bottom: 0;
}

a {
  color: var(--color-text);
}

a:hover {
  color: var(--color-accent);
}

@media (max-width: 40rem) {
  :root {
    --shadow-offset: 5px;
  }

  main {
    padding: var(--space-3);
  }

  .site-header {
    padding: var(--space-3);
  }

  .step-card {
    padding: var(--space-3);
  }

  .setup-screen {
    margin-top: var(--space-4);
  }

  .key-row button,
  .file-picker {
    width: 100%;
    text-align: center;
  }

  .results-screen {
    margin-top: var(--space-4);
  }

  .results-header h2 {
    flex: 1 0 100%;
  }

  .results-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: var(--space-3);
  }

  .card-actions {
    flex-direction: column;
  }
}