.learn { min-height: 100dvh; }
.lbar { display: flex; align-items: center; justify-content: space-between; padding: calc(12px + env(safe-area-inset-top)) 16px 12px; position: sticky; top: 0; background: var(--paper); z-index: 2; border-bottom: 1px solid var(--tone); }
.lbar .brand { display: flex; align-items: center; gap: 8px; font-weight: 600; color: var(--ink); text-decoration: none; }
.streak { color: var(--soft); font-size: .95rem; font-weight: 500; }
.lmain { max-width: 560px; margin: 0 auto; padding: 12px 16px calc(32px + env(safe-area-inset-bottom)); }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin: 8px 0 18px; }
.stats div { background: var(--card); border: 1px solid var(--tone); border-radius: var(--radius); padding: 14px 10px; text-align: center; }
.stats b { display: block; font-size: 1.8rem; font-variant-numeric: tabular-nums; letter-spacing: -0.02em; }
.stats span { color: var(--soft); font-size: .85rem; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 12px 0; }
.actions .btn { flex: 1; justify-content: center; border: 0; cursor: pointer; font: inherit; font-weight: 600; }
.btn.small { padding: .55em 1em; font-size: .9rem; flex: 0 1 auto; }
.empty, .list { background: var(--card); border: 1px solid var(--tone); border-radius: var(--radius); padding: 14px 16px; margin: 14px 0; }
.list summary { cursor: pointer; font-weight: 600; }
.list input[type=search] { width: 100%; margin: 12px 0 6px; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--tone); background: var(--paper); color: var(--ink); font: inherit; }
.list ul { list-style: none; margin: 0; padding: 0; }
.list li { display: flex; gap: 10px; justify-content: space-between; align-items: flex-start; padding: 10px 0; border-bottom: 1px solid var(--tone); }
.list li p { margin: 0; overflow-wrap: anywhere; }
.list li small { color: var(--soft); display: block; }
.list li button { border: 0; background: none; color: var(--soft); font-size: 1.1rem; cursor: pointer; padding: 0 4px; }
.fine { color: var(--soft); font-size: .9rem; line-height: 1.5; }
.toast { background: var(--accent-soft); border-radius: 10px; padding: 10px 14px; margin: 8px 0; }
.progress { display: flex; justify-content: space-between; align-items: center; color: var(--soft); margin: 4px 0 12px; font-size: .9rem; }
.back { border: 0; background: none; color: var(--accent); font: inherit; font-weight: 600; cursor: pointer; padding: 6px 0; }

/* 3D Realistic Physical Flashcard */
.flash {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 14px;
  width: 100%;
  min-height: 48dvh;
  padding: 28px 24px;
  border: 1px solid var(--tone);
  border-radius: 24px;
  background: var(--card);
  color: var(--ink);
  box-shadow: 0 14px 34px -10px rgba(0, 0, 0, 0.12), 0 2px 6px rgba(0, 0, 0, 0.04);
  font: inherit;
  text-align: center;
  cursor: pointer;
  perspective: 1200px;
  transform-style: preserve-3d;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.flash:active {
  transform: scale(0.985);
}
.flash.static { min-height: 22dvh; cursor: default; }
.face { font-size: clamp(1.3rem, 6vw, 2.1rem); font-weight: 700; line-height: 1.35; overflow-wrap: anywhere; white-space: pre-wrap; }
.face.answer {
  font-size: clamp(1.1rem, 5vw, 1.55rem);
  font-weight: 600;
  color: var(--accent);
  border-top: 1px solid var(--tone);
  padding-top: 16px;
  animation: card-flip-reveal 0.38s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  transform-origin: center top;
}

@keyframes card-flip-reveal {
  0% {
    opacity: 0;
    transform: rotateX(65deg) translateY(10px);
  }
  100% {
    opacity: 1;
    transform: rotateX(0deg) translateY(0);
  }
}

.face .detail { display: block; margin-top: 8px; font-size: .95rem; color: var(--soft); font-weight: 400; }
.speak {
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 14px auto 0;
  border: 1px solid var(--tone);
  background: var(--card);
  border-radius: 999px;
  width: 44px;
  height: 44px;
  font-size: 1.2rem;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease;
}
.speak:hover {
  border-color: var(--accent);
  transform: scale(1.05);
}
.speak:active {
  transform: scale(0.92);
}
.hint { text-align: center; color: var(--soft); font-size: .9rem; margin-top: 10px; }

/* Tactile SRS Rating Buttons */
.grades {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 18px;
  animation: grades-fade-in 0.25s ease-out;
}
.grades[hidden] { display: none; }

@keyframes grades-fade-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.grades button {
  padding: 12px 4px;
  border: 1px solid var(--tone);
  border-radius: 16px;
  background: var(--card);
  color: var(--ink);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease, background 0.15s ease;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03);
}
.grades button:hover {
  border-color: var(--accent);
}
.grades button:active {
  transform: scale(0.95);
}
.grades button small { display: block; color: var(--soft); font-weight: 400; font-size: .78rem; margin-top: 2px; }

.grades [data-grade="0"] { color: #e11d48; }
.grades [data-grade="1"] { color: #d97706; }
.grades [data-grade="2"] { color: #0284c7; }
.grades [data-grade="3"] { color: #059669; }

.choices { display: grid; gap: 10px; margin: 16px 0; }
.choices button { padding: 14px 16px; border: 2px solid transparent; border-radius: 14px; background: var(--card); color: var(--ink); font: inherit; text-align: left; cursor: pointer; overflow-wrap: anywhere; box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03); }
.choices .right { border-color: #16a34a; background: color-mix(in srgb, #16a34a 10%, var(--card)); }
.choices .wrong { border-color: #dc2626; opacity: .85; }
#quiz-next { width: 100%; justify-content: center; border: 0; cursor: pointer; font: inherit; font-weight: 600; }
#done { text-align: center; padding-top: 12dvh; }
.done-big { font-size: 3.5rem; margin: 0; }
.lmain section { padding: 0; }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .flash {
    box-shadow: 0 16px 36px -10px rgba(0, 0, 0, 0.45);
  }
  :root:not([data-theme="light"]) .grades [data-grade="0"] { color: #fb7185; }
  :root:not([data-theme="light"]) .grades [data-grade="1"] { color: #fbbf24; }
  :root:not([data-theme="light"]) .grades [data-grade="2"] { color: #38bdf8; }
  :root:not([data-theme="light"]) .grades [data-grade="3"] { color: #34d399; }
  :root:not([data-theme="light"]) .choices .right { border-color: #22c55e; }
  :root:not([data-theme="light"]) .choices .wrong { border-color: #ef4444; }
}

:root[data-theme="dark"] .flash {
  box-shadow: 0 16px 36px -10px rgba(0, 0, 0, 0.45);
}
:root[data-theme="dark"] .grades [data-grade="0"] { color: #fb7185; }
:root[data-theme="dark"] .grades [data-grade="1"] { color: #fbbf24; }
:root[data-theme="dark"] .grades [data-grade="2"] { color: #38bdf8; }
:root[data-theme="dark"] .grades [data-grade="3"] { color: #34d399; }
:root[data-theme="dark"] .choices .right { border-color: #22c55e; }
:root[data-theme="dark"] .choices .wrong { border-color: #ef4444; }