.home .hero[data-action="study"]{cursor:pointer;border:0;background:transparent;box-shadow:none;padding:0;border-radius:24px}
.home .hero[data-action="study"]:focus-visible{outline:3px solid var(--accent);outline-offset:3px}
.home .study-invite{position:relative;flex:0 0 auto;grid-column:1;grid-row:4;text-align:center;align-self:center;width:100%;max-width:340px;margin:0 auto 12px;padding:0 15px;color:var(--accent);font-size:13px;font-weight:700;line-height:1.4;text-wrap:balance}
@media(orientation:portrait) and (max-width:900px){.home .hero.original-cards{margin-bottom:4px}.home .study-invite{font-size:12px;margin-bottom:10px}}
#app:has(.study){height:100dvh;min-height:0;overflow:auto;background:#fff8e8}
.study{box-sizing:border-box;width:100%;max-width:620px;min-height:100%;margin:auto;padding:max(14px,env(safe-area-inset-top)) 18px max(18px,env(safe-area-inset-bottom));display:flex;flex-direction:column;gap:14px;color:#20354a;background:#fff8e8}
.study button{touch-action:manipulation;color:inherit;font:inherit;cursor:pointer}
.study-header{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-shrink:0}
.study-header strong{font-size:18px;letter-spacing:-.02em;text-align:center}
.study-header button{width:46px;height:46px;border:1px solid #ddd6c5;background:#fffdf6;border-radius:16px;font-size:25px;box-shadow:0 2px 0 #20354a10}
.study-header span{min-width:46px;text-align:right;font-size:14px;font-weight:700;font-variant-numeric:tabular-nums}
.study progress{width:100%;height:8px;border:0;border-radius:99px;overflow:hidden;accent-color:var(--accent);flex-shrink:0;background:#e6dfd0}
.study progress::-webkit-progress-bar{background:#e6dfd0;border-radius:99px}.study progress::-webkit-progress-value{background:var(--accent);border-radius:99px}
.study-picture{position:relative;flex:1 1 300px;min-height:220px;max-height:560px;width:100%;border:2px solid #20354a;border-radius:24px;background:#fffdf6;box-shadow:0 6px 0 #20354a12;perspective:1000px;overflow:hidden}
.study-face{position:absolute;inset:0;padding:16px 20px 14px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;backface-visibility:hidden;transition:transform .35s}
.study-front{transform:rotateY(0)}.study-back{transform:rotateY(180deg)}
.is-flipped .study-front{transform:rotateY(-180deg)}.is-flipped .study-back{transform:rotateY(0)}
.study-face img{width:100%;height:calc(100% - 26px);min-height:0;object-fit:contain}
.study-face small{font-size:12px;font-weight:600;color:#687684;flex-shrink:0}
.study-back strong{font-size:clamp(24px,7vw,42px);overflow-wrap:anywhere}.study-back>span{font-size:22px}
.study-slots{display:flex;justify-content:center;gap:8px;flex-shrink:0;padding-top:4px}
.study-slots>span{width:clamp(44px,13vw,58px);height:clamp(44px,13vw,58px);border:1px solid #c9c8bd;border-radius:14px;display:grid;place-items:center;font-weight:900;font-size:26px;color:#aaa;background:#fffdf6}
.study-slots>.filled{color:#20354a}.study-slots>.current{border:3px solid var(--accent);background:#fff}
.study-feedback{min-height:22px;margin:-2px 0 0;text-align:center;font-size:15px;font-weight:650;flex-shrink:0}
.study-choices{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;flex-shrink:0}
.study-choices button{min-height:58px;border:2px solid var(--accent);border-radius:17px;background:#fffdf6;box-shadow:0 4px 0 var(--accent);font-size:28px;font-weight:900}
.study-choices button:disabled{opacity:.3;box-shadow:none}.study-choices .study-next{grid-column:1/-1;background:var(--accent);color:white;font-size:20px}
@media(max-height:700px){.study{gap:9px;padding:10px 14px;min-height:100%}.study-picture{flex-basis:210px;min-height:180px}.study-choices button{min-height:50px}.study-slots>span{width:42px;height:42px}.study-face{padding:10px}.study-header button{width:42px;height:42px}}
@media(prefers-reduced-motion:reduce){.study-face{transition:none}}
.study-meaning-front{width:min(90%,430px);min-height:150px;padding:28px;display:grid;place-items:center;border:3px solid #20354a;border-radius:22px;background:#fff;color:#20354a;font-size:clamp(30px,9vw,54px);line-height:1.3;word-break:keep-all;box-shadow:0 7px 0 #20354a16}.study-front .image-fallback{display:none}