/* ============================================================================
   MARC Serials Toolkit — shared UI
   ----------------------------------------------------------------------------
   One stylesheet for both the converter and the pattern detector, served by
   each Flask app at /ui.css.

   Design targets (the primary user is a cataloger with low vision):
     - the browser's own font-size setting is the baseline; never overridden
     - body text ~18px at a default 16px root; nothing below 14px
     - body and muted text at WCAG AAA contrast (>=7:1); borders >=3:1
     - every control at least 44x44px
     - the layout reflows when text grows instead of clipping

   App-specific rules stay in each template's own <style> block.
   ========================================================================== */

/* ── Reset ───────────────────────────────────────────────────────────────── */

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

/* ── Tokens ──────────────────────────────────────────────────────────────── */

:root {
  color-scheme: light;

  /* Light theme. Every value verified against bg, surface and surface-2:
     text 14.7-17.8:1, muted 7.0-8.5:1, accents >=5.4:1, borders >=4.0:1 */
  --bg:          #ffffff;
  --surface:     #f3f5f8;
  --surface-2:   #e6eaef;
  --text:        #16181d;
  --text-muted:  #474d57;
  --border:      #6b7280;
  --border-soft: #c3cad3;
  --accent:      #8a5000;   /* converter overrides; detector overrides */
  --accent-soft: #f7ede0;
  --ok:          #14672f;
  --ok-soft:     #e4f4ea;
  --warn:        #7a5200;
  --warn-soft:   #fbf0d8;
  --danger:      #a4262c;
  --danger-soft: #fbe9e9;
  --focus:       #0b57d0;
  --shadow:      0 1px 3px rgba(0, 0, 0, 0.12);

  /* Type scale. Body is --fs-md; nothing in either app may go below --fs-xs. */
  --fs-xs:   0.875rem;   /* 14px */
  --fs-sm:   1rem;       /* 16px */
  --fs-md:   1.125rem;   /* 18px  <- body */
  --fs-lg:   1.375rem;   /* 22px */
  --fs-xl:   1.75rem;    /* 28px */
  --fs-2xl:  2.25rem;    /* 36px */

  --sp-1: 0.25rem;
  --sp-2: 0.5rem;
  --sp-3: 0.75rem;
  --sp-4: 1rem;
  --sp-5: 1.5rem;
  --sp-6: 2rem;

  --radius: 6px;
  --control-min: 2.75rem;          /* 44px at a 16px root */
  --ease: 150ms ease;

  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
               Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Consolas,
               "Liberation Mono", Menlo, monospace;
}

/* Dark theme: explicit choice wins, system preference is the fallback. */
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg:          #0f1116;
  --surface:     #181b22;
  --surface-2:   #232833;
  --text:        #eef1f6;
  --text-muted:  #b9c1cf;
  --border:      #79818f;
  --border-soft: #333a46;
  --accent:      #e8bd58;
  --accent-soft: #2a2418;
  --ok:          #63d891;
  --ok-soft:     #16271d;
  --warn:        #f2b93c;
  --warn-soft:   #2a2313;
  --danger:      #ff9a94;
  --danger-soft: #2d1b1b;
  --focus:       #8ab8ff;
  --shadow:      0 1px 3px rgba(0, 0, 0, 0.5);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg:          #0f1116;
    --surface:     #181b22;
    --surface-2:   #232833;
    --text:        #eef1f6;
    --text-muted:  #b9c1cf;
    --border:      #79818f;
    --border-soft: #333a46;
    --accent:      #e8bd58;
    --accent-soft: #2a2418;
    --ok:          #63d891;
    --ok-soft:     #16271d;
    --warn:        #f2b93c;
    --warn-soft:   #2a2313;
    --danger:      #ff9a94;
    --danger-soft: #2d1b1b;
    --focus:       #8ab8ff;
    --shadow:      0 1px 3px rgba(0, 0, 0, 0.5);
  }
}

/* ── Base ────────────────────────────────────────────────────────────────── */

/* 100% keeps the reader's own browser setting as the baseline; --ui-scale is
   the in-app A / A+ / A++ control multiplying on top of it. Both compound, so
   someone who has already set a 20px default gets 20px * their chosen scale. */
html {
  font-size: calc(100% * var(--ui-scale, 1));
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-md);
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1 { font-size: var(--fs-xl);  line-height: 1.25; }
h2 { font-size: var(--fs-lg);  line-height: 1.3;  }
h3 { font-size: var(--fs-md);  line-height: 1.35; }

a { color: var(--focus); }
a:hover { text-decoration-thickness: 2px; }

code, pre, .mono { font-family: var(--font-mono); }

/* Sentence case, at a readable size. The previous design set these in
   letter-spaced uppercase at 8-10px, which is the hardest combination to read
   for exactly the audience this tool serves. */
.section-label {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: var(--sp-3);
  letter-spacing: 0;
  text-transform: none;
}

label {
  display: block;
  font-size: var(--fs-sm);
  color: var(--text-muted);
  margin-bottom: var(--sp-1);
  font-weight: 500;
}

.small { font-size: var(--fs-sm); }
.dim   { color: var(--text-muted); }
.ok    { color: var(--ok); }
.err   { color: var(--danger); }
.mt-05 { margin-top: var(--sp-1); }
.mt-1  { margin-top: var(--sp-2); }
.mt-2  { margin-top: var(--sp-4); }

/* ── Focus and motion ────────────────────────────────────────────────────── */

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
  border-radius: 2px;
}
:focus:not(:focus-visible) { outline: none; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ── Form controls ───────────────────────────────────────────────────────── */

input[type="text"], input[type="number"], textarea, select {
  width: 100%;
  min-height: var(--control-min);
  background: var(--bg);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  line-height: 1.5;
  padding: var(--sp-2) var(--sp-3);
  transition: border-color var(--ease);
}
input[type="text"]:hover, textarea:hover, select:hover { border-color: var(--text-muted); }
input[type="text"]:focus, textarea:focus, select:focus { border-color: var(--focus); }
textarea { resize: vertical; min-height: 9rem; }
select { font-family: var(--font-sans); cursor: pointer; }

input[type="checkbox"] {
  width: 1.25rem;
  height: 1.25rem;
  min-height: 0;
  accent-color: var(--focus);
  cursor: pointer;
}

.form-group { margin-bottom: var(--sp-4); }

/* Checkbox + label as one full-size hit target. */
.check-row {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--text);
  cursor: pointer;
  margin-bottom: var(--sp-2);
  min-height: var(--control-min);
}

/* ── Buttons ─────────────────────────────────────────────────────────────── */

.btn {
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  font-weight: 600;
  min-height: var(--control-min);
  padding: var(--sp-2) var(--sp-4);
  border-radius: var(--radius);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background var(--ease), border-color var(--ease);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  line-height: 1.3;
}
.btn-primary   { background: var(--accent); color: var(--bg); border-color: var(--accent); }
.btn-primary:hover   { filter: brightness(1.12); }
.btn-secondary { background: var(--bg); color: var(--text); border-color: var(--border); }
.btn-secondary:hover { background: var(--surface-2); }
.btn-ghost     { background: transparent; color: var(--text); border-color: transparent; }
.btn-ghost:hover     { background: var(--surface-2); }
.btn-success   { background: var(--bg); color: var(--ok); border-color: var(--ok); }
.btn-success:hover   { background: var(--ok-soft); }
.btn-danger    { background: var(--bg); color: var(--danger); border-color: var(--danger); }
.btn-danger:hover    { background: var(--danger-soft); }

/* Still a full-size hit target -- only the label and padding shrink. */
.btn-sm { font-size: var(--fs-xs); padding: var(--sp-1) var(--sp-3); }

.btn:disabled { opacity: 0.5; cursor: not-allowed; filter: none; }
.btn-row { display: flex; gap: var(--sp-2); flex-wrap: wrap; margin-top: var(--sp-3); }

/* ── Tabs ────────────────────────────────────────────────────────────────── */

.tabs { display: flex; border-bottom: 2px solid var(--border-soft); }
.tab-btn {
  flex: 1;
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  font-weight: 600;
  min-height: var(--control-min);
  padding: var(--sp-2) var(--sp-3);
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  color: var(--text-muted);
  cursor: pointer;
  margin-bottom: -2px;
}
.tab-btn:hover  { color: var(--text); background: var(--surface-2); }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }
.tab-panel        { display: none; }
.tab-panel.active { display: block; }

/* ── Alerts ──────────────────────────────────────────────────────────────── */

.alert {
  padding: var(--sp-3) var(--sp-4);
  border-radius: var(--radius);
  border: 2px solid;
  font-size: var(--fs-sm);
  line-height: 1.5;
  display: flex;
  gap: var(--sp-2);
  align-items: flex-start;
}
.alert-ok   { background: var(--ok-soft);     border-color: var(--ok);     color: var(--text); }
.alert-warn { background: var(--warn-soft);   border-color: var(--warn);   color: var(--text); }
.alert-err  { background: var(--danger-soft); border-color: var(--danger); color: var(--text); }
.alert-info { background: var(--surface-2);   border-color: var(--border); color: var(--text); }

/* ── Pills ───────────────────────────────────────────────────────────────── */

.pill {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  font-size: var(--fs-xs);
  font-weight: 600;
  padding: var(--sp-1) var(--sp-2);
  border-radius: var(--radius);
  border: 2px solid var(--border);
  color: var(--text);
  background: var(--bg);
  white-space: nowrap;
}

/* ── Misc shared ─────────────────────────────────────────────────────────── */

.divider { width: 2px; align-self: stretch; background: var(--border-soft); }

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--sp-4);
  color: var(--text-muted);
  text-align: center;
  padding: var(--sp-6);
  font-size: var(--fs-md);
}

@keyframes spin { to { transform: rotate(360deg); } }
.spinner {
  width: 1.15rem;
  height: 1.15rem;
  border: 3px solid var(--border-soft);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  display: inline-block;
  vertical-align: middle;
}

/* ── Header, and the accessibility controls ──────────────────────────────── */

header {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--sp-4);
  padding: var(--sp-4) var(--sp-5);
  border-bottom: 2px solid var(--border-soft);
  background: var(--surface);
}

.ui-controls {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  flex-wrap: wrap;
}
.ui-controls fieldset { border: 0; display: flex; align-items: center; gap: var(--sp-1); }
.ui-controls legend {
  float: left;
  font-size: var(--fs-xs);
  color: var(--text-muted);
  margin-right: var(--sp-2);
  padding: 0;
}
.ui-size-btn {
  min-width: var(--control-min);
  min-height: var(--control-min);
  padding: var(--sp-1) var(--sp-2);
  background: var(--bg);
  color: var(--text);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: 1;
}
.ui-size-btn:hover { background: var(--surface-2); }
.ui-size-btn[aria-pressed="true"] {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}
.ui-size-btn.s1 { font-size: var(--fs-sm); }
.ui-size-btn.s2 { font-size: var(--fs-md); }
.ui-size-btn.s3 { font-size: var(--fs-lg); }

.ui-theme-btn {
  min-height: var(--control-min);
  padding: var(--sp-2) var(--sp-3);
  background: var(--bg);
  color: var(--text);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
}
.ui-theme-btn:hover { background: var(--surface-2); }

/* Skip link — first tab stop, visible only once focused. */
.skip-link {
  position: absolute;
  left: -9999px;
  top: var(--sp-2);
  padding: var(--sp-2) var(--sp-4);
  background: var(--bg);
  border: 2px solid var(--focus);
  border-radius: var(--radius);
  z-index: 100;
}
.skip-link:focus { left: var(--sp-2); }

/* ── Dialog ──────────────────────────────────────────────────────────────── */
/* Settings that are consulted rarely belong here rather than in a column they
   have to share. Native <dialog> brings focus trapping, Esc-to-close and page
   inertness without script. */

dialog {
  max-width: min(42rem, 92vw);
  max-height: 85dvh;
  overflow-y: auto;
  padding: var(--sp-5);
  background: var(--bg);
  color: var(--text);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
}
dialog::backdrop { background: rgba(0, 0, 0, 0.55); }
dialog[open] { display: block; }

.dialog-title {
  font-size: var(--fs-lg);
  font-weight: 700;
  color: var(--text);
  margin-bottom: var(--sp-4);
}
/* Sticks to the bottom of the dialog's own scroll area, so the way out is
   always in view however long the form gets. */
.dialog-actions {
  position: sticky;
  bottom: calc(var(--sp-5) * -1);
  margin: var(--sp-4) calc(var(--sp-5) * -1) calc(var(--sp-5) * -1);
  padding: var(--sp-3) var(--sp-5);
  background: var(--surface);
  border-top: 2px solid var(--border-soft);
  display: flex;
  justify-content: flex-end;
  gap: var(--sp-2);
}

/* ── Footer and about dialog ─────────────────────────────────────────────── */

.app-footer {
  /* flex: none is load-bearing. In the bounded column below, a shrinkable
     footer would be squashed the same way the pattern cards once were. */
  flex: none;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--sp-3);
  padding: var(--sp-1) var(--sp-4);
  border-top: 2px solid var(--border-soft);
  background: var(--surface);
}

.version-badge {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--text-muted);
  background: none;
  border: 2px solid transparent;
  border-radius: var(--radius);
  padding: var(--sp-1) var(--sp-2);
  min-height: var(--control-min);
  cursor: pointer;
}
.version-badge:hover { color: var(--text); border-color: var(--border); }

/* Changelog inside the about dialog */
.about-section { margin-bottom: var(--sp-4); }
.about-section p { margin-bottom: var(--sp-2); }
.about-status {
  border-left: 4px solid var(--warn);
  background: var(--warn-soft);
  padding: var(--sp-3);
  border-radius: var(--radius);
}
.release {
  border-top: 2px solid var(--border-soft);
  padding-top: var(--sp-3);
  margin-top: var(--sp-4);
}
.release-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: var(--sp-2);
  margin-bottom: var(--sp-1);
}
.release-version { font-size: var(--fs-md); font-weight: 700; color: var(--text); }
.release-date { font-size: var(--fs-xs); color: var(--text-muted); }
.release-summary { color: var(--text-muted); margin-bottom: var(--sp-3); }
.release-changes { list-style: none; display: flex; flex-direction: column; gap: var(--sp-3); }
.release-changes li { display: flex; gap: var(--sp-3); align-items: flex-start; }
.change-tool {
  flex: none;
  min-width: 8.5rem;
  font-size: var(--fs-xs);
  font-weight: 700;
  color: var(--text);
  background: var(--surface-2);
  border: 2px solid var(--border-soft);
  border-radius: var(--radius);
  padding: var(--sp-1) var(--sp-2);
  text-align: center;
}
@media (max-width: 40rem) {
  .release-changes li { flex-direction: column; gap: var(--sp-1); }
  .change-tool { min-width: 0; align-self: flex-start; }
}

/* ── Layout ──────────────────────────────────────────────────────────────── */

/* Sidebars are sized in rem so they grow with the text rather than clipping it,
   and the shell scrolls instead of hiding overflow. */
main {
  display: grid;
  grid-template-columns: minmax(20rem, 26rem) 1fr;
  flex: 1;
  min-height: 0;
}

@media (max-width: 60rem) {
  main { grid-template-columns: 1fr; }
  #sidebar { border-right: none; border-bottom: 2px solid var(--border-soft); }
}

/* Two-pane widths only: bound the shell so each pane scrolls on its own and a
   long record list cannot stretch the document. Once the layout stacks -- a
   narrow window, or a reader at the largest text size -- the page returns to
   normal flow, so no container can clip its contents. In the bounded case
   everything stays reachable by scrolling a pane, so resize-text still holds. */
@media (min-width: 60rem) {
  body { height: 100dvh; overflow: hidden; }
  main { overflow: hidden; }
  #workspace { overflow-y: auto; min-height: 0; }
}

/* The workspace is a flex column, so its children are flex items and may be
   shrunk to fit. A flex item's automatic minimum size is its content height --
   except when its overflow is not `visible`, where the spec makes that minimum
   zero. Cards that clip their own corners (overflow: hidden) are therefore free
   to collapse to a few pixels and hide everything inside them, instead of the
   column scrolling. Pinning flex-shrink makes scrolling the overflow mechanism
   again, which is what the bounded shell above assumes. */
#workspace > * { flex-shrink: 0; }