.yl-fc-study{background:var(--color-bg);color:var(--color-fg);font-family:var(--font-sans);padding:12px 16px calc(16px + env(safe-area-inset-bottom,0px));z-index:120;flex-direction:column;gap:12px;display:flex;position:fixed;inset:0}.yl-fc-study:focus{outline:none}.yl-fc-head{align-items:center;gap:12px;min-height:40px;display:flex}.yl-fc-close{border:1px solid var(--color-border);border-radius:var(--radius-control);color:var(--color-fg);cursor:pointer;font:500 18px/1 var(--font-sans);touch-action:manipulation;height:40px;transition:background-color var(--motion-fast) var(--ease-out-soft);background:0 0;justify-content:center;align-items:center;width:40px;display:inline-flex}.yl-fc-close:hover{background:var(--color-surface-muted)}.yl-fc-close:focus-visible{outline:2px solid var(--color-accent);outline-offset:2px}.yl-fc-count{color:var(--color-fg);font:650 15px/1 var(--font-mono);text-align:center;flex:1}.yl-fc-stacks{gap:10px;display:inline-flex}.yl-fc-stack{font:650 13px/1 var(--font-mono);border-radius:999px;padding:6px 10px}.yl-fc-stack--known{background:var(--color-success-soft);color:var(--color-success)}.yl-fc-stack--learning{background:var(--color-surface-muted);color:var(--color-muted)}.yl-fc-stack{animation:yl-fc-pulse var(--motion-fast) var(--ease-out-soft)}@keyframes yl-fc-pulse{0%{transform:scale(1)}50%{transform:scale(1.18)}to{transform:scale(1)}}.yl-fc-resume{color:var(--color-muted);font:500 13px/1.4 var(--font-sans);text-align:center;margin:0}.yl-fc-stage{flex:1;width:100%;max-width:480px;min-height:0;margin:0 auto;position:relative}.yl-fc-card{touch-action:pan-y;position:absolute;inset:0}.yl-fc-card--next{transform:scale(.94)translateY(12px)}.yl-fc-card--fly-right,.yl-fc-card--fly-left{opacity:0;transition:transform var(--motion-base) var(--ease-out-soft), opacity var(--motion-base) var(--ease-out-soft)}.yl-fc-card--fly-right{transform:translate(120%)rotate(8deg)}.yl-fc-card--fly-left{transform:translate(-120%)rotate(-8deg)}.yl-fc-card--rejected{animation:yl-fc-rubber var(--motion-fast) var(--ease-out-soft)}@keyframes yl-fc-rubber{0%{transform:translate(0)}45%{transform:translate(10px)}to{transform:translate(0)}}.yl-fc-flip{color:inherit;cursor:pointer;font:inherit;perspective:1200px;text-align:center;background:0 0;border:0;width:100%;height:100%;padding:0;display:block}.yl-fc-flip:focus-visible .yl-fc-face--front,.yl-fc-flip:focus-visible .yl-fc-face--back{outline:2px solid var(--color-accent);outline-offset:2px}.yl-fc-flip-inner{height:100%;transform-style:preserve-3d;transition:transform var(--yl-fc-flip-ms,.42s) var(--ease-out-soft);width:100%;display:block;position:relative}.yl-fc-flip.is-flipped .yl-fc-flip-inner{transform:rotateY(180deg)}.yl-fc-face{backface-visibility:hidden;background:var(--color-card);border:1px solid var(--color-border);border-radius:var(--radius-card);box-shadow:var(--shadow-soft);flex-direction:column;justify-content:center;align-items:center;gap:14px;padding:20px;display:flex;position:absolute;inset:0;overflow:hidden}.yl-fc-face--back{transform:rotateY(180deg)}.yl-fc-speak{background:var(--color-card);border:1px solid var(--color-border);color:var(--color-muted);cursor:pointer;touch-action:manipulation;height:40px;transition:background-color var(--motion-fast) var(--ease-out-soft);z-index:1;border-radius:999px;justify-content:center;align-items:center;width:40px;display:inline-flex;position:absolute;top:12px;right:12px}.yl-fc-speak:hover{background:var(--color-surface-muted);color:var(--color-fg)}.yl-fc-speak:focus-visible{outline:2px solid var(--color-accent);outline-offset:2px}.yl-fc-face-label{color:var(--color-muted);font:650 11px/1 var(--font-sans);letter-spacing:.08em;text-transform:uppercase}.yl-fc-face-text{font:500 20px/1.4 var(--font-sans);overflow-wrap:anywhere;white-space:pre-wrap;margin:0}.yl-fc-face-media{background:var(--color-surface-muted);border-radius:var(--radius-panel);flex:none;width:100%;height:38%;min-height:88px;max-height:220px;overflow:hidden}.yl-fc-face-media img{object-fit:contain;width:100%;height:100%;display:block}.yl-fc-hint{color:var(--color-muted);font:500 13px/1.4 var(--font-sans);text-align:center;min-height:18px;margin:0}.yl-fc-actions{gap:12px;width:100%;max-width:480px;min-height:42px;margin:0 auto;display:flex}.yl-fc-actions .yl-ui-button{flex:1}.yl-fc-screen{text-align:center;flex-direction:column;flex:1;justify-content:center;align-items:center;gap:14px;width:100%;max-width:480px;margin:0 auto;display:flex}.yl-fc-screen h2{font:750 24px/1.2 var(--font-sans);margin:0}.yl-fc-screen p{color:var(--color-muted);font:400 15px/1.6 var(--font-sans);margin:0}.yl-fc-screen .yl-ui-button{min-width:220px}.yl-fc-score{color:var(--color-fg);font:650 15px/1 var(--font-mono)}@media (prefers-reduced-motion:reduce){.yl-fc-stack,.yl-fc-card--rejected{animation:none}.yl-fc-card--fly-right,.yl-fc-card--fly-left{opacity:1;transition:none;transform:none}.yl-fc-flip-inner,.yl-fc-flip.is-flipped .yl-fc-flip-inner{transition:none;transform:none}.yl-fc-face{backface-visibility:visible;transition:opacity var(--motion-fast) var(--ease-out-soft)}.yl-fc-face--back{transform:none}.yl-fc-flip:not(.is-flipped) .yl-fc-face--back,.yl-fc-flip.is-flipped .yl-fc-face--front{opacity:0}}