/* ===== FX — motion & visual-polish layer =====
   Loaded last so it can refine rules from the other sheets. Everything here
   resolves from the design tokens in main.css and degrades gracefully:
   prefers-reduced-motion is already zeroed globally, and heavier effects sit
   behind @supports guards. */

:root {
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-in: cubic-bezier(0.55, 0, 0.55, 0.2);
}

/* ===== Micro-interactions: press states ===== */
.btn-primary:active, .btn-ghost:active, .btn-generate:active:not(:disabled),
.start-study-btn:active, .start-quiz-btn:active, .study-btn:active,
.quiz-option:active:not(.disabled), .filter-btn:active, .topic-chip:active,
.input-tab:active, .demo-btn:active, .btn-share:active, .btn-copy:active,
.timer-option:active, .quiz-next-btn:active, .lang-btn:active {
  transform: scale(0.97);
  transition-duration: 0.06s;
}

/* ===== Aurora home background ===== */
#input-view { position: relative; isolation: isolate; }

#input-view::before,
#input-view::after {
  content: '';
  position: fixed;
  z-index: -1;
  width: 46vmax;
  height: 46vmax;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.16;
  pointer-events: none;
}

#input-view::before {
  background: radial-gradient(circle at 35% 35%, var(--primary), transparent 65%);
  top: -18vmax;
  left: -10vmax;
  animation: auroraA 26s ease-in-out infinite alternate;
}

#input-view::after {
  background: radial-gradient(circle at 60% 60%, var(--secondary), transparent 65%);
  bottom: -20vmax;
  right: -12vmax;
  opacity: 0.11;
  animation: auroraB 32s ease-in-out infinite alternate;
}

@keyframes auroraA {
  from { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(9vmax, 6vmax) scale(1.15); }
  to   { transform: translate(2vmax, 12vmax) scale(0.95); }
}

@keyframes auroraB {
  from { transform: translate(0, 0) scale(1); }
  50%  { transform: translate(-8vmax, -7vmax) scale(1.12); }
  to   { transform: translate(-3vmax, -13vmax) scale(1.02); }
}

:root[data-theme="light"] #input-view::before { opacity: 0.12; }
:root[data-theme="light"] #input-view::after { opacity: 0.09; }

/* ===== Glass topbar ===== */
@supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
  .topbar {
    background: color-mix(in srgb, var(--surface) 78%, transparent);
    backdrop-filter: blur(14px) saturate(1.3);
    -webkit-backdrop-filter: blur(14px) saturate(1.3);
  }
}

/* ===== Sliding study-tab indicator ===== */
.study-tabs { position: relative; }

.tab-indicator {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  border-radius: 2px 2px 0 0;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  transition: transform 0.35s var(--ease-spring), width 0.35s var(--ease-spring);
  pointer-events: none;
  will-change: transform;
}

/* The moving pill replaces the per-tab underline on desktop. */
.study-tab.active { border-bottom-color: transparent; }

@media (max-width: 768px) {
  .tab-indicator { display: none; }
}

/* ===== Directional tab-content transitions ===== */
.tab-content.tab-slide-left { animation: tabSlideLeft 0.3s var(--ease-out) both; }
.tab-content.tab-slide-right { animation: tabSlideRight 0.3s var(--ease-out) both; }

@keyframes tabSlideLeft {
  from { opacity: 0; transform: translateX(26px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes tabSlideRight {
  from { opacity: 0; transform: translateX(-26px); }
  to   { opacity: 1; transform: translateX(0); }
}

/* ===== Staggered entrances =====
   Give children style="--i:n" and the container renders them as a cascade.
   `both` keeps the `from` state during the per-item delay. */
.fade-up {
  animation: fadeUpIn 0.5s var(--ease-out) both;
  animation-delay: calc(var(--i, 0) * 35ms);
}

@keyframes fadeUpIn {
  from { opacity: 0; transform: translateY(14px) scale(0.985); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

/* Scroll-reveal (notes sections) — FX.observe() flips .in via IntersectionObserver. */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.55s var(--ease-out), transform 0.55s var(--ease-out);
  transition-delay: calc(min(var(--i, 0), 6) * 45ms);
}

.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; }
}

/* ===== Flashcard grid: difficulty tints, springy flip, tilt ===== */
.flashcard-inner {
  transition: transform 0.55s var(--ease-spring);
}

.flashcard {
  transition: transform 0.25s var(--ease-out);
  will-change: transform;
}

.flashcard-front { background: linear-gradient(150deg, #7c3aed, #5b21b6); }
.flashcard.diff-easy .flashcard-front { background: linear-gradient(150deg, #0d9488, #065f56); }
.flashcard.diff-hard .flashcard-front { background: linear-gradient(150deg, #9333ea, #6d1fa8 55%, #86198f); }

.flashcard-front::after, .flashcard-back::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(120% 90% at 20% 0%, rgba(255, 255, 255, 0.14), transparent 55%);
  pointer-events: none;
}

/* ===== Study mode: springy flip + drag physics ===== */
.study-card-inner { transition: transform 0.55s var(--ease-spring); }

.study-card {
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

.study-card.flipped { cursor: grab; }
.study-card.dragging { cursor: grabbing; }
.study-card.dragging .study-card-inner { transition: none; }

/* Spring back to center after an under-threshold drag. */
.study-card.spring-back { transition: transform 0.45s var(--ease-spring); }

/* Directional glow while dragging toward a rating. */
.study-card.drag-right .study-card-back {
  box-shadow: 0 0 0 3px rgba(34, 197, 94, 0.75), 0 24px 64px rgba(34, 197, 94, 0.35);
}
.study-card.drag-left .study-card-back {
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.75), 0 24px 64px rgba(239, 68, 68, 0.35);
}
.study-card.drag-up .study-card-back {
  box-shadow: 0 0 0 3px rgba(251, 191, 36, 0.75), 0 24px 64px rgba(251, 191, 36, 0.35);
}

/* Fly-off exits (start from the current inline transform). */
.study-card.fly-right { animation: flyRight 0.32s var(--ease-in) forwards; }
.study-card.fly-left { animation: flyLeft 0.32s var(--ease-in) forwards; }
.study-card.fly-up { animation: flyUp 0.32s var(--ease-in) forwards; }

@keyframes flyRight { to { transform: translate(120vw, -8vh) rotate(24deg); opacity: 0; } }
@keyframes flyLeft { to { transform: translate(-120vw, -8vh) rotate(-24deg); opacity: 0; } }
@keyframes flyUp { to { transform: translateY(-120vh) rotate(-6deg); opacity: 0; } }

/* Next-card entrance (replaces the old slideInRight reset trick). */
.study-card.card-enter { animation: cardEnter 0.4s var(--ease-spring) both; }

@keyframes cardEnter {
  from { opacity: 0; transform: translateX(48px) scale(0.94) rotate(2deg); }
  to   { opacity: 1; transform: none; }
}

.deck-complete-card { animation: popIn 0.45s var(--ease-spring) both; }

@keyframes popIn {
  from { opacity: 0; transform: scale(0.86) translateY(14px); }
  to   { opacity: 1; transform: none; }
}

/* ===== Quiz feedback ===== */
.shake { animation: shakeX 0.4s var(--ease-out); }

@keyframes shakeX {
  20%, 60% { transform: translateX(-7px); }
  40%, 80% { transform: translateX(7px); }
}

.quiz-option { transition: all var(--transition), transform 0.15s var(--ease-out); }
.quiz-option:not(.disabled):hover { transform: translateY(-1px); }

.opt-check, .opt-cross {
  width: 20px;
  height: 20px;
  margin-left: auto;
  flex-shrink: 0;
}

.opt-check path {
  stroke: var(--correct);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  stroke-dasharray: 26;
  stroke-dashoffset: 26;
  animation: drawCheck 0.35s var(--ease-out) 0.1s forwards;
}

@keyframes drawCheck { to { stroke-dashoffset: 0; } }

.opt-cross path {
  stroke: var(--wrong);
  stroke-width: 3;
  stroke-linecap: round;
  fill: none;
  stroke-dasharray: 20;
  stroke-dashoffset: 20;
  animation: drawCheck 0.25s var(--ease-out) forwards;
}

/* ===== Animated score ring (exam results) ===== */
.quiz-score-ring {
  position: relative;
  width: 152px;
  height: 152px;
  margin: 0 auto 14px;
}

.quiz-score-ring svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.ring-track {
  fill: none;
  stroke: var(--border);
  stroke-width: 9;
}

.ring-fill {
  fill: none;
  stroke: url(#ring-grad);
  stroke-width: 9;
  stroke-linecap: round;
  stroke-dasharray: 100;
  stroke-dashoffset: calc(100 - var(--pct, 0));
  transition: stroke-dashoffset 1.1s var(--ease-out) 0.15s;
}

.ring-center {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
}

.ring-center .quiz-score-value {
  font-family: var(--font-display);
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1;
}

.ring-center .quiz-score-percent {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.quiz-grade { animation: gradePop 0.5s var(--ease-spring) 0.65s both; }

@keyframes gradePop {
  from { opacity: 0; transform: scale(0.4) rotate(-8deg); }
  to   { opacity: 1; transform: none; }
}

.quiz-result-stat { animation: fadeUpIn 0.45s var(--ease-out) both; animation-delay: calc(var(--i, 0) * 60ms + 0.3s); }

/* ===== Stats ===== */
.stat-tile { animation: fadeUpIn 0.45s var(--ease-out) both; animation-delay: calc(var(--i, 0) * 50ms); }

.stat-bar {
  transform-box: fill-box;
  transform-origin: bottom;
  animation: barGrow 0.6s var(--ease-out) both;
  animation-delay: calc(var(--i, 0) * 30ms + 0.15s);
}

@keyframes barGrow { from { transform: scaleY(0); } }

.stat-bar-num {
  animation: fadeUpIn 0.4s ease both;
  animation-delay: calc(var(--i, 0) * 30ms + 0.55s);
}

.stat-line {
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: drawLine 1.1s var(--ease-out) 0.2s forwards;
}

@keyframes drawLine { to { stroke-dashoffset: 0; } }

.stat-dot {
  animation: dotIn 0.3s var(--ease-spring) both;
  animation-delay: calc(var(--i, 0) * 70ms + 0.25s);
  transform-box: fill-box;
  transform-origin: center;
}

@keyframes dotIn {
  from { opacity: 0; transform: scale(0); }
  to   { opacity: 1; transform: scale(1); }
}

/* Activity heatmap + forecast (no entrance animation on cells — the level
   classes drive opacity and an animation would fight them) */
.heat-0 { fill: var(--border); opacity: 0.55; }
.heat-1 { fill: var(--primary); opacity: 0.3; }
.heat-2 { fill: var(--primary); opacity: 0.55; }
.heat-3 { fill: var(--primary); opacity: 0.8; }
.heat-4 { fill: var(--primary); opacity: 1; }
.forecast-bar { fill: var(--secondary); }

.flame {
  display: inline-block;
  animation: flicker 1.6s ease-in-out infinite;
  transform-origin: 50% 85%;
}

@keyframes flicker {
  0%, 100% { transform: scale(1) rotate(-2deg); }
  30% { transform: scale(1.12) rotate(2deg); }
  60% { transform: scale(0.96) rotate(-1deg); }
}

/* Empty state */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  padding: 56px 20px;
  text-align: center;
  color: var(--text-muted);
}

.empty-state svg { width: 72px; height: 72px; opacity: 0.55; }
.empty-state p { font-size: 0.95rem; max-width: 340px; }

/* ===== Toast: spring in + auto-dismiss progress ===== */
.toast {
  position: relative;
  overflow: hidden;
  animation: toastSpring 0.45s var(--ease-spring);
}

@keyframes toastSpring {
  from { opacity: 0; transform: translateX(56px) scale(0.92); }
  to   { opacity: 1; transform: none; }
}

.toast-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  opacity: 0.6;
  animation: toastDrain linear forwards;
}

@keyframes toastDrain { from { width: 100%; } to { width: 0%; } }

/* ===== Generation progress: stage checklist + skeleton ===== */
.gen-progress {
  margin-top: 14px;
  padding: 16px 18px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  animation: fadeUpIn 0.35s var(--ease-out);
}

.gen-step {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 5px 0;
  font-size: 0.88rem;
  color: var(--text-muted);
  transition: color 0.3s ease;
}

.gen-step.active { color: var(--text); }
.gen-step.done { color: var(--text-muted); }

.gen-step-icon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.gen-step .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--border-strong);
}

.gen-step.active .spinner { width: 15px; height: 15px; color: var(--primary); }

.gen-step.done .gen-check {
  width: 15px;
  height: 15px;
}

.gen-check path {
  stroke: var(--correct);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  stroke-dasharray: 26;
  stroke-dashoffset: 26;
  animation: drawCheck 0.35s var(--ease-out) forwards;
}

.gen-live {
  margin-top: 6px;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--secondary);
  min-height: 0;
}

.gen-live:empty { display: none; }

.gen-skeleton {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.gen-skeleton span {
  height: 10px;
  border-radius: 5px;
  background: linear-gradient(90deg, var(--border) 25%, var(--border-strong) 42%, var(--border) 60%);
  background-size: 220% 100%;
  animation: shimmer 1.4s linear infinite;
}

.gen-skeleton span:nth-child(1) { width: 72%; }
.gen-skeleton span:nth-child(2) { width: 92%; }
.gen-skeleton span:nth-child(3) { width: 58%; }

@keyframes shimmer {
  from { background-position: 160% 0; }
  to   { background-position: -60% 0; }
}

/* ===== Deck library: mastery ring + stagger ===== */
.deck-card { align-items: center; }
.deck-card .deck-card-body { flex: 1; }

.deck-ring-wrap {
  position: relative;
  width: 42px;
  height: 42px;
  flex-shrink: 0;
}

.deck-ring { width: 100%; height: 100%; transform: rotate(-90deg); }

.deck-ring-bg { fill: none; stroke: var(--border); stroke-width: 3.5; }

.deck-ring-fill {
  fill: none;
  stroke: var(--primary);
  stroke-width: 3.5;
  stroke-linecap: round;
  stroke-dasharray: var(--pct, 0) 100;
  animation: ringIn 0.9s var(--ease-out) 0.2s both;
}

@keyframes ringIn { from { stroke-dasharray: 0 100; } }

.deck-ring-num {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.58rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

/* ===== Deck management: kebab menu + search ===== */
.deck-card { position: relative; }

.deck-card-menu-btn {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 1.1rem;
  line-height: 1;
  color: var(--text-muted);
  opacity: 0.65;
  transition: all var(--transition);
}

.deck-card-menu-btn:hover { opacity: 1; color: var(--text); background: var(--card-raised); }

.deck-menu {
  position: absolute;
  top: 40px;
  right: 10px;
  z-index: 60;
  min-width: 150px;
  background: var(--card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  animation: paletteIn 0.18s var(--ease-out);
}

.deck-menu button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 9px 14px;
  font-size: 0.85rem;
  color: var(--text);
}

.deck-menu button:hover { background: var(--surface); }
.deck-menu .deck-menu-danger { color: var(--wrong); }

.deck-search {
  padding: 6px 12px;
  font-size: 0.82rem;
  border-radius: 50px;
  background: var(--surface);
  max-width: 200px;
}

.deck-search-empty {
  padding: 18px 4px;
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* Mistake notebook (exam ready screen) */
.mistakes-row { margin-top: 16px; text-align: center; }
.mistakes-btn { border-color: rgba(239, 68, 68, 0.4); color: var(--wrong); }
.mistakes-btn:hover { border-color: var(--wrong); background: rgba(239, 68, 68, 0.08); color: var(--wrong); }
.mistakes-hint { margin-top: 6px; font-size: 0.76rem; color: var(--text-muted); }

.explain-btn { margin-top: 8px; font-size: 0.8rem; }

/* ===== Sync modal + library tools ===== */
.deck-library-tools { display: flex; align-items: center; gap: 8px; }
.deck-sync-btn { font-size: 0.78rem; padding: 5px 12px; border-radius: 50px; }

.sync-card { max-width: 420px; }
.sync-desc { font-size: 0.88rem; color: var(--text-muted); margin-bottom: 16px; line-height: 1.55; }
.sync-warn { font-size: 0.76rem; color: var(--highlight); margin: 10px 0 4px; }
.sync-last { font-size: 0.76rem; color: var(--text-muted); margin-bottom: 14px; }
.sync-actions { display: flex; gap: 10px; margin-top: 12px; }

/* URL importer row (paste panel) */
.url-import-row { display: flex; gap: 8px; margin-top: 10px; }
.url-import-row input { flex: 1; min-width: 0; font-size: 0.88rem; background: var(--bg); }
.url-import-row .btn-ghost { white-space: nowrap; }

/* ===== Sound toggle ===== */
.sound-toggle {
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: all var(--transition);
  flex-shrink: 0;
  position: relative;
}

.sound-toggle:hover { color: var(--text); border-color: var(--border-strong); }
.sound-toggle svg { width: 17px; height: 17px; }
.sound-toggle .icon-sound-off { display: block; }
.sound-toggle .icon-sound-on { display: none; }
.sound-toggle.on { color: var(--primary); border-color: var(--primary); }
.sound-toggle.on .icon-sound-on { display: block; }
.sound-toggle.on .icon-sound-off { display: none; }

/* ===== Command palette ===== */
.palette-backdrop {
  position: fixed;
  inset: 0;
  background: var(--backdrop);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 8000;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 12vh 16px 16px;
  animation: fadeIn 0.15s ease;
}

.palette {
  width: 100%;
  max-width: 520px;
  background: var(--card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  animation: paletteIn 0.25s var(--ease-spring);
}

@keyframes paletteIn {
  from { opacity: 0; transform: translateY(-14px) scale(0.97); }
  to   { opacity: 1; transform: none; }
}

.palette-input {
  width: 100%;
  border: none;
  border-bottom: 1px solid var(--border);
  border-radius: 0;
  background: transparent;
  padding: 16px 18px;
  font-size: 1rem;
}

.palette-input:focus { box-shadow: none; border-color: var(--border); }

.palette-list {
  max-height: 46vh;
  overflow-y: auto;
  padding: 6px;
}

.palette-section {
  padding: 10px 12px 4px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.palette-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  text-align: left;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  color: var(--text);
  cursor: pointer;
}

.palette-item .palette-item-hint {
  margin-left: auto;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.palette-item.selected { background: var(--primary-tint); color: var(--primary); }

.palette-empty { padding: 24px; text-align: center; color: var(--text-muted); font-size: 0.9rem; }

.palette-footer {
  display: flex;
  gap: 14px;
  padding: 9px 14px;
  border-top: 1px solid var(--border);
  font-size: 0.72rem;
  color: var(--text-muted);
}

.palette-footer kbd {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  margin-right: 4px;
}

/* ===== Theme toggle: circular reveal (View Transitions API) ===== */
@supports (view-transition-name: root) {
  ::view-transition-old(root), ::view-transition-new(root) {
    animation: none;
    mix-blend-mode: normal;
  }

  ::view-transition-new(root) {
    clip-path: circle(0 at var(--tt-x, 50%) var(--tt-y, 0%));
    animation: themeReveal 0.5s var(--ease-out) forwards;
  }

  @keyframes themeReveal {
    to { clip-path: circle(150vmax at var(--tt-x, 50%) var(--tt-y, 0%)); }
  }
}

/* ===== Modals: scale + fade ===== */
.share-modal { animation: popIn 0.35s var(--ease-spring) both; }

/* ===== Progress bars: subtle moving sheen ===== */
.study-progress-fill, .quiz-progress-fill, .progress-fill {
  position: relative;
  overflow: hidden;
}

.study-progress-fill::after, .quiz-progress-fill::after, .progress-fill::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.35), transparent);
  background-size: 200% 100%;
  animation: shimmer 2s linear infinite;
}

/* ===== Exam: question entrance + countdown ring ===== */
#tab-quiz .quiz-container { animation: fadeUpIn 0.35s var(--ease-out); }
#quiz-feedback > * { animation: fadeUpIn 0.3s var(--ease-out); }

.quiz-timer-wrap {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  float: right;
}

.quiz-timer-wrap .quiz-timer { float: none; animation: none; }

.quiz-timer-wrap svg {
  width: 25px;
  height: 25px;
  transform: rotate(-90deg);
}

.qt-track { fill: none; stroke: var(--border); stroke-width: 3.5; }

.qt-fill {
  fill: none;
  stroke: var(--secondary);
  stroke-width: 3.5;
  stroke-linecap: round;
  stroke-dasharray: 100;
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 1s linear, stroke 0.3s ease;
}

.quiz-timer-wrap.warning .qt-fill { stroke: var(--wrong); }
.quiz-timer-wrap.warning .quiz-timer { color: var(--wrong); animation: pulse 0.5s ease infinite alternate; }

/* ===== Notes reading progress ===== */
.read-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  height: 2.5px;
  width: 0;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 0 2px 2px 0;
  transition: width 0.15s linear;
  pointer-events: none;
}

/* ===== Keyboard shortcuts overlay ===== */
.shortcuts-backdrop {
  position: fixed;
  inset: 0;
  background: var(--backdrop);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 7000;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.15s ease;
}

.shortcuts-card {
  background: var(--card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  padding: 22px 24px;
  width: 90%;
  max-width: 380px;
  box-shadow: var(--shadow-lg);
  animation: popIn 0.35s var(--ease-spring);
}

.shortcuts-card h3 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  margin-bottom: 12px;
}

.shortcut-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 8px 0;
  font-size: 0.88rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}

.shortcut-row kbd {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 2px 8px;
  color: var(--text);
  white-space: nowrap;
}

/* ===== Study card drag-discovery nudge ===== */
.study-card.drag-hint { animation: dragHint 1.5s var(--ease-out) 0.4s; }

@keyframes dragHint {
  0%, 100% { transform: none; }
  18% { transform: translateX(26px) rotate(2deg); }
  46% { transform: translateX(-20px) rotate(-1.5deg); }
  72% { transform: translateX(9px) rotate(0.8deg); }
}

/* ===== Chat: message + starter entrances ===== */
.chat-message { animation: fadeUpIn 0.35s var(--ease-out); }

.chat-starters .chat-starter { animation: fadeUpIn 0.4s var(--ease-out) both; }
.chat-starters .chat-starter:nth-child(2) { animation-delay: 0.05s; }
.chat-starters .chat-starter:nth-child(3) { animation-delay: 0.1s; }
.chat-starters .chat-starter:nth-child(4) { animation-delay: 0.15s; }
.chat-starters .chat-starter:nth-child(5) { animation-delay: 0.2s; }
.chat-starters .chat-starter:nth-child(6) { animation-delay: 0.25s; }

/* ===== Reduced motion: keep decorative layers still ===== */
@media (prefers-reduced-motion: reduce) {
  #input-view::before, #input-view::after { animation: none; }
  .gen-skeleton span, .study-progress-fill::after,
  .quiz-progress-fill::after, .progress-fill::after { animation: none; }
  .flame { animation: none; }
}