/* Learn Reader — app chrome. The PDF pages themselves stay white in both themes. */

:root {
  --bg: #f6f5f2;
  --surface: #ffffff;
  --surface-2: #efede8;
  --ink: #1d1d1f;
  --muted: #6b6a66;
  --line: #e2dfd8;
  --accent: #2c6e60;
  --accent-ink: #ffffff;
  --accent-soft: #dcebe6;
  --danger: #b4232c;
  --viewer-bg: #e6e3dc;
  --shadow: 0 1px 2px rgba(20, 20, 20, 0.06), 0 6px 24px rgba(20, 20, 20, 0.10);
  --radius: 12px;
  --toolbar-h: 52px;
  --panel-w: 340px;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);

  --c-yellow: 255, 204, 0;
  --c-green: 52, 199, 89;
  --c-blue: 0, 122, 255;
  --c-pink: 255, 45, 135;

  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #18191b;
    --surface: #222326;
    --surface-2: #2b2c30;
    --ink: #ececec;
    --muted: #9b9ba1;
    --line: #36373c;
    --accent: #6cc3ad;
    --accent-ink: #0d1f1a;
    --accent-soft: #233a34;
    --danger: #ff6b6b;
    --viewer-bg: #0f1012;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 28px rgba(0, 0, 0, 0.5);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #18191b;
  --surface: #222326;
  --surface-2: #2b2c30;
  --ink: #ececec;
  --muted: #9b9ba1;
  --line: #36373c;
  --accent: #6cc3ad;
  --accent-ink: #0d1f1a;
  --accent-soft: #233a34;
  --danger: #ff6b6b;
  --viewer-bg: #0f1012;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}
body[data-view="reader"] { overflow: hidden; overscroll-behavior: none; }
[hidden] { display: none !important; }
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
a { color: var(--accent); }
button, input, select, textarea { font: inherit; color: inherit; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.92em; background: var(--surface-2); padding: 0.1em 0.35em; border-radius: 5px; }
.muted { color: var(--muted); }
.small { font-size: 13px; }

.icon {
  width: 20px; height: 20px; flex: none;
  fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round;
}

/* ------------------------------------------------------------------ buttons */

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  min-height: 38px; padding: 0 16px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--surface); cursor: pointer;
  font-weight: 550; text-decoration: none; color: var(--ink);
}
.btn:hover { background: var(--surface-2); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { background: var(--accent); filter: brightness(1.07); }
.btn-primary:disabled { opacity: 0.6; cursor: progress; }
.btn-ghost { background: transparent; border-color: transparent; }
.btn-small { min-height: 32px; padding: 0 12px; font-size: 14px; }
.btn-danger-text { color: var(--danger); }

.icon-btn {
  position: relative;
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; padding: 0; border-radius: 10px;
  border: 0; background: transparent; color: var(--ink); cursor: pointer; text-decoration: none;
}
.icon-btn:hover { background: var(--surface-2); }
.icon-btn[aria-pressed="true"] { background: var(--accent-soft); color: var(--accent); }
.icon-btn:focus-visible, .btn:focus-visible, .swatch:focus-visible, .sync-pill:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 2px;
}

.badge {
  position: absolute; top: 3px; right: 2px; min-width: 16px; height: 16px; padding: 0 4px;
  border-radius: 8px; background: var(--accent); color: var(--accent-ink);
  font-size: 10px; font-weight: 700; line-height: 16px; text-align: center;
}
.badge:empty { display: none; }

/* colour swatches */
.swatch {
  width: 28px; height: 28px; border-radius: 50%; padding: 0; cursor: pointer;
  border: 2px solid var(--surface); box-shadow: 0 0 0 1px var(--line);
  background: rgb(var(--c));
}
.swatch-sm { width: 20px; height: 20px; }
.swatch[aria-pressed="true"] { box-shadow: 0 0 0 2px var(--ink); }
.c-yellow { --c: var(--c-yellow); }
.c-green { --c: var(--c-green); }
.c-blue { --c: var(--c-blue); }
.c-pink { --c: var(--c-pink); }

/* sync pill */
.sync-pill {
  display: inline-flex; align-items: center; gap: 6px;
  height: 32px; padding: 0 12px 0 9px; border-radius: 16px;
  border: 1px solid var(--line); background: var(--surface); cursor: pointer;
  font-size: 13px; color: var(--muted); white-space: nowrap;
}
.sync-pill .icon { width: 16px; height: 16px; }
.sync-pill[data-state="synced"] .icon { color: var(--accent); }
.sync-pill[data-state="pending"] .icon { color: #c98a00; }
.sync-pill[data-state="error"], .sync-pill[data-state="offline"] { color: var(--danger); }
.sync-pill[data-state="syncing"] .icon { animation: spin 0.9s linear infinite; color: var(--accent); }
.sync-pill.compact { padding: 0 9px; }
.sync-pill.compact .sync-text { display: none; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ------------------------------------------------------------------ setup & library pages */

.view-page { min-height: 100%; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: -0.01em; font-size: 17px; }
.brand-mark { width: 26px; height: 26px; fill: none; stroke: var(--accent); stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }

#view-setup { display: grid; place-items: center; padding: calc(24px + var(--safe-top)) 16px 32px; }
.setup-card {
  width: 100%; max-width: 480px; background: var(--surface); border: 1px solid var(--line);
  border-radius: 18px; padding: 28px; box-shadow: var(--shadow);
}
.setup-card h1 { font-size: 24px; letter-spacing: -0.02em; margin: 22px 0 8px; }
.lead { color: var(--muted); margin: 0 0 22px; }
.field { display: grid; gap: 6px; margin-bottom: 14px; font-size: 13px; font-weight: 600; color: var(--muted); }
.field input {
  height: 42px; padding: 0 12px; border-radius: 10px; border: 1px solid var(--line);
  background: var(--bg); color: var(--ink); font-size: 15px; font-weight: 400;
}
.field input:focus { outline: 2px solid var(--accent); outline-offset: -1px; border-color: transparent; }
.check { display: flex; gap: 10px; align-items: flex-start; font-size: 14px; margin: 2px 0 14px; cursor: pointer; }
.check input { margin-top: 3px; accent-color: var(--accent); }
.howto { margin: 4px 0 16px; font-size: 14px; }
.howto summary { cursor: pointer; color: var(--accent); font-weight: 550; }
.howto ol { padding-left: 20px; margin: 10px 0; }
.howto li { margin: 4px 0; }
.howto p { color: var(--muted); margin: 0; }
.form-error { color: var(--danger); font-size: 14px; }
.form-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }

.lib-header {
  position: sticky; top: 0; z-index: 5;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: calc(10px + var(--safe-top)) max(16px, calc((100% - 880px) / 2)) 10px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.lib-actions { display: flex; align-items: center; gap: 4px; }
.lib-main { max-width: 880px; margin: 0 auto; padding: 18px 16px calc(40px + var(--safe-bottom)); }
.lib-tools { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
#lib-search {
  flex: 1; min-width: 0; height: 42px; padding: 0 14px; border-radius: 11px;
  border: 1px solid var(--line); background: var(--surface); font-size: 15px;
}
#lib-search:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
.lib-repo { color: var(--muted); font-size: 13px; white-space: nowrap; }
.notice { background: var(--surface-2); border-radius: 10px; padding: 10px 14px; font-size: 14px; }
.lib-empty { text-align: center; padding: 48px 16px; }
.lib-group { margin-bottom: 26px; }
.lib-group-title {
  font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted);
  font-weight: 650; margin: 0 0 10px;
}
.book-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.book-card {
  display: flex; gap: 14px; align-items: stretch; height: 100%;
  padding: 14px; border-radius: var(--radius); border: 1px solid var(--line);
  background: var(--surface); color: var(--ink); text-decoration: none;
  transition: border-color 0.15s, transform 0.15s;
}
.book-card:hover { border-color: var(--accent); }
.book-card:active { transform: scale(0.99); }
.book-spine {
  flex: none; width: 34px; border-radius: 4px 7px 7px 4px; min-height: 46px;
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.18), transparent 22%), var(--accent);
  opacity: 0.85;
}
.book-info { display: grid; gap: 4px; min-width: 0; align-content: center; }
.book-title { font-weight: 620; line-height: 1.25; overflow-wrap: anywhere; }
.book-meta { color: var(--muted); font-size: 13px; display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.badge-offline {
  font-size: 11px; padding: 1px 6px; border-radius: 6px; background: var(--accent-soft); color: var(--accent); font-weight: 600;
}
.dot-pending { width: 7px; height: 7px; border-radius: 50%; background: #d99a00; display: inline-block; }

.dialog {
  border: 1px solid var(--line); border-radius: 16px; padding: 22px; width: min(440px, calc(100% - 32px));
  background: var(--surface); color: var(--ink); box-shadow: var(--shadow);
}
.dialog::backdrop { background: rgba(0, 0, 0, 0.35); }
.dialog h2 { margin: 0 0 8px; font-size: 18px; }

/* ------------------------------------------------------------------ reader */

#view-reader { position: fixed; inset: 0; background: var(--viewer-bg); }

.toolbar {
  position: absolute; left: 0; right: 0; top: 0; z-index: 20;
  height: calc(var(--toolbar-h) + var(--safe-top)); padding: var(--safe-top) 8px 0;
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
  background: var(--surface); border-bottom: 1px solid var(--line);
}
.tb-group { display: flex; align-items: center; gap: 2px; min-width: 0; }
.tb-left { flex: 1 1 0; }
.tb-center { flex: none; }
.tb-right { flex: 1 1 0; justify-content: flex-end; }
.tb-divider { width: 1px; height: 22px; background: var(--line); margin: 0 6px; flex: none; }
.reader-title {
  font-weight: 600; font-size: 14px; margin-left: 4px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; min-width: 0;
}
.page-box {
  display: inline-flex; align-items: center; gap: 4px; height: 32px; padding: 0 8px;
  border-radius: 8px; background: var(--surface-2); font-size: 14px; color: var(--muted);
  font-variant-numeric: tabular-nums;
}
#page-input {
  width: 3.2ch; min-width: 28px; border: 0; background: transparent; text-align: right;
  color: var(--ink); font-weight: 600; padding: 0; font-variant-numeric: tabular-nums;
}
#page-input:focus { outline: none; }
.zoom-select {
  height: 32px; border-radius: 8px; border: 0; background: var(--surface-2); padding: 0 6px; font-size: 13px; cursor: pointer;
}
.tool-colors { display: inline-flex; gap: 6px; padding: 0 6px; }

#viewerContainer {
  position: absolute; left: 0; right: 0; bottom: 0;
  top: calc(var(--toolbar-h) + var(--safe-top));
  overflow: auto; -webkit-overflow-scrolling: touch;
  touch-action: pan-x pan-y;
  background: var(--viewer-bg);
  padding-bottom: calc(24px + var(--safe-bottom));
}
#viewer.pdfViewer { transition: none; }
.pdfViewer .page { --page-border: 9px; }

/* panel docked on wide screens */
@media (min-width: 900px) {
  #view-reader.panel-open #viewerContainer { right: var(--panel-w); }
}

/* immersive mode (fullscreen fallback, e.g. iPhone Safari) */
#view-reader.immersive .toolbar { display: none; }
#view-reader.immersive #viewerContainer { top: 0; }
.exit-immersive {
  position: absolute; top: calc(10px + var(--safe-top)); right: 12px; z-index: 25;
  width: 40px; height: 40px; border-radius: 20px; border: 0; cursor: pointer;
  background: rgba(30, 30, 30, 0.55); color: #fff; display: grid; place-items: center;
  backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
}

/* back after following a link */
.jump-back {
  position: absolute; z-index: 26; left: 12px;
  top: calc(var(--toolbar-h) + var(--safe-top) + 10px);
  display: inline-flex; align-items: center; gap: 6px; height: 36px; padding: 0 12px 0 8px;
  border-radius: 18px; border: 1px solid var(--line); cursor: pointer;
  background: var(--surface); color: var(--ink); box-shadow: var(--shadow);
  font-size: 13px; font-weight: 600;
}
.jump-back[hidden] { display: none; }
#view-reader.immersive .jump-back { top: calc(10px + var(--safe-top)); }

#view-reader[data-mode="area"] .page,
#view-reader[data-mode="note"] .page { cursor: crosshair; touch-action: none; }
#view-reader[data-mode="area"] .textLayer,
#view-reader[data-mode="note"] .textLayer,
#view-reader[data-mode="area"] .annotationLayer,
#view-reader[data-mode="note"] .annotationLayer { pointer-events: none; }
.tool-hint {
  position: absolute; left: 50%; transform: translateX(-50%); z-index: 22;
  top: calc(var(--toolbar-h) + var(--safe-top) + 10px); margin: 0;
  padding: 8px 14px; border-radius: 18px; font-size: 13px;
  background: var(--ink); color: var(--bg); box-shadow: var(--shadow); white-space: nowrap;
}

/* annotation layer (inserted by the app into each .page) */
/* no z-index: a stacking context would isolate the layer and break mix-blend-mode */
.hl-layer { position: absolute; inset: 0; pointer-events: none; }
.hl { position: absolute; border-radius: 2px; }
.hl-text { background: rgba(var(--c), 0.42); mix-blend-mode: multiply; }
.hl-area { background: rgba(var(--c), 0.18); border: 2px solid rgba(var(--c), 0.9); border-radius: 4px; mix-blend-mode: multiply; }
.hl.is-active { outline: 2px solid rgba(var(--c), 1); outline-offset: 1px; }
.hl-text.has-note { box-shadow: 0 2px 0 rgba(var(--c), 1); }
.hl-draft { border-style: dashed; }
.note-pin {
  position: absolute; pointer-events: auto; transform: translate(-50%, -50%);
  width: 26px; height: 26px; border-radius: 7px 7px 7px 2px; border: 0; padding: 0; cursor: pointer;
  background: rgb(var(--c)); color: rgba(0, 0, 0, 0.7); font-size: 14px; line-height: 26px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.35);
}
.note-pin.is-active { outline: 2px solid #1d1d1f; outline-offset: 2px; }
.bm-ribbon {
  position: absolute; right: 10px; pointer-events: auto; width: 16px; height: 24px; border: 0; padding: 0; cursor: pointer;
  background: rgb(var(--c)); clip-path: polygon(0 0, 100% 0, 100% 100%, 50% 72%, 0 100%);
  filter: drop-shadow(0 1px 1px rgba(0, 0, 0, 0.35));
}
.bm-ribbon.is-active { outline: 2px solid #1d1d1f; outline-offset: 2px; }
@media print { .hl-layer { display: none; } }

/* loading */
.reader-loading {
  position: absolute; inset: calc(var(--toolbar-h) + var(--safe-top)) 0 0; z-index: 15;
  display: grid; place-items: center; padding: 16px; background: var(--viewer-bg);
}
.loading-card {
  width: min(420px, 100%); background: var(--surface); border-radius: 16px; padding: 22px;
  box-shadow: var(--shadow); text-align: center; display: grid; gap: 14px; justify-items: center;
}
.loading-card p { margin: 0; }
.reader-loading:not(.is-error) .loading-back { display: none; }
.reader-loading.is-error p { color: var(--danger); }
.progress { width: 100%; height: 6px; border-radius: 3px; background: var(--surface-2); overflow: hidden; }
.progress span { display: block; height: 100%; width: 0; background: var(--accent); transition: width 0.2s; }

/* side panel */
.panel {
  position: absolute; z-index: 18; right: 0; bottom: 0;
  top: calc(var(--toolbar-h) + var(--safe-top)); width: var(--panel-w);
  display: flex; flex-direction: column;
  background: var(--surface); border-left: 1px solid var(--line);
}
@media (max-width: 899px) {
  .panel { width: min(420px, 100%); box-shadow: var(--shadow); }
}
.panel-head { display: flex; align-items: center; gap: 6px; padding: 8px 8px 8px 12px; border-bottom: 1px solid var(--line); }
.tabs { display: flex; gap: 2px; flex: 1; min-width: 0; background: var(--surface-2); padding: 3px; border-radius: 10px; }
.tabs button {
  flex: 1; min-width: 0; padding: 0 4px; border: 0; background: transparent; height: 30px; border-radius: 8px; cursor: pointer;
  font-size: 13px; font-weight: 600; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.panel-head .icon-btn { flex-shrink: 0; }
.tabs button[aria-selected="true"] { background: var(--surface); color: var(--ink); box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1); }
.panel-body { flex: 1; overflow: auto; padding: 8px 8px calc(16px + var(--safe-bottom)); }
.panel-empty { color: var(--muted); font-size: 14px; padding: 12px 8px; margin: 0; }
.ann-list { list-style: none; margin: 0; padding: 0; }
.ann-item {
  display: flex; gap: 10px; width: 100%; text-align: left; padding: 10px 8px; border: 0; border-radius: 10px;
  background: transparent; cursor: pointer;
}
.ann-item:hover { background: var(--surface-2); }
.ann-swatch { flex: none; width: 4px; border-radius: 2px; background: rgb(var(--c)); }
.ann-body { display: grid; gap: 3px; min-width: 0; }
.ann-meta { font-size: 12px; color: var(--muted); font-weight: 600; }
.ann-text {
  font-size: 14px; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.ann-note {
  font-size: 13px; color: var(--muted); font-style: italic;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.outline ul { list-style: none; margin: 0; padding: 0; }
.outline .outline-sub { padding-left: 14px; }
.outline-item {
  display: block; width: 100%; text-align: left; border: 0; background: transparent; cursor: pointer;
  padding: 7px 8px; border-radius: 8px; font-size: 14px; line-height: 1.3;
}
.outline-root > li > .outline-item { font-weight: 600; }
.outline-item:hover { background: var(--surface-2); }
.outline-item:disabled { color: var(--muted); cursor: default; }
.find-form { display: flex; gap: 4px; padding: 4px; }
.find-form input {
  flex: 1; min-width: 0; height: 38px; padding: 0 12px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg);
}
.find-status { color: var(--muted); font-size: 13px; padding: 0 8px; }

/* selection bar */
.selection-bar {
  position: absolute; z-index: 30; left: 50%; transform: translateX(-50%);
  bottom: calc(18px + var(--safe-bottom));
  display: flex; align-items: center; gap: 8px; padding: 8px 8px 8px 14px; border-radius: 16px;
  background: var(--surface); border: 1px solid var(--line); box-shadow: var(--shadow);
  white-space: nowrap; user-select: none; -webkit-user-select: none;
}
.sel-label { font-size: 13px; font-weight: 600; color: var(--muted); }
.sel-colors { display: inline-flex; gap: 8px; }

/* popover */
.popover {
  position: absolute; z-index: 32; right: 16px; bottom: calc(16px + var(--safe-bottom));
  width: min(380px, calc(100% - 32px));
  background: var(--surface); border: 1px solid var(--line); border-radius: 16px; box-shadow: var(--shadow);
  padding: 12px 14px 14px; display: grid; gap: 10px;
}
@media (min-width: 900px) {
  #view-reader.panel-open .popover { right: calc(var(--panel-w) + 16px); }
}
@media (max-width: 720px) {
  .popover { left: 0; right: 0; bottom: 0; width: 100%; border-radius: 18px 18px 0 0; padding-bottom: calc(14px + var(--safe-bottom)); }
}
.pop-head { display: flex; align-items: center; gap: 8px; }
.pop-meta { flex: 1; font-size: 12px; font-weight: 650; color: var(--muted); text-transform: uppercase; letter-spacing: 0.05em; }
.pop-colors { display: inline-flex; gap: 6px; }
.pop-quote {
  margin: 0; padding: 2px 0 2px 10px; border-left: 3px solid var(--line); color: var(--muted); font-size: 14px;
  max-height: 6.2em; overflow: auto;
}
.pop-note {
  width: 100%; resize: vertical; min-height: 76px; padding: 10px 12px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--bg); font-size: 15px; line-height: 1.4;
}
.pop-note:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
.pop-foot { display: flex; justify-content: space-between; }

/* toasts */
.toasts {
  position: fixed; z-index: 100; left: 50%; transform: translateX(-50%);
  top: calc(var(--toolbar-h) + var(--safe-top) + 12px); display: grid; gap: 8px; justify-items: center;
  pointer-events: none; width: calc(100% - 32px);
}
.toast {
  pointer-events: auto; display: flex; align-items: center; gap: 12px;
  max-width: 520px; padding: 10px 14px; border-radius: 12px; font-size: 14px;
  background: var(--ink); color: var(--bg); box-shadow: var(--shadow);
  transition: opacity 0.3s, transform 0.3s;
}
.toast-error { background: var(--danger); color: #fff; }
.toast-hide { opacity: 0; transform: translateY(-6px); }
.toast-action {
  border: 0; background: transparent; color: inherit; font-weight: 700; cursor: pointer; text-decoration: underline; padding: 0;
}

/* ------------------------------------------------------------------ narrow screens */

@media (max-width: 720px) {
  :root { --toolbar-h: 50px; }
  .hide-narrow { display: none !important; }
  .reader-title { display: none; }
  .tb-left { flex: 0 0 auto; }
  .toolbar { padding-left: 4px; padding-right: 4px; gap: 2px; }
  .icon-btn { width: 36px; height: 36px; }
  .lib-repo { display: none; }
  .sync-pill .sync-text { display: none; }
  .sync-pill { padding: 0 9px; }
  .selection-bar { left: 12px; right: 12px; transform: none; justify-content: space-between; }
}

/* ------------------------------------------------------------------ home panels */

.home-title { margin: 0; font-size: 20px; font-weight: 680; letter-spacing: -0.01em; flex: 1; }
.subject-card .next-title { font-size: 15px; font-weight: 560; }
.home-review { margin-bottom: 24px; }
#lib-home { margin-left: -8px; }
.home-panels { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); margin-bottom: 24px; }
.panel-card {
  background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 16px;
  display: grid; gap: 6px; align-content: start;
}
.eyebrow { font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); font-weight: 650; }
.next-title { margin: 2px 0 0; font-weight: 620; font-size: 16px; line-height: 1.3; }
.panel-card p { margin: 0; }
.panel-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.panel-actions .icon { width: 18px; height: 18px; }
.review-counts { color: var(--muted); }
.review-counts .big { font-size: 26px; font-weight: 700; color: var(--ink); font-variant-numeric: tabular-nums; }
.review-counts .sep { margin: 0 4px; }
.btn.is-disabled { opacity: 0.55; }

/* ------------------------------------------------------------------ review */

#view-review { position: fixed; inset: 0; background: var(--bg); display: flex; flex-direction: column; }
#view-review .toolbar { position: relative; flex: none; }
.review-count { font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
.review-main {
  flex: 1; min-height: 0; overflow: auto; display: flex; justify-content: center;
  padding: 20px 16px calc(16px + var(--safe-bottom));
}
.review-stage { width: 100%; max-width: 720px; display: flex; flex-direction: column; gap: 16px; min-height: 100%; }
.review-card {
  flex: 0 0 auto; min-height: min(260px, 40vh); background: var(--surface); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow);
  padding: clamp(18px, 4vw, 36px); cursor: pointer; overflow-wrap: anywhere;
  font-size: clamp(17px, 2.2vw, 20px); line-height: 1.55;
}
.review-meta { margin: 0 0 14px; font-size: 12px; color: var(--muted); font-weight: 650; text-transform: uppercase; letter-spacing: 0.06em; }
.review-front { font-weight: 560; }
.review-back { color: var(--ink); }
.review-divider { border: 0; border-top: 1px dashed var(--line); margin: 20px 0; }
.review-card .math-display { margin: 0.6em 0; overflow-x: auto; overflow-y: hidden; padding: 2px 0; }
.review-card .katex { font-size: 1.08em; }
.review-card code { font-size: 0.9em; }
.review-actions { flex: none; display: grid; gap: 10px; margin-top: auto; position: sticky; bottom: 0; padding-top: 8px; background: linear-gradient(transparent, var(--bg) 30%); }
.btn-wide { width: 100%; min-height: 52px; font-size: 16px; }
.btn kbd {
  font: 600 11px/1 ui-monospace, monospace; padding: 3px 5px; border-radius: 4px;
  background: rgba(255, 255, 255, 0.2); margin-left: 6px;
}
.review-ratings { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.rate {
  display: grid; gap: 2px; justify-items: center; padding: 10px 4px; min-height: 58px; border-radius: 12px; cursor: pointer;
  border: 1px solid var(--line); background: var(--surface); color: var(--ink);
}
.rate:hover { filter: brightness(0.97); }
.rate-label { font-weight: 650; font-size: 15px; }
.rate-ivl { font-size: 12px; color: var(--muted); font-variant-numeric: tabular-nums; }
.rate-again { border-color: #e5a3a3; }
.rate-again .rate-label { color: #b4232c; }
.rate-hard .rate-label { color: #a76a00; }
.rate-good { border-color: color-mix(in srgb, var(--accent) 55%, var(--line)); }
.rate-good .rate-label { color: var(--accent); }
.rate-easy .rate-label { color: #1d6fc9; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .rate-again .rate-label { color: #ff8a8a; }
  :root:not([data-theme="light"]) .rate-hard .rate-label { color: #f0b44c; }
  :root:not([data-theme="light"]) .rate-easy .rate-label { color: #7db6ff; }
  :root:not([data-theme="light"]) .rate-again { border-color: #6b3535; }
}
.review-done { align-self: center; display: grid; justify-items: center; gap: 14px; text-align: center; padding: 40px 16px; }
.review-done p { font-size: 18px; margin: 0; }
.done-mark { width: 56px; height: 56px; fill: none; stroke: var(--accent); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
@media (max-width: 720px) {
  .rate { min-height: 62px; }
  .rate-label { font-size: 14px; }
  .btn kbd { display: none; }
}

/* ------------------------------------------------------------------ course: progress & documents */

#view-course { position: fixed; inset: 0; background: var(--bg); display: flex; flex-direction: column; }
#view-course .toolbar { position: relative; flex: none; }
#view-course .tb-left { flex: 1 1 0; min-width: 0; }
#view-course .tb-right { flex: none; }
.course-title { display: block !important; flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.checklist-summary { list-style: none; cursor: pointer; display: grid; gap: 8px; }
.checklist-summary::-webkit-details-marker { display: none; }
.checklist-summary .eyebrow::after { content: ' ▾'; }
.checklist:not([open]) .checklist-summary .eyebrow::after { content: ' ▸'; }
.check-label .katex { font-size: 1em; }
.course-main {
  flex: 1; min-height: 0; overflow: auto; -webkit-overflow-scrolling: touch;
  padding: 18px max(16px, calc((100% - 820px) / 2)) calc(48px + var(--safe-bottom));
  display: grid; gap: 16px; align-content: start;
}
.pbar { height: 8px; border-radius: 4px; background: var(--surface-2); overflow: hidden; }
.pbar > span { display: block; height: 100%; background: var(--accent); border-radius: 4px; transition: width 0.25s; }
.progress-summary { gap: 10px; }
.track-bars { display: grid; gap: 8px; margin-top: 6px; }
.track-row { display: grid; grid-template-columns: 52px 1fr 48px; align-items: center; gap: 10px; font-size: 13px; }
.track-name { font-weight: 650; }
.track-num { color: var(--muted); text-align: right; font-variant-numeric: tabular-nums; }
.block .lib-group-title { margin-top: 6px; }
.session-list, .doc-links { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.session-row {
  display: grid; grid-template-columns: 14px 44px 1fr auto; align-items: center; gap: 10px;
  padding: 12px 14px; border-radius: 12px; border: 1px solid var(--line); background: var(--surface);
  color: var(--ink); text-decoration: none;
}
a.session-row:hover { border-color: var(--accent); }
.session-row.is-disabled { opacity: 0.6; }
.session-id { font-weight: 700; font-variant-numeric: tabular-nums; }
.session-title { display: grid; gap: 2px; min-width: 0; }
.session-track { font-size: 12px; color: var(--muted); }
.session-state { font-size: 12px; color: var(--muted); white-space: nowrap; }
.status-dot { width: 12px; height: 12px; border-radius: 50%; border: 2px solid var(--line); }
.status-dot.s-done { background: var(--accent); border-color: var(--accent); }
.status-dot.s-started { border-color: var(--accent); background: linear-gradient(90deg, var(--accent) 50%, transparent 50%); }
.status-dot.s-skipped { border-style: dashed; border-color: var(--muted); }
.status-dot.s-dropped { border-color: var(--line); background: var(--line); }
.is-dropped .session-row { opacity: 0.55; }
.is-dropped .session-title { text-decoration: line-through; }
.doc-links a { display: block; padding: 10px 14px; border-radius: 10px; background: var(--surface); border: 1px solid var(--line); text-decoration: none; color: var(--ink); }
.doc-links a:hover { border-color: var(--accent); }

/* checklist */
.check-count { margin-left: auto; font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }
.panel-card-head { display: flex; align-items: center; }
.check-list { list-style: none; margin: 6px 0 0; padding: 0; display: grid; gap: 2px; }
.check-list li { display: flex; align-items: center; gap: 10px; padding: 5px 0; }
.check-list li.is-checked .check-label { color: var(--muted); text-decoration: line-through; }
.check-label { flex: 1; min-width: 0; color: var(--ink); text-decoration: none; font-size: 14px; line-height: 1.35; }
a.check-label:hover { color: var(--accent); }
.chk {
  flex: none; width: 22px; height: 22px; border-radius: 6px; padding: 0; cursor: pointer;
  border: 2px solid color-mix(in srgb, var(--muted) 60%, transparent); background: var(--surface);
  display: inline-grid; place-items: center; vertical-align: -4px; margin-right: 8px;
}
.chk::after { content: ''; width: 6px; height: 11px; border: solid transparent; border-width: 0 2.5px 2.5px 0; transform: translateY(-1px) rotate(45deg); }
.chk[aria-checked="true"] { background: var(--accent); border-color: var(--accent); }
.chk[aria-checked="true"]::after { border-color: var(--accent-ink); }
.chk:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.check-list .chk { margin-right: 0; }
.small-x { width: 28px; height: 28px; font-size: 18px; color: var(--muted); }
.add-row { display: flex; gap: 8px; margin-top: 8px; }
.add-input, .error-form textarea {
  flex: 1; min-width: 0; height: 38px; padding: 0 12px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg); font-size: 14px;
}
.error-form { display: grid; gap: 8px; margin-top: 8px; }
.error-form textarea { height: auto; padding: 8px 12px; resize: vertical; }
.error-form .btn { justify-self: start; }
.error-list { list-style: none; margin: 4px 0 0; padding: 0; display: grid; gap: 6px; }
.error-list li { display: flex; gap: 8px; align-items: flex-start; padding: 8px 10px; border-radius: 10px; background: var(--surface-2); font-size: 14px; }
.err-text { flex: 1; display: grid; gap: 2px; }
.err-fix { color: var(--muted); font-size: 13px; }
.end-actions { margin-top: 14px; }

/* rendered markdown */
.md { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: clamp(16px, 3vw, 28px); line-height: 1.6; font-size: 16px; overflow-wrap: anywhere; }
.md > :first-child { margin-top: 0; }
.md h1 { font-size: 22px; line-height: 1.25; letter-spacing: -0.01em; }
.md h2 { font-size: 18px; margin: 1.6em 0 0.6em; padding-top: 0.6em; border-top: 1px solid var(--line); }
.md h3 { font-size: 16px; }
.md p, .md ul, .md ol { margin: 0.6em 0; }
.md ul, .md ol { padding-left: 1.4em; }
.md li { margin: 0.25em 0; }
.md a { color: var(--accent); }
.md code { font-size: 0.88em; }
.md pre { background: var(--surface-2); padding: 12px 14px; border-radius: 10px; overflow-x: auto; font-size: 13px; line-height: 1.45; }
.md pre code { background: none; padding: 0; font-size: inherit; }
.md blockquote { margin: 0.8em 0; padding: 4px 14px; border-left: 3px solid var(--line); color: var(--muted); }
.md hr { border: 0; border-top: 1px solid var(--line); margin: 1.4em 0; }
.md .table-wrap { overflow-x: auto; margin: 0.8em 0; }
.md table { border-collapse: collapse; width: 100%; font-size: 14px; }
.md th, .md td { border: 1px solid var(--line); padding: 6px 10px; text-align: left; vertical-align: top; }
.md th { background: var(--surface-2); }
.md .math-display { overflow-x: auto; overflow-y: hidden; margin: 0.6em 0; }
.md .has-check.is-checked { opacity: 0.75; }
.md h2.has-check .chk { vertical-align: -3px; }
.solutions-title { font-size: 18px; margin: 8px 0 0; }
.solutions { display: grid; gap: 12px; }
.md hr + h2 { border-top: 0; padding-top: 0; }

/* session stepper: "where am I" */
.stepper {
  position: sticky; top: -18px; z-index: 5; margin: -18px 0 0; padding: 14px 0 10px;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
}
.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-auto-flow: column; grid-auto-columns: 1fr; gap: 6px; }
.step button {
  width: 100%; display: flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 44px; padding: 6px 8px; border-radius: 12px; cursor: pointer;
  border: 1px solid var(--line); background: var(--surface); color: var(--muted); font-weight: 600; font-size: 14px;
}
.step-dot {
  flex: none; width: 24px; height: 24px; border-radius: 50%; display: grid; place-items: center;
  font-size: 12px; font-weight: 700; border: 2px solid currentColor;
}
.step-label { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.step.s-done button { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.step.s-done .step-dot { border-color: transparent; background: rgba(255, 255, 255, 0.22); }
.step.s-next button { border-color: var(--accent); color: var(--ink); }
.step-hint { margin: 8px 2px 0; font-size: 13px; color: var(--muted); }
.skip-box { margin: 6px 2px 0; display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: 13px; }
.skip-box.is-skipped, .skip-box.is-asking { padding: 10px 12px; border: 1px dashed var(--line); border-radius: 12px; }
.skip-msg { margin: 0; flex: 1 1 220px; color: var(--muted); }
.skip-actions { display: flex; flex-wrap: wrap; gap: 6px; }
.link-btn { padding: 4px 0; border: 0; background: none; color: var(--muted); font: inherit; text-decoration: underline; cursor: pointer; }
.link-btn:hover { color: var(--ink); }
.md h2.is-done { color: var(--muted); }
.md h2.is-done::after { content: '  ✓'; color: var(--accent); }
.session-reminders { margin: 12px 0; }
.session-reminders .check-list { margin-top: 2px; }
@media (max-width: 520px) {
  .step button { flex-direction: column; gap: 3px; min-height: 58px; font-size: 12px; padding: 6px 4px; }
}