:root {
  --colour-bg: #fafafa;
  --colour-bg-secondary: #f4f4f5;
  --colour-border: #d4d4d8;
  --colour-text: #18181b;
  --colour-text-secondary: #52525b;
  --colour-primary: #2563eb;
  --colour-primary-hover: #1d4ed8;
  --colour-primary-light: #dbeafe;
  --colour-block-bg: #ffffff;
  --colour-block-border: #e4e4e7;
  --colour-shadow: rgba(0, 0, 0, 0.08);

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 0.75rem;
  --space-lg: 1rem;
  --space-xl: 1.5rem;
  --space-2xl: 2rem;

  /* Reading preferences — overridden from JS / settings */
  --reading-size: 1.125rem;
  --reading-width: 42rem;
  --reading-family: Georgia, 'Iowan Old Style', 'Times New Roman', Times, serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --colour-bg: #0a0a0a;
    --colour-bg-secondary: #171717;
    --colour-border: #2a2a2a;
    --colour-text: #fafafa;
    --colour-text-secondary: #a1a1aa;
    --colour-primary-light: #1e3a8a;
    --colour-block-bg: #141414;
    --colour-block-border: #262626;
    --colour-shadow: rgba(0, 0, 0, 0.5);
  }
}

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

[hidden] {
  display: none !important;
}

html,
body {
  height: 100%;
}

body {
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue',
    Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--colour-text);
  background: var(--colour-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  overflow-wrap: break-word;
}

/* Shared icon mask technique */
.icon-mask {
  display: inline-block;
  background-color: currentColor;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-position: center;
  mask-position: center;
  -webkit-mask-size: contain;
  mask-size: contain;
}

.icon-settings {
  width: 1.25rem;
  height: 1.25rem;
  -webkit-mask-image: url(/icons/settings.svg);
  mask-image: url(/icons/settings.svg);
}

/* Drop overlay — covers the page during drag */
body.dragover::after {
  content: 'Drop your PDF';
  position: fixed;
  inset: var(--space-lg);
  border: 3px dashed var(--colour-primary);
  background: var(--colour-primary-light);
  color: var(--colour-primary);
  font-size: 1.25rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.75rem;
  z-index: 2000;
  pointer-events: none;
}

/* Empty state — centred prompt */
.empty {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
}

.empty-card {
  width: 100%;
  max-width: 32rem;
  background: var(--colour-block-bg);
  border: 2px dashed var(--colour-border);
  border-radius: 0.75rem;
  padding: var(--space-2xl);
  text-align: center;
  cursor: pointer;
  color: var(--colour-text);
  font: inherit;
  transition:
    border-color 0.15s ease,
    background 0.15s ease,
    transform 0.15s ease;
}

.empty-card:hover,
.empty-card:focus-visible {
  border-color: var(--colour-primary);
  outline: none;
  transform: translateY(-1px);
}

.empty-icon {
  width: 3rem;
  height: 3rem;
  margin: 0 auto var(--space-lg);
  color: var(--colour-primary);
}

.empty-title {
  font-family: Georgia, 'Times New Roman', Times, serif;
  font-weight: 700;
  font-size: 1.5rem;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-sm);
}

.empty-text {
  color: var(--colour-text-secondary);
  font-size: 0.9375rem;
}

.empty-text kbd {
  display: inline-block;
  padding: 0.1em 0.4em;
  margin: 0 0.1em;
  font-family:
    ui-monospace, 'SF Mono', 'Cascadia Code', Menlo, Monaco, Consolas, monospace;
  font-size: 0.8125rem;
  background: var(--colour-bg-secondary);
  border: 1px solid var(--colour-border);
  border-radius: 0.25rem;
  color: var(--colour-text);
}

.empty-loading {
  display: none;
  color: var(--colour-text-secondary);
  font-size: 0.9375rem;
  animation: empty-pulse 1.4s ease-in-out infinite;
}

@keyframes empty-pulse {
  0%,
  100% {
    opacity: 0.5;
  }

  50% {
    opacity: 1;
  }
}

.empty.loading .empty-text {
  display: none;
}

.empty.loading .empty-loading {
  display: block;
}

.empty.loading .empty-card {
  cursor: progress;
}

.empty-error {
  margin-top: var(--space-lg);
  color: #b91c1c;
  font-size: 0.875rem;
}

@media (prefers-color-scheme: dark) {
  .empty-error {
    color: #f87171;
  }
}

/* Reading progress bar — tracks the scroll position in real time */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 20;
  background: var(--colour-primary);
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
  will-change: transform;
}

/* Top toolbar */
.toolbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: color-mix(in srgb, var(--colour-bg) 88%, transparent);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--colour-border);
}

.toolbar-name {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 0.875rem;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.toolbar-progress {
  flex: 0 0 auto;
  font-size: 0.75rem;
  color: var(--colour-text-secondary);
  white-space: nowrap;
}

.action-btn {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: 0.4rem 0.6rem;
  font: inherit;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--colour-text);
  background: var(--colour-block-bg);
  border: 1px solid var(--colour-border);
  border-radius: 0.375rem;
  cursor: pointer;
  transition:
    background 0.15s ease,
    border-color 0.15s ease;
}

.action-btn:hover {
  background: var(--colour-bg-secondary);
  border-color: var(--colour-text-secondary);
}

.action-btn.icon-only {
  padding: 0.4rem;
}

/* Reading surface */
.reader {
  max-width: var(--reading-width);
  margin-inline: auto;
  padding: var(--space-xl) var(--space-lg) 6rem;
}

.doc {
  font-family: var(--reading-family);
  font-size: var(--reading-size);
  line-height: 1.7;
  color: var(--colour-text);
}

.doc-title {
  font-size: 1.6em;
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 0.8em;
}

.doc h2,
.doc h3,
.doc h4,
.doc h5,
.doc h6 {
  font-family: var(--reading-family);
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 1.4em 0 0.5em;
  scroll-margin-top: 4rem;
}

.doc h2 {
  font-size: 1.4em;
}

.doc h3 {
  font-size: 1.2em;
}

.doc h4 {
  font-size: 1.05em;
}

.doc h5,
.doc h6 {
  font-size: 1em;
}

.doc p {
  margin: 0 0 0.9em;
  overflow-wrap: break-word;
  hyphens: auto;
}

.doc ul,
.doc ol {
  margin: 0 0 0.9em;
  padding-left: 1.4em;
}

.doc li {
  margin-bottom: 0.3em;
}

.doc strong {
  font-weight: 700;
}

.doc em {
  font-style: italic;
}

.doc figure {
  margin: 1.2em 0;
  text-align: center;
}

.doc img {
  max-width: 100%;
  height: auto;
  border-radius: 0.375rem;
  background: var(--colour-block-bg);
}

.pdf-page + .pdf-page {
  margin-top: 1.5em;
}

/* faint page divider so long docs stay legible */
.pdf-page::before {
  content: '';
  display: block;
}

.pdf-page:not(:first-child)::before {
  margin: 1.8em 0;
  border-top: 1px dashed var(--colour-border);
}

/* Table of contents (collapsed by default) */
.toc {
  margin: 0 0 1.8em;
  border: 1px solid var(--colour-border);
  border-radius: 0.5rem;
  background: var(--colour-block-bg);
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue',
    Arial, sans-serif;
}

.toc summary {
  list-style: none;
  cursor: pointer;
  padding: 0.65rem 0.9rem;
  font-weight: 600;
  font-size: 0.9375rem;
  display: flex;
  align-items: center;
}

.toc summary::-webkit-details-marker {
  display: none;
}

.toc summary::before {
  content: '▸';
  display: inline-block;
  margin-right: 0.5em;
  color: var(--colour-text-secondary);
  transition: transform 0.15s ease;
}

.toc[open] summary::before {
  transform: rotate(90deg);
}

.toc nav {
  padding: 0 0.9rem 0.6rem;
}

.toc ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.toc li {
  margin: 0.1em 0;
}

.toc a {
  display: block;
  padding: 0.25rem 0;
  color: var(--colour-primary);
  text-decoration: none;
  font-size: 0.9375rem;
  line-height: 1.35;
}

.toc a:hover {
  text-decoration: underline;
}

/* Settings dialog */
dialog {
  margin: auto;
  width: min(28rem, calc(100vw - 2rem));
  max-width: 28rem;
  padding: 0;
  border: 1px solid var(--colour-border);
  border-radius: 0.75rem;
  background: var(--colour-block-bg);
  color: var(--colour-text);
  box-shadow: 0 12px 40px var(--colour-shadow);
}

dialog::backdrop {
  background: rgba(0, 0, 0, 0.45);
}

.dialog-inner {
  padding: var(--space-xl);
}

.dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-lg);
}

.dialog-header h2 {
  font-size: 1.125rem;
  font-weight: 700;
}

.dialog-close {
  font-size: 1.5rem;
  line-height: 1;
  background: none;
  border: none;
  color: var(--colour-text-secondary);
  cursor: pointer;
  padding: 0 0.25rem;
}

.field {
  margin-bottom: var(--space-lg);
}

.field-label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--colour-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: var(--space-sm);
}

.segmented {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
}

.segmented button {
  flex: 1 1 auto;
  min-width: 3.5rem;
  padding: 0.5rem 0.6rem;
  font: inherit;
  font-size: 0.875rem;
  color: var(--colour-text);
  background: var(--colour-bg-secondary);
  border: 1px solid var(--colour-border);
  border-radius: 0.375rem;
  cursor: pointer;
  transition:
    background 0.15s ease,
    border-color 0.15s ease,
    color 0.15s ease;
}

.segmented button[aria-pressed='true'] {
  background: var(--colour-primary);
  border-color: var(--colour-primary);
  color: #fff;
}

.dialog-divider {
  border: none;
  border-top: 1px solid var(--colour-border);
  margin: var(--space-lg) 0;
}

.field-hint {
  font-size: 0.8125rem;
  color: var(--colour-text-secondary);
  line-height: 1.45;
  margin-bottom: var(--space-md);
  text-transform: none;
  letter-spacing: 0;
}

.input-label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 500;
  margin-bottom: var(--space-xs);
}

.input-label .muted {
  color: var(--colour-text-secondary);
  font-weight: 400;
}

.field input[type='url'],
.field input[type='text'],
.field input[type='password'] {
  width: 100%;
  padding: 0.5rem 0.6rem;
  margin-bottom: var(--space-md);
  font: inherit;
  font-size: 0.875rem;
  color: var(--colour-text);
  background: var(--colour-bg-secondary);
  border: 1px solid var(--colour-border);
  border-radius: 0.375rem;
}

.field input:focus-visible {
  outline: 2px solid var(--colour-primary);
  outline-offset: 1px;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.action-btn.primary {
  background: var(--colour-primary);
  border-color: var(--colour-primary);
  color: #fff;
}

.action-btn.primary:hover {
  background: var(--colour-primary-hover);
  border-color: var(--colour-primary-hover);
}

.action-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.couch-status {
  margin-top: var(--space-sm);
  font-size: 0.8125rem;
  color: var(--colour-text-secondary);
  min-height: 1.2em;
}

.couch-status[data-state='error'] {
  color: #b91c1c;
}

.couch-status[data-state='ok'] {
  color: #15803d;
}

@media (prefers-color-scheme: dark) {
  .couch-status[data-state='error'] {
    color: #f87171;
  }

  .couch-status[data-state='ok'] {
    color: #4ade80;
  }
}

.share-url-row {
  display: flex;
  gap: var(--space-sm);
  align-items: center;
}

.share-url-row input[type='url'] {
  flex: 1;
  min-width: 0;
  padding: 0.5rem 0.6rem;
  font: inherit;
  font-size: 0.875rem;
  color: var(--colour-text);
  background: var(--colour-bg-secondary);
  border: 1px solid var(--colour-border);
  border-radius: 0.375rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.share-url-row input[type='url']:focus-visible {
  outline: 2px solid var(--colour-primary);
  outline-offset: 1px;
}

@media (max-width: 639px) {
  dialog {
    inset: 0;
    margin: 0;
    width: 100vw;
    height: 100dvh;
    max-width: 100vw;
    max-height: 100dvh;
    border-radius: 0;
  }

  dialog.share-dialog {
    top: 50%;
    left: 50%;
    right: auto;
    bottom: auto;
    transform: translate(-50%, -50%);
    margin: 0;
    width: min(28rem, calc(100vw - 2rem));
    max-width: min(28rem, calc(100vw - 2rem));
    height: auto;
    max-height: calc(100dvh - 2rem);
    border-radius: 0.75rem;
  }

  .reader {
    padding-inline: var(--space-md);
  }
}