.study-wrap{display:flex;flex-direction:column;min-height:calc(100vh - 110px)}.study-top{margin-bottom:12px}.study-progress-line{display:flex;align-items:center;gap:10px;font-size:.8rem;color:var(--text-dim)}.flashcard{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;background:var(--bg-elev);border:1px solid var(--border);border-radius:var(--radius);padding:28px 20px;box-shadow:var(--shadow);min-height:300px;user-select:none;cursor:pointer}.flashcard .prompt-word{font-size:2.4rem;font-weight:700;letter-spacing:-.01em}.flashcard .prompt-pos{margin-top:6px;color:var(--text-faint);font-size:.9rem}.flashcard .answer{margin-top:18px;padding-top:18px;border-top:1px solid var(--border);width:100%}.flashcard .answer .trans{font-size:1.5rem;font-weight:600}.flashcard .reading{margin-top:6px;font-size:1rem;color:var(--accent);letter-spacing:.02em}.flashcard .answer .ex{margin-top:14px;font-size:.95rem;color:var(--text-dim);line-height:1.6}.flashcard .answer .ex .en{color:var(--text)}.flashcard .tap-hint{margin-top:20px;font-size:.8rem;color:var(--text-faint)}.cefr-tag{position:absolute;top:12px;right:14px}.rate-row{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:14px}.rate-btn{display:flex;flex-direction:column;align-items:center;gap:2px;min-height:60px;border:none;border-radius:var(--radius-sm);color:#fff;font-weight:700;padding:6px 2px}.rate-btn .when{font-size:.68rem;font-weight:500;opacity:.92}.rate-btn .key{font-size:.6rem;opacity:.7}.rate-btn[data-r="1"]{background:var(--again)}.rate-btn[data-r="2"]{background:var(--hard)}.rate-btn[data-r="3"]{background:var(--good)}.rate-btn[data-r="4"]{background:var(--easy)}.session-done{text-align:center;padding:40px 20px}.session-done .emoji{font-size:3rem}.sleep-note{background:var(--accent-soft);border:1px solid var(--border);border-radius:var(--radius-sm);padding:14px 16px;color:var(--text);font-size:.92rem;margin:16px 0}.chunk-break{text-align:center;padding:30px 20px}.heatmap{display:grid;grid-auto-flow:column;grid-template-rows:repeat(7,1fr);gap:3px;overflow-x:auto;padding-bottom:4px}.heatmap .cell{width:13px;height:13px;border-radius:3px;background:var(--heat-0)}.heatmap .cell[data-lv="1"]{background:var(--heat-1)}.heatmap .cell[data-lv="2"]{background:var(--heat-2)}.heatmap .cell[data-lv="3"]{background:var(--heat-3)}.heatmap .cell[data-lv="4"]{background:var(--heat-4)}.state-table{width:100%;border-collapse:collapse;font-size:.85rem}.state-table th,.state-table td{text-align:left;padding:8px 6px;border-bottom:1px solid var(--border)}.state-table th{color:var(--text-dim);font-weight:600;position:sticky;top:0;background:var(--bg)}.state-scroll{max-height:360px;overflow-y:auto}.diag-choice{display:block;width:100%;text-align:left;margin-bottom:10px;min-height:var(--tap);padding:12px 14px;background:var(--bg-elev);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-size:1rem;transition:background var(--transition),border-color var(--transition)}.diag-choice:active{background:var(--accent-soft)}.diag-choice.correct{border-color:var(--good);background:#30a46c24}.diag-choice.wrong{border-color:var(--again);background:#e5484d24}.strength-bar{display:flex;align-items:center;gap:8px;margin-bottom:8px;font-size:.85rem}.strength-bar .track{flex:1;height:8px;background:var(--bg-elev2);border-radius:999px;overflow:hidden}.strength-bar .track>span{display:block;height:100%;background:var(--good)}.line-chart{width:100%;height:auto;display:block}