.flash-wrap{max-width:520px;margin:0 auto;perspective:1400px}.flash-card{position:relative;height:340px;transform-style:preserve-3d;transition:transform .5s cubic-bezier(.3,1.2,.4,1);cursor:pointer}.flash-card.flipped{transform:rotateY(180deg)}.flash-face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;background:var(--surface);border:1px solid var(--line);border-radius:var(--r-l);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px;box-shadow:var(--shadow-m);padding:24px;text-align:center}.flash-face.back{transform:rotateY(180deg)}.flash-face .hanzi{font-family:var(--f-hz);font-size:80px;line-height:1.2}.flash-face .py{font-size:24px;font-weight:600}.flash-face .mean{font-size:19px;color:var(--ink-2)}.flash-face .hint{position:absolute;bottom:16px;font-size:12px;color:var(--muted)}.flash-face .mode-tag{position:absolute;top:16px;left:18px}.srs-btns{display:grid;grid-template-columns:repeat(2,1fr);grid-gap:9px;gap:9px;margin-top:18px}.srs-btn{min-height:48px;padding:12px 6px;border-radius:12px;font-weight:700;font-size:14px;border:1.5px solid transparent;transition:all .13s;display:flex;flex-direction:column;gap:2px;align-items:center}.srs-btn small{font-size:10.5px;font-weight:600;opacity:.75}.srs-btn:active{transform:scale(.96)}.srs-btn.again{background:var(--brand-soft);color:var(--danger)}.srs-btn.hard{background:var(--gold-soft);color:var(--gold)}.srs-btn.good{background:var(--jade-soft);color:var(--jade)}.srs-btn.easy{background:var(--blue-soft);color:var(--blue)}.srs-btn:hover{border-color:currentColor}@media (max-width:900px){.flash-card{height:300px}.flash-face .hanzi{font-size:64px}}