.study-navigation { display: grid; gap: 13px; }
.study-arrows { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.study-arrows .btn { min-width: 142px; min-height: 46px; }
.study-history-hint { color: var(--muted); font-size: .78rem; text-align: center; }
.study-history { border: 1px solid var(--line); background: var(--panel); border-radius: 16px; overflow: hidden; }
.study-history summary { display: flex; align-items: center; gap: 8px; cursor: pointer; padding: 14px 16px; font-size: .86rem; font-weight: 700; color: var(--muted); }
.study-history summary::after { content: '+'; font-size: 1.15rem; margin-left: auto; }
.study-history[open] summary::after { content: '−'; }
.study-history summary:focus-visible { outline: 2px solid var(--violet); outline-offset: -4px; border-radius: 12px; }
.study-history summary span { padding: 2px 7px; border-radius: 7px; background: var(--card); color: var(--text); }
.study-history-list { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; padding: 0 12px 12px; max-height: 240px; overflow: auto; }
.study-history-list button { display: flex; align-items: center; gap: 9px; min-height: 44px; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--text); padding: 9px; text-align: left; }
.study-history-list button:hover, .study-history-list button[aria-current] { border-color: var(--violet); background: color-mix(in srgb, var(--violet) 13%, var(--panel)); }
.study-history-list strong { overflow-wrap: anywhere; min-width: 0; font-size: .83rem; }
.study-history-list button > span { color: var(--muted); font-size: .75rem; }
.study-history-list svg { margin-left: auto; color: var(--success-ink); }
.study-history-banner { display: flex; gap: 10px; align-items: center; color: var(--violet); border-radius: 14px; background: color-mix(in srgb, var(--violet) 9%, var(--panel)); padding: 12px 16px; }
.study-history-banner strong { font-size: .87rem; }
.study-history-banner p { margin-top: 3px; font-size: .79rem; color: var(--muted); line-height: 1.5; }
.study-history-card { display: grid; gap: 10px; text-align: center; justify-items: center; align-content: center; min-height: 310px; padding: 32px 24px; background: var(--flash-bg, var(--panel)); touch-action: pan-y; animation: history-card-in 180ms ease-out; }
.study-history-card .flash-word { font-size: clamp(2rem, 7vw, 4.3rem); }
.study-history-card .eyebrow { letter-spacing: .06em; }
.study-history-card .actions { justify-content: center; margin-top: 14px; }
@keyframes history-card-in { from { opacity: .5; transform: translateX(-12px); } to { opacity: 1; transform: none; } }
@media (max-width: 550px) {
  .study-history-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .study-arrows .btn { min-width: 0; flex: 1; }
  .study-history-card { padding: 24px 16px; }
}
@media (prefers-reduced-motion: reduce) { .study-history-card { animation: none; } }