:root {
  --bg: #f4f6fb;
  --bg-soft: #ffffff;
  --bg-alt: #eef1f8;
  --text: #17202e;
  --text-soft: #55617a;
  --line: #dde3ee;
  --primary: #2f6fed;
  --primary-soft: #e5edff;
  --accent: #14b8a6;
  --warn: #b45309;
  --warn-bg: #fff7e6;
  --warn-line: #f2ce85;
  --dup: #7c3aed;
  --dup-bg: #f3ecff;
  --gpos: #6d4de0;
  --gpos-bg: #ece6ff;
  --gneg: #e0446a;
  --gneg-bg: #ffe8ee;
  --mark: #ffe680;
  --shadow: 0 2px 10px rgba(23, 32, 46, .08);
  --radius: 14px;
  --mono: "Cascadia Mono", Consolas, "Courier New", monospace;
}

[data-theme="dark"] {
  --bg: #0f141d;
  --bg-soft: #161d29;
  --bg-alt: #1c2533;
  --text: #e8edf6;
  --text-soft: #a4b0c4;
  --line: #2a3547;
  --primary: #6f9bff;
  --primary-soft: #1e2b45;
  --accent: #2dd4bf;
  --warn: #fbbf24;
  --warn-bg: #2a2113;
  --warn-line: #6b5320;
  --dup: #c4b5fd;
  --dup-bg: #241d3a;
  --gpos: #b6a4ff;
  --gpos-bg: #241f3d;
  --gneg: #ff8fa8;
  --gneg-bg: #341c26;
  --mark: #6b5a13;
  --shadow: 0 2px 12px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", Tahoma, "Noto Naskh Arabic", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.7;
}

body { padding-bottom: 40px; }

a { color: var(--primary); text-decoration: none; }

mark {
  background: var(--mark);
  color: inherit;
  padding: 0 3px;
  border-radius: 4px;
}

button {
  font-family: inherit;
  font-size: .92rem;
  cursor: pointer;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--bg-soft);
  color: var(--text);
  padding: 7px 12px;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
  transition: background .15s, border-color .15s, transform .05s;
}

button:hover { background: var(--bg-alt); border-color: var(--primary); }
button:active { transform: translateY(1px); }

input[type="search"], input[type="text"] {
  font-family: inherit;
  font-size: .92rem;
  padding: 8px 12px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--bg-soft);
  color: var(--text);
  width: 100%;
}

.hidden { display: none !important; }
.muted { color: var(--text-soft); font-size: .85rem; }
.num { direction: ltr; unicode-bidi: isolate; display: inline-block; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 16px;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line);
  box-shadow: var(--shadow);
  flex-wrap: wrap;
}

.brand { display: flex; align-items: center; gap: 10px; margin-inline-end: auto; }
.brand-ico { font-size: 1.6rem; }
.brand strong { display: block; font-size: 1.02rem; }
.brand small { display: block; color: var(--text-soft); font-size: .74rem; letter-spacing: .01em; }

.tools { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.search-wrap { position: relative; min-width: 220px; }
.search-wrap input { padding-inline-end: 32px; }
.search-wrap .mini-btn { position: absolute; inset-inline-end: 6px; top: 50%; transform: translateY(-50%); }

.icon-btn { font-size: 1.1rem; line-height: 1; padding: 8px 10px; }
.tool-btn { white-space: nowrap; }
.tool-btn.active { background: var(--primary-soft); border-color: var(--primary); color: var(--primary); font-weight: 600; }

.mini-btn { padding: 2px 6px; font-size: .8rem; border-radius: 8px; }

.layout { display: flex; align-items: flex-start; gap: 18px; padding: 18px; max-width: 1500px; margin: 0 auto; }

.sidebar {
  width: 280px;
  flex: 0 0 280px;
  position: sticky;
  top: 76px;
  max-height: calc(100vh - 96px);
  overflow-y: auto;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  box-shadow: var(--shadow);
}

.sidebar h2 { font-size: .95rem; margin: 6px 4px 10px; color: var(--text-soft); }

.sidebar-head { display: none; align-items: center; justify-content: space-between; gap: 8px; margin-bottom: 8px; padding-bottom: 8px; border-bottom: 1px solid var(--line); }
.sidebar-head strong { font-size: .95rem; }

.nav-lecture { margin-bottom: 10px; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.nav-lecture > button {
  width: 100%;
  text-align: start;
  border: none;
  border-radius: 0;
  background: var(--bg-alt);
  display: flex;
  gap: 8px;
  align-items: baseline;
  justify-content: space-between;
  font-weight: 600;
  padding: 10px 12px;
}
.nav-lecture > button:hover { background: var(--primary-soft); }
.nav-lecture .lec-tag { font-size: .72rem; color: var(--text-soft); font-weight: 400; }

.nav-topics { list-style: none; margin: 0; padding: 6px; display: none; }
.nav-lecture.open .nav-topics { display: block; }
.nav-topics li { margin: 2px 0; }
.nav-topics button {
  width: 100%;
  text-align: start;
  border: none;
  background: transparent;
  font-size: .86rem;
  padding: 6px 10px;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  align-items: center;
}
.nav-topics button:hover { background: var(--bg-alt); }
.nav-topics button.current { background: var(--primary-soft); color: var(--primary); font-weight: 600; }
.nav-dot { width: 9px; height: 9px; border-radius: 50%; border: 1px solid var(--line); flex: 0 0 auto; }
.nav-dot.done { background: var(--accent); border-color: var(--accent); }

.nav-links { display: flex; flex-direction: column; gap: 6px; margin-top: 10px; padding-top: 10px; border-top: 1px solid var(--line); }
.nav-links button { text-align: start; }

.app { flex: 1 1 auto; min-width: 0; }

.card {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
  margin-bottom: 16px;
}

.page-title { margin: 0 0 4px; font-size: 1.45rem; }
.page-sub { margin: 0 0 14px; color: var(--text-soft); font-size: .92rem; }

.grid { display: grid; gap: 14px; }
.grid.cols-2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

.lecture-card { cursor: pointer; transition: border-color .15s, transform .1s; }
.lecture-card:hover { border-color: var(--primary); transform: translateY(-2px); }
.lecture-card h3 { margin: 0 0 6px; font-size: 1.1rem; }
.lecture-card .date-chip {
  display: inline-block;
  background: var(--primary-soft);
  color: var(--primary);
  border-radius: 999px;
  padding: 1px 10px;
  font-size: .76rem;
  font-weight: 700;
  margin-inline-start: 6px;
}

.progress {
  height: 10px;
  border-radius: 999px;
  background: var(--bg-alt);
  overflow: hidden;
  border: 1px solid var(--line);
}
.progress > span { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--primary)); width: 0; transition: width .25s; }
.progress-row { display: flex; align-items: center; gap: 10px; margin-top: 10px; }
.progress-row .progress { flex: 1; }
.progress-num { font-size: .8rem; color: var(--text-soft); min-width: 58px; text-align: center; direction: ltr; unicode-bidi: isolate; }

.topic-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.topic-list a, .topic-list button.link-like {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  width: 100%;
  text-align: start;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 10px 12px;
  background: var(--bg-soft);
  color: var(--text);
  font-size: .93rem;
}
.topic-list a:hover, .topic-list button.link-like:hover { border-color: var(--primary); background: var(--bg-alt); }

.badge {
  font-size: .72rem;
  border-radius: 999px;
  padding: 2px 9px;
  border: 1px solid var(--line);
  background: var(--bg-alt);
  color: var(--text-soft);
  white-space: nowrap;
}
.badge.done { background: var(--primary-soft); color: var(--primary); border-color: var(--primary); }
.badge.warn { background: var(--warn-bg); color: var(--warn); border-color: var(--warn-line); }

.notice {
  border-radius: 12px;
  padding: 10px 14px;
  font-size: .9rem;
  margin-bottom: 14px;
  border: 1px solid;
}
.notice.missing { background: var(--warn-bg); border-color: var(--warn-line); color: var(--warn); }
.notice.dup { background: var(--dup-bg); border-color: var(--dup); color: var(--dup); }
.notice.info { background: var(--primary-soft); border-color: var(--primary); color: var(--primary); }

.slide {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}
.slide-head { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.slide-head h2 { margin: 0; font-size: 1.15rem; }
.slide-head .idx { font-size: .8rem; color: var(--text-soft); font-family: var(--mono); }

.points { list-style: none; margin: 14px 0 0; padding: 0; display: grid; gap: 10px; }
.points > li {
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-inline-start: 4px solid var(--primary);
  border-radius: 10px;
  background: var(--bg-soft);
}
.point-en { direction: ltr; text-align: left; font-family: "Segoe UI", Arial, sans-serif; }
.point-ar {
  direction: rtl;
  text-align: right;
  margin-top: 6px;
  padding-top: 6px;
  border-top: 1px dashed var(--line);
  color: var(--text-soft);
  font-size: .92rem;
  display: none;
}
body.show-ar .point-ar { display: block; }

.slide-nav { display: flex; gap: 10px; align-items: center; margin-top: 16px; flex-wrap: wrap; }
.slide-nav .progress { flex: 1; min-width: 140px; }
.key-hint { font-size: .78rem; color: var(--text-soft); }

.kw-list { margin-top: 10px; display: flex; gap: 6px; flex-wrap: wrap; }
.kw-list span { font-size: .74rem; background: var(--bg-alt); border: 1px solid var(--line); border-radius: 999px; padding: 1px 8px; color: var(--text-soft); }

.profile-card { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--bg-soft); box-shadow: var(--shadow); }
.profile-head { padding: 12px 14px; border-bottom: 1px solid var(--line); display: flex; justify-content: space-between; gap: 10px; align-items: center; flex-wrap: wrap; }
.profile-head h3 { margin: 0; font-size: 1.02rem; }
.gram-pill { font-weight: 700; font-size: .78rem; padding: 2px 10px; border-radius: 999px; border: 1px solid; }
.gram-pos { background: var(--gpos-bg); color: var(--gpos); border-color: var(--gpos); }
.gram-neg { background: var(--gneg-bg); color: var(--gneg); border-color: var(--gneg); }
.gram-na { background: var(--bg-alt); color: var(--text-soft); border-color: var(--line); }
.profile-card.g-pos { border-top: 4px solid var(--gpos); }
.profile-card.g-neg { border-top: 4px solid var(--gneg); }
.profile-card.g-na { border-top: 4px solid var(--accent); }

.profile-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.profile-row { padding: 9px 14px; border-bottom: 1px solid var(--line); }
.profile-row .k { font-size: .78rem; color: var(--text-soft); }
.profile-row .v { direction: ltr; text-align: left; font-size: .9rem; }
.profile-row .v-ar { direction: rtl; text-align: right; font-size: .85rem; color: var(--text-soft); display: none; }
body.show-ar .profile-row .v-ar { display: block; }

.flashcard { perspective: 1200px; margin-bottom: 14px; }
.flashcard-inner {
  position: relative;
  min-height: 210px;
  transition: transform .45s;
  transform-style: preserve-3d;
}
.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }
.flashcard-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 10px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-soft);
  box-shadow: var(--shadow);
}
.flashcard-face.back { transform: rotateY(180deg); background: var(--bg-alt); }
.flashcard-face .label { font-size: .74rem; color: var(--text-soft); }
.flashcard-face .txt { font-size: 1.02rem; direction: ltr; text-align: left; }
.flashcard-face .txt-ar { direction: rtl; text-align: right; color: var(--text-soft); font-size: .9rem; display: none; }
body.show-ar .flashcard-face .txt-ar { display: block; }

.cell-ar { display: none; direction: rtl; text-align: right; color: var(--text-soft); font-size: .86rem; }
body.show-ar .cell-ar { display: block; }

table.data-table { width: 100%; border-collapse: collapse; background: var(--bg-soft); font-size: .87rem; }
table.data-table th, table.data-table td { border: 1px solid var(--line); padding: 8px 10px; text-align: start; vertical-align: top; }
table.data-table th { background: var(--bg-alt); font-size: .84rem; }
table.data-table td .cell-ar { display: none; direction: rtl; color: var(--text-soft); font-size: .84rem; }
body.show-ar table.data-table td .cell-ar { display: block; }
body.show-ar table.data-table td .cell-en { display: block; }
.table-scroll { overflow-x: auto; border-radius: 12px; border: 1px solid var(--line); }

.summary-box { border: 1px solid var(--accent); border-radius: var(--radius); padding: 14px; background: var(--bg-soft); }
.summary-box h3 { margin: 0 0 10px; font-size: 1rem; color: var(--accent); }
.mnemonic { background: var(--primary-soft); border: 1px dashed var(--primary); border-radius: 12px; padding: 10px 12px; margin-top: 10px; font-size: .9rem; }
.mnemonic strong { color: var(--primary); }

.q-block { border: 1px solid var(--line); border-radius: 12px; padding: 14px; margin-bottom: 12px; background: var(--bg-soft); }
.q-block .q-text { font-weight: 600; margin-bottom: 10px; }
.q-block .q-text .ar { display: none; color: var(--text-soft); font-weight: 400; font-size: .9rem; }
body.show-ar .q-block .q-text .ar { display: block; }
.opt {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  margin-bottom: 6px;
  cursor: pointer;
  font-size: .9rem;
}
.opt:hover { background: var(--bg-alt); }
.opt.correct { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 12%, transparent); }
.opt.wrong { border-color: var(--gneg); background: var(--gneg-bg); }
.opt input { margin-top: 5px; }
.q-actions { display: flex; gap: 8px; align-items: center; margin-top: 10px; flex-wrap: wrap; }
.explain {
  margin-top: 10px;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px dashed var(--accent);
  background: var(--bg-alt);
  font-size: .89rem;
}
.explain .ar { display: none; color: var(--text-soft); margin-top: 4px; }
body.show-ar .explain .ar { display: block; }
.match-row { display: flex; gap: 8px; align-items: center; margin-bottom: 8px; flex-wrap: wrap; }
.match-row .left { flex: 1 1 200px; font-size: .9rem; }
.match-row select { flex: 1 1 200px; padding: 7px 10px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg-soft); color: var(--text); font-family: inherit; font-size: .88rem; }
.fill-input { max-width: 320px; margin: 6px 0; direction: ltr; }
.result-msg { font-size: .86rem; font-weight: 600; }
.result-msg.ok { color: var(--accent); }
.result-msg.no { color: var(--gneg); }

.search-panel {
  position: fixed;
  inset-block-start: 78px;
  inset-inline-end: 18px;
  width: min(560px, calc(100vw - 36px));
  max-height: 70vh;
  overflow-y: auto;
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 12px 40px rgba(0,0,0,.22);
  z-index: 60;
  padding: 12px;
}
.search-panel-head { display: flex; gap: 10px; align-items: center; margin-bottom: 10px; }
.search-panel-head strong { margin-inline-end: auto; }
.result-item { border: 1px solid var(--line); border-radius: 10px; padding: 9px 11px; margin-bottom: 8px; cursor: pointer; background: var(--bg-soft); }
.result-item:hover { border-color: var(--primary); background: var(--bg-alt); }
.result-item .where { font-size: .74rem; color: var(--text-soft); }
.result-item .snippet { font-size: .88rem; direction: ltr; text-align: left; }
.result-item .snippet.ar { direction: rtl; text-align: right; color: var(--text-soft); }

.mermaid-wrap { overflow-x: auto; background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius); padding: 12px; }
.mermaid { min-width: 640px; }
.mermaid-fallback { display: none; direction: rtl; }
.mermaid-fallback.active { display: block; }
.tree { list-style: none; padding-inline-start: 18px; }
.tree li { margin: 6px 0; }
.tree > li > .node-label { font-weight: 700; }
.tree .node-label { display: inline-block; border: 1px solid var(--line); border-radius: 8px; padding: 3px 10px; background: var(--bg-soft); font-size: .88rem; cursor: pointer; }
.tree .node-label:hover { border-color: var(--primary); background: var(--primary-soft); }

.chain { display: grid; gap: 12px; }
.chain-step { border: 1px solid var(--line); border-radius: var(--radius); background: var(--bg-soft); overflow: hidden; }
.chain-step-head { padding: 10px 14px; background: var(--bg-alt); display: flex; justify-content: space-between; gap: 10px; align-items: center; flex-wrap: wrap; font-weight: 700; }
.chain-step-body { padding: 12px 14px; font-size: .9rem; }
.chain-arrow { text-align: center; color: var(--primary); font-size: 1.2rem; }

.glossary-item { border-bottom: 1px solid var(--line); padding: 9px 2px; }
.glossary-item .term { font-weight: 700; font-family: var(--mono); font-size: .9rem; }
.glossary-item .def-ar { color: var(--text-soft); font-size: .87rem; }

.fab-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.fab-row button.active { background: var(--primary-soft); border-color: var(--primary); color: var(--primary); font-weight: 600; }

.empty { text-align: center; color: var(--text-soft); padding: 26px 10px; }

.toast {
  position: fixed;
  inset-block-end: 20px;
  inset-inline-start: 50%;
  transform: translateX(-50%);
  background: var(--text);
  color: var(--bg);
  padding: 9px 18px;
  border-radius: 999px;
  font-size: .86rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s;
  z-index: 80;
}
.toast.show { opacity: .95; }

.print-area { display: none; }

.backdrop {
  position: fixed;
  inset: 0;
  background: rgba(10, 15, 25, .5);
  z-index: 85;
  opacity: 0;
  transition: opacity .2s;
}
.backdrop.show { opacity: 1; }
@media (min-width: 981px) { .backdrop { display: none !important; } }

@media (max-width: 980px) {
  .layout { flex-direction: column; padding: 12px; }
  .sidebar {
    position: fixed;
    top: 0;
    bottom: 0;
    inset-inline-start: 0;
    height: 100dvh;
    max-height: 100dvh;
    width: 84vw;
    max-width: 340px;
    border-radius: 0;
    z-index: 95;
    transform: translateX(-115%);
    visibility: hidden;
    pointer-events: none;
    transition: transform .22s ease, visibility .22s;
    padding: 14px 14px calc(24px + env(safe-area-inset-bottom));
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    box-shadow: 0 0 30px rgba(0, 0, 0, .28);
  }
  html[dir="rtl"] .sidebar { transform: translateX(115%); }
  .sidebar.open,
  html[dir="rtl"] .sidebar.open {
    transform: translateX(0);
    visibility: visible;
    pointer-events: auto;
  }
  .search-wrap { min-width: 150px; }
  .sidebar-head { display: flex; }
}

@media (max-width: 820px) {
  body { font-size: 15.5px; -webkit-text-size-adjust: 100%; }

  .topbar {
    padding: 8px 10px;
    gap: 8px;
    align-items: center;
    justify-content: space-between;
    padding-top: calc(8px + env(safe-area-inset-top));
  }
  #menuBtn { min-width: 44px; min-height: 44px; display: flex; align-items: center; justify-content: center; }
  .brand { margin-inline: auto; margin-inline-end: auto; text-align: center; justify-content: center; }
  .brand-ico { font-size: 1.35rem; }
  .brand strong { font-size: .95rem; }

  .tools {
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 6px;
    order: 3;
  }
  .search-wrap {
    grid-column: 1 / -1;
    min-width: 0;
  }
  .search-wrap input { font-size: 16px; padding: 10px 34px 10px 12px; }
  .tool-btn { width: 100%; text-align: center; padding: 10px 4px; font-size: .8rem; white-space: nowrap; }
  .icon-btn { padding: 9px 11px; font-size: 1.05rem; }
  #themeBtn { grid-column: 4; }
  #searchClear { inset-inline-end: 8px; }

  .search-panel {
    inset: auto 10px auto 10px;
    inset-block-start: calc(60px + env(safe-area-inset-top));
    inset-inline-start: 10px;
    inset-inline-end: 10px;
    width: auto;
    max-height: 72vh;
  }

  .card { padding: 14px; border-radius: 12px; }
  .page-title { font-size: 1.25rem; }
  .slide { padding: 14px; border-radius: 12px; }
  .slide-head h2 { font-size: 1.08rem; }

  button { min-height: 42px; padding: 10px 12px; }
  .mini-btn { min-height: 32px; padding: 2px 8px; }

  .points { gap: 8px; }
  .points > li { padding: 11px 12px; font-size: .95rem; }
  .point-en, .point-ar { font-size: .95rem; }

  .profile-grid { grid-template-columns: 1fr; }
  .profile-head { padding: 11px 12px; }
  .profile-row { padding: 10px 12px; }

  .topic-list a, .topic-list button.link-like { padding: 13px 12px; min-height: 54px; }
  .nav-topics button { padding: 11px 12px; min-height: 46px; }

  .slide-nav {
    position: sticky;
    bottom: calc(6px + env(safe-area-inset-bottom));
    z-index: 20;
    background: var(--bg-soft);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 8px;
    gap: 8px;
    box-shadow: 0 -2px 14px rgba(0, 0, 0, .12);
  }
  .slide-nav button { flex: 1 1 0; }
  .slide-nav .progress { order: -1; flex: 1 1 100%; min-width: 0; }
  .slide-nav .key-hint { display: none; }

  .fab-row button { flex: 1 1 140px; }

  .opt { padding: 11px 12px; min-height: 48px; font-size: .95rem; }
  .match-row { gap: 6px; }
  .match-row .left, .match-row select { flex: 1 1 100%; }
  .match-row select { font-size: 16px; padding: 10px; }
  .fill-input { font-size: 16px; max-width: 100%; }

  .table-scroll {
    -webkit-overflow-scrolling: touch;
    position: relative;
  }
  table.data-table { font-size: .84rem; }
  table.data-table th, table.data-table td { padding: 8px; }
  table.data-table tr > *:first-child { position: sticky; inset-inline-start: 0; background: var(--bg-alt); z-index: 2; }
  table.data-table thead tr > *:first-child { background: var(--bg-alt); }

  .mermaid { min-width: 520px; }
  .mermaid-wrap { -webkit-overflow-scrolling: touch; }

  .flashcard-inner { min-height: 260px; }
  .flashcard-face { padding: 18px; overflow-y: auto; }
  .flashcard-face .txt { font-size: 1rem; }

  .chain-step-head { padding: 10px 12px; font-size: .92rem; }
  .chain-step-body { padding: 11px 12px; }

  .glossary-item { padding: 11px 2px; }

  .toast { inset-block-end: calc(16px + env(safe-area-inset-bottom)); width: max-content; max-width: 90vw; font-size: .82rem; }
}

@media (max-width: 560px) {
  .brand small { display: none; }
  .search-wrap { min-width: 0; }
  .tools { grid-template-columns: 1fr 1fr 1fr 1fr; }
  .tool-btn { font-size: .74rem; padding: 9px 2px; }
  .brand strong { font-size: .9rem; }
  .lecture-card h3 { font-size: 1rem; }
  .grid.cols-2, .grid.cols-3 { grid-template-columns: 1fr; }
  .slide-nav { bottom: calc(4px + env(safe-area-inset-bottom)); }
  .fab-row button { flex: 1 1 120px; font-size: .86rem; }
}

@media print {
  .no-print, .topbar, .sidebar, .search-panel, #app { display: none !important; }
  .print-area { display: block !important; }
  body { background: #fff; color: #000; font-size: 12pt; }
  .print-area .card { box-shadow: none; border: 1px solid #999; page-break-inside: avoid; }
  .print-area table.data-table { font-size: 10pt; }
  .print-area h1 { font-size: 16pt; }
  .print-area h2 { font-size: 13pt; }
}